Initial Investigations into the Potential and Limitations of Remote Sensed Data for Irrigation Scheduling in High Value Horticultural Crops

OutlineBackground irrigation system requirements into the future

Use of NDVI in irrigation scheduling

Thermal the ultimate irrigation scheduling tool?

Background Ongoing switch from flood/furrow irrigation to drip in perennial horticulture Supported through the Integrated Horticulture Systems Project in the Murrumbidgee Irrigation Area Aims to see majority of horticulture converted to pressurized irrigation systems by 2010

Drip and Flood Water Use

Yields

Managing High Tech Irrigation Systems6 Soil probes for 6 ha paddockAssume each probe measured 1m2So we know what is happening on:

Method lacks ability to see what is happening over the whole vineyardOnly infer the plant stress based on the soil moisture, plants can also be stressed due to a number of other factors such as soil salinity,

Can we get something better ?

Large Scale Low Cost Irrigation Scheduling - NDVI for Irrigation Scheduling/Management/Benchmarking

NDVINDVI = (RNIR Rred) / (RNIR + Rred)

NDVI = (Band 4 - Band 3) / (Band 4 + Band 3)

Irrigation Scheduling FAO 56ETc = ETo x KcReadily available fromWeather stations/SILORelates actual water use of the crop to reference water use Large variation and crop/management specific

NDVI to Kc functional relationship

Canopy Cover and Light Interception Vs WUWilliams and Ayars (2005)McClymont et al.ECC = 1.2 NDVI 0.2

(extrapolated from Johnson and Scholasch, 2005)

Irrigation Scheduling from Remote Sensing indicesDetermination of Kc from NDVI / EAS DataETo from Weather StationIncorporates management/soil/water/salinity constraintsOn GroundNDVI / EAS Images from Satellite or quad bikeRepresenting Individual PaddocksSatellite, airborne or On-groundSpatial MeasurementsPotential Evaporation based on Atmospheric DemandETc = ETo X KcActual crop evapotranspiration across regions

CRC IF Irrigateway serverNDVI + ETo data HarvestingDaily delivery of tailored irrigation scheduling information direct to irrigator on SMSInitialisation data system parametersBenchmarking and data miningETc = ETo x kc

SMS Drip SchedulerUses simple SMS text messages for delivering irrigation scheduling informationWill be tested with 20 horticultural growers this coming season in MIA

NAFENAFE 06 NDVI data will be used for fine tuning of EAS/ECC relationships to NDVI

Investigation into scaling effects from high resolution NDVI (NAFE 06) data to Landsat NDVI in relation to providing irrigation scheduling information sensitivity analysis

Thermal

Crop Water Stress Index (CWSI) What is CWSI?Relates canopy temperature to an index between 0 and 1 indicating how stressed the plant is:0 = No stress1 = High stress

Measured with IR temperature sensor or thermal camera(Tc-Ta)NWSBL = Non water stressed base line equated fully open stomata and fully transpiring canopy(Tc-Ta)NTUBL = non-transpiring upper baseline equated to temp. of non-transpiring canopy with stomata closed(Tc-Ta)NWSBL(Tc-Ta)NTUBL

Agrosense - Irriscan

Trials undertaken in MIA in 2002 Collaboration with MIGAL Galilee Technology Centre, Israel 0.1 m2 Resolution1250 ha per dayOn-site calibration

Results

Canopy Temperature and Salinity Stress1432

Crop Water Stress Index (CWSI) Jones et al.What is CWSI?Relates canopy temperature to an index between 0 and 1 indicating how stressed the plant is:0 = No stress1 = High stress

Measured with IR temperature sensor or thermal cameraTdry = upper bound for canopy temp. equated to temp. of non-transpiring canopy with stomata closedTwet = non-stressed baseline equated fully open stomata and fully transpiring canopy

Wet Reference Surfaces

ResultsWet Reference Surfaces

NAFEAssessment of alternative methods of determining baselines for CWSI

Comparison of PLMR data with high intensity on-ground gravimetric soil moisture content sensing

Thank you