OverviewINTRODUCTION• MORE CROP PER DROPTechnology supports growers to cope with water shortage challengesPOLICY BRIEF• SCIENCE AND TECHNOLOGY FOR EFFICIENT IRRIGATIONTools for growers to cope with water scarcity and the Water Framework DirectiveTECHNOLOGY BRIEFS• A ROBUST DIELECTRIC TENSIOMETER FOR VERY DRY SOILSSensing when to start your irrigation• A WIRELESS SENSOR SYSTEM FOR IRRIGATION MANAGEMENTAlways and everywhere access to soil water information• A CROP PLANNING AND FARM ZONING TOOLOptimizing gross margin with a decision support system• A CROP STRESS RESPONSE MODELUnderstanding the effect of water-shortage and salinity• A DECISION SUPPORT SYSTEM FOR IRRIGATION UNDER DEFICITOptimal irrigation and fertilizer management in dry regions• SENSOR-ACTIVATED IRRIGATION CONTROLLERSMinimizing wastage and environmental damage• SENSOR-ACTIVATED FERTIGATION CONTROLManaging fertigation in container cropsCASE STUDY RESULTS• LEBANONOptimizing eggplant production by using smart irrigation controllers• JORDANGrowing tomatoes with treated wastewater• TURKEYMinimal percolation losses in cucumber production in greenhouses• ITALYIrrigation of pot ornamentals with lower quality water• THE NETHERLANDSReducing nitrate emission in rain-fed and soil-grown iceberg lettuce• SPAIN-LEBANONOptimizing crop patterns under water scarcity and saline conditionsPARTNERSLITERATURECOLOPHON
Science and technology for efficient irrigationTools for growers to cope with water shortage challengesWATER SCARCITYGrowers have to deal with new challenges. Climate change and water shortage forces them to adopt deficit irrigationpractices. They also have to deal with new legislation, such as the Water Framework Directive (WFD). Having lesswater at their disposal makes it difficult for growers to avoid crop damage and income loss. It is therefore necessaryto manage water and nutrients more precisely. This will contribute to the reduction of leaching, one of the major aimsof the WFD.New technology based on innovative tools can help growers to meet the challenges of the future. By making the bestpossible operational decisions, yields will increase and fertilizer costs will decrease. This will result in a better income,which enables growers to invest in the new technologies.Policy BriefWATER FRAMEWORK DIRECTIVEIn the nearby future the use of water and the management of water resources in Europe will be governed by theWater Framework Directive (WFD). The WFD aims at achieving a ’good ecological status’ of water bodies in Europeby 2015. This is the reason for promoting Integrated Water Resources Management, involving all stakeholders frompolicy-makers to water suppliers and end-users.High-value, intensively grown horticultural crops need a lot of water and fertilizers. Nowadays, water shortage forcesgrowers to apply less water than needed for optimum production. They are also required to irrigate with water of alower quality. This practice leads to soil salinization due to the accumulation of nutrients and sodium chloride, notused by the crop. Growers then use over-irrigation to force leaching, either continuously or in multiple events to cleantheir soils.
Policy briefPOTENTIAL IMPACTAs good water is becoming scarce, the availability is of major concern to all. Growers sometimes negate their responsibilitytowards the environment as they make ample use of water. Fortunately less available water of lower qualityforces them to improve water management to ensure a high quality crop. Although this will be primarily driven byeconomic arguments, controlled use of water and fertilizers is also the key approach to reduce the environmentalload. Combining both targets into a single practical management approach opens perspectives for introducing a newtype of irrigation practice.In the FLOW-AID project new techniques and methodologies have been developed, enabling growers to make betterdecisions on how to mix water from different sources and of different qualities (dual water or treated water). FLOW-AID proved that the use of these new tools can substantially reduce the nitrate load of groundwater sources and savewater, while maintaining good crop quality and sometimes even slightly higher yields.IMPLEMENTATIONThe results of this project will make new technologies affordable for third partner countries. However, growers arereluctant to change their way of irrigation due to lack of knowledge about the technology. Furthermore, many growersdo not seem to be aware that legislation will force them to stop emitting nutrients in the near future. The FLOW-AIDapproach can help to increase economic efficiency of water application and decrease the pressure on water resources.Policy-makers might stimulate the successful introduction of new technologies by supporting a number of actions. Thepresented methodology is a prototype which has shown its benefits in a limited number of case studies. First, moreresearch should be supported. Then, engineering companies should be enabled to start transferring this prototype intonew readily available cost-effective products. Finally, capacity building programs for training are needed to ensure abroad and wide implementation of the tools.
A robust dielectric tensiometer for very dry soilsSensing when to start your irrigationAPPROACHThe output of water-filled tensiometers, particularly indrying soils, can result in serious measurement errors.Therefore partners in FLOW-AID worked together todevelop an innovative prototype tensiometer, whichmeasures soil hydraulic pressure using a novel dielectricmeasurement principle. The prototype dielectrictensiometer aims to be: low-cost, easy to install, lowmaintenance and independent of soil type.RESULTSA prototype dielectric tensiometer to measure thematric potential has successfully been developed.Evaluation during the FLOW-AID project demonstratedthat under dry and very dry conditions theprototype dielectric tensiometer gives more accuratereadings and is more reliable than standard hydraulictensiometers. It has been shown that low-cost die lectrictensiometer technology has significant potential tohelp enable wider use of deficit irrigation practices.TechnologyIMPLEMENTATIONThe results from the prototype dielectric tensiometerdevelopment and evaluation will help enable Delta-TDevices and Rothamsted Research to develop lowcostdielectric tensiometer products for the end-userirrigation market. The system aims initially to meet theeconomic and physical conditions of non-Europeanmarkets, where the largest growth for irrigation equipmentis expected.USER BENEFITSA dielectric tensiometer is easier to set-up and installthan a hydraulic tensiometer. Furthermore, the dielectrictensiometer can cope with significant dryingevents that would normally result in the user having toremove and service a hydraulic tensiometer. Using adielectric tensiometer to measure matric potential alsosimplifies the setting up of a deficit irrigation controlleras soil-dependent soil-moisture calibrations are notrequired.PARTNERSRothamsted Research – United KingdomDelta-T Devices – United Kingdom
TechnologyA wireless sensor system for irrigation managementAlways and everywhere access to soil water informationAPPROACHOptimum and precision irrigation control requires alarge number of sensors that are spread out on eachplot of the farm. These sensors have to communicatewith the irrigation system. A wireless sensor networkhas been developed based on commercially availablecomponents. These components have been intensivelytested and adapted to the boundary conditions.Field experiments with different systems werecarried out in ornamental container crops and fieldgrown lettuce.RESULTSIt is shown that with the wireless sensor network itis possible to monitor soil temperature, moisture andelectrical conductivity (EC) in a robust manner. Distancesup to 500 meter between base station andfield and up to 200 meter between two sensor nodescan be achieved. The used system is solar poweredand self recharging and practically maintenance-free.Data can be transferred automatically over internetand processed by a remote decision support systemfor irrigation.IMPLEMENTATIONThe costs of application in container crops were calculated.The assumption of a necessary high densitysensor grid of 10 meter x 10 meter resulted in the conclusionthat the costs per sensor node should be nomore than 100 euro. Current costs are still too highfor this and cheaper systems have to be developed.Nevertheless, the current system has demonstrated tohave the potential to be used at a lower density in anumber of other applications like for instance in soilgrown horticultural crops.USER BENEFITSUsers can at any time and location obtain informationabout the actual soil water status for their croppingfields, and thus optimize their irrigation managementpractices. Installation costs of sensors may be keptlow due to the wireless concept.PARTNERSWageningen University & Research centre –The NetherlandsUniversity of Pisa – ItalyCentro Sperimentale Vivaismo, Pistoia – Italy
A crop planning and farm zoning toolOptimizing gross margin with a decision support systemAPPROACHTo reach an acceptable income, a grower has tomake the correct decision on which crop he is goingto grow. Many factors are determining profits,such as harvest prices, availability of water for irrigation,climate conditions, subsidy policies, resultsof previous years. A decision support system, basedon an earlier developed model performing yield calculationsfor multiple irrigation strategies (MOPECOmodel),has been developed.RESULTSParticipating growers have received an easy to usetool to make an optimal decision on which crop togrow. An on-line version of the MOPECO modelhas been developed which was extended for deficitconditions in order to make the decision supportsystem available to a great number of users. The softwareis available in English and Spanish and can beeasily translated into any other language. It can bedownloaded from http://mopeco.agr-ab.uclm.es orwww.mopeco.uclm.es.TechnologyIMPLEMENTATIONThe model has been offered to growers in EasternMancha (Spain) and South Bekaa (Lebanon). Theyare now entering their own crop data. Researchersare working on validation of the decision support systemwith these data. The next objective is to increasethe number of users by dissemination tasks andtraining courses for technicians and local growers inboth areas.USER BENEFITSGrowers will be able to optimize their crop planningand farm zoning by using the new tool. They caneasily enter a great number of data related totheir farms in the programme. The decision supportsystem then automatically generates an advice that willimprove the efficiency of their business.PARTNERSRegional Centre of Water Research (CREA),University of Castilla La Mancha – Spain
TechnologyA crop stress response modelUnderstanding the effect of water-shortage and salinityAPPROACHTo optimize irrigation scheduling, growers need tounderstand plant-water relations and the relatedeffects on the plant, such as reduced growth andwilting. World-wide a great effort has been undertakento obtain the response of a large number ofagricultural and horticultural crops. To disclose newknowledge about the effect of crop water stress, thisinformation was collected from the literature andincorporated into a database.RESULTSA practical database was designed providing informationabout the response to water constraints of aselection of representative irrigated crop species. Amathematical model was developed to predict thegross effect of reduced water supply or increasingsalinity on crop yield and economic profit.IMPLEMENTATIONThe database is designed in such a way that it allowsusers to modify the data provided for specific cropsas well as to add new crops. The data can easily beexported, as the database generates two tables thatare compatible with other software.USER BENEFITSThe information in the database can help growers toimprove crop selection in regions affected by watershortage and/or salinity. Optimization of crop selectionwill help growers to increase their yield with minimaluse of water.PARTNERSUniversity of Pisa – ItalyRegional Centre of Water Research (CREA),University of Castilla La Mancha – Spain
A decision support system for irrigation under deficitOptimum irrigation and fertilizer management in dry regionsAPPROACHScarce water should be applied with the highestpossible efficiency and crop damage must belimited when using water of poor quality. A decisionsupport system that combines information fromvarious sources (visual observations, sensors,expert examinations and forecasts) has beendeveloped. The tool has been evaluated at siteslocated in Lebanon, Jordan, Turkey, Italy, theNetherlands and Spain.RESULTSA decision support system for irrigationmanagement has been evaluated. The system isbased on soil-water-plant reactions and fertilizerbalance encoded knowledge. It combinesinformation of wireless soil water sensors and datafrom a database of crop response to drought andsalinity. All other tools developed within the FLOWAIDproject can be easily interfaced with the decisionsupport system. It is robust, safe and easy to use, andis interoperable with other affordable deficit irrigationequipment and management tools.TechnologyIMPLEMENTATIONAt all locations, irrigation based on the newsystem has reduced water use without loss of yieldor quality. The results will now be implemented intoadequate and appropriate products for the enduserirrigation market. The participation of theMediterranean test sites ensures that the final productswill also be fine-tuned to both the economic and thephysical con ditions of non-European markets.USER BENEFITSGrowers will obtain affordable hard- and software,such as a maintenance-free tensiometer, awireless and low-power sensor network and an expertsystem for farm zoning, crop planning and irrigationscheduling. These instruments will help them to increasethe efficiency of their water use and fertilizationmanagement under soil water deficit conditions.PARTNERSWageningen University & Research centre –The NetherlandsGeomations – Greece
TechnologySensor-activated irrigation controllersMinimizing wastage and environmental damageAPPROACHHaving a low-cost irrigation controller with soil conditionfeedback takes out the guesswork of deficitirrigation. The GP1 data logger has therefore beendesigned to control irrigation. Sensors are connectedto the data logger to feedback information onsoil condition, such as soil water content, and EC(obtained with WET-sensors) and matrix potential.This information is used in a decision support system,which now has been evaluated on five sites locatedin Italy, Turkey, Lebanon, Jordan and the Netherlands.RESULTSGP1 loggers have been successfully installed in a networkwith remote access and control capability. Alocal computer regularly reads out sensor dataand updates autonomously the running schedulingprogram. The decision support system helps thegrower to optimize irrigation. Up to ten GP1’s can benetworked on a single Ethernet adapter channel.IMPLEMENTATIONThe improved decision support software and the GP1based irrigation controller have resulted in a tool thatis suited for scientific studies and to assist the furtherdevelopment of practical irrigation control strategies.The software capabilities of the GP1 logger/controllerhave been enhanced to include safety features suchas: sensor misreporting, overdue irrigation, meteredirrigation quantity, cut sensor cables or irrigationdelivery failure to improve crop security andirrigation overshoot.USER BENEFITSThe flexible GP1 based irrigation controller makesmore precise water management possible. Environmentaldamages will be limited, water will be savedand crop yields are maximized.PARTNERSDelta-T Devices – United Kingdom
Case studyCase study lebanonOptimizing eggplant production by using smart irrigation controllersCHALLENGESLimited water availability has placed immediaterestraints on agricultural growth in the BekaaValley in Lebanon. Traditional irrigation techniquesare not economical and only eight percent of theirrigated lands receive water with more efficient dripirrigation. The costs of irrigation are increasing andlack of operation and maintenance work has led toserious shortages. Modern techniques have to beincorporated in daily practice in Lebanon to ensureenough water for a profitable agriculture.APPROACHThe GP1-loggers and sensors in combination withsmart sensor-activated irrigation control offer perspectivesfor more efficient irrigation methods. Field installationswere made at Tal Amara Research Station inthe 2008 and 2009 summer periods. Eggplants weretransplanted in an experimental field using drip irrigation.Traditional irrigation regimes were comparedwith deficit irrigation based on sensor-activated irrigationcontrol.RESULTSThe sensors were used to make an irrigation schedulebased on soil water levels. This allowed good timingand management of the applied water volumes andresulted in nearly twenty per cent water saving, whencalculated over the whole growing season. At productionlevel, data showed that grower’s productionlevels in the trials were high (15-20 t/ha). The GP1proves to be a smart irrigation controller that offers areliable irrigation system.USER BENEFITSThe new approach makes it is possible to monitor thesoil water content under good and deficit irrigationconditions. Water requirements of eggplants can bedetermined by various irrigation regimes. The effectsof deficit irrigation on growth and production can beevaluated. A water saving strategy that enables theLebanese growers to produce more eggplants withminimal water use can be developed.PARTNERSLebanese Agricultural Research Institute – LebanonDelta-T Devices – United Kingdom
Case study jordanGrowing tomatoes with treated wastewaterCHALLENGESJordan has very limited fresh water resources. Thedemand on water is ever increasing and is nowestimated at about 1.2 billion cubic meters per year.Rainfall is not enough to meet growers’ needs. Andgrowers do not know the water requirements of theircrops. It is necessary to increase water use efficiencyand to improve wastewater for reuse to bridge thegap between available water and needed water.APPROACHA field test with tomatoes was carried out in the formof two experiments in the period 2007 to 2009. Inthe experiments, fresh water and treated waste waterwere compared. Both water content sensors andtensiometers were used to schedule irrigation in theplots. Two irrigation schedules were simulated, onewith adequate water and one with deficit conditions.The performance of the soil sensors was evaluatedand the different irrigation strategies were compared.Case studyRESULTSWater use efficiency in the innovative irrigationschedules is higher in all treatments except for thetreatment with only treated wastewater. Lowest yieldswere obtained with deficit irrigation with treatedwastewater. Highest yields were obtained when thetomatoes received sufficient treated dual water. Thesensor technology has proven its value and is readyto be put into practice.USER BENEFITSSensor technology contributes to a more efficientwater use. Dual water can be used to producetomatoes. Yields can be increased by introducinginnovative irrigation schedules in Jordan.PARTNERSJordan University of Science and Technology – JordanWageningen University & Research centre –The NetherlandsDelta-T Devices – United Kingdom
Case studyCase study turkeyMinimal percolation losses in cucumber production in greenhousesCHALLENGESThe Tahtali Dam is the most important drinkingwater source of Izmir, the third largest city of Turkey. Inthis area greenhouse production is an importantagricultural activity. In order to prevent pollutionof drinking water by nutrients or pesticides, irrigationis restricted. Nevertheless, the growers are stillusing excessive amounts of water. This causesenvironmental impact in the region. A method fordeficit irrigation should be developed to reduce theimpact of greenhouse production.APPROACHAn on-farm project was started to evaluate whetherdeficit irrigation could reduce leaching and at thesame time increase water use efficiency. A three-yearstudy has been carried out with greenhouse cucumberproduction under growers’ conditions. The commonlyused irrigation strategy was compared with sensoractivatedirrigation scheduling. In the sensor-basedculture the water content in the root zone was kept ata constant level as much as possible for full irrigationand two deficit levels.RESULTSThe averaged three-year results show thathigher crop yields (14%) can be obtained withautomated irrigation and soil moisture control in thefull irrigation treatment in comparison with growers’practices. This result was obtained without anynotable percolation losses, while traditional growerpractice showed significant percolation losses andover-irrigation. A slightly deficit irrigation programprevented leaching with acceptable crop yield.USER BENEFITSThe new technology can be easily adapted to severalspecific growing conditions. However, it seems thatthe implementation of this technology will take sometime since the cost of the equipment is still rather highfor small farms.PARTNERSEge University Faculty of Agriculture – TurkeyRothamsted Research – United KingdomWageningen University & Research centre –The NetherlandsDelta-T Devices – United KingdomSpagnol Agricultural Automation Systems – ItalyGeomations – Greece
Case study italyIrrigation of pot ornamentals with lower quality waterCHALLENGESThe production of ornamental nursery stock inTuscany provides a substantial contribution to theItalian gross income. However, the environmentalimpact is significant due to the waste ofwater and the pol lution of rivers and groundwater.Competition for water between agriculture and otherusers is affecting the future development of the nurseryindustry. Efficient water management systems andtechniques to exploit reclaimed urban wastewater aretherefore needed.APPROACHMost ornamental species are sensitive to salt stressand toxicity. This makes it necessary to developan appropriate irrigation and fertigation strategyto avoid salinization of the growing medium whendual water is used. A fertigation device and softwarewere tested in an experiment with pot ornamentalplants simulating the use of a dual water source. Twofertigation regimes were compared, one based on atimer and the other based on a WET-sensor.Case studyRESULTSThe device successfully modulated the EC of thenutrient solution. In both years, compared to the timer,the WET-based scheduling did not affect plant growthand significantly reduced (-35%) seasonal water useof a multi-crop plot and the drain fraction due to alower irrigation frequency. In the WET-dual watertreatment the use of groundwater was reduced by68% (2008) or 62% (2009) compared to the timer.USER BENEFITSProducers of ornamental crops will be able to replacegroundwater by dual water without production losses.The environmental impact of the nurseries in Tuscanywill be reduced substantially.PARTNERSUniversity of Pisa – ItalySpagnol Agricultural Automation Systems – ItalyCentro Sperimentale Vivaismo, Pistoia – Italy
Case studyCase study the netherlandsReducing nitrate emission in rain-fed and soil-grown iceberg lettuceCHALLENGESDue to environmental legislation like the WaterFramework Directive (WFD), there is a strongfocus on controlling water and nutrient flows in theNetherlands. Growers need new techniques tooptimize fertigation, especially for crops grown insoil. When grown on sandy soils, crops may soonsuffer from drought. In addition, during heavyrainfall, valuable nutrients might leach into the groundwaterand damage the environment.APPROACHThe use of drip irrigation and covering of soil withfoil, in combination with controlled fertigation, wasevaluated in an experiment. Iceberg lettuce wasgrown in a standard cropping system with minoradaptations. The aim was to reduce the emissionof nitrate to the environment and at the same timeincrease crop yield while keeping the quality. Anautomatic sensor-activated irrigation control incombination with a decision support system wastested.RESULTSA slightly higher (10%) crop yield was obtained in thefertigated and sensor-activated situations, while maintainingcrop quality compared to grower-controlledirrigation management. Under the foil, the automatedsystem assured a less wet environment keeping soilmoisture more constant and homogeneous. This preventedleaching of water and valuable nutrients. Thetechnical systems, including the wireless links, workedwell.USER BENEFITSThe decision support system has to be adapted insuch a way that it relieves the grower from checkingand fine-tuning irrigation. The price of the automaticsensor-activated irrigation system is still a bottleneckfor introduction in daily practice. However, growersare advised to apply water and nutrients at lowerdose levels, with a closer match with crop demand.This will reduce emissions, increase yields and quality,and will save a lot of work.PARTNERSWageningen University & Research centre –The NetherlandsDelta-T Devices – United KingdomGeomations – Greece