Central Rice Research Institute Annual report...2011-12

Enhancing and Sustaining the Productivity of Rice Based Farming Systems
Management of Fe toxicity and Zn deficiency
in rice
A field experiment was conducted at OUAT farm,
Bhubaneswar with four cultivars (two each susceptible
and tolerant) with different soil management options
in Fe toxic soil to study the tolerance mechanism. It was
found that the tolerant cultivar, Lalat produced the highest
grain yield followed by Naveen. The lowest yield
was obtained with Pusa 44 across the soil management
treatments. However, susceptible cultivars responded
better under different Fe toxicity management practices
as compared to tolerant cultivars. The tolerant cultivars
retained much of the Fe in the roots and translocated
less to the shoots as compared to susceptible cultivars.
Another experiment was conducted at OUAT farm,
Ranital to quantify the relative effects of different physiological
mechanisms of Zn efficiency in four rice genotypes
viz., tolerant (IR36 and Tapaswini) and susceptible
(IR64 and Pusa 44). The level of Zn application
were 0, 2.5, 5 and 10 kg Zn ha -1 . The grain yield was
significantly affected by zinc application and varied
from 3.25 to 3.82 t ha -1 across different doses of Zn
(Table 28). Maximum grain yield (3.82 t ha -1 ) was recorded
in IR-36. The results indicated that application
of zinc enhanced the yield of all the four cultivars, which
might be due to root proliferation and higher uptake.
Development of Cropping Systems for
Different Rice Ecologies
Development and evaluation of rice based
cropping systems for soil sustainability and
productivity
A field experiment was carried out in split plot design
with three rice-based cropping systems (RBCSs)
viz., Rice–Potato–Sesame, Rice–Maize–Cowpea and
Rice–Groundnut–Green gram in main plots and three
nutrient management options viz., Recommended dose
of fertiliser (RDF), INM (25% N based substitution with
FYM) and RDF + Crop residue incorporation of previous
crop) in sub plots to improve productivity and different
nutrient management options under RBCS.
Experimental results revealed that grain yield of rice
did not differ significantly with respect to cropping system
in wet season. However, the highest rice equivalent
yield (REY) was achieved with potato (7.58 t ha -1 )
grown after rice which was significantly higher over
groundnut but was at par with maize. Among the three
summer crops, sesame produced significantly highest
Table 28. Grain yield (t ha -1 ) of rice genotypes under
different doses of Zn
Level of Zn, kg ha -1
Genotypes 0 2.5 5 10 Mean
IR36 3.51 3.71 3.92 4.13 3.82
Tapaswini 3.42 3.63 3.76 3.91 3.68
Pusa 44 3.11 3.32 3.55 3.67 3.41
IR64 2.83 3.17 3.45 3.53 3.25
Mean 3.22 3.46 3.67 3.81
LSD (P=0.05); Genotypes=0.17; Zn=0.21; GxZn=NS
REY (2.51 t ha -1 ). The total productivity of the rice-potato-sesame
cropping system (14.91 t ha -1 ) was found
to be highest among the systems with 15.6 and 29.8%
higher yield over Rice-Maize-Cowpea and Rice-
Groundnut-Greengram cropping system, respectively.
The lowest land utilization efficiency but highest production
efficiency was observed in rice-potato-sesame
cropping system although rice-maize-cowpea was
found to be the most economical system. The highest
REY of 13.65 t ha -1 was recorded with RDF + crop residue
incorporation of preceding crop which was significantly
higher than RDF alone. At the 2 nd cycle of the
cropping system rice-groundnut-greengram system recorded
highest available nitrogen of 216.0 kg ha -1 and
available potassium (113.7 kg ha -1 ) which was significantly
higher over other two systems. Among the nutrient
management treatments at the end of the 2 nd cycle of
cropping sequence highest available nitrogen, potassium
and organic carbon was found in RDF + crop
residue incorporation treatment which was at par with
INM treatment (RDF with 25% nitrogen based substitution)
but significantly higher than RDF alone.
Assessing the impact of climate variability on
rice productivity and developing adaptation
strategies for rice based cropping system of
Eastern India
Water balance analysis of Cuttack which falls under
hot moist sub humid ecological sub region indicated
a water surplus of 1046 mm in a normal rainfall
year (2005) and during excess rainfall year (2003) it is
around 1555 mm during the crop growing season (23–
46 MSW). Even during a deficit rainfall year like 1996,
there was a water surplus of 146 mm during the crop
growing season indicating the opportunity for water
harvesting and storage. The harvested water can be used
for supplemental irrigation to mitigate the drought, extend
crop growing season and irrigation for the dry
CRRI ANNUAL REPORT 2011-12
69