PDF5 - Govind Ballabh Pant University Of Agriculture and Technology

Deficit Irrigation for Reducing Agricultural Water Use
R.D. Misra
Ex-Professor & Head ,
Department of Agronomy,
G. B. Pant University of Agriculture & Technology, Pantnagar
At present and more so in the future, irrigated agriculture will take place under
water scarcity. Insufficient water supply for irrigation will be the norm rather than the
exception, and irrigation management will shift from emphasizing production per unit
area towards maximizing the production per unit of water consumed, the water
productivity. To cope with scarce supplies, deficit irrigation, defined as the application of
water below full crop-water requirements (evapotranspiration), is an important tool to
achieve the goal of reducing irrigation water use. While deficit irrigation is widely
practised over millions of hectares for a number of reasonsfrom inadequate network
design to excessive irrigation expansion relative to catchment suppliesit has not
received sufficient attention in research. Its use in reducing water consumption for
biomass production, and for irrigation of annual and perennial crops is reviewed here.
There is potential for improving water productivity in many field crops and there is
sufficient information for defining the best deficit irrigation strategy for many situations.
One conclusion is that the level of irrigation supply under deficit irrigation should be
relatively high in most cases, one that permits achieving 60100% of full
evapotranspiration. Several cases on the successful use of regulated deficit irrigation
(RDI) in fruit trees and vines are reviewed, showing that RDI not only increases water
productivity, but also farmers profits. Research linking the physiological basis of these
responses to the design of RDI strategies is likely to have a significant impact in
increasing its adoption in water-limited areas. Forecasts of water withdrawals on a global
scale predict sharp increases in future demand to meet the needs of the urban, industrial,
and environmental sectors. This is due to the fact than more than one billion people do
not yet have access to running water or sanitary facilities, and also to insufficient
attention being paid, until now, to meet the water requirements of natural ecosystems.
Given that the single biggest water problem worldwide is scarcity there is significant
uncertainty about what the level of water supply will be for future generations.
Irrigated agriculture is the primary user of diverted water globally, reaching a
proportion that exceeds 7080% of the total in the arid and semi-arid zones. It is
therefore not surprising that irrigated agriculture is perceived in those areas as the
primary source of water, especially in emergency drought situations. Currently, irrigated
agriculture is caught between two perceptions that are contradictory; some perceive that
agriculture is highly inefficient by growing water-guzzling crops, while others
emphasize that irrigation is essential for the production of sufficient food in the future,
given the anticipated increases in food demand due to world population growth and
changes in diets. Globally, food production from irrigation represents >40% of the total
and uses only about 17% of the land area devoted to food production. Nevertheless,
irrigated agriculture is still practiced in many areas in the world with complete disregard
to basic principles of resource conservation and sustainability. Therefore, irrigation water
management in an era of water scarcity will have to be carried out most efficiently,
aiming at saving water and at maximizing its productivity. Irrigation is applied to avoid
water deficits that reduce crop production. The process of crop water use has two main
components: one due to evaporation losses from the soil and the crop, usually called
evapotranspiration (ET), and the other that includes all the losses resulting from the
distribution of water to the land. All irrigation waters contain salts and, as water

evaporates, salts concentrate in the soil profile and must be displaced below the root zone
before they reach a concentration that limits crop production. Salt leaching is achieved
by the movement of water applied in excess of ET. Thus, some of the water losses are
unavoidable and are needed to maintain the salt balance; however, they can be
minimized with efficient irrigation methods and by appropriate management. Reducing
ET without a penalty in crop production is much more difficult, however, because
evaporation from crop canopies is tightly coupled with the assimilation of carbon. A
water supply constraint that decreases transpiration below the rate dictated by the
evaporative demand of the environment is paralleled by a reduction in biomass
production. Given the high costs of irrigation development, until now the paradigmatic
irrigation strategy has been to supply irrigated areas with sufficient water so that the
crops transpire at their maximum potential and the full ET requirements are met
throughout the season. This approach is increasingly challenged by segments of society
in regions where water is scarce, because of both the large amounts of water required by
irrigation and the negative effects that such diversions and use have on nature. Thus, a
strategic change in irrigation management is taking place, one that limits the supply
available for irrigation to what is left after all other sectors of higher priority satisfy their
needs. Under such situations, farmers often receive water allocations below the
maximum ET needs, and either have to concentrate the supply over a smaller land area or
have to irrigate the total area with levels below full ET.
The application of water below the ET requirements is termed deficit irrigation
(DI). Irrigation supply under DI is reduced relative to that needed to meet maximum ET.
Therefore, water demand for irrigation can be reduced and the water saved can be
diverted for alternative uses. Even though DI is simply a technique aimed at the
optimization of economic output when water is limited, the reduction in the supply for
irrigation to an area imposes many adjustments in the agricultural system. Thus, DI
practices are multifaceted, inducing changes at the technical, socio-economical, and
institutional levels. Nevertheless, the focus of this paper is on providing further
understanding of the DI concept for biological scientists interested in the relationships
between plants and water, leading to the broader issues that govern the optimization of a
limited supply of water in crop production. Scientist have proposed a number of
physiological approaches to enhance irrigation practices under limited water conditions.
Hopefully, the application of research conducted at the various levels of biological
organization, that is, from molecular to whole plant physiology, will offer new avenues
for involving plant biologists in the improvement of DI practices in the future.
Features of deficit irrigation
In the humid and sub-humid zones, irrigation has been used for some time to
supplement rainfall as a tactical measure during drought spells to stabilize production.
This practice has been called supplemental irrigation and, although it uses limited
amounts of water due to the relatively high rainfall levels, the goal is to achieve
maximum yields and to eliminate yield fluctuations caused by water deficits.
Furthermore, supplemental irrigation in humid climates has often been advocated as
more efficient than irrigation in the arid zones, because the lower water vapour deficits
of the humid zones lead to higher transpiration efficiency than in the arid zones. More
recently, the term supplemental irrigation has been used in arid zones to define the
practice of applying small amounts of irrigation water to winter crops that are normally
grown under rain-fed conditions. In this case, this is a form of DI, as maximum yields are
not sought. Thus, the terms deficit or supplemental irrigation are not interchangeable,
and each DI situation should be defined in terms of the level of water supply in relation
to maximum crop ET. One consequence of reducing irrigation water use by DI is the
greater risk of increased soil salinity due to reduced leaching, and its impact on the

sustainability of the irrigation. To quantify the level of DI it is first necessary to define
the full crop ET requirements. Fortunately, since Penman developed the combination
approach to calculate ET, research on crop water requirements has produced several
reliable methods for its calculation. At present, the PenmanMonteith equation is the
established method for determining the ET of the major herbaceous crops with sufficient
precision for management purposes. There is, however, more uncertainty when using the
same approach to determine the ET requirements of tree crops and vines. When irrigation
is applied at rates below the ET, the crop extracts water from the soil reservoir to
compensate for the deficit. Two situations may then develop. In one case, if sufficient
water is stored in the soil and transpiration is not limited by soil water, even though the
volume of irrigation water is reduced, the consumptive use (ET) is unaffected. However,
if the soil water supply is insufficient to meet the crop demand, growth and transpiration
are reduced, and DI induces an ET reduction below its maximum potential. The
difference between the two situations has important implications at the basin scale. In the
first case, DI does not induce net water savings and yields should not be affected. If the
stored soil water that was extracted is replenished by seasonal rainfall, the DI practice is
sustainable and has the advantage of reducing irrigation water use. In the second case,
both water use and consumption (ET) are reduced by DI but yields may be negatively
affected. The challenge of quantifying the ET reduction effected by DI (net water
savings) remains, as direct measurements are complex, and the models used to estimate
the actual ET of stressed canopies are still quite empirical. In many world areas,
irrigation delivery at the farm outlet is less than what is required. The high costs of
irrigation and its benefits offer a justification to expand the networks beyond reasonable
limits in order to reach the highest possible number of farmers. This approach has been
used in many countries and has led to chronic DI. Sometimes, the cropping intensity
used in the original design becomes obsolete due to marketing reasons, and another of
higher intensity and thus of greater water demand is adopted. Inadequate estimation of
the crop water requirements in project design is another reason for insufficient network
capacity. Finally, in drought periods, irrigated agriculture has the lowest priority and the
delivery from irrigation networks may be drastically curtailed. In most of the cases
described above, the farmers are at the mercy of the delivery agencies and there is very
little margin for them to manage the limited supply efficiently. In particular, drought
periods represent a threat to the sustainability of irrigation, not only because water
supply is restricted, but also because of the uncertainty in determining when it will be
available. Because of chronic water scarcity, in some areas inadequate irrigation supply
is becoming the norm rather than the exception, as in Andalusia, Spain, where during the
period between 1980 and 1995 in the Guadalquivir Valley, only in four years was there a
normal irrigation supply. When the supply is restricted, farmers are often faced with
having to use DI to achieve the highest possible returns. Even though the economics of
DI are relatively straightforward, the reality is that there are many engineering, social,
institutional, and cultural issues that determine the distribution and the management of
irrigation water. Furthermore, in any attempt to optimize water use for irrigation, there is
significant uncertainty in the anticipated results and, often, the alternatives that anticipate
higher net returns also have higher risks. To reduce uncertainty and risk, computer
models that simulate irrigation performance, together with social research, can aid in
assisting water managers to optimize a limited supply of irrigation water. Nevertheless,
until now there has been little or no flexibility in most collective networks to manage
irrigation with the degree of precision needed in optimal DI programmes, where
controlling the timing of application is essential for avoiding the detrimental effects of
stress. Contrary to the rigid delivery schedules experienced by farmers located in many
collective networks, those that have access to water supply on demand or can irrigate
directly from groundwater sources, have the capability of managing water with much
more flexibility. The ability to adjust the timing and amount of irrigation makes it

possible to design first and then to manage and control the best possible DI programme
when supply is restricted. The use of permanent, pressurized irrigation systems also
makes it possible for small amounts at frequent intervals to be applied, providing an
additional tool for stress management. It is therefore possible in water-limited situations,
if sufficient knowledge exists, to manage DI optimally with the objective of maintaining
or even increasing farmers profits while reducing irrigation water use.
Deficit irrigation and water productivity
When water supplies are limiting, the farmer's goal should be to maximize net
income per unit water used rather than per land unit. Recently, emphasis has been placed
on the concept of water productivity (WP), defined here either as the yield or net income
per unit of water used in ET. WP increases under DI, relative to its value under full
irrigation, as shown experimentally for many crops. There are several reasons for the
increase in WP under DI. Small irrigation amounts increase crop ET, more or less
linearly up to a point where the relationship becomes curvilinear because part of the
water applied is not used in ET and is lost. At one point, yield reaches its maximum
value and additional amounts of irrigation do not increase it any further. The location of
that point is not easily defined and thus, when water is not limited or is cheap, irrigation
is applied in excess to avoid the risk of a yield penalty. The amount of water needed to
ensure maximum yields depends on the uniformity of irrigation. Under low uniformity,
irrigation efficiency decreases and water losses are high. Because water cannot be
applied with perfect uniformity, variations in applied water over the field are ranked and
plotted against the fraction of the area. The depth of water is normalized against the
required depth. Generalized relationships between applied irrigation water, ET, and crop
grain yield. In addition to the factors associated with the disposition of irrigation water,
WP is also affected by the yield response to irrigation. Yield responses to irrigation and
to ET deficits have been studied empirically for decades. It turned out that it is not only
biomass production that is linearly related to transpiration, but the yield of many crops is
also linearly related to ET. The design of a DI programme must be based on knowledge
of this response but the exact characteristics of the response function are not known in
advance. Also, the response varies with location, stress patterns, cultivar, planting dates,
and other factors. In particular, many crops have different sensitivities to water stress at
various stages of development, and the DI programme must be designed to manage the
stress so that yield decline is minimized. However, when the yield decline, in relative
terms, is less than the ET decrease, WP under DI increases relative to that under full
irrigation. Nevertheless, from the standpoint of the farmer, the objective is not WP per
se, but net income, low risk, and other issues related to the sustainability of irrigation are
more important. Knowledge of the crop response to DI is essential to achieve such
objectives when water is limited.

References:
Stewart BA, Nielsen DR, Fereres E, Goldhamer DA. Deciduous fruit and nut trees. In:
Stewart BA, Nielsen DR, editors. Irrigation of agricultural crops, Agronomy 30.
Madison, WI: ASA, CSSA, SSSA; 1990. p. 987-1017.
Fereres E, Goldhamer DA, Parsons LR. Irrigation water management of horticultural
crops. Historical review compiled for the American Society of Horticultural
Science's 100th Anniversary. HortScience 2003;38:1036-1042.
Buxton DR, Shibles R, Forsberg RA, Blad BL, Asay KH, Paulsen GM, Wilson RF,
Fereres E, Orgaz F, Villalobos FJ. Water use efficiency in sustainable
agricultural systems. In: Buxton DR, Shibles R, Forsberg RA, Blad BL, Asay KH,
Paulsen GM, Wilson RF, editors. International crop science. Madison, WI: Crop
Science Society of America; 1993. p. 83-89.
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Nanotechnology in Agriculture
Rajeew Kumar
Junior Research Officer (Agronomy)
G.B. Pant University of Agriculture & Technology, Pantnagar-263 145
Nanotechnology is emerging technological platform for the next wave of
development and transformation of agricultural systems. Nanotechnology is attracting
large-scale investment from global food corporations, is backed by academic science,
and has captured financial and ideological support from many governments around the
world. As a result, nanotechnology is rapidly moving from the laboratory and onto the
farm, supermarket shelves and the kitchen table. For example, a new range of smart
agricultural inputs and products are being developed, such as nano-seed varieties with inbuilt
pesticides that will release under certain environmental conditions; nanoencapsulation
techniques may make it possible to alter the nutritional composition,
flavour and other attributes of food to match consumers personal tastes and
physiological requirements; and smart food packaging able to detect the presence of
pathogens. These and other applications of nanotechnology across the agri-food system
are emerging from a growing alliance between the corporate food sector and scientific
communities. Nanotechnology represents the most powerful set of techniques yet
developed to take apart and reconstitute nature at the atomic level. In terms of economic
relations, nanotechnology provides new opportunities for the extension and further
integration of corporate ownership and control within and between sectors of the agrifood
system.
DEFINITION OF NANOTECHNOLOGY:
The realization that there are small things in the world that are not visible to the
naked eye extends back into human history. The development of the natural sciences
created an interest in the microworld, in order to enable a better understanding of the
world and the processes therein. Therefore, the development of new microscopic
imaging methods represents certain milestones in the natural sciences. The microworld
was approached by extending the range available for the direct visualization of objects
through the enhancement of microscopic resolution. Microtechnology has changed our
lives dramatically. The most striking impact is apparent in computer technology, which
is essential for todays industry, and also for our individual life styles. Apart from
microelectronics, microtechnology influences many other areas. The size of typical
structures that is accessible is in the sub-micrometer range, which is at the limits of
optical resolution and barely visible with a light microscope. This is about 1/1000
smaller than structures resolvable by the naked eye, but still 1000 times larger than an
atom. Todays developments are addressing the size range below these dimensions.
Because a typical structure size is in the nanometer range, the methods and techniques
are defined as nanotechnology.
The prefix nano, derived from the Greek nano signifying dwarf, is becoming
increasingly common in scientific literature. Nano is now a popular label for much of
modern science, and many nano- words have recently appeared in dictionaries,
including: nanometer, nanoscale, nanoscience, nanotechnology, nanostructure, nanotube,
nanowire, and nanorobot. Although the idea of nanotechnology: producing nanoscale
objects and carrying out nanoscale manipulations, has been around for quite some time,
the birth of the concept is usually linked to a speech by Rachard Feyman at the
December 1959 meeting of the American Physical Society [16] where he asked, What
would happen if we could arrange the atoms one by one the way we want them?

APPLICATIONS OF NANO-TECHNOLOGY IN COMMERCIAL
AGRICULTURAL
In the agricultural sector, nanotech research and development is likely to facilitate
and frame the next stage of development of genetically modified crops, animal
production inputs, chemical pesticides and precision farming techniques. While
nano-chemical pesticides are already in use, other applications are still in their early
stages, and it may be many years before they are commercialized. These applications are
largely intended to address some of the limitations and challenges facing large-scale,
chemical and capital intensive farming systems. This includes the fine-tuning and more
precise micro-management of soils; the more efficient and targeted use of inputs; new
toxin formulations for pest control; new crop and animal traits; and the diversification
and differentiation of farming practices and products within the context of large-scale
and highly uniform systems of production.
GENETICALLY MODIFIED CROPS:
Through the convergence of nano and bio techniques, it may be possible to
improve the precision of genetic engineering breeding programs, thereby ensuring
greater control in delivering new character traits to plant and crop varieties. Researchers
are attempting to use nanoparticles, nanofibres and nanocapsules to introduce foreign
DNA and chemicals into cells. For example, silica nanoparticles have been used to
deliver DNA and chemicals into plant and animal cells and tissues. Researchers in this
field have also already succeeded in drilling holes through the membrane of rice cells
to enable the insertion of a nitrogen atom, to stimulate rearrangement of the rice DNA.
This technique has been successful in altering the colour of rice, and researchers aim to
use this technique to extend the growing season for rice, enabling year round production.
There is, however, little evidence of any commercial applications of such nano-genetic
engineering research at this stage. The perhaps more distant prospect of not merely reengineering
existing plants, but of creating novel plant varieties from scratch using
synthetic biology would enable significantly greater control over crop traits.
CHEMICAL INPUTS:
Techniques at the nano-scale are also being applied in an attempt to enable the
targeted delivery or increased toxicity of pesticide applications. This includes the
insertion of nano-scale active ingredients into pesticides. The specific properties of these
nano-scale materials, such as their ability to dissolve in water or their increased stability,
are designed to maximize the effectiveness of these pesticides. Leading agri-chemical
companies including BASF, Bayer Crop Science, Monsanto and Syngenta are engaged in
nanotech research in these areas. Pesticides may also be encapsulated via nanoencapsulation
techniques. These encapsulation techniques enable greater control over the
circumstances in which encapsulated pesticides will be released. For example, pesticides
could be released quickly or slowly depending on need and under specific conditions,
such as moisture and heat levels. Syngenta have obtained a patent for a gutbuster
microcapsule containing pesticides that will break open in alkaline environments,
including the stomach of certain insects . Such nano-encapsulation techniques not only
provide in-built pesticides for crops in some ways similar to genetically modified Bt
insecticidal crops but also in-built switches to control the release and subsequent
availability of pesticides. One of the rationales for these nano-particle pesticide
applications lies in their improved capacity for absorption into plants compared to larger
particles. As such, they may not be washed off as readily, thereby increasing their
effectiveness, but also posing a new order of risks to consumers of these products. Farm
workers and rural residents are also being exposed to these nano-pesticides, in the
absence of any required safety testing or regulation of nano-scale formulations of already
approved chemical pesticides. The size and dissolvability of nanoparticle pesticides may

also mean they contaminate soils, waterways and foodchains across a wider geographical
area, while nano-encapsulated pesticides may release their toxins in other environments
or in the stomachs of other living organisms. Nano-pesticide research and development is
concentrated within a small number of large agri-chemical companies that already
dominate the agri-chemical and seed market, and these corporate actors are likely to
further extend their control of these markets, and therefore over farmers. Proponents
argue that pesticidal applications of nanotechnology promise to reduce pesticide use, due
to their more precise and targeted nature. As such, nanotechnology is frequently
portrayed as introducing environmental benefits.
SLOW RELEASE FERTILIZER (NANO-ENCAPSULATION)
— Slow-release fertilizers are excellent alternatives to soluble fertilizers.
— Nutrients are released at a slower rate throughout the season, plants are able to
take up most of the nutrients without waste by leaching.
— A slow-release fertilizers is more convenient, since less frequent application is
required.
— Slow-release fertilizers may be more expensive than soluble types, but their
benefits outweigh their disadvantages.
NANO SENSOR:
Another development being looked at is a network of nanosensors and
dipenserthroughout a food corp. The sensors recognize when a plant needs nutrients or
water, before you could see any sign that the plant is deficient. The dispensers then
release fertilizer, nutrients, or water as needed, optimizing the growth of each plant in the
field one by one. Nanosensors or nano-scale, wireless sensors represent the
intersection of nanotechnologies and information technologies. Alongside geographical
positioning systems and other information technologies, nanosensors could be scattered
across farmers fields to enable the real time monitoring of crops and soils, and the
early detection of potential problems, such as pest attacks and declining soil nutrient
levels. Nanosensors have the capacity to extend the logic of precision farming in new
and novel ways to both identify and rectify agronomic problems in a very short time
frame. The US Department of Agriculture, for example, is reported to be developing a
Smart Field System that automatically detects, locates, reports and applies water,
fertilisers and pesticides going beyond sensing to automatic application. Nanosensors
may thereby introduce greater efficiencies within and thereby facilitate the expansion of
large scale farming operations.
RESEARCH FINDINGS IN DIFFERENT CROPS
Nano particles Country Response
Buckyball Japan Effect not clear
TiO2 Nano Mixture Korea Patent on a liquid after which time it dissolves in the groundwater
and becomes indistinguishable from naturally occurring iron.
Seeding Iron Russian Improvement in the germination of the seed
Soil Binder USA Patent of soil set
Soil clean up China Groundwater and soil cleanup
NANO RESEARCH AREA
— Nanoscale Phenomena And Processes: plant/animal cells;
genomics/proteomics; biosafety; crop/ animal production processes; natural
resources cycles

— Nanomaterials: nano fertilizers and nanocides for efficient use of inputs , soil
erosion control; packaging
— Nanodevices and Systems: Biosensors for precision agriculture; diagnostics;
pathogen/contaminant detection
— Smart delivery systems for genes/drugs/vaccines
— Nanofiltration: nanobrushes for soil & water purification
— Smart systems integration
— Environment, social, ethical, health implications
— Education
CONCLUSION
Reference:
— Nanotechnology could facilitate a second green revolution in Indian
agriculture if the following are emphasized:
— Strategic approach to nanotechnology research and development across
the agricultural value chain.
— Environmentally and socially responsible development of the technology.
— Anticipatory design of effective regulatory mechanisms and strong
governance systems designed with involvement of all the stakeholders.
— Ultimate acceptance by the stakeholders.
· Roco, M.C.; Williams, S.; Alivisatos, P., eds. Nanotechnology Research
Directions: Interna-tional Working Group on Nanoscience, Engineering,
and Technology Workshop Report; 1999.
http://www.wtec.org/loyola/nano/IWGN.Research. Directions/.
· Stearns, R.C., Paulauskis, J.D., Godleski, J.J., 2001. Endocytosis of
ultrafine particles by A 549 cells. Am. J. Respir. Cell Mol. Biol. 24, 108-
115.
· Tsien, A., Diaz-Sanchez, D., Ma, J., Saxon, A., 1997. The organic
component of diesel exhaust particles and phenanthrene, a major
polyaromatic hydrocarbon constituent, enhances IgE production by IgEsecreting
EBV-transformed human B cells in vitro. Toxical. Appl. Pharm.
142, 256-263.
**********

Precision Agriculture
Rajeew Kumar
Junior Research Officer (Agronomy)
G.B. Pant University of Agriculture & Technology, Pantnagar-263 145
Traditional agriculture provides goods required by the farming family usually
without any significant surplus or sale. But burgeoning population compel us to go for
more food, which resulted unstable farming system. The traditional agriculture is an
important reserve and source of biodiversity. Food demand laid the birth of modern
agriculture where more crops can be grown on less land. Modern agriculture is
dependent on fossil fuels, mostly for mechanized agriculture. The goal of modern
agriculture practices is to help farmers provide an affordable supply of food to meet the
demands of a growing population. The challenge for the future is how to increase yields
in traditional systems while retaining a certain measure of their integrity. Future
agriculture requires to produce more food per unit land simultaneously consider the
threat of deterioration of natural resources as well as environment. Modern agriculture is
based on uniform recommendation technique. However, this is need of hour to take care
of individual site/plant to enhance their productivity. Under such circumstances precision
agriculture is only alternative.
1. PRECISION AGRICULTURE
Precision agriculture (PA) also known as precision farming, prescription
farming, variable rate technology (VRT) and site specific agriculture is a current buzz
word among the agricultural circles and considered as the agricultural system of the 21 st
century, as it symbolizes a better balance between reliance on traditional knowledge and
information and management intensive technologies. It is an integrated agricultural
management strategy where farmers can adjust input use and cultivation methods
including seed, fertilizer, pesticide, and water application, varietal selection, planting,
tillage, harvesting according to varying soil, crop and other field conditions. In brief,
precision agriculture refers to tailoring crop and soil management practices according to
variation in crop and soil conditions within each field. PF differs from conventional
farming that is based on uniform treatments across a field. A key difference between
conventional management and precision agriculture is the application of modern
information technologies can be viewed as technologies that improves the efficiency of
inputs applied but requires higher investment capital and labor than traditional
technology. It involves mapping and analyzing within field variability and linking spatial
relationships to management decisions, thereby helping farmers to look at their farms,
crops and practice from and entirely new perspective. PA thus provides a framework of
information with farmers can make both production and management decisions.
PA promises to revolutionize form management as it offers a variety of potential
benefits in profitability, productivity, sustainability, crop quality, environmental
protection, on farm quality of life, food safety, and rural economic development.
Studies in USA, Canada, Europe and Australia have shown that PF permits reductions in
input application rates without sacrificing crop yields. Refinement and wider application
of PA technologies in India can help in lowering production costs, enhancing higher
productivity and environmental benefits, and better utilization of natural resources. For
example, site specific application of irrigation in wheat of Punjab and Haryana,
pesticides in cotton and fertilizers applications in plantations of oil palm in South India
and coffee and tea garden of Eastern India can greatly reduce production costs and
decrease environmental loading of chemicals.

When PA technologies judiciously implemented, farmers could be benefited in
many ways. In the short term, growers can use forecast based on remote sensing and
alleviate problems such as water stress, nutrient deficiency and pests/diseases more
effectivity. Database building benefits will be in the form of accurate farm document
keeping for effective management of inputs, property, machinery and labor, and efficient
monitoring of environmental quality through recording the amounts and location of input
through applying at exact locations that produce maximum profit margins. PF
technologies also increase opportunities for skilled employment in farming, and provide
new tools for evaluating multifunctional character (including non market functions) or
agriculture and land.
2. INTREGATED TECHNOLOGY COMPONESTS
Precision agriculture technologies provide three basic requirements for precise
and sustainable agricultural management. These are: Ability to identify precise location
of field, 2. Ability to gather and analysis information on spatio temporal variability of
soil and crop conditions at field level, and 3. Ability to adjust input use and farming
practices to maximize benefits from each field location. Precision farming involves
integrated technologies such as (GPS), (GIS), Remote Sensing, Variable Rate
Technology (VRT), Crop models, yield monitors and precision irrigation. Various
configurations of these technologies are suitable for different PF operations. Information
technology such as the Internet is good means for some agri business companies to
deliver their services and products.
2.1 GPS
More recently farmer in USA have gained access to site specific technology
through use of GPS. Currently a constellation of 27 satellites developed by the US
Department of Defense provides geospatial accuracy to farm practices and enables
farmers to identify and compare characteristic of each field site (location of soil sample
or pest data are collection and compared to soil and crop vigor map, respectively). A
minimum of four satellites is required to get good position information. If a GPS receiver
is used along with a ground reference station (Differential GPS), any location on earth
can be identified to within one square meter. The value of knowing a precise location
within inches is that 1) locations of soil samples and the laboratory results can be
compared to a soil map, 2) fertilizer and pesticides can be prescribed to fit soil properties
(clay and organic matter content) and soil conditions (relief and drainage), 3) tillage
adjustments can be made as one finds various conditions across the field, and 4) one can
monitor and record yield date as one goes across the field.
2.2 GIS
Geographic information system is a computerized data base management and
retrieval system, which offers spatial solutions to many problems relating crop
productivity and agronomic management. It can integrate all types of spatial and non
spatial information collected form different sources and interface with other decision
support tools such as crop models. GIS can display analyzed information in maps that
allow (a) better understanding of interactions among crop vigor, yield, nutrients status,
pests & disease stress, weeds and other factors, and (b) decision-making based on such
spatial relationships. Recently, many types of commercial and user specific GIS software
with varying functionality are now available. For example, AGROMA from PCI,
AGRIMAPPER, DSSAT v 3.5 with Arc/View interface from IBSNAT A comprehensive
farm GIS contains base maps such as topography, soil type, N, P, K and other nutrient
levels, soil moisture, pH, etc. data on crop rotations, tillage, nutrient and pesticide
applications, yields, etc. can also be stored. GIS is useful to create fertility, weed and

pest intensity maps, which can then be used for making maps that show recommended
application rate of nutrients or pesticides.
2.3 Remote Sensing
Satellite has inherent quality of providing information on spatial variability in
crops caused by natural and agronomic practices. Some farmers have already received
benefits from satellite data. Remotely sensed images from LANDSAT, SPOT and IRS
LISS III have been used to distinguish crop species and locate crop stress areas.
Commercial satellites to be launched in future are expected to have ideal sensors
specifications for Precision farming such as 3-day repeat coverage, 1 to 4 meter spatial
resolution and image delivery to users within 15 minutes after acquisition. At present,
IKONOS satellite from Imaging has capability to provide multi-spectral data with 1 to 4
meters spatial resolution for India which make it possible to have information on actual
state of crop in the field. IKONOS is clearly paving the way toward making agricultural
monitoring a reality so that farmers are able to reach their management and planning
goals. Moreover, merged of LISS III + PAN from current IRS series satellites can also
shows all crop fields and thereby helps in field boundary detection and updating of
cadastral information along with cultural and management details. Remotely sensed
images can show all fields in a village or block and spot problems sooner than ground
survey, thereby allowing remedial treatments to be taken up before the stress spreads to
other parts of the field. In a field survey, GPS can be used to pinpoint the stressed area
for a detailed examination. Crop vitality indicators can also be determined using images
acquired at different times during a season. Such data when use with crop, models
through calibration of re-initialization of model, can be useful in predicting crop yields.
2.4. Variable rate technology
One method of controlling variability within field is VRT. VRT allows grower to
apply the quantity of crop inputs needed at a precise location in the field based on the
individual characteristics of that location. Typical VRT system includes a computer
controller, GPS receiver, and GIS map databases. Computer controller adjusts the
equipment application rate of the crop input applied. The computer controller is
integrated with the GIS database, which contains the flow rate instructions for the
application equipment. The computer controller uses the location coordinates from the
GPS unit to find the equipment location on the map provided by the GIS unit. The
computer controller reads the instructions from the GIS system and varies the rate of the
crop input being applied as the equipment crosses the field. The computer controller will
record the actual rates applied at each location in the field and store the information in
the GIS system, thus maintaining precise field maps of materials applied.
3. ROLE OF PRECISION AGRICULTURE
The real value of precision agriculture for the farmer is that he can adjust seeding
rates, plan more accurate crop protection programs, perform more timely tillage and
know the yield variation within a field. These benefits will enhance the overall cost
effectiveness of his crop production.
3.1. Seeding
Hybrid seeds perform best when placed at spacing that allows the plants to obtain
such benefits as maximum sunlight and moisture. This is best accomplished by varying
the seeding rate according to the soil conditions such as texture, organic matter and
available soil moisture. One would plant fewer seeds in sandy soil as compared to silt
loam soils because of less available moisture. The lower seed population usually has
larger heads (ears) of harvested seeds providing for a maximum yield. Since soils vary
even across an individual farm field, the ability to change seeding rates as one goes
across the field allows the farmer to maximize this seeding rate according to the soil

conditions. A computerized soil map of a field on a computer fitted on the tractor along
with a GPS can tell farmers where they are in the field allowing the opportunity to adjust
this seeding rate as they go across their fields.
3.2. Crop Protection
The application of chemicals and fertilizers in proper proportions are of
environmental and economic concern to the farmers. Environmental regulations are
calling for the discontinuance of certain pesticide applications within 100 feet of a stream
or water body or well or within 60 feet of an intermittent stream. Using a GPS along with
a digital drainage map, the farmer is able to apply these pesticides in a safer manner. In
fact, the spraying equipment can be preprogrammed to automatically turn off when it
reaches the distance limitation or zone of the drainage feature. Additionally, farmers can
preprogram the rate of pesticide of fertilize to be applied so that only the amount needed
determined by the soil condition is applied varying this rate from one area of the field to
another. This saves money and allows for safer use of these materials.
3.3 Tillage
The ability to vary the depth of tillage along with soil conditions is very
important to proper seedbed preparation, control of weeds and fuel consumption and
therefore cost to the farmer. Most farmers are using conservation tillage which means
leaving residues on the soil surface for erosion control. The use of GPS in making
equipment adjustments as one goes across the different soil types would mean higher
yields and safer production at lower costs. This part of precision farming is in its infancy.
The equipment companies will be announcing tillage equipment with GPS and selected
controls tailored to precision farming in the near future.
3.4 Harvesting
The proof in the use of variable rate technology (adjusting seed, pesticide,
fertilizer and tillage) as one goes across the field is in knowing the precise yields.
Combines and other harvesting equipment can be equipped with weighing devices that
are coupled to a GPS. One literally measures yields on the go. With appropriate software,
a yield map is produced showing the yield variation throughout the field. This allows
farmers to inspect the precise location of the highest and the lowest yielding areas of the
field and determine what caused the yield difference. It allows one to program cost and
yield to determine the most profitable practices and rates that apply to each field
location. In my opinion, the use of yield monitors is a good place to start if one wants to
get started in precision farming. Yield data from the same field over 3 + years would
define the weak spots in the field and narrow down the probability of what is causing a
log yield.
4. ROLE OF REMOTE SENSING IN PRECISION AGRICULTURE
4.1 Management Zone and Soil Maps
Soil maps are also sometimes used to determine management zones. Soil maps
are becoming part of the GIS database. Except for semi detailed country soil surveys,
remote sensing has not gained wide acceptance as a mapping tool for soil characteristics.
This is because the reflectance characteristics of the desired soil properties (e.g., organic
matter, texture, iron content) are often confused by variability in soil moisture content,
surface roughness, climate factors, solar zenith angle, and view angle.
4.2 Monitor Crop Health
Remote sensing data and images provide farmers with the ability to monitor the
health and condition of crops. Stressed plants reflect various wavelengths of light that are

different from healthy plants. Healthy plants reflect more infrared energy from the
spongy mesophyll plant leaf tissue than stressed plants. By being able to detect areas of
plant stress before its becomes visible, farmers will have additional time to analyze the
problem area and apply a treatment.
4.3 Water Stress
The use of remote sensors to directly measure soil moisture has had very limited
success. Synthetic Aperture Radar (SAR) sensors are sensitive to soil moisture and
they have been used to directly measure soil moisture. SAR data requires extensive use
of processing to remove surface induced noise such as soil surface roughness, revelation,
and topography. A crop evapo-transpiration rate decrease is an indicator of crop water
stress or other crop problems such as plant infestation. Remote sensing images have been
combined with a crop water stress index (CWSI) model to measure field variations.
4.4 Weed Management
Aerial remote sensing has not yet proved to be very useful in monitoring and
locating dispersed weed populations. Some difficulties encountered are that weeds often
will be dispersed throughout a crop that is spectrally similar, and very large-scale high
resolution images will be needed for detection and identification.
4.5 Insect Detection
Aerial or satellite remote sensing has not been successfully used to identify and
locate insects directly. Indirect detection of insects though the detection of plant stress
has generally not been used in annual crops. The economic injury level for treatment is
usually exceeded by the time plant stress is detected by remote sending.
4.6 Nutrient Stress
Plant nitrogen stress areas can be located in the field using high-resolution color
infrared aerial images. The reflectance of near infrared, visible red and visible green
wavelengths have a high correlation to the amount of applied nitrogen in the field.
Canopy reflectance of red provides a good estimate of actual crop yields.
4.7 Yield Forecasting
For crops such as wheat, grain sorghum, production yields, leaf area index
(LAI), crop height and biomass have been correlated with NDVI data obtained from
multispectral images. In order to get reasonably accurate yield predictions this data must
be combined with input from crop growth and weather models during the growing
season.
5. SCOPE OF PRECISION AGRICULTURE IN INDIA
Precision farming technologies is a suite of many high-tech tools but there is no
need to adopt all PF technologies at once to start benefiting from them. Many farmers
can begin by using only a part of the technology, as even partial use can bring many
benefits. In fact, applying the entire range of technologies is not profitable in several
cases, particularly for technologies that are not scale-neutral. For example, small farmers
in India cannot afford on their own, but some private sector support is needed for the
advancement of data acquisition and analysis methods, including sensing technologies,
sampling methods, data base systems, and geospatial methods. Some of the agribusiness
companies like Nagarjun Fertilizers Company Limited, BAYER India Ltd. and Mahyco
Seeds Pvt. Limited should come forward and get actively involved in extending the
services on precision farming technologies to the farmers someway. There are many
companies have involved in these extension activities and helping to the farmers.

Precision farming technologies is likely to provide a greater profitability
advantage for (a) high-value crops, (b) areas where input costs are high, and (c) areas
where production conditions are very heterogeneous. The implementation of precision
agriculture technologies in India should have two different strategies one for the low
input subsistence agriculture and the other for input-intensive profit-making agriculture.
In case of former, the increase in productivity is the prime concern. Here, the system has
to be converted to information-based agriculture, where farmer has spatial information
about the soil and crop. This information can be used for efficient input application.
Since the field size are small in this situation individually bunded field or a group of field
can be considered as a unit for variable rate application. However, for the latter case,
such as rice and wheat of Indo-Gangetic belt and the horticultural crops like grape
(Maharashtra), potato (Punjab), tea (Assam) where the field size arer large and farmers
are rich, input use efficiency is prime concern. Here, remote sensing data can be used to
identify the spatial and temporal variability and necessary actions can be adopted using
sophisticated equipments like variable rate technology. Adoption of PF techniques aimed
at irrigation management, nutrient management and integrated pest management will
obviously be a priority for such crops.
6. LIMITAIONS FOR ADOPTION OF PRECISION AGRICULTUTE IN INDIA
There are many limitations in adopting this high-tech precision farming
technology in India. Some of them include:
· High cost of obtaining site-specific satellite data
· Lack of willingness to share spatial data among various organizations
· Complexity of tools and techniques requiring new skills
· Culture, attitude and perceptions of farmers including resistance to adoption of new
techniques and lack of awareness of agro-environmental problems
· Farmers inability to afford High-tech farm equipments
· Small farms, heterogeneity of cropping systems, and land tenure/ownership restrictions
· Infrastructure and institutional constraints including market imperfections
· Lack of success stories of PE adoption and lack of demonstrated impacts on yields
· Lack of local technical expertise
· Uncertainty on returns from investments to be made on new equipment and information
management system
· Lack of transformation of technical know how to farmers in local language, and
· Knowledge and technological gaps including
· Inadequate understanding of agronomic factors and their interaction.
· Lack of understanding of the geostatistics necessary for displaying spatial
variability of crops and soils using current mapping software, and
· Limited ability to integrate information from diverse sources with varying
resolutions and intensities.
**********

Climate Change Effect on Water Availability and
Management
Sumit Chaturvedi and Vipin C. Dhyani
Assistant Professors, (Agronomy)
G.B. Pant University of Agriculture & Technology, Pantnagar-263 145
Water is the most critical component of life support systems. India shares about
16% of the global population but it has only 4% of the total water resource. The
irrigation sector, which uses 83% of water, is the main consumer of this resource. The
main water resources in India consist of precipitation on the Indian Territory estimated
to be around 4000 cubic kilometers per year (km3/year) and transboundary flows,
which it receives in its rivers and aquifers from the upper riparian countries. Precipitation
over a large part of India is concentrated in the monsoon season during June to
September/October.
Table 1. Water resources of India
Due to various
constraints of
topography there is
uneven distribution of
precipitation over space
and time. Precipitation
varies from 100
millimeters (mm) in the
western parts of
Rajasthan to over
11,000 mm at
Cherrapunji in
Meghalaya. Out of the
total precipitation,
including snowfall, the
availability from
surface water and
replenishable groundwater is estimated at 1,869 km 3 . It has been estimated that only
about 1,123 km 3 , including 690 km 3 from surface water and 433 km 3 from groundwater
resources, can be put to beneficial use. Table 1 shows the water resources of the country
at a glance (MoWR, 2010).
CURRENT AND LOOMING CHALLENGES:
Km 3
4000
Estimated Annual Precipitation (including
Snowfall)
Runoff received from upper riparian countries 500
Average annual natural flow in rivers and aquifers 1869
Estimated utilizable water 1123
(i) Surface 690
(ii) Ground 433
Water demand_utilization (for year 2000) 634
(i) Domestic 42
(ii) Irrigation 541
(iii) Industry, energy & others 51
Source: National Water Mission under National Action Plan on
Climate Change, MoWR, GOI, 2010
Traditionally, India has been well
endowed with large freshwater reserves,
but the increasing population and over
exploitation of surface and groundwater
over the past few decades has resulted in
water scarcity in some regions. Growth
of the Indian economy is driving
increased water usage across sectors.
Wastewater is increasing significantly
and in the absence of proper measures
for treatment and management, the
existing Freshwater reserves are being
polluted. Increased urbanization is
driving an increase in per capita water
consumption in towns and cities.
Urbanization is also driving a change in
consumption patterns and increased
demand for water-intensive agricultural
crops and industrial products. From
1997 to 2050, India will move toward
water scarcity due to growing demand
and a drop in the supply of clean water.
Total water demand

is projected to increase by 89% due to
rapid increase in population. Per
capita water availability is projected
to decrease by ~44% during the same
period. Regional disparities in
reserves and replenishment are
expected to intensify water scarcity.
Agricultures share of total water
consumption is expected to decrease
between 2000 and 2050 from current
89% to 71%. More efficient methods
of irrigation and lower reliance on
agriculturally-based products are
expected to lead to this reduction.
Fig 1 Water availability and population
projection over India.
Domestic and industrial sectors are projected to constitute a growing share of the
total water consumption between 2000 and 2050. The industrial sector demand is
expected nearly quadruple due to rapid industrialization and economic growth. The
availability of sufficient water resources is
one of the major crises with
overarching implications for many
other world problems especially
poverty, hunger, ecosystem
degradation, desertification, climate
change, and even world peace and
security. Water scarcity is projected to
become a more important determinant
of food scarcity than land scarcity,
according to the view held by the UN
(UNDP, 2007). Scarcity and declining
water quality in many areas of the
world are held to pose key challenges,
including:
Fig 2 Utilizable water, demand and residual
which is not used in India.
1. Increased competition for water within and between sectors, transferring water out of
agriculture and leaving less water for food.
2. Increased inequity in access to water creating water haves and have nots,
perpetuating poverty and widening the inequalities in access to water for food.
3. Surge in the incidence of water borne diseases affecting human health and labour
productivity.
4. Deterioration of freshwater ecosystems impacting ecosystem health and services.
5. Tension over the use and control of water and potential for conflict at local, national and
transnational levels with a potential to afflict harm on the agricultural communities
dependent on water for food.
6. Reduced rainfall and enhanced vulnerability to extreme wet and dry events can
potentially reduce crop yield, cause short-term crop failure and long-term production
declines.
7. Decline in per capita food production threatening future food security.
8. Constrain on human capacity for crafting institutions and policies for responding to
emerging food security challenges.
ADDING TO THE THREAT: CLIMATE CHANGE IMPACTS

Climate change poses significant threats to food security and peace due to changes in
water supply and demand, impacts on crop productivity, impacts on food supply, and high
costs of adaptation to climate change. Climate change may affect agriculture and food
security by altering the spatial and temporal distribution of rainfall, and the availability of
water, land, capital, biodiversity and terrestrial resources. Modeling shows that future
socioeconomic development and climate change may impact on regional and global
irrigation requirements and thus on agricultural water withdrawals. Net irrigation
requirements may increase by 2050. Even with improvements in irrigation efficiency, gross
water withdrawals may increase by 20%. Some fairly sound conclusions that emerge from
climate change analysis on agriculture and food availability show that:
(a) Food shortages due to decrease in agricultural production and access to water and energy
(b) Increase in the number of people at risk of hunger and poverty;
(c) Impact on undernourishment will depend on the level of economic development and
poverty reduction in the future and its effects on distribution, and human responses to
climate change
(d) Mitigation of climate change can positively effect on agricultural productivity and food
security
(e) Current gaps between developed and developing countries will deepen.
There have been observed fluctuations in surface temperature, rainfall, evaporation
and extreme events since the beginning of the 20th century. The atmospheric concentration
of carbon dioxide has increased from about 280 ppmv to about 369 ppmv and the global
temperature of the earth has increased by about 0.6°C. The global mean sea level has risen
by 10 to 20 cm. There has been a 40% decline in Arctic Sea ice thickness in late summer to
early autumn in the past 45 50 years (Climate Change 2001). The frequency of severe
floods in large river basins has increased during the 20th century. Also, synthesis of rivermonitoring
data reveals that the average annual discharge of freshwater from six of the
largest Eurasian rivers to the Arctic Ocean has increased by 7% from 1936 to 1999. In
India, several studies show that there is increasing trend in surface temperature, no
significant trend in rainfall, but decreasing/increasing trends in rainfall at some locations
(Mall et al 2006).
Climate change observed over India
All India mean annual temperature has shown significant warming trend of 0.05°C
/10yr during the period 1901-2003 , the recent period 1971-2003 has seen a relatively
accelerated warming of 0.22°C/10yr, which is largely due to unprecedented warming during
the last decade (Kothawale and Rupakumar, 2005). On a regional basis, stations of southern
and western India show a rising trend of 1.06 and 0.36°C/100 yr respectively, while stations
of north Indian plains show a falling trend of -0.38°C/100 yr. The seasonal mean
temperature has increased by 0.94°C/ 100 yr for the post monsoon season and by 1.1°C/100
yr for the winter season (Ramakrishna, 2007). Some of the instances of observed spatial
variability in the temperature phenomena during last few years include extreme cold winter
during 2002-03; wide spread prevailing drought situations during July, 2004, 20 day heat
wave in A.P. during May, 2003. The trend analysis of rainfall data from 1140
meteorological stations carried out at CRIDA showed negative trend among the stations
situated in deep southern parts, central India, parts of North Indian region and N.E.
Year Season Temperature change
(°C)
2020s
Annual
Rabi
kharif
Rainfall change
(%)
Lowest Highest Lowest Highest
1.00
1.08
0.87
1.41
1.54
1.17
2.16
-1.95
1.81
5.97
4.36
5.10

2050s
2080s
Annual
Rabi
kharif
Annual
Rabi
kharif
2.23
2.54
1.81
3.53
4.14
2.91
2.87
3.18
2.37
5.55
6.31
4.62
5.36
-9.22
7.18
7.48
-24.83
10.10
9.34
3.82
10.52
9.90
-4.50
15.18
Table 2. Projected change
in over India (Agarwal PK,
2009)
regions. However part of
the country comprising the
areas in central parts
covering eastern U.P., eastern M. P., west coast and greater parts of Northwest India did not
show any changes. Among the rainfed districts, 40 per cent stations showed negative trend
48 per cent with positive trend and 12 per cent no change in rainfall (Rao, 2007). However,
Lal (2001) projected increase in annual rainfall over India but greater variability was during
rabi season observed with reduced rainfall (Table 2).
Climate risks and water resources
Water resources are at the risk from changes in temperature, glacier retreat, floods and
droughts and sea level rise. Predictions on alarming rate of retreat of glaciers, as for
example the Gangotri glacier, signal the reduction of rivers flows and their impacts on food
production. Average annual rate of retreat of Gangotri glacier, the source of Ganges, has
increased from 14.6 m during 1934-1974 to 35.4m during 1962-2000 (142% increases) and
has around 2 km since 1780. Any further warming is likely to increase the melting of
glaciers more rapidly than the accumulation. Glacial melt is expected to increase under
changed climate conditions, which would lead to increased summer flows in some river
systems for a few decades, followed by a reduction in flow as the glaciers disappear.
As a result of increase in temperature significant changes in rainfall pattern have
been observed during the 20th century in India. A serious environmental problem has also
been witnessed in the Indo-Gangetic Plain Region (IGPR) in the past whereby different
rivers (including Kosi, Ganga, Ghaghara, Son, Indus and its tributaries and Yamuna)
changed their course a number of times. The recent devastating floods in Nepal and Bihar
due to change of course of River Kosi is a case in point.
Available study suggests that food production has to be increased to the tune of 300
m t by 2020 in order to feed Indias ever-growing population, which is likely to reach 1.30
billion by the year 2020. The total food grain production has to be increased by 50 per cent
by 2020 to meet the requirement. It is feared that the fast increasing demand for food in the
next two or three decades could be quite grim particularly in view of the serious problem of
soil degradation and climate change. The rise in population will increase the demand for
water leading to faster withdrawal of water and this in turn would reduce the recharging
time of the water tables. As a result, availability of water is bound to reach critical levels
sooner or later. During the past four decades, there has been a phenomenal increase in the
growth of groundwater abstraction structures. Growing demand of water in agriculture,
industrial and domestic sectors, has brought problems of overexploitation of the
groundwater resource to the fore. The falling groundwater levels in various parts of the
country have threatened the sustainability of the groundwater resources.
At present, available statistics on water demand shows that the agriculture sector is
the largest consumer of water in India. About 83% of the available water is used for
agriculture alone.
Table 3. Possible identified implications of climate change on
water resources
1. Decline in the glaciers and the snowfields in the Himalayas;
2. Increased drought like situations due to overall decrease in the
number of rainy days over a major part of the country;
3. Increased flood events due to overall increase in the rainy day
intensity;
4. Effect on groundwater quality in alluvial aquifers due to
increased flood and drought events;
5. Influence on groundwater recharge due to changes in

If used judiciously, the demand
may come down to about 68% by
the year 2050, though agriculture
will still remain the largest
precipitation and evapo-transpiration; and
6. Increased saline intrusion of coastal and island aquifers due to
rising sea levels;
consumer. In order to meet this demand, augmentation of the existing water resources by
development of additional sources of water or conservation of the existing resources and
their efficient use will be needed. It is evident that the impact of global warming threats is
many and alarming. Water security in terms of quantity and quality pose problems for both
developed and developing countries. However, the consequences of future climatic change
may be felt more severely in developing countries such as India, whose economy is largely
dependent on agriculture and is already under stress due to current population increase and
associated demands for energy, freshwater and food.
Nearly 70 % of Earths surface comprises of water in the form of seas and oceans. Sea
level rise under warming is inevitable. Sea level rise is both due to thermal expansion as
well as melting of ice sheets. Thermal expansion would continue for many centuries even
after GHG concentrations have stabilized causing an eventual sea level rise much larger
than projected for the 21st century. If warming in excess of 1.9 to 4.6°C above preindustrial
level be sustained over many centuries then the final rise in sea level due to
melting polar ice could be several meters, because it will be in addition to that of rise of sea
level due to thermal expansion. The present scenario clearly indicates that the sea levels will
definitely rise.
Satellite observations available since the early 1990s show that since 1993, sea level has
been rising at a rate of around 3 mm per year, significantly higher than the average during
the previous half-century. IPCC predicts that sea levels could rise rapidly with accelerated
ice sheet disintegration. Global temperature increases of 34°C could result in 330 million
people being permanently or temporarily displaced through flooding. Warming seas will
also fuel more intense tropical storms. With over 344 million people currently exposed to
tropical cyclones, more intensive storms could have devastating consequences for a large
group of countries. The 1 billion people currently living in urban slums on fragile hillsides
or flood-prone river banks face acute vulnerabilities. People living in the Ganges Delta and
lower Manhattan share the flood risks associated with rising sea levels.
Weather extremes such as drought, flooding, cyclones etc. are expected to rise.
Flooding will displace a large number of people from the coasts putting a greater pressure
on the civic amenities and rapid urbanization. Sea water percolation due to inundations can
diminish freshwater supplies making water scarcer. The states along the coasts like Orissa
will experience worse cyclones. Many species living along the coastline are also threatened.
The coral reefs that India has in its biosphere reserves are also saline sensitive and thus the
rising sea level threatens their existence too, not only the coral reefs but the phytoplankton,
the fish stocks and the human lives that are dependent on it are also in grave danger.
TACKLING WATER SCARCITY AND CLIMATE CHANGE
Climate change challenges to future food security seem immense. There are two
potential pathways in dealing with climate change, i.e. mitigation and adaptation. Mitigation
is about gasses. Adaptation is about water. Water sector adaptations can address water
scarcity and food security issues but the costs of adaptation are particularly high in the
developing world. Under population growth and climate change scenarios, irrigated land
will be expected to produce most or about 70% of the additional food supplies, placing
increased pressure on existing water supplies.
Agricultural Water Management for Solution
As there is no additional water available, the needed increase in food production must
come from increasing water productivity through two basic pathways (Molden et al., 2007),
namely:

1. Extending the yield frontier in areas where present yields are close to their potential
yield .
2. Closing the yield gap where considerable yield gains can be achieved with modern
technology.
Producing more crops per drop of water and energy can achieve a further increase
in food production, using already available land, water and energy resources. Water and
energy saving measures would allow considerable gains in yield. In many irrigated systems
now facing water scarcity, water use efficiency and productivity could easily be doubled
(Molden et al., 2007); rainwater harvesting and light irrigation would enable significant
production growth in rainfed systems (Rockström et al., 2010). Enhancing water use
efficiency holds the key to tackling water scarcity and food security issues in smallholder
agricultural systems.
1. Water productivity improvements can effectively address food insecurity and poverty
alleviation.
2. Management practices that increase agricultural yields also improve water productivity.
3. The greatest potential to increase yields and water productivity is in areas where
agricultural productivity is currently low- Rainfed and arid and semi arid regions
particularly with development of water harvesting, supplemental and deficit irrigation,
and field water conservation to reduce nonproductive evaporation, improved nutrients,
and drought resistance varieties. Intervention like agroforestry, integrated farming
system, and conservation agriculture also holds key solutions.
4. Major opportunities to improve water productivity are found in water management
practices along the continuum from rainfed to partially and fully irrigated farming
systems- The key is to integrate non-structural and structural measures and investments
targeted at crop management, soil and water conservation, and irrigation practices like
drip, sprinkler and improved surface irrigation.
5. Water productivity gains are realized also by non-water management interventions-These
measures include the choice of crop varieties particularly drought, flood and saline
tolerant, fertilizer investment, carbon sequestration and residue management through
biochar, pest and weed management, timely operations and post harvest management.
6. Improving livestock water productivity should be an integral part of water resource
management -Livestock provide livelihood support and a store of wealth for many of the
worlds poor. The water requirements of livestock and efforts to improve crop water
productivity.
7. Water productivity gains in agriculture can secure water resources for other landscape
uses and ecosystem services.
8. Integrated water and land management at the watershed scale is the key to improving
water productivity and enabling sustainable water resource management-Tapping the
opportunity of improved water productivity will require an integrated management of
green and blue water resources, which in turn will require a downscaling of the focus of
IWRM from the river basin to the watershed level. The challenge for IWRM is to
manage trade-offs when re-allocating green and blue water across scales from field to
watershed level, and to limit negative side-effects such as reductions in downstream
water availability due to upstream land management activities.
9. Targeted policy actions can support integrated water and land management for improved
water productivity.
10. Capacity building and awareness are essential.
SELECTED REFERNCES:
Agarwal P.K. (2009) Vulnerability of Indian Agriculture to Climate Change: Current State
of Knowledge MOEF_NATCOM; 14th October 2009.

Anonymous (2010) National Water Mission under National Action Plan on Climate
Change, MoWR, GOI.
Climate Change 2001, Contribution of Working Group I to the Third Assessment Report of
the Intergovernmental Panel on Climate Change (eds Houghton, J. T. et al.),
Cambridge University Press, Cambridge, UK, 2001, p. 881.
http://www.iwmi.cgiar.org/Topics/index.aspx
Intergovernmental Panel on Climate Change (IPCC), 2001. Climate Change 2001:
Synthesis Report. Intergovernmental Panel on Climate Change (IPCC) Secretariat,
Geneva, Switzerland.
Kothawale, D. R., and K. Rupa Kumar (2005), On the recent changes in surface temperature
trends over India, Geophys. Res. Lett., 32, L18714, doi:10.1029/2005GL023528.
Kothawale, D.R. and Rupakumar (2005). On the recent changes in surface temperature
trends over India. Geophys. Res. Lett., 32, L18714, doi:10.1029/2005GL023528.
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**********

Enhancing Water Productivity Through Abiotic Stress Management
V C Dhyani and Sumit Chaturvedi
Assistant professors, (Agronomy)
G.B. Pant University of Agriculture & Technology, Pantnagar-263 145
Todays world population of 6 billion is expected to reach about 8 million by 2030,
a jump of 35%. The burgeoning population will need considerable additional food.
Simultaneously, water demand from non-agricultural sectors will keep growing in both
developed and developing countries. About 40% of the land in the world is under arid and
semi-arid climatic conditions (Gamo, 1999). Abiotic stresses are the primary cause of crop
loss in these areas for most crops. Droughts, floods and salinity are becoming particularly
widespread in many regions, and may cause serious Stalinization of more than 50% of all
arable lands by the year 2050. (Wang et al. 2003) Environmental stresses such as erratic
and insufficient rainfall, extreme temperatures, salinity, alkalinity, aluminium toxicity,
acidity, stoniness and others limit yield and productivity of many cultivated crop plants. Not
only are such problems serious today, it seems they are inevitably worsening. Future
estimates of climate change, including temperature increases and unreliable rainfall patterns
for the region, may add stress to crop production. Thus, addressing opportunities for water
productivity gains may sometimes lie far beyond the conventional water management arena.
Where water productivity (WP) increases with yield increases, the opposite is true for
increases in certain abiotic stresses. Crop production systems subject to such stresses will
decrease yields without equal decreases in water use. Water productivity can therefore be
achieved through non-water management interventions. In this chapter we will be
discussing how we are able to reduce the adverse effect of salinity, droughts and floods. If
these are tackled well obviously water productivity will be increased as there will be
increase in productivity without much change in water consumption.
SALINITY
Many arid region soils naturally contain high concentrations of soluble salts,
because soil weathering processes dependent upon precipitation have not been sufficiently
intense to leach salts out of soils. Salt- affected soils are an important ecological entity in
the landscape of any arid and semi-arid region. In India nearly 9.38 million ha area is
occupied by salt-affected soils out of which 5.5 million ha are saline soils (including
coastal) and 3.88 million ha alkali soils (IAB 2000). Irrigation water and fertilizers contain
salts that may contribute further to the problem. Poor soil drainage due to the presence of
compacted layers (hardpans, plough pans, caliche, clay lenses), heavy clay texture, or
sodium problems may prevent downward movement of water and salts, making
implementation of soil salinity control measures difficult. Adequate soil drainage, needed
to allow leaching of water and salts below the root zone of the trees, is absolutely essential
for effective management of soil salinity. The risk of soil salinity formation is always
greater in fine-textured (heavy) soils than in coarse-textured soils. This is because sandy
soils naturally have larger pores that allow for more rapid drainage. Soil horizons high in
clay content anywhere within the root zone may cause poor drainage and result in soil salt
accumulation.

Dangers of Soil Salinity
The most serious problem caused by soil salinity is the decreased osmotic potential
of soil water. This has the effect of reducing plant-available water. Therefore crops grown
in salty soils will experience a moisture deficit sooner than those in non-salty soils. This
will be exhibited by reduced growth rate, grain/fruit size, and yield. A soil salinity level of
3.5 dS/m (measured in a saturated paste; equivalent to 2200 ppm) can reduce growth by
approximately 25%. Severe consequences can occur at soil salinity levels of 5 dS/m (3200
ppm), and trees may die when soil salinity reaches or exceeds 6 dS/m (3800 ppm)
(Miyamoto et al., 1986). Treatment of Saline soils cannot be reclaimed by chemical
amendments, conditioners or fertilizers. A field can only be reclaimed by removing salts
from the plant root zone. In some cases, selecting salt-tolerant crops may be needed in
addition to managing soils. There are three ways to manage saline soils. First, salts can be
moved below the root zone by applying more water than the plant needs. This method is
called the leaching requirement method. The second method, where soil moisture conditions
dictate, combines the leaching requirement method with artificial drainage. Third, salts can
be moved away from the root zone to locations in the soil, other than below the root zone,
where they are not harmful. This third method is called managed accumulation. Use of
arbuscular mycorhiza (AM) Plant Growth Promoting Rhizobacteria (PGPR) and transgenic
are the areas where lot of research has been on these days.
Cardon (http://www.ext.colostate.edu/pubs/crops/00503.html) gave a brief account
of measures that can be taken to combat salt problem. These are
Leaching Requirement
For most surface irrigation systems irrigation inefficiency (or over-irrigation)
generally is adequate to satisfy the leaching requirement. However, poor irrigation
uniformity often results in salt accumulation in parts of a field or bed. Surface irrigators
should compare leaching requirement values to measurements of irrigation efficiency to
determine if additional irrigation is needed. Adding more water to satisfy a leaching
requirement reduces irrigation efficiency and may result in the loss of nutrients or pesticides
and further dissolution of salts from the soil profile. Leaching is accomplished on a limited
basis at key times during the growing season, particularly when a grower may have high
quality water available. Surface water in most areas tends to have lower salinity than
shallow, alluvial groundwater. Deep groundwater may have an even lower salinity than
either shallow groundwater or surface water. In situations where a grower has multiple
water sources of varying quality, consider planned leaching events at key salinity stress
periods for a given crop. Most crops are highly sensitive to salinity stress in the germination
and seedling stages. Once the crop grows past these stages, it can often tolerate and grow
well in higher salinity conditions. Planned periodic leaching events might include a postharvest
irrigation to push salts below the root zone to prepare the soil (especially the
seedbed/surface zone) for the following spring.
Leaching plus artificial drainage
Where shallow water tables limit the use of leaching, artificial drainage may be
needed. Cut drainage ditches in fields below the water table level to channel away drainage
water and allow the salts to leach out. Drainage tile or plastic drainpipe can also be buried in
fields for this purpose. With all artificial drainage systems one must also consider disposal
of the drainage water. In the case of regulated discharge, treatment or collection and
evaporation of the water on site may be required and may add significant costs. The
advantage of artificial drainage is that it provides the ability to use high quality, low salinity
irrigation water (if available to a farmer) to completely remove salts from the soil. However,
artificial drainage systems will not work where there is no saturated condition in the soil.
Water will not collect in a drain if the soil around it is not saturated.

After drainage appears adequate, the leaching process can begin.
Managed Accumulation
In addition to leaching salt below the root zone, salts can also be moved to areas
away from the primary root zone with certain crop bedding and surface irrigation systems.
The goal is to ensure the zones of salt accumulation stay away from germinating seeds and
plant roots. Irrigation uniformity is essential with this method. Without uniform distribution
of water, salts will build up in areas where the germinating seeds and seedling plants will
experience growth reduction and possibly death. Double-row bed systems require uniform
wetting toward the middle of the bed. This leaves the sides and shoulders of the bed
relatively free from injurious levels of salinity. Without uniform applications of water (one
furrow receiving more or less than another), salts accumulate closer to one side of the bed.
Periodic leaching of salts down from the soil surface and below the root zone may still be
required to ensure the beds are not eventually salted out.
Alternate furrow irrigation may be desired for single-row bed systems. This is accomplished
by irrigating every other furrow and leaving alternating furrows dry. Salts are pushed across
the bed from the irrigated side of the furrow to the dry side. Care is needed to ensure enough
water is applied to wet all the way across the bed to prevent build up in the planted area.
This method of salinity management can still result in plant injury if large amounts of
natural rainfall fill the normally dry furrows and push salts back across the bed toward the
plants. This phenomenon also occurs if the normally dry furrows are accidentally irrigated.
Sprinkler Irrigation
Sprinkler-irrigated fields with poor water quality present a challenge because it is
difficult to apply enough water to leach the salts and you cannot effectively utilize row or
bed configurations to Other Management Options Residue Management Crop residue at the
soil surface reduce evaporative water losses, thereby limiting the upward movement of salt
(from shallow, saline groundwater) into the root zone. Evaporation and thus, salt
accumulation, tends to be greater in bare soils. Fields need to have 30 percent to 50 percent
residue cover to significantly reduce evaporation. Under crop residue, soils remain wetter,
allowing fall or winter precipitation to be more effective in leaching salts, particularly from
the surface soil layers where damage to crop seedlings is most likely to occur. Plastic
mulches used with drip irrigation effectively reduce salt concentration from evaporation.
Sub-surface drip irrigation pushes salts to the edge of the soil wetting front, reducing
harmful effects on seedlings and plant roots.
Pre-plant Irrigation
As mentioned before, most crop plants are more susceptible to salt injury during
germination or in the early seedling stages. An early-season application of good quality
water, designed to fill the root zone and leach salts from the upper 6 to 12 inches of soil,
may provide good enough conditions for the crop to grow through its most injury-prone
stages.

Irrigation Frequency Management
Salts are most efficiently leached from the soil profile under higher frequency
irrigation (shorter irrigation intervals). Keeping soil moisture levels higher between
irrigation events effectively dilutes salt concentration. in the root zone, thereby reducing the
salinity hazard. Most surface irrigation systems (flood or furrow systems) cannot be
controlled to apply less than 3 or 4 inches of water per application and are not generally
suited to this method of salinity control. Sprinkler systems, particularly center-pivot and
linear-move systems configured with low energy precision application (LEPA) nozzle
packages or properly spaced drop nozzles, and drip irrigation systems provide the best
control to allow this type of salinity management.
Plant Growth Promoting Rhizobateria
Salt tolerance due to PGPR has been cited in the literature and shown in Figure 1 (Yang et
al 2008)
1. Due to reduced ethylene content. Ethylene content in tomato seedlings exposed to high
salt was reduced by application of Achromobacter piechaudii, indicating that bacterial
ACC dea-minase was functional. A. piechaudii, which produces ACC, increased the
growth of tomato seedlings by as much as 66% in the presence of high salt contents.
2. Bacterial volatile organic compounds (VOCs) mediated transcriptional expression of
HIGH-AFFINITY K+ TRANSPORTER 1 (HKT1), which controls Na+ import in roots,
was decreased. HKT1 has been shown to adjust Na+ and K+ levels differentially,
depending on the plant tissue. Exposure of an athkt1 mutant to bacterial volatile organic
compounds (VOCs) not only resulted in typical salt-stress phenotypes, such as stunting,
but also led to the inhibition of seedling growth. Transcriptional validation revealed that
bacterial VOCs down regulated HKT1 expression in roots, but upregulated it in shoot
tissues, thereby orchestrating lower Na+ levels in the whole plant
Source: Yang et al 2008
Figure: 1 Induced Systemic Tolerance (IST) elicited by PGPR against drought, salt and
fertility stresses underground (root) and aboveground (shoot). Broken arrows indicate
bioactive compounds secreted by PGPR; solid arrows indicate plant compounds affected by
bacterial components.

Arbuscular mycorrhiza
Through experimental and field studies, it is clear that arbuscular mycorrhizal fungi
(AMF) possess considerable tolerance to soil (Sengupta & Chaudhuri 1990). The role of
arbuscular mycorrhizal fungi in alleviating salt are enhanced nutrient acquisition (P, N, Mg
and Ca), maintenance of the K + : Na + ratio, biochemical changes (accumulation of proline,
betaines, polyamines, carbohydrates and antioxidants), physiological changes
(photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation,
nodulation and nitrogen fixation), molecular changes (the expression of genes:PIP,
Na + /H + antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. (Evelin, et al
2009 )
Transgenics
Wild plants that tolerate salt and grow in saline environments have high intracellular
salt levels. A major component of the osmotic adjustment in these cells is accomplished by
ion uptake. The utilization of inorganic ions for osmotic adjustment would suggest that salttolerant
plants must be able to tolerate high levels of salts within their cells. However,
enzymes extracted from these plants show high sensitivity to salt, suggesting that these
plants are able to keep Na + ions away from the cytosol.
Plants can use three strategies for the maintenance of a low cytosolic sodium
concentration: sodium exclusion, compartmentation, and secretion. One mechanism for
sodium transport out of the cell is through operation of plasma membrane-bound
Na + /H + antiports, as confirmed by the characterization of SOS1, a putative plasma
membrane Na + /H + antiport from Arabidopsis thaliana. The efficient compartmentation of
sodium is likewise accomplished through operation of vacuolar Na + /H + antiports that move
potentially harmful ions from cytosol into large, internally acidic, tonoplast-bound
vacuoles. 2 These ions, in turn, act as an osmoticum within the vacuole to maintain water
flow into the cell. 3 Antiports use the protonmotive force generated by vacuolar H + -
translocating enzymes, H + -adenosine triphosphatase (ATPase) and H + -inorganic
pyrophosphatase (PP i ase), to couple downhill movement of H + (down its electrochemical
potential) with uphill movement of Na + (against its electrochemical potential) (Zhang et al
2001 wrote in reference cited himself citing several references).
DROUGHT
Drought is a natural hazard, it has a slow onset, and it evolves over months or even
years. It may affect a large region and causes little structural damage. The United Nations
Convention to Combat Desertification or UNCCD, defines drought as the naturally
occurring phenomenon that exists when precipitation has been significantly below normal
recorded levels, causing serious hydrological imbalances that adversely affect land resource
production systems.
The impacts of drought can be reduced through preparedness and mitigation. Mitigation
means actions that we can take before, or at the beginning of, drought to help reduce the
impacts of drought. Mitigating drought involves a wide range of agricultural practices
including finding additional water supplies and conserving water that is already available.
However, it is not enough to make drought plans based only on agricultural practices. There
are many other strategies at government level that are just as important.
Thus the components of a drought preparedness and mitigation plan are the following:
• Prediction
• Monitoring
• Impact assessment

• Response.
Prediction can benefit from climate studies which use coupled ocean/atmosphere models,
survey of snow packs, anomalous circulation patterns in the ocean and atmosphere, soil
moisture, assimilation of remotely sensed data into numerical prediction models, and
knowledge of stored water available for domestic, stock, and irrigation uses.
Monitoring exists in countries which use ground-based information such as rainfall,
weather, crop conditions and water availability. Satellite observations complement data
collected by ground systems. Satellites are necessary for the provision of synoptic, widearea
coverage.
Impact assessment is carried out on the basis of land-use type, persistence of stressed
conditions, demographics and existing infrastructure, intensity and areal extent, and its
effect on agricultural yield, public health, water quantity and quality, and building
subsidence.
Response includes improved drought monitoring, better water and crop management,
augmentation of water supplies with groundwater, increased public awareness and
education, intensified watershed and local planning, reduction in water demand, and water
conservation.
Soil and water conservation measures to combat drought
The crop based strategies that will help to mitigate drought are :
Land planning system
Some lands can only sustain limited cultivation because they are prone to drought.
These are best used for alternate uses rather than normal food grain crops. Growing of short
duration legume crops, like mungbean (green gram), cowpea etc.
Land-use systems give stability to dry land production systems and also make good use of
the land and rainfall during the off-season.
· Establishing perennial grasses for livestock farming
· Alley-cropping, Agroforestry or Silvipasture practices.
Soil management techniques
Tillage during the off-season or in pre-rainy season, helps with rain water intake by
breaking the hard soil and making the soil surface more permeable.
1. This allows water to seep to the deeper soil layers and keeps the soil wet for longer
time.
2. The result is the soil will have more moisture during sowing the crop.
3. Tillage also controls weeds which depletes the soil moisture.
4. Off-season tillage also destroys the eggs, cocoons and larvae of some pests by
exposing them to the sun which otherwise affect the already stressed crop plants.
Crop management techniques:
Selection of crops and varieties
1. Avoid growing of drought prone crops like maize, cotton etc.
2. Growing drought resistant grain crops like sorghum, pearl millet, finger millet, fox
tail millet etc.
3. Growing drought resistant legume crops like pigeonpea, green gram, horse gram etc.
4. Growing of oil seed crops like castor, sunflower, niger, sesame, safflower etc.
5. Intercropping practices

6. Intercropping refers to growing more than one crop in the same land area in rows of
definite proportion and pattern.
7. Intercropping system provides insurance against total crop failure in drought prone
areas.
A few examples of suitable intercropping systems under drought are
1. Sorghum and Red gram
2. Pearl millet and Red gram
3. Pearl millet and Cowpea
4. Sunflower and Horsegram etc.
Plant Density
1. It is important to keep optimum plant population and row spacing. Generally wider
plant spacing is preferred in drought prone areas.
2. You must careful not to space the plants too widely. This will not use the available
soil moisture to the capacity.
3. Remember that more plants do not necessarily means more yield. In dry lands more
healthy plants needed for better yield.
Weed Control
1. Weeds compete with crops for soil moisture and nutrients.
2. Weeds also host some pests and diseases and these will migrate and affect the crops
which are already under stress under drought conditions.
3. So, good weed control from the early stages of crops is essential in drought areas.
Mulching
1. Surface mulching either by timely intercultivation or by covering the soil surface
with plant residues benefits the crops.
2. Reduces evaporation of water from soil.
3. Water runoffs from the cropped fields can be curtailed.
4. Reduces menace of weeds.
5. Adds organic matter to the soil and improves soil quality in terms of soil physical
chemical and biological properties.
Integrated Plant Nutrient management (IPNM)
INM takes care of physical, chemical and biological needs of the soil. It meets the
nutrient needs of the soil from the use of organic and inorganic fertilizers.
Benefits of INM:
1. Increases water holding capacity of the soil.
2. Increases the amount of nutrients in the soil.
3. The soil will be free from disease causing organisms.
4. Reduces loss of nutrients.
5. Increases nutrient use efficiency
6. Reduces cost of production.
Integrated watershed management (IWM)
IWM is the an efficient way to continually manage land and water resources in the drought
prone areas. The focus of IWM is conservation and efficient way of using rain water. IWM
combines several approaches to minimize the risk of drought. These approaches are:
1. Soil and water conservation
2. Rain water harvesting
3. Efficient land and crop management
Other practices

Use of transgenics
Transgenics can be very helpful in reducing the effect of drought. In rice cultivar,
Nipponbare was used for transformation with the barley HVA1gene. The two transgenic
(#3054 and 3059) and the variety Nipponbare were tested for the drought stress
Construction of the Act1-HVA1 plasmid for production of transgenic plants, During the
initial 14 days after withholding water, there was no significant decrease in plant water
status, viz. RWC (Figure 2 A), either in the transgenic or NT rice lines. Rice plants
maintained near turgid water status without symptoms of leaf rolling for more than 12 days
after cessation of rain under field conditions in rainfed ecosystem. Thus, the rice plants were
subjected to a prolonged stress cycle were subjected very similar to field drought stress in
the target production environment. The differences in plant water status between the
transgenic and NT lines however, became evident during the third week of the stress cycle.
RWC declined to 85.6% in the NT line, while it was relatively higher in the transgenic lines
(95.0 and 94.1%, respectively in #3059 and 3054) 21 days after stress (Fig. 2 A).
Transgenic plants had better cell membrane stability under drought stress as compared to
NT plants. Figure 1B suggest that the improved drought resistance in these two transgenic
lines might have been achieved via cell membrane protection as very less leakage was
observed in transgenics..
A
B
Figure: 2 Memberane leakage (A), Changes in leaf relative water content (B), and osmotic
potential (D) in non-transgenic and transgenic lines (#3059 and 3054) of rice (cv.
Nipponbare) under progressive water stress. Source: Chandra Babu et al 2005
PGPR: Investigations into how drought stress affects plant hormone balance revealed an
increase in abscisic acid (ABA) content in the leaves, indicating that the reduction of
endogenous cytokinin levels magnifies ABA content, eliciting stomata closure (Cowan, et al
1999) {Figure 1}. The cytokinin ABA antagonism might be the result of metabolitic
interactions because they share a common biosynthetic origin. It will be interesting to
determine whether cytokinin produced by P. polymyxa affects ABA signaling of plants or
rhizobia-elicited nodulation (Figueiredo, et al 2008). Co-inoculation of lettuce (Lactuca
sativa L.) with PGPR Pseudomonas mendocina and arbuscular mycorrhizal fungi (Glomus
intraradices or G. mosseae) augmented an antioxidant catalase under severe drought
conditions, suggesting that they can be used in inoculants to alleviate the oxidative damage
elicited by drought (Figure 1).
FLOOD
The term "flood" is a general or temporary condition of partial or complete
inundation of normally dry land areas from overflow of inland or tidal waters or from the
unusual and rapid accumulation or runoff of surface waters from any source. The
agricultural land use is considered as one mean to prevent floods and to reduce the risk of
damage after a flood. The main argument addresses on one hand the impact of agricultural
practices on the formation of flood events by hindering water infiltration and increasing run-

off. On the other hand, the opinion is stipulated that a substantial reduction of flood
damages is possible if farmers choose the appropriate land use practices. While the evidence
for the influence of agriculture on the flood risk has to be proved by natural scientists, flood
risk protection is a governmental responsibility. The promotion of specific agricultural land
use measures so called non-structural measures might be one of the tools of an
appropriate administrative flood risk management.
Suitable agricultural practices are very important in flood management programme because
reducing risk from floods is also directly related to reducing risk of livelihood in many
countries. Most of the flood prone area of the country is located near the river banks. But
due to changing climate and increasing intensities of floods most of the traditional non
prone areas are also becoming prone to floods. However considering the traditional flood
prone areas one has to take into account rice crop because it is one of the most important
crop of flood prone areas. If farmers are able to save this crop from floods then major risk
from floods is averted. In this chapter thus I am concentrating on management of rice crop
in flood prone areas.
Different management technologies in flood prone areas are
1. Crop and varietal selection
2. Nursery management
3. Transplanting
4. Post submergence nutrient management in the main field
5. Double and triple transplanting
6. Water Management
Varietal selection
1. Good seedling vigour
2. Essentially, a plant type of the high yielding varieties is needed with the ability to
elongate, if the water level increases (rapid elongation is not necessary)
3. Submergence tolerance is necessary Flood tolerance is related to high carbohydrate
supply during submergence
4. The role of CHO is probably for the maintenance and survival
5. Old seedlings tend to have more carbohydrate reserve and thus good survival during
submergence
6. Genetic diversity in carbohydrate concentration of plants prior to submergence exist
in nature.
7. Photoperiod sensitivity should assure flowering at a time when plants are least
vulnerable to submergence.
8. Intermediate plant height (about 130 cm tall at 5cm water depth) is needed. In fact, if
water level is low or drought sets in, the plant height will be about 100 cm.
Flash flooding adversely affects rice productivity in vast areas of rainfed lowlands in
South and Southeast Asia. It is major form of crop loss because water inundation is for
10-12 days, sufficient to kill even the rice plants. Deep water rice varieties may not
perform well because they are adaptive to continuous water inundation. In one study
(Das et al 2005) tolerant genotypes were identified and key traits such as high levels of
non-structural carbohydrates (NSC, starch and soluble sugars) and limited underwater
elongation were found to be associated with tolerance. In this study, authors evaluated
the role of NSC before and after submergence and shoot elongation during submergence
in submergence tolerance using genotypes that contrast in initial NSC content and
elongation ability during submergence. The traits were further manipulated using a
growth promoter, GA3, and a potent gibberellin synthesis inhibitor, paclobutrazol (PB).
Submergence for 10 days resulted in higher mortality of IR42 (intolerant), followed by

Sabita and Hatipanjari (Table 1). The latter two cultivars have a high initial NSC similar
to that of the tolerant cultivar, FR13A, but elongated to higher extent under water.
Exogenous GA3 enhanced underwater elongation and depletion of NSC and reduced
survival. Conversely, PB suppressed elongation, improved the retention of NSC and
enhanced survival. FR13A is less responsive to PB but more responsive to GA,
suggesting its inherently low GA concentration under submergence. Underwater
elongation is associated with NSC consumed during submergence but not with NSC
level before submergence.
Table : 1 Inhibition of GA biosynthesis improved survival
Treatment FR13A Sabita Hatipanjari IR42
Submerged 83b 19c 31c 8c
S+ GA3 56d 2d 22d 4c
S+ PB 94a 74a 75a 53a
Mean 77 37 46 26
Note: Values followed by same letter are not significantly different. (Das et al, 2005)
Nursery management
1. Select a proper seedbed site.
2. Use a low seed rate in the nursery
3. Do thorough land preparation of the nursery
4. Use proper water management : Do not flood only saturate the nursery
5. Use proper nutrition The following amounts 6 g of N, 4 g of P2O5, 2 g of Zn, and 1
kg of FYM per m2 of the nursery area
6. Transplanting
7. Timing: Use older (about 3545 days old) seedlings.
8. Plant density and spacing: Use 23 seedlings per hill. Closer spacing (15 × 15 cm) in
the field
Post submergence nutrient management in the main field
1. If the floodwater goes down (field water depth of

varieties (e.g., late-duration or hot period-intolerant varieties seem to be better adapted) or
proper management of seedlings in nurseries or upon transplanting in the field.
Submergence-tolerant rice?
Submergence-tolerant rice contains the submergence 1 (SUB1) gene that allows it to survive
1014 days of complete submergence and to renew growth when the water subsides.
However, the duration of survival is also influenced by environmental factors such as water
turbidity, temperature, and light, and other factors such as seedling age. Plants become more
tolerant as they get older (www.irri.org).
CONCLUSION
Major boost in water productivity in abiotic stress areas comes from non water
management options. Salinity is widespread, floods and droughts are are inevitable but
considering them as natural calamity will not serve the purpose. Droughts, salinity and
Flash floods are most harmful for the agriculture Selection of suitable crops and variety is
most important management option available in agriculture. There is availability of stress
tolerant crops and varieties in the country Transgenics with LEA genes, Sub-1 gene has
given a whole new avenue to agronomy in mitigating droughts, floods salinity and host of
other abiotic stresses Use of mycorhizae and PGPR in saline and drought affected areas
need to be promoted. Already proven technologies for droughts have not penetrated in the
rainfed/dry areas. There should be long term integrated abiotic stress management
programme to tackle the flood situation where experts from all the fields right from the
engineers, agriculture scientists, social scientist and above all policy makers sit together and
make plan.

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IAB. 2000. Indian Agriculture in Brief. (27 th edition). Agriculture Statistics Division,
Ministry of Agriculture, Govt. of India, New Delhi
Jungwook Yang, Joseph W. Kloepper and Choong-Min Ryu 2008 Rhizosphere bacteria
help plants tolerate abiotic stress 10.1016/j.tplants.2008.10.004
R. Chandra Babu, Jingxian Zhang, A. Blumc, T.-H. David Ho, R. Wu, H.T. Nguyen 2004
HVA1, a LEA gene from barley confers dehydration tolerance in transgenic rice
(Oryza sativa L.) via cell membrane protection Plant Science 166: 855862
Sengupta, A. & Chaudhuri, S. (1990) Vesicular arbuscular mycorrhiza (VAM) in pioneer
salt marsh plants of the Ganges river delta in West Bengal (India). Plant and Soil 122:
111±113.
Wang, W., B. Vinocur and A. Altman. 2003. Plant response to drought, salinity and extreme
temperatures: towards genetic engineering for stress tolerance. Planta 218:114.
www.irri.org
Zhang, H. X., Hodson, J. N.; Williams, J. P., and Blumwald, E. 2001 Engineering salttolerant
Brassica plants: Characterization of yield and seed oil quality in transgenic
plants with increased vacuolar sodium accumulation Proceedings of the national
acdemy of sciences of the United States of America 98 (22):1283212836
http://www.pnas.org/content/98/22/12832.full.pdf+html
**********

Soil Microbiology in Relation to Water Productivity
Ramesh Chandra
Professor and Head (Soil Science)
G.B. Pant University of Agriculture and Technology, Pantnagar-263145
Soil is a dynamic living matrix comprising complex mixture of mineral matter, organic
matter, living organisms, air, and water. It is a critical resource not only to agricultural
production and food security but also to the maintenance of most life processes on
terrestrial eco-systems. Soils contain enormous numbers of diverse living organisms
assembled in complex and varied communities ranging from the myriad of invisible
microbes, bacteria and fungi to the more familiar macro-fauna such as earthworms and
termites. Soil biota includes microflora, microfauna and macrofauna. Microflora is a diverse
group consisting of bacteria, fungi and actinomycetes whereas microfauna include protozoa,
nematodes, and some arthropods, primarily mites and springtails (collembola). Microfauna are
usually defined as being smaller than 0.2 mm, although some soil nematodes can reach lengths
of 5.0 mm. One tea spoonful of soil contains 100 million to 1 billion bacteria, several yards of
fungal hyphae, 1000s of protozoa, 10 to 20 nematodes, Insects & mollusks : 100s / cubic foot,
earthworms, 5 30 per cubic foot and 4000 kg plant roots per hectare in top 20 cm of soil
(Chhonkar and Pareek, 2002). Each hectare top soil contains approximately 1000 kg of
different fungi, 500 kg of bacteria, 750 kg actinomycetes and 150 kg of algae and many
protozoa (Table 1). These diverse microorganisms interact with one another and with the
plants and animals in the ecosystem forming a complex system of biological activity.
Besides, the well-being and prosperity of earths ecological balance, the sustainability of
agricultural production systems directly depends on the extent and status of microbial
diversity of soil. These microorganisms in soil also have direct and indirect influence on
utilization of water by plants.
Table 1. Population and biomass of microorganisms is soil
Group of microorganism
Average population
(g -1 soil)
Average biomass (Kg
ha -1 )
Bacteria
Fungi
Actinomycetes
Algae
10 7 -10 8
500
10 5 -10 6
1,000
10 6 -10 7
750
10 3 -10 4 150
(Alexander, 1977)
Soil Biota and Water productivity
Soil microorganisms consisting of flora as well as fauna influence the water use
efficiency directly by influencing the water uptake and plant water retionship and indirectly
through increasing plant growth, organic mater decomposition and humus synthesis,
nutrient transformation and mobilization etc.

Direct effect of mycorrhzal fungi on plant water relation
Mycorrhizal fungi forms the direct link between soil and plant roots. Mainly there
are two type of Mycorrhizaal assocaitions: (i) ectomycorrhiza: Generally found in trees and
is important for forest trees. (ii) Endomycorrhza: They are found in majority of crop plants
and play role in supply of phosphorus and other nutrients. Among these Arbuscular
Mycorrhiza (AM) are common in field crops. AM is a symbiotic interaction between one or
more species of coenocytic fungi and roots of higher plants. These associations have been
studied widely for their beneficial role in absorption of phosphorus and micronutrients for
most field crops. The benefits of mycorrhizal fungi in improving the water use efficiency
has been attributed to increase in nutritional status, especially P, of host, which in turn
increased the hydraulic conductivity of the roots ( Nelson, 1987). In order to find out
possible mechanism for the involvement of mycorrhizal association in improving water
uptake by pants, Hardie and Layton (1981) reported that:
1. The hydraulic conductivity of mycorrhizal plants was 2-3 times higher than non
mycorrhizal clover plants. It attributed partly due the grater length and diameter of
the mycorrhizal roots. It suggested that that this increase in hydraulic conductivity
might enhance translocation of water in or hyphae extending out into the soil.
2. It was observed that under adequate soil moisture, transpiration rates of mycorrhizal
plants were much higher than non infected plants, due to higher root conductivities,
larger leaf surface and lower leaf diffusion rates. It may cause rapid wilting of
mycorrhizal plants.
3. When water availability becomes limiting, leaf resistance of mycorrhizal plants
increased value equal to non-mycorrhizal plants and transpiration rate rate were
below that of to non-mycorrhizal plants.
4. Mycorrhizal plants extracted soil moisture content more efficiently, down to lower
water potentials (

fragmentation to finer particles creates new surface areas for microbial colonization and
consequently speeds up the decomposition and mineralization processes.
Biological N 2 fixation
Biological N 2 fixation (BNF) is an important activity of microorganisms in soil. The
contribution of legume-rhizobia associations alone is about 40 % of total 175 million tones
of BNF. In the presence of a suitable host the bacteria infect the plant roots and forms root
nodules. Within these nodukes, rhizobia fixes atmospheric N 2. Besides, there are number of
diazotrophic bacteria e.g. Azotobacter, Azospirillum, Herbaspirillum, Gluconoacetobacter,
which fixes atmospheric N 2 and improve the plant growth and water use efficiency. Out of
these Azotobacter and Azospirillum are known to economize the nitrogen in cereals,
vegetables. The efficiency of BNF depends on the strains, crop management and several soil
factors like available soil nitrogen, soil moisture, pH, temperature etc.
Phosphate solubilising bacteria
Several soil bacteria, particularly those belonging to genera Pseudomonas and Bacillus and
fungi belonging to Penicillium and Asprergillus genera have the ability to solublize the
insoluble inorganic phosphorus in soil to make it available for plants. The mechanisms of
solublization appears to be either acid production or chelation of metal and release of
phosphorus. Many a times these phosphate solublizers are also producers of plant growth
harmones like Indole acetic acid, Gibberellic acid etc. Bioinoculants of these
microorganisms can be used in all crops. Normally these bacteria can solubilize about 15-20
kg P/ha/season. Their inoculation was found to increase the yield of the crops by 10-20 per
cent.
Plant Growth promoting rhizobactera
Recently, biofertilizers have arrived with a new concept of plant growth promoting
rhizobacteria (PGPR). These bacteria colonize the plant root system and promote the plant
growth through various mechanism (Kloepper and Schroth, 1978). PGPR are generally free
living, soil-borne bacteria, isolated from the rhizosphere, when applied to seeds or crops,
enhances the growth of the plant through at least one mechanisms eg., suppression of plant
disease (bioprotectants), improved nutrient acquisition (biofertilizers) or phytohormone
production (biostimulants) (Kloepper et al., 1980). PGPR induce plant growth and
development either directly or indirectly by several mechanism such as nitrogen fixation,
phosphate solubilization and mobilization, solublization of plant nutrients or increasing the
uptake of nutrients such as N, P, Zn, Fe, Mn etc either by changing physiology of plant or
by converting nutrients into available form. Impact of PGPR on agronomically important
crops has resulted in increased yield up to 30%, however, their growth promoting ability is
highly crop and genotype dependent. Use of different beneficial microorganisms in
consortia such as PSB and/ or PGPR is taking a serious turn in maximizing the BNF and
yield of different crops. However, compatibility of these microorganisms needs to be
evaluated because of the possibility of the antagonistic interactions among them.

Humus formation
Humus synthesis is one of the important activities of microorganisms in soil. The
benefits of soil organic matter on water holding capacity are well known. Thus a soil rich in
organic matter may retain the water for longer period for utilization by the plants and to
avoid its loss through transpiration and leaching. Raverkar et al (2011) compared the water
use efficiency under farmers, INM and organic farming practices for rice, wheat and
vegetable pea in Uttrakhand. The irrigation use efficiency under farmers, INM and organic
farming practices for rice were 0.252, 0.276 and 0.254 q ha -1 -cm, for wheat 1.16, 1.57 and
1.35 q ha -1 -cm and for vegetable pea 12.0. 16.6 and 13.6 q ha -1 -cm, respectively. This also
resulted in net profit to the farmers and improved soil quality.
Various processes executed by the microorganisms particularly the decomposition of
organic resides and formation of humus in addition to other roles as discussed above
contribute toward improving water use efficiency. However, further specific studies are
warranted to utilize the soil biota holistically for the enhanced water use efficiency.
REFERENCES:
Alexender, Martin 1985. Introduction to Soil Microbiology. Wiley Eastern Ltd. p. 467.
Chhonkar, P.K. and Pareek, R.P. 2002. Organisms in soil and their activities In.
Fundamental of Soil Science (Sekhon et al eds.) ISSS. New Delhi P. 433-454.
Hardie, K. and Layton, L. 1981. The influence of Vaesicular arbuscular mycorrhiza on
growth and water relations of red clover. New Phytol. 89: 599.
Kloepper J.W.; Leong J.; Teintze M. and Schroth, M.N. 1980. Enhanced plant growth by
siderophores produced by plant growth promoting rhizobacteria, Nature, 286, 885-
886.
Kloepper, J.W. and Schroth, M.N. 1978. Plant growth promoting rhizobacteria on radishes.
Fourth International Conference on Plant Pathogen Bacteria, Angers, France, Vol. 2,
pp. 879-882.
Nelson C. 1987. The water relations of Vesicular arbuscular mycorrhizal systeme. In:
Ecophysiology of V A mycorrhizal plants (Safir, G.E. Ed).CRC Press Inc. pp.71-91.
Raverkar, K.P et al. 2011. Agro-Technology for enhancing water productivity of rice, wheat
and vegetable pea in Uttrakhand., FPARP Bulletin No. 01, GBPUAT, Pantnagar
**********

Crop Coefficients Computation and Application in Irrigation
Management*
H.S. Kushwaha
Professor (Soil Science)
G.B. Pant University of Agriculture and Technology, Pantnagar-263145
BACKGROUND
For efficient water management, there is a need for adoption of appropriate cropping
pattern based on soil, crop, climate and weather, adopting technologies which tend to
enhance water productivity. The irrigated area on the globe is around 241.5 mha, which is
15.98 per cent of the total cultivable arable land and land under permanent crops in the
world. These data vary with years due to obvious regions. Comparing Egypt which has 100
per cent irrigated area, India has 34 per cent. Increasing area under irrigation would be a
complex problem and the scopes are very much limited, though some solutions like
changing cropping pattern by including low water requirement crops by replacing rice and
sugarcane which has many implications from society and Government policy side.
Therefore there is need for efficient water management practices for increasing water use
efficiency.
Crop evapotranspiration (ET) rate is greatly dependent on evaporative demand of the
atmosphere, crop growth stage, and availability of water in the root zone. The evaporative
demand is often expressed as reference evapotranspiration (ET 0 ), which represents the ET
rate of an extended surface of an 0.08 0.15 m tall green grass cover, actively growing,
completely shading the ground and not short of water. The reference crop
evapotranspiration (ET 0 ) can also be calculated using meteorological data, and is related
with crop ET by the relation
ET = Kc . ET 0
...(1)
Where,
ET = actual evepotranspiration of a healthy crop well supplied
with water, mm d -1 ,
ET 0 = reference crop ET or potential ET, mm d -1 , and
Kcs = crop growth stage coefficient.
The Kc varies with crop, development stage of the crop, and method used to
determine ET 0 . Kc increases from planting to full development of the crop, and declines
thereafter until maturity. In this presentation crop ET was determined using lysimeters
(Tripathi et al., 1987), and ET 0 estimated from Jensen and Haise (1963) method to calculate
Kc for important crops of this region.
CROP WATER REQUIREMEN T
Water is essential for human, animal and plant life. Without water life is not possible
on the earth. Water plays a key role in photosynthesis and acts as a medium for transport of
nutrients. Therefore crop production depends on the availability of water. The life cycle of a
crop and its stages of crop growth help for better understanding of the crop water
requirement. The crop developmental stages applicable to most of the crops are germination
and emergence, seedling stage, maximum vegetation growth stage, primordial
differentiation, flowering, fruit growth, fruit maturity, physiological maturity and harvest.

Water requirement varies according to stages of crop. Usually less water in the initial stages
and more water in the vegetative, flowering and pod or fruit initiation stage. For example in
wheat the crown root initiation (21 to 25 days), jointing (65 to 70 days) and milking (100-
105 days) stages are very important. Similarly other crops.
Water requirement of crops is calculated by
ETc = ETo x Kc
Where,
ETc = Crop water requirement
ETo = Potential Evapotranspiration
Kc = Crop Coefficient.
Method of Reference crop evapotranspiration, estimation ET 0
As per Jensen Haise (1963) method, ET 0 , mm d -1 , can be calculated as
ET 0 = C T (T - T X ) Rs × 0.0171 ..(2)
Where T is mean daily air temperature, 0 C, and Rs is daily solar radiation, cal cm -2 d -1 . The
factor 0.0171 converts Rs into equivalent depth of evaporation in mm. C T is air temperature
coefficient, degree -1 , calculated as
in which
C
T
1
= .(3)
C + C C
1
2
H
C 1 = 38 (2 0 C. elevation in m/305)
(4a)
C 2 = 7.6 0 50 mb
C, and C H =
(4b)
e 2
- e 1
where e 2 and e 1 are saturation vapour pressures in mb at mean maximum and mean
minimum air temperatures, respectively, during the warmest month in the area based on
long-term monthly temperature records. The T X is calculated as
T X = - 2.5 0.14 (e 2 e 1 ) 0 C/mb elev. in m/550 (5)
Both C T and T X are constants for the area. Daily maximum and minimum temperatures, and
Rs can be taken from the meteorological observatory. Daily Rs can also be estimated for
Pantnagar situations from bright sunshine hour, n, as (Tripathi, 1992)
Rs = 34.98 n + 155.83 , R 2 = 0.73 (6)
Computation of Crop evapotranspiration, ET
Dependence of daily crop ET on prevailing meteorological conditions (Fig.1)
emphasizes its daily assessment for use in precision agriculture. However, average values at
shorter intervals are also useful in scheduling of irrigations. Figures 2-4 presents 2 days
average ET of rice (Oryza sativa L) wheat (Tritcum aestivum L), chickpea (Cicer arietinum,
L), fieldpea (Pisum sativum L.), lentil (Lens culinaris medic), maize (Zea mays L), toria
(Brassica compestris), and sugarcane (Saccarum officinarum) under Tarai conditions of
Uttaranchal. Total seasonal ET (Table 1) and optimum depth to the water table along with
irrigation requirements of some crops

Rice crop requires 75 mm irrigation 3 days after disappearance of the
ponded water from the surface of the medium to fine textured soils (Tripathi et al.,
1986), and 2 days after disappearance of the ponded water from the surface of the
coarse textured soils.
Crop growth stage coefficient, Kc
Crop growth stage coefficient (Kc) varies with location,

ET and Pc, mm d -1
15
12
9
6
R ice
Pc = 14.93 - 0.19d - 6.18 × 10 -3 d 2 + 2.82 × 10 -4 d 3
- 3.88 × 10 -6 d 4 + 1.76 × 10 -8 d 5 , R 2 = 0.99
3
E T = 1.18 + 0.34 d – 1.43 × 10 -2 d 2 + 4.52 × 10 -4 d 3
0
– 5.87 × 10 -6 d 4 + 2.45 × 10 -8 d 5 , R 2 = 0.97
0 10 20 30 40 50 60 70 80 90 100
6
W heat
ET, mm d -1
4
2
0
E T = 1.54 + 6.26 × 10 -2 d - 4.82 × 10 -3 d 2 + 1.21 × 10 4 d 3 –
1.07 × 10 -6 d 4 + 3.02 × 10 -9 d 5 , R 2 = 0.76
0 20 40 60 80 1 00 120 140
D ays from planting, d
F ig .2. E v apotranspiration (E T ) and percolation rate
(P c) in rice culture and E T of W heat (3 -year data)
6
C h i c k p e a
4
Evapotranspiration, ET, mm d -1
2
0
6
4
2
0
6
E T = 1 . 1 + 3 . 8 × 1 0 - 2 d - 9 . 6 6 × 1 0 - 4 d 2 + 1 . 6 5 × 1 0 - 5 d 3
- 2 . 0 5 × 1 0 - 8 d 4 - 3 . 7 1 × 1 0 - 1 0 d 5 , R 2 = 0 . 7 6
F i e l d p e a
E T = 1 . 7 7 - 5 . 6 3 × 1 0 - 2 d + 3 × 1 0 - 3 d 2 - 5 . 3 2 × 1 0 - 5 d 3 +
5 . 5 9 × 1 0 - 7 d 4 - 2 . 2 7 × 1 0 - 9 d 5 , R 2 = 0 . 9 9
L e n t il
4
2
E T = 1 . 5 8 - 2 . 7 9 × 1 0 - 2 d + 1 . 9 1 × 1 0 - 3 d 2 - 3 . 9 × 1 0 - 5 d 3
0
+ 4 . 9 2 × 1 0 - 7 d 4 - 2 . 2 1 × 1 0 - 9 d 5 , R 2 = 0 . 9 9
0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0
D a y s a f t e r s o w i n g , d
F i g . 3 . T w o d a y s a v e r a g e E T o f c h i c k p e a , f i e l d p e a a n d l e n t i l
( 2 - y e a r d a t a )
(Wright, 1982; Tripathi, 1992; Tripathi, 2004). Values of well- correlated Kc are often not
available due to lack of precise data on daily ET of crops.

8
6
Spring maize
4
Evapotranspiration, ET, mm d -1
2
0
4
3
2
1
0
8
6
ET= -1E - 08d 5 + 4E - 06d 4 - 0.0004d 3
+ 0.015d 2 - 0.098d + 1.35, R 2 = 0.89
0 20 40 60 80 100 120
0
Toria
ET = 3E - 07d 4 - 5E - 05d 3 + 0.0021x 2
+ 0.0402x + 1.066 R 2 = 0.94
20 40 60 80 100
Sugarcane
4
2
0
ET = 2E - 09d 4 - 2E - 06d 3 + 0.0005d 2 –
0.014d + 1.47 R 2 = 0.90
0 100 200 300 400
Days after sowing, d
Table 1: Seasonal ET of common crops in Tarai
Crops ET, mm Crops ET, mm
Arhar 491 Soybean 468
Chickpea 436 Sugarcane 1296
Fieldpea 373 Sunflower 354
Lentil 341 Toria 326
Linseed 314 Triticale 368
Maize 412 Urd (Kharif) 417
Mung (Kharif) 418 Wheat 410
Rice 690 Wheat (Durum) 381

Table 2: Optimum depth to the water table and irrigation requirements of some crops in
Tarai
Crops
Depth to the water
table, m
Irrigations
required
Arhar 0.9-1.4 0
Chickpea 0.9-1.4 0-1
Fieldpea 0.9-1.4 1-2
Lentil 0.9-1.4 0-1
Maize (Monsoon) 0.9-1.5 0-1
Maize (Spring) 0.4-0.9 2-3
Mung (Monsoon) 0.9-1.4 0
Mung (Spring) 0.3-0.9 2-3
Rice (Monsoon) 0.1-0.4 4-7
Rice (Spring) 0.1-0.4 18-25
Soybean 0.9-1.4 0-1
Sugarcane 0.6-1.4 4-7
Sunflower 0.6-1.4 0-1
Toria 0.9-1.5 0-1
Urd 0.9-1.4 0
Wheat 0.6-0.9 1-2
Figures: 5-7 present Kc of rice, wheat, chickpea, fieldpea, lentil, maize, toria and
conditions of Uttaranchal.
sugarcane, under Tarai
2
Rice
Crop coefficient, Kc
1
0
Kc = 0.36 + 1.33 × 10 -2 d + 8.32 × 10 -4 d 2 - 8.26 ×10 -6 d 3
– 1.04 × 10 -7 d 4 + 9.01 × 10 -10 d 5 , R 2 = 0.90
0 10 20 30 40 50 60 70 80 90 100
1.5
1.0
Wheat
Crop coefficient, Kc
0.5
Kc= 0.476 + 0.698 × 10 -3 d + 0.252 × 10 -3 d 2 –
0.216 ×10 -5 d 3 R 2 = 0.90
0
0 20 40 60 80 100 120 140
Days after planting, d
Fig. 5. Crop coefficients for rice and wheat

Chickpea
Kc = 0.47 - 3.44 × 10 -2 d + 1.97 × 10 -3 d 2 - 3.55 × 10 -5 d 3 +
2.43 × 10 -7 d 4 - 6.52 × 10 -10 d 5 , R 2 = 0.99
Fieldpea
Crop coefficient, Kc
Kc = 0.52 - 4.22 × 10 -2 d + 2.36 × 10 -3 d 2 - 4.11 ×
10 -5 d 3 + 3.1 × 10 -7 d 4 - 8.71 × 10 -10 d 5 , R 2 = 0.98
Lentil
Kc = 0.41 - 2.44 × 10 -2 d + 1.54 × 10 -3 d 2 - 2.56 × 10 -5 d 3
+ 1.83 × 10 -7 d 4 - 4.96 × 10 -10 d 5 , R 2 = 0.96
Days after sowing (d)
Fig. 6. Crop coefficients for chickpea, fieldpea and lentil

1
0.8
Spring maize
Crop coefficient, Kc
0.6
0.4
0.2
0
0.8
0.6
0.4
Kc = -1E - 09d 5 + 4E - 07d 4 - 4E - 05d 3 +
0.0015d 2 - 0.0032d + 0.1979, R 2 =0.86
0 40 80 120
0.2 Kc = 2E - 09d 5 - 3E - 07d 4 + 1E - 05d 3 - 0.0001d 2
+ 0.0054d + 0.2112, R 2 =0.93
0
0 20 40 60 80 100
1.2
Sugarcane
0.8
Toria
0.4
0
Kc = -1E - 07d 3 + 6E - 5d 2 - 0.0032d
+ 0.3415, R 2 =0.94
0 100 200 300 400
Days after sowing, d
Fig.7. Two days average Kc of spring maize, toria and
sugarcane
Application in irrigation management
Water requirement of crop is the quantity of water needed for normal growth
and yield and may be supplied by precipitation or by irrigation or by both. Water is
needed mainly to meet the demands of evaporation, transpiration and metabolic needs of
plants. But water used in the metabolic activities of plant is negligible and is less than 1
per cent of the quantity of water passing through the plants. Different losses like
percolation, seepage, runoff etc. occur during transport and application of irrigation
water. The application of crop coefficients in water management are numerous. Since
crop coefficient varies with the growth stage, we can assess the water need of crop at a
given stage of crop and during entire

References:
Jensen, M.E. and Haise, H.R. 1963. Estimating evapotranspiration from solar
radiation. J. Irrig. Drain. Div. ASCE, 89 (IR 4): 15-41.
Tripathi, R.P. 1992. Irrigation timing for wheat based on climate, crop and soil data. J. Irrig.
Drain. Div. ASCE, 118(3): 370-381
Tripathi, R.P. 2004. Evapotranspiration and crop coefficients for rice, wheat and pulses
under shallow water table conditions of Tarai region of Uttaranchal. J. Agromet. 6
(1): 17-29
Tripathi, R.P., Kushwaha. H.S. and Agrawal, A. 1987. A Simple non-weighing lysimeter
installation with rain shelter. Agric. For. Meteorol., 41: 275-288
Tripathi, R. P., Kushwaha, H. S. and Mishra, R. K. (1986). Irrigation requirement of rice
under shallow water table conditions. Agril. Water Manage. 12: 127-136.
Wright, J.L. 1982. New evapotranspiration crop coefficients. J. Irrig. Drain. Div. ASCE,
109 (IR2): 57-74.
**********

Water Management in Degraded Soils
M. S. Pal
Professor Agronomy
G. B. Pant University of Agriculture & Technology, Pantnagar-263145
Land Degradation
Soil degradation is the loss of actual or potential productivity as a result of natural
and anthropogenic factors which reduce the productivity of the soil and its beneficial effects
on the environment. Soil degradation can be an entirely natural process, human activities
often accelerate the natural processes. Land degradation may involve not only soil
degradation but also damage to the vegetation, changes in landforms so that the hydrology
and water relations suffer, and changes to the climate. Many include land alienation to
urban and industrial uses as part of land degradation.
Magnitude & Effect of Soil Degradation
World
Humans use about 8.7 billion hectares of land worldwide.
About 3.2 billion hectares are potentially arable, of which a little less than half is
used to grow crops.
The remaining 1.7 billion hectares of potentially arable land, along with most non
arable land, function as pasture, forest, and woodland.
Recent global studies estimate that soil quality on three-quarters of the worlds
agricultural land has been relatively stable since the middle of the twentieth century.
Degradation is widespread and the overall pace of degradation has accelerated in the
past 50 years.
Productivity has declined substantially on approximately 16 percent of agricultural
land in developing countries, especially on cropland in Africa and Central America,
pasture in Africa, and forests in Central America.
Almost 75%of Central Americas agricultural land, 20% of Africas and 11 % of
Asias have been seriously degraded.
Estimates of land loss due to degradation vary widely, from 5 to 12 million hectares
every year. Assuming that land loss continues at current rates, an additional 150 to
360 million hectares would go out of production by 2020 (Sara J. Scherr, 1999).
India
Category
Area (1996-97) (M ha)
1. Geographical area 329
2. Water & Wind erosion 144.12
3. Area degraded through special problems 29.52
a. Waterlogged area 8.53
b. Alkali soils 3.88
c. Acid soils 4.50
d. Saline soils +coastal sandy area 5.50
e. Ravines and gullies 3.97
f. Shifting cultivation 4.91
g. Riverine & torrents 2.73
Total (a to g) 34.02
Total problem area (2 + 3) 173.64

Extent of Wasteland
a. Saline & Alkaline lands : 7.165 m ha
Leading states are: UP>Gujrat>WB>Rasthanj>Punjab
b. Wind eroded area : 12.926 m ha
Leading states: Raj>Haryana>Gujrat
c. Water eroded area : 73.600 m ha
Leading states are: M P>Maharashtra >A P >Karnatika >Rajasthan>U P
d. Non Forest degraded area: 93.691 m ha
Leading states are: Rajasthan >M P >Maharashtra >A P >Karnatika >Gujrat
e. Forest degraded area : 35.889 m ha
Leading states: M P > Orissa > A P > Maharashtra >Karnatika.
f. Total :129.580 m ha
Leading states: MP>Raj>MS>AP>Karn.
(Sources: 1. Forestry Statistics of India, 2000, &
2. Compendium of Environment Statistics, 2001(Govt of India)
Water management in Problematic
a. Waterlogged area
Causes
1. Heavy rainfall with high intensity,
2. Heavy infiltration,
3. Presence of hard pan,
4. Low infiltration rate,
5. Absence of natural drainage,
6. Over irrigation,
7. Seepage from water bodies,
8. Flooding,
9. Absence of artificial drainage
10. Unauthorized occupation,

11. Silting & weed growth in drains.
Approaches of water management in waterlogged area
Prevention of high water table & waterlogged area,
Breaking of hard pan,
Adoption of proper drainage system
a. Surface drainage,
b. Sub surface drainage
c. Pumping out water
Systems of surface drainage
1. Regular system: Level land- parallel ditches,
2. Random system: Uneven land,
3. Bedding (Levees): regular furrows (Levees),
4. Cross slope or terrace system: sloppy lands,
5. Ridge terrace system: ridges are mde along the border of terrace.
Field drains: i. 22-45 cm deep with suitable slopes,
ii. Spaced usually 120 m apart in clay & 300 m in sandy soils,
iii. Slope: 0.05 to 0.15 %.
Sub surface drainage
Drains are made of clay, concrete or plastic pipes, fibrous wood materials, stone &
bituminous fibrous materials.
Specifications: Diameter: 10-30 cm,
Length: 30-45 cm,
Depth: 6-120 cm in sandy soils and 90 cm in clay soils.
Spacing: 9-18 m in clay loam, 18-30 cm silt and silt clay and 30-90 cm in
sandy loam soils.
Systems of Sub surface drainage
Tile drainage,
Mole drainage,
Sump and Pump drainage,
Vertical sub surface system.
Classification of Good Drainage
a. Good: : >200 cm depth
b. Fair : 120-200 cm
c. Poor :

2. Water management
a. Utilizing soil water storage,
b. Increasing frequency of irrigation,
c. Prolonging irrigation time,
d. Alteration of flow (water) characteristics, and
e. Increasing wetted area.
d. Drought prone areas
Following approaches can be adopted;
Rain water harvesting,
Managing reducing water tables,
Management of canal water,
Optimum irrigation schedules,
Optimum irrigation methods,
Managing high water tables
??
Table 1.Soil moisture as influenced by ploughing before the onset of rains in Alfisols of
Bangalore.
Depth of soil cm)
Moisture (%() after a total of 81 mm rainfall in May
Ploughed area
Unploughed area
0-15 10.7 3.6
15-30 13.2 7.1
30-60 13.3 8.7
60-90 13.4 dry
Source: Monograph of AICRPDA (Anonymous, 1984)
Revitalizing Waste Water
a. Definition of Waste Water
Wastewater means water which has been spent or wasted in any form of its use.
Generally speaking Wastewater indicates a mixture of sewage from lavotories,
urinals, etc., sullage from bathrooms, kitchen sinks, roof top run off and untreated
industrial effluents. Now a days "wastewater" has become a global terminology
instead of earlier term of sewage.
Wastewater is liquid waste discharged by domestic residences, commercial
properties, industry, agriculture, which often contains some contaminants that result
from the mixing of wastewater from different sources.
Based on its origin wastewater can be classed as sanitary, commercial, industrial,
agricultural or surface runoff. Term wastewater need to be separated from the term
sewage, sewage is subset of wastewater that is contaminated with feces or urine
though many people use term sewage referring to any waste water.
Spent or used water with dissolved or suspended solids, discharged from homes,
commercial establishments, farms, and industries.
b. Quantification of Waste Water in India
Domestic wastewater
23000 MLD generated (300 Class I Cities and 345 Class II towns)
Only 6000 MLD is treated
Industrial wastewater
13000 MLD generated by 1,35,000 polluting industries

60% is treated (large & medium industries)
c. Applications of Waste Water
Since water is a scarce input and its share to agriculture is shrinking due to
emergence and high demand of new sectors, therefore, the waste water has manifold
uses as listed below;
i. Irrigation of agricultural land,
ii. Aquaculture,
iii. Landscape irrigation,
iv. Urban and industrial uses,
v. Recreational and environmental uses, and
vi. Artificial groundwater recharge.
d. Powerful drivers for the expansion of wastewater irrigation
i. Unavailability of fresh water, and too expensive,
ii. Increasing water stress (in part due to climate change),
iii. Increasing urbanization,
iv. Growing urban wastewater flows due to the expansion of water supply and
sewerage services, more urban households engaged in agricultural activities
that could be intensified with additional sources of irrigation water and
nutrients, and
iv. Protecting public health and the environment
e. The risks and benefits of wastewater use in agriculture
a. Microbial risks to public health - Bacteria, viruses, protozoa and
helminths may cause ascariasis and hookworm, diarrhea, typhoid, and
cholera.
b. Chemical risks to public health - heavy metals (such as cadmium, lead,
and mercury) and by many organic compounds (such as pesticides) ,
c. Risks to plant health- Variable electrical conductivity, the sodium
adsorption ratio, boron, total nitrogen, and pH may adversely affect plant
health.
d. Environmental risks

f. Possible levels of pathogens in municipal waste Water
Pathogen Scientific name Possible conc./ litre 1
1
Viruses Enteroviruses 2 5000
Bacteria B
a
s
e
d
Protozoa
o
Helminths n
Pathogenic E. coli 3
Salmonella spp.
Shigella spp.
Vibrio cholerae
Entamoeba histolytica
Ascaris Lumbricoides
?
7000
7000
1000
4500
600
1
0
0
Hookworms 4 32
Schistosoma mansoni 1
Taenia saginata 10
Trichuris trichiura 120
l
pcd of mu1 Based on 100 lped of munnicipal sewage and 90% inactivation of
excreted pathogens
2 Includes polio-, echo- and coxsackieviruses
3 Includes enterotoxigenic, enteroinvasive and enteropathogenic E. coli
4Anglostoma duedenale and Necator americanus Source: Feachem et al.
(1983)

g. Wastewater quality guidelines for agricultural use
Table. Recommended microbial quality guidelines for waste water use in agriculture
Categ
ory
Reuse
condition
Exposed
group
Intestinal
nematod
es
(arithmeti
c mean
no. of
eggs per
litre
Faecal
coliforms
(geometric
mean no.
per 100 ml)
Wastewater treatment
expected to achieve
the required
microbiological quality
A
Irrigation of
crops likely to
be eaten
uncooked,
sports fields,
public parksd
Workers,
consumers,
public
< 1 < 1000 A series of
stabilization ponds
designed to achieve
the microbiological
quality indicated, or
equivalent treatment
B
Irrigation of
cereal crops,
industrial
crops, fodder
crops, pasture
and trees
Workers < 1 No standard
recommend
ed
Retention in
stabilization ponds for
8-10 days or
equivalent helminth
and faecal coliform
removal
C
Localized
irrigation of
crops in
category B if
exposure of
workers and
the public
does not
occur
None
Not
applicabl
e
Not
applicable
Pretreatment as
required by the
irrigation technology,
but not less than
primary sedimentation
h. Guidelines for interpretation of water quality for irrigation
Potential irrigation
problem
Ec
w
1
Units
None
Salinity
Degree of restriction on use
Slight to
moderate
Severe
dS/m < 0.7 0.7 - 3.0 > 3.0
or
TDS mg/l < 450 450 - 2000 > 2000
Infiltration
SAR 2 = 0 - 3 and EC
w
> 0.7 0.7 - 0.2 < 0.2
3 -6 > 1.2 1.2 - 0.3 < 0.3
6-12 > 1.9 1.9 - 0.5 < 0.5

12-20 > 2.9 2.9 - 1.3 < 1.3
20-40 > 5.0 5.0 - 2.9 < 2.9
Specific ion toxicity
Sodium (Na)
Surface irrigation SAR < 3 3 - 9 > 9
Sprinkler irrigation me/I < 3 > 3
Chloride (Cl)
Surface irrigation me/I < 4 4 - 10 > 10
Sprinkler irrigation
m 3 /l
< 3 > 3
Boron (B) mg/l < 0.7 0.7 - 3.0 > 3.0
Miscellaneous effects
3
Nitrogen (NO -N)
3
mg/l < 5 5 - 30 > 30
Bicarbonate (HCO ) me/I < 1.5 1.5 - 8.5 > 8.5
3
pH Normal range 6.5-8
i. Waste Water treatment
A. Conventional wastewater treatment processes
1. Preliminary treatment
2. Primary treatment
3. Secondary treatment
4. Tertiary and/or advanced treatment
5. Disinfection
6. Effluent storage
7. Reliability of conventional and advanced wastewater treatment
B. Natural biological treatment systems
1 Wastewater stabilization ponds
2. Overland treatment of wastewater
3. Macrophyte treatment, and
4. Nutrient film technique
References :
Compendium of Environment Statistics. 2001. Govt. of India.
FAO. (1985) Water quality for agriculture. R.S. Ayers and D.W. Westcot. Irrigation
and Drainage Paper 29 Rev. 1. FAO, Rome. 174 p.
FAO. 1992. Waste Water Treatment and Use in Agriculture. Natural Resources
management and Environment. FAO irrigation and drainage paper 47.
Feachem R.G., Bradley D.J., Garelick H. and Mara D.D. (1983) Sanitation and
Disease: Health Aspects of Excreta and Wastewater Management. John Wiley,
Chichester.
UN Department of Technical Cooperation for Development. (1985) The use of nonconventional
water resources in developing countries. Natural Water Resources
Series No. 14. United Nations DTCD, New York.
WHO. (1989) Health guidelines for the use of wastewater in agriculture and
aquaculture. Technical Report No. 778. WHO, Geneva 74 p.

WHO. 2010. Improving Waste Water Use in Agriculture: An Emerging Priority.
Energy Transport and Water Department Water Anchor (ETWWA).The World
Bank.
**********

Advances in Water Management for Horticultural Crops
L. D. Bisht
Former Professor of Horticulture
G. B. Pant University of Agriculture & Technology, Pantnagar-263145
Water is a vital constituent of plant tissues. Depending on the type and stages of
growth, the plant generally comprises about 95 per cent water in leaves, 60 to 90 per
cent in roots and about 70 to 90 per cent in the fleshy fruits and vegetables. As
compared to other plants, fruit plants and vegetables have higher requirement of water.
The requirement of water varies in different stages of growth of fruit and vegetable
plants. It is difficult to meet the entire requirement from natural precipitations available
for 3 to 4 months only. Artificial application of water (irrigation) is therefore, required
in an orchard or vegetable field so as to ensure adequate and timely supply of water to
the plants. Being costliest of all inputs, misuse is not justifiable by any means, which
can be prevented by supplying efficiently when needed and in appropriate amount. The
techniques of removal of excess water (drainage) from the field and preservation of
excess water (conservation) during rainy season may be helpful in proper management
of water.
Irrigation
There are many methods of application of water to the plants. As far as possible
the conventional methods of irrigation may be replaced by modern efficient methods to
avoid excessive wastage besides avoiding the problems like water logging and salinity.
Modern systems of irrigation like micro irrigation coupled with other improved water
management practices enhance the water use efficiency and productivity without
injurious effect on soil health.
Methods irrigation:
In accordance to the placement of water, there are three systems that are
followed in irrigating the orchards.
Methods of irrigation
Surface Sub-surface Micro
1. Flooding 1. Perforated pipeline 1. Drip method
2 Plot method 2. Trench drip method 2. Sprinkler method
3. Basin method 3. Pitcher method
4 Ring method

1. Surface irrigation
i. Flood irrigation
Under this system, the irrigation water is flooded on the entire surface of the field
through a channel.
ii. Plot irrigation
In this system, the water is applied through a series of parallel furrows which are in
turn connected with the main channel. Fruit crops like mango, banana, guava, citrus, papaya
and grapes are also irrigated by furrow irrigation method.
iii. Basin irrigation
In this method, water is applied directly to the basin through siphons, spills or bund
break. This method is generally adopted for fruit crops.
iv. Ring irrigation
In this method, the water is applied in small strips of land, known as rings, which are
uniformly graded. The rings along the borders help to guide the water to flow down the
field. Fruit crops like mango, litchi, guava, citrus, papaya and sapota are also irrigated by
furrow irrigation method (Singh et al., 2007).
2. Sub-surface irrigation
Trencjh drip
Perforated pipeline
3. Micro irrigation:
Micro irrigation is a system that operates under low pressure with small- sized
wetting at a low discharge. It may be done by spraying, misting, sprinkling or dropping.
Generally all modern methods viz Drip method, Trench drip method, Sprinkler method and
Pitcher method come under this group
1. Drip irrigation system:
Drip irrigation is also known as trickle irrigation or pressurized irrigation .Water is
applied in the form of drops or tiny streams to the root zone. It optimizes the use of
irrigation water by providing it uniformly and directly to the roots of the plants, through a
close network of plastic pipes and emitters. It can be applied by both surface and sub -
surface method. In surface drip irrigation method the pipelines and drippers are laid on
ground. Hence, some times it can create problem during cultural practices like weeding. But
in trench drip irrigation method the main pipelines and lateral lines are placed in trenches.
The water is dropped inside the trenches from the drippers and thus, dripping takes place
inside the soil surface close to the feeder roots.
2. Sprinkler system without moving parts:
Water is applied in the form of fine jet/ spray in full or part circle on the surface at
very low height

Just like micro jet, sprays water at height < 1m. Incorporates moving parts, and thus
having greater discharge rate and large coverage range than drippers and micro jets.
Suitable for sandy soil where infiltration rate is very high. Potential for controlling frost,
lower susceptibility to clogging. Suitable for irrigation of nurseries, and widely spaced
canopy crops
Components of a drip irrigation system:
A drip irrigation system consists of emitters, lateral lines, main lines, filters,
control valves and, as in all systems, a pumping plant and water source. The pumping plant
and water source are usually the most expensive items.
Advantages of micro irrigation systems:
1. Water savings:
Irrigation water requirement can be smaller with micro irrigation compared to other
irrigation methods. This is due to irrigation of a smaller portion of soil volume, decreased
evaporation from the soil surface, and the reduction or elimination of the runoff. In fruit
crops use of drip irrigation saves irrigation water up to 40-70%.
Fruit crops Water savings (%)
Banana 45
Grape 48
Sweet lime 61
Pomegranate 45
Papaya 68
Water melon 36
(Srinivas, 2000)
2. Smaller flow rates:
Smaller sources of water can be used for irrigation of the same acreage. The delivery
pipes, the pump and other components of the system can be smaller and therefore more
economical.
3. Application of agro-chemicals:
. The plants can be supplied with the exact amount of fertilizer, insecticides,
pesticides etc. required at a given time. Since they are applied directly to the root zone a
reduction in the total amount of chemical used is possible.
4. Improves yield
National committee on plastic culture application in horticulture reported that use of
drip irrigation in fruit crops increases yield up to 20-100% when compared to flood
irrigation system.
Fruit Crop
Yield (kg/ acre)
Flood Drip Difference (%)
Papaya 5,200 9,200 76.92
Sweetlime 4000 6000 50.00
Mosambi 40,000 60,000 50.00
Pomegranate 6,050 11,700 93.39
Mango 3,000 5,400 80.00
Banana 23,000 53,000 52.17
Watermelon 9,610 15,500 61.208,
Grape 8,000 12,000 50.00
Kinnow 2,720 3,920 44.12
Guava 160 220 37.50
(NCPAH, 2003)
5.Increases water use efficiency:
Use of drip irrigation also increases water use efficiency than flood irrigation system. It
may be up to 70% (NCPAH, 2003).

Water use (m3 per acre)
Fruit Crop
Flood Drip Difference (%)
Papaya 9120 29,20 67.98
Sweetlime 6640 2560 61.45
Mosambi 6640 2560 6145
Pomegranate 3920 2196 43.45
Mango 5100 3324 34.82
Banana 7040 3880 44.89
Watermelon 1680 1000 40.48
Grape 3520 2320 34.09
Kinnow 884 692 21.72
(NCPAH, 2003)
6. Possible to supply water sources with high salt content:
A significant advantage of micro irrigation is that water with relatively high salt
content can be used by the system
7. Improves quality of the crop:
Micro irrigated plants are supplied very frequently with small amount of water and
the stress due to the moisture fluctuation in the root zone is reduced to the minimum, often
resulting in larger and better quality yield. In arid climates, or during dry seasons, the
harvest timing can be controlled by proper water management.
8. Adoption to any topography:
Micro irrigation system can operate efficiently on hilly terrain if appropriately
designed and managed. Well managed micro irrigation system will not create runoff even
on hilly terrain.
Drainage
Drainage is removal of excess water, to avoid water logging. Proper drainage system is
required to remove excess water during rainy season. Most horticultural plants do not
withstand prolonged water logging. Some fruits and vegetables are prone to even very short
duration of water stagnation.
Prone fruits: peach, avocado, litchi, melons
Prone vegetables: peas, beans, green vegetables, tomato
Conservation
Water harvesting and storage
Water shed approach is required for developing water harvesting systems. Several
streams of foot hills region have base flow, which varies according to location, size of
watershed vegetation cover condition and time of the year. The surface and sub surface
flow of perennial and rain water can be harvested by using following types of structures:
Roof top rain water harvesting
Harvesting of rainwater from roof-tops and storage in tanks made at the basement has
been common in hills.
Cement concrete /brick masonry/plastic lining small storage tanks
Harvesting of trickles of surface flow emerging from hill slopes into small storage tanks
of cement concrete/brick masonry/plastic lining has been common in hills.
Inward sloping of contour beds

It is used in hilly areas. This method involves collection of rain water by developing
contours and trench with slightly inward slope. It ensures efficient utilization of rain
water which is conserved in the soil over a long period
Mulching after rain or snowfall
Straw ,leaves or black plastic sheets are used for mulching for conservation of soil
moisture.
Sod culture : The orchard soil is left uncultivated. The naturally growing grass is chopped
off and left in the ground as mulch.
Incorporation of organic matter: Organic matter enhances water holding capacity of the
soil. Use FYM , vermin- compost etc.
Trenching: Trench formation is done at the back of the tree for trapping water during
rainfall/snow fall.
Shade nets: Reducing transpiration by using shade nets in the orchards during intense heat.
Other measures
Use of wind breaks for protection against desiccating winds and application of anti
transpirants and PBRs such as cytokinins, ABA, etc and use of slow water release
compounds in the soil may be helpful in conserving water.
References:
NCPAH, 2003. National Committee on Plasticulture Application in Horticulture
Singh, G., Mishra, R. and Pandey, S. 2007. Manual of Microirrigation. C. I. S. H.
Rehmankhera, Lucknow.
Srinivas, K.2000. Drip irrigation in fruit crops. S.S. eds. pp 84-95.
**********

Advances in Sprinkler Irrigation and Agro-Techniques for Their
Higher Use Efficiency
Rajesh P. Singh
Professor
Deptt. of Irrigation & Drainage Engg.
G. B. Pant University of Agriculture & Technology, Pantnagar-263145
Sprinkler is an important method of pressurized irrigation
system. Sprinkler system consists of pump to provide the needed
pressure, main lines through which the entire flow is transmitted,
laterals into which the flow branches, sprinkler risers which direct the
discharge to the sprinkler head and the nozzles which direct the jet into
the air. The system is described in the following sections
Advantages
1. It can be used for almost all crops except rice and jute.
2. It is suitable for irrigating all soils except soils having infiltration
rates lower than 4 mm/hr.
3. It is adaptable to the most topographic conditions saving the cost of
land preparation.
4. With little extra expenditure on equipment it can be economically
used for applying soluble fertilizers, herbicides and fungicides.
5. More land area is available for cropping as field supply channels,
bunds and ridges are not required.
6. High values plantation crops like tea, coffee, cardamom and
orchards can be best irrigated by using automated sprinkler
irrigation system.
Limitations
1. It can not be efficiently used in high windy conditions.
2. To protect the components of the system, water must be clean, free
of sand, debris and dissolved salts
3. High initial and operating costs are involved.
4. High pressure pump is needed.
5. Losses of energy for irrigating fine textured soils in hot windy areas.
Uniformity Coefficient
Christiansen (1942) proposed a measurable index for the evaluation
of the uniformity of sprinkler irrigation. This coefficient is based on the
sum of the absolute deviations of each observation from the mean
observation. It is expressed by –
Cu = 100[1.0 – (∑X/mn)] --------(1)

Pumping set: is required to lift water from the source and o push it through sprinkler
distribution system or to boost the water in an existing water distribution line to force it
through the sprinkler system at desired pressure.
Main lines: may be permanent or portable depending upon the field conditions. Permanent
lines are made of steel, PVC and asbestos cement. Portable lines are made of light weight
aluminium pipes.
Lateral lines: are usually portable. Quick-coupled aluminium pipes are best for portable
laterals. Usual lengths are 5,6 or 12 m. Each length has quick couplings.
Sprinkler heads: most important component of a sprinkler system. The sprinkler heads
through nozzles direct the jet stream into the air.
Debris screens: are usually needed when surface water is used as the source of irrigation.
Its function is to keep the system free of trash that might plug the sprinkler nozzles. When
heavy loads are expected two or more screens of progressively finer mesh can be used.
Desilting basins: are required to trap sand or suspended silts when the water comes from
steams, open ditches or well water having silt. Sometimes desilting basins and debris
screens are built as a combination structure.
Booster pumps: are used when a sprinkler irrigation system is used with an existing
pumping system installed in a well and the pump capacity is insufficient to force the water
through sprinklers.
Take off-valves: are needed to control pressures in the lateral lines.
Flow control-valves: are used to regulate pressure and discharge of individual sprinkler
when unevenness of the ground causes an unequal distribution of pressure along the lateral.
Types of Sprinkler system
On the basis of the arrangement for spraying water two major types are:
1. Rotating head system: Along the length of the lateral pipe, risers are fixed at uniform
intervals with small size nozzles placed on them.
2. Perforated pipe system: Holes are perforated in the lateral irrigation pipes. It is usually
designed for low operating pressure of .5 to 2.5 kg/cm 2 and is used for irrigating lawns,
gardens, vegetable fields and other plots with crop height not exceeding 40 to 60 cm.
Based on portability, classified in the following types
1. Portable system: consists of portable main lines, laterals and pumping units.
2. Semi-portable system: except location of water source and pumping plant all other parts
are portable.
3. Semi-permanent system: consists of portable lateral lines, permanent main lines, submains,
stationary water source and pumping plant.
4. Solid set system: laterals are positioned in the field early in the crop season and remain
for the season.
5. Permanent system: consists of permanently laid mains, sub mains and laterals and a
stationary water source and pumping plant.
Uniformity of coverage
· The irrigation efficiency of sprinkler will depend upon the degree of uniformity of water
application.

· The water spray distribution characteristics of sprinkler and their spacing will regulate
the uniformity of water application.
· With lower pressure, the drops are larger and water from the nozzle falls in a ring away
from the sprinkler.
· With higher pressure, water from the nozzle breaks up into fine drops and fall very near
the sprinkler.
· High wind velocity distorts the application pattern.
· Under favorable condition, the depth of water applied, surrounding the sprinkler,
decreases as the distance from the sprinkler increases.
· To obtain uniformity of water application, the wetted circle of the adjacent sprinklers
should be overlapping.
Uniformity Coefficient
Christiansen (1942) proposed a measurable index for the evaluation of the uniformity of
sprinkler irrigation. This coefficient is based on the sum of the absolute deviations of each
observation from the mean observation. It is expressed by
where
Cu = 100[1.0 (X/mn)] --------(1)
m = average value of all observations,mm
n = total no. of observation points, and
X = numerical deviation of individual observations from the average application
rate, mm
A uniformity coefficient of 85% or more is considered to be satisfactory.
Design Considerations of Sprinkler Irrigation System
A sprinkler irrigation system is specially designed to achieve high efficiencies in its
performance and economy to suit the conditions of a particular site. The step-by-step
procedure in the planning and design of a sprinkler irrigation system is enumerated below:
1. Inventory of Resources and Conditions
i. Map of the area
ii. Water supply source, availability and dependability
iii. Climatic conditions
iv. Depth of irrigation
v. Irrigation interval
vi. Water application rate (suggested guidelines in Table 1.1)
vii. Sprinkler spacing (suggested guidelines in Table 1.2)
viii. Power source

2. Types of Systems and Layout
To provide the optimum application rate with the greatest degree of uniformity of
distribution, the location of the pumping unit, the orientation of mains and laterals, sprinkler
spacing, operating pressure, and nozzle sizes are determined.
I. Location and nature of water supply
· The well may be located at a high corner or, more likely, at the center of the farm to
minimize the distance the water must be pumped.
Table 1.1. Suggested maximum application rates for sprinklers for average soils, slope
and tilth.
Soil texture and profile
0 5%
slope
5 8%
slope
8 12%
slope
12 16%
slope
cm/hr cm/hr cm/hr cm/hr
1. coarse sandy soil to 2 m 5.0 3.7 2.5 1.3
2. coarse sandy soil over more
1.0
3.7 2.5 2.0
compact soils
3. light sandy loams to 2 m 2.5 2.0 1.5 1.0
4. light sandy loams over more
compact soils
2.0 1.3 1.0 0.8
5. silt loams to 2 m 1.3 1.0 0.8 0.5
6. silt loams over more compact
soils
0.8 0.6 0.4 0.3
7. Heavy textured clays or clay
loams
0.4 0.3 0.2 0.1
Table 1.2. Maximum spacing of sprinklers under windy conditions.
Sl.No. Average wind speed
Spacing
1. No wind 65% of the diameter of the water spread area of a sprinkler
2. 0 6.5 km/hr. 60% of the diameter of the water spread area of a sprinkler
3. 6.5 13 km/hr. 50% of the diameter of the water spread area of a sprinkler
4. Above 13 km/hr. 30% of the diameter of the water spread area of a sprinkler
II. Orientation of laterals
· The main should be located in the general direction of the steepest slope, with the
laterals at right angles and as close as is practical to the contour.
· The arrangement selected should provide for a minimal investment in irrigation pipe,
have a lower labour requirement

· Any system in which the laterals are moved should be planned for successive irrigations
in strict rotations, so that the interval between irrigations is the same for each portion of
a field.
· The possible arrangements for mains, laterals and sprinklers should provide for a
minimal investment in irrigation pipe, have a lower labour requirement and provide for
an application of water over the total area in the required period of time.
3. Sprinkler Selection and Spacing
The selection of the sprinkler depends mainly on the diameter of coverage
required, pressure available and sprinkler discharge. The required discharge of an
individual sprinkler is determined by
where
Q = ( S i * S m * I)/360 ------(2)
Q = required discharge of individual sprinkler, lit/sec
S i = spacing of sprinklers along the laterals, m
S m = spacing of laterals along the main, m
I = optimum application rate, cm/hr
Height of sprinkler riser pipes:
The minimum height of riser is 30 cm when the riser pipe is of 2.5 cm diameter
and 15 cm when it is of 1.8 to 2 cm diameter.
4. Capacity of the Sprinkler System:
Q = 2780 [ (A * D)/ (F* H* E)] -----(3)
where Q = discharge capacity of the pump, lit/sec
A = area to be irrigated, ha
D = net depth of water application
F = no. of days allowed for the completion of one irrigation
H = no. of actual operating hours per day
E = water application efficiency, percent
5. Hydraulic Design of Sprinkler Systems:
Discharge of sprinkler Nozzle: The discharge of a sprinkler nozzle may be computed from
the formula
Q = C.a. (2.g.h) ----(4)
where C = co-efficient of discharge
a = cross- sectional area of nozzle, m 2
h = pressure head at the nozzle , m
g = acceleration due to gravity , m/sec 2
Reference :
Michael A. M. (1999) Irrigation Theory and Practice. Vikas Publishing House Pvt Ltd.
New Delhi.
Keller J. and Bliesner R. D. Sprinkle and Trickle Irrigation. Van Nostrand Reinhold,
New York
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Water Management for Sustainable Livestock Management
C.V. Singh
Prof & Head/

Jt. Director Dairy Farm
Department of Genetics and Animal Breeding
G. B. Pant University of Agriculture & Technology, Pantnagar
Little is known about water depleted to produce feed, the efficiency with which feed
is converted into animal products and services, and the impact animals have on water
resources. A seventy fold difference in feed-water productivity (ratio of the benefits of
livestock goods and services produced to the water depleted in producing them) is reported
in the scientific literature. There are also large variations in animal productivity and animal
impacts on water resources. Thus, generalized estimates of livestock water productivity
require Livestock production, one of the most important agricultural subsectors worldwide,
is practiced in range land areas and in mixed crop-livestock systems that cover about 60%
of the land area of developing countries. In developing countries cattle, sheep, and goats
total about 1.2 billion tropical livestock units (converted at the rate of 250 kilograms of live
animal weight per tropical livestock unit). Animal densities are strongly correlated with
human densities and are highest in areas of intensified agriculture, especially in and around
irrigation systems. Animals are heavily dependent on water for feed production, using an
estimated 500 billion cubic meters or more a year for maintenance. Total water needed may
be more than double this amount, with drinking water less than 2% of that required for feed
production. In appropriate grazing and watering practices contribute to wide spread
degradation of water and land resources, particularly around watering sites. Investments in
water and livestock have often failed to achieve maximum and sustainable returns because
of a lack of integration of the two.
Despite many efforts to develop water and livestock in developing countries over
thepast 50 years, sustainability and gender-equitable returns on investments have been
disappointing.
Global experience indicates that integrating water and livestock development creates
opportunities to sustainably increase benefits in ways that independent development
efforts cannot achieve. Without integration, opportunities to achieve maximum and
sustainable returns on investments in both sectors will be lost.
Livestock are an important part of global agriculture, providing meat, milk, eggs,
blood,hides, cash income, farm power, and manure for fuel and soil nutrient replenishment .
Livestock also have important cultural values and are a means for poor people to
accumulate wealth. Large numbers of poor farmers and herders depend on livestock for
their livelihoods. Livestock depend on water, but when poorly managed, they contribute to
the degradation and contamination of water resources.
Livestock keeping represents a diverse set of geographically varying livelihoods that
benefit both poor and wealthy people in rangelands and in rainfed and irrigated croplivestock
farming systems.
Agricultural intensification often correlates with higher livestock densities.
Understanding spatial changes in the distribution and structure of livestock production
systems in relation to agricultural water can help to identify areas where considerations of
livestock-water interactions can enhance the sustainability and returns on livestock
investments. South Asia and Sub-Saharan Africa are priority regions for integrating
livestock and water development for poverty reductions, but benefits can be expected
elsewhere as well.
Rapidly growing demand for meat and milk in urban areas of developing countries
will place substantial new demands on agricultural water resources, especially for feed
production. Meeting this demand will require much more water but will also provide
opportunities for rural farmers to generate needed income. This trend may also increase
competition for agricultural water, marginalizing some farmers and herders, provoking
conflict, and driving them deeper into poverty. Households will need adequate agricultural

water to maintain animals that remain important providers of quality nutrition and on farm
power and a preferred means of wealth savings.
A livestock water productivity framework, with a gender dimension, enables a better
Understanding of livestock-water interactions. The frame work identifies four basic
livestock development strategies that can lead to more productive and sustainable use of
water resources: improving the sourcing of animal feeds; enhancing animal productivity
(products, services, and cultural values) through better veterinary care , genetics, marketing
of animal products scrutiny , and global assessments of livestock water productivity are
needed. While there is still much to learn about site- and production system-specific policy,
technologies, and practices that can lead to increased and sustainable livestock water
productivity, integration of existing knowledge of animal production with range and water
resources management options affords good opportunities to increase sustainability and the
productivity of water used for livestock production.
Water and livestock for human development
Drinking water is essential for animal survival, but the amount needed is small
comparedwith other uses of agricultural wate .
Investing in drinking water makes strategic sense given the high value of animals
and animal products and the smallamount of water used. One liter of drinking water
provided in areas of surplus feed effectively makes available an additional 100 liters of
otherwise unusable agricultural water evapo transpired from rangeland vegetation and
greatly increases livestock water productivity.
Strategic placement and provision of adequate quality drinking water enables
animals, particularly cattle, to source feed in otherwise inaccessible grazing areas and
enhances the production of meat and milk. Selecting animals adapted to dry land conditions
may reduce the need for drinking water. Careful management of areas adjacent to drinking
water is necessary to avoid water and land degradation.
The widespread perception that livestock production is a wasteful use of the world’s
water resources does not apply to conditions in many developing country contexts .
Livestock can be efficient and effective users of water when they depend largely on crop
residues and by-products and on well managed rangelands unsuitable for crop production.
Application of livestock water productivity concepts may lead to some of the greatest
enhancements in productivity of future agricultural water use in developing countries.
Achieving this requires improved integrated governance of livestock and water resources.
The overarching message of this chapter is that livestock-water interactions are
important and under-researched and that huge opportunities exist to improve the
productivity of water associated with livestock production.
Water, livestock, and human development
The Times of India (2004) reports that one liter of milk requires 3,000liters of water,
and it attributes rapid declines in groundwater to wasteful dairy production. Goodland and
Pimental (2000) and Nierenberg (2005) state that producing 1 kilogram(kg) of grain fed
beef requires about 100,000 liters of water, while producing 1 kg of potatoes takes only 500
liters. However, SIWI and others (2005) estimate that grain fed beef uses only 15,000 liters
of water. Thus, while there is little agreement on the precise amount of water needed for
grain fed beef production, the literature does agree that it takes much more water to
produce 1 kg of grain fed beef than 1 kg of crops (Chapagain and Hoekstra 2003;Hoekstra
and Hung 2003). Much of the literature is flawed, however, in comparing water used for
production (kilogram fresh weight) of human foods without correcting for their water
content and in using data of questionable relevance to developing countries.
The water productivities of dry weight protein from crops and animal products
differless than those of fresh weight production. For example, Renault and Wallender
(2000) estimate protein water productivity at 41 grams per cubic meter for eggs, 40 for
milk, 33 for poultry meat, 21 for pork, and 10 for beef compared with 150 grams per cubic

meter for potatoes, 77 for maize, 76 for bean, 74 for wheat, 49 for rice, and 14 for
groundnuts. . In poverty-prone regions of the world farmers and herders cattle graze or
feed mostly on crop residues, processes that require much less water than does grain for
production.
Furthermore, the amino acid mix of crop proteins is less suitable for human nutrition
unless people consume appropriate mixtures of grains and pulses or obtain quality protein
from other sources. And some crop foods such as potatoes, although their protein water
productivity is high, have a very low protein content. Adults would have to consume2,700
kilocalories a day of potato energy to obtain minimal daily protein requirements of75 grams
(Beaton 1991). Meat consumed beyond the 75 grams of protein needed daily tends to be
used by the human body as an energy source. Thus, the water used to meet the first 75
grams of dietary protein is more effectively used than the water used to produce additional
protein if the body converts it to energy. Modest amounts of meat in the diets of African
children appear to improve mental, physical, and behavioral development (Sigmanand
others 2005; Neumann and others 2003), demonstrating that meat should not be evaluated
only in terms of weight produced. However, the literature on livestock-water interactions
does not address this important topic.
The contributions of livestock to rural livelihoods have been under estimated
because of a past focus on productivity, limited consideration of no monetized products and
services, and neglect of small stock, such as goats and poultry. But poor and subsistence
households obtain multiple benefits from the use of livestock (Shackleton and others
1999;Landefeld and Bettinger 2005).Beyond meat production and consumption, water used
to support animals provides great value. Livestock contribute to the livelihoods of at least
70% of the worlds rural poor and strengthen their capacity to cope with income shocks
(Ashley, Holden, and Bazeley1999). They provide milk, blood, manure, hides, and farm
power essential to cultivation and marketing of crops. Livestock assets are often an
important source of wealth security.
Livestock keeping is one of the most important agriculture livelihood practiced in
the country and particularly so in water scare arid and semi arid regions. Globally, livestock
make up, on average 45% of agriculture contribution of GDP and more than half in some
African countries. While demand for food must grow by 50% over the next 20 year to
sustain human population growth, the demand for livestock products is expected to double
during the same period. Already, food production uses more than 70% of managed water in
developing countries. Achieving a 50% increase in food production without increasing
water use efficiency. Because of the current importance and the higher rate of growth
production of livestock production, there is a great need of factor livestock production into
planning for water resource development. As countries become more industrialized,
livestock can use up to half of all agriculture water, and there is growing interest in using
waste water for feed production. Water requirement for production of animal feed may be as
much as 100 times greater than that needed for drinking. Animal raised on irrigated forage
require much more managed water than those raised on rainfed grazing land. Even as
rainfed mixed farming production of water demanding feed such as Napier grass may
completed with farmers ability to grow food crops. The challenge is to develop strategies of
how, when and where to produce animal feed in order to minimize demand on irrigated
water and to reduce competition with rainfed crop production. Increasing use of crop
residue for animal feed and shifting feed sourcing to land unsuitable for rainfed crop
production may be part of the solution. The trade off between using irrigated water for
forage production and food crops must be considered. Livestock water demand for direct
consumption is expected to increase by 71% worldwide by 2025, the highest increase taking
place in the developing countries (Rosegrant et. al. 2002).
Livestock required more than seven times more water than crop for each kilogram
produced. This has led to some suggest that there is a need to change eating habit and slow

or reverse the trend to meat based diets. Many people in industrial countries eat more food
than is necessary and healthy.
Animal production, particularly production of grain feeds and forages, is one of the worlds
largest uses of agriculture water. If properly targeted for reform, this sub sector may well
hold the key to improve water productivity in agriculture. Livestock scientist are arguing
that by reviewing the sourcing of livestock feed, increasing animal productivity, and
improving grazing and watering practices, water productivity in agriculture could increase
dramatically.
Livestock scientist are further challenging comparisons often made between
livestock and crop water productivity. Most comparison focus on fresh weights of human
foods; yet the water content of diverse food such as meat, milk, potatoes and grains varies
widely from about 10-80%, making such comparisons virtually meaningless, say Peden.
Much criticism of high water use by livestock has emphasized grain-fed beef production,
but livestock in developing countries consume very little grain, depending almost entirely
on grass and crop residues and byproducts.
Arising from evaluations of water use in livestock production systems as a part of a
wider comprehensive Assessment of Water Management in Agriculture, Scientists say
greater use of crop residues and by-products to feed livestock, a widespread practice in
developing countries, could obviate the need for huge amounts of water now used to
produce grains and other animal feeds in developed countries.
One entry point for improving global agricultural water productivity is strategic
sourcing of animal feeds such as grains, crop residues and by-products, pastures, fodder and
forage crops. This issue has been largely ignored in 50 years of research on both livestock
and water management.
Equally important is the need to improve animal productivity through better
breeding, animal health and nutrition. Also needed are improved watering and grazing
practices that reduce run-off, flooding, degradation and contamination of water resources.
Sub- Saharan Africa and South Asia are two of the most important livestock
production areas in developing regions. In Africa, 500 million people live in livestockproducing
areas, half of them below the poverty line. In South Asia, 1.2 billion people are
involved in livestock production, 40 percent living on less than a dollar a day. In these two
regions, per capita meat consumption in about one-seventh of that in developed countries.
The poor in these developing regions often suffer from lack of dietary protein, vitamins A
and B12, zinc, iron and selenium.
The booming dairy sector in India has led to severe pressure upon ground water
resources. In the north of the Gujrat state improved cattle breeds, feed sources and
veterinary services as well as the production of irrigated feeds like alfalfa contributed to the
strong and continuous growth of the dairy sector. It was calculated that for one liter of milk
between 1960 and 4600 liters of water were depleted, much of it coming from ground water
productivity of the forage crops by applying water saving technology like drip irrigation and
bringing virtual water into the system in the form of imported feed (Singh and Kishor,
2004). Considering that north Gujrat is classified as absolute water scarce this example
shows that investments which leads to increase productivity of livestock might have
negative implications if the production system is not implemented according to the specific
resource situation of the area.
Use of ground water in water scarce environment may be a good option if the water
is used for drinking rather than for production of feed, livestock are fed crop residues, and if
extraction of ground water for crops is kept to a level below the rate of ground water
recharge.
The challenge is to enable poor livest6ock keepers to get more form their animals
while using less water and reducing degradation of land and water resources.
Strategies for improving livestock water productivity

The brief outlines four strategies for improving livestock water productivity, to
reduce the amount of water used in livestock production and to increase the benefits form
livestock per unit of water used.
Strategic sourcing of animal feeds
Reducing the amount of water depleted to produce animal feed may be one of the
most effective ways to improve water productivity globally. Three basic ways of
accomplishing this are
v Promoting non-grain food sources with high water productivity
v Use of crop residues and by-products as feed
v Practices that encourage more efficient grazing
Enhancing animal productivity and reducing herd sizes
In much of the developing world livestock productivity is less than 50% of genetic
potential. Milk production is low-often less than two liters per cow per day- as opposed to
15 liters or more. Promoting better health, genetics, nutrition and animal husbandry
practices would enable livestock keepers to get more form fewer animals.
Reducing negative environmental impacts
Loss of vegetation due to overgrazing results in increased soil erosion, downslope
sedimentation and reduced water infiltration. Research indicates that low to moderate
grazing pressure has little negative impact on hydrology. Managing animals in ways that
reduce land and water degradation, for example, by restricting animal access to certain areas
and more integrated management of grazing land will help to reduce negative
environmental effects.
Strategic provision of drinking water
The amount, quality and location of livestock drinking water can have a big impact
on livestock water productivity. Water deprivation reduces feed intake and can greatly
lower milk production. Providing adequate quality drinking water- strategically placedenables
animals to reach otherwise inaccessible grazing areas, keeps them from
contaminating domestic water sources, and enhances production of meat and milk. Given
the high value of animals, particularly to poor households, and the relatively small amount
of water animals drink, strategic provision of drinking water is a good investment.

Recommendations for strategies to increase water productivity through better
livestock management
Livestock water productivity could be improved through the production of feed
sources that would utilize transpired water efficiently and the use of livestock species and
breeds that would have higher conversion rate for the available feed. In all the cases, it will
be important to consider the sustainability of the agroecosystems. Improving the grazing
and watering management of livestock will benefit the productive capacity of the land
through better soil and water conservation and diminish pollution with positive
environmental impacts. The recommendations that come from this livestock water review
arev
The livestock water productivity should be quantified at household,
watershed/community and basin levels. This would require developing a
methodology for including livestock water productivity into the water productivity
equation.
v Improving the quantity and quality of crop residue especially the protein through the
introduction of legume forages without affecting the major crop should be looked
into from the socio-economic perspective.
v Assess the trade off between using crop residues as animal feed or for soil
management. This study would have an impact on the water balance of the whole
basin though the adoption would be at farm level.
v Assess which livestock species and breeds could improve water productivity (in
economical as well as environmental aspects) for the different environmental niches
especially in water stressed areas.
v Optimizing irrigation schemes by growing suitable forages (near main and
secondary canals for minimizing evaporation) for animals without reducing the
water available for the main crop production.
v
Assess the socio-economic impacts of changes in the traditional system where the
role of livestock is intensified or diminished. Livestock water productivity could be
one of the major assessing criteria.
This analysis suggest that there are numerous livestock keeping strategies that could
lead to more effective use of water in irrigated and rainfed production systems. Case-bycase
assessments are needed, but because so little attention has been given to livestock
water productivity in developing countries, considerable scope exists for improvement.
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