Kingaroy, Queensland, Australia, 4610 Accurate Regional to Field Scale Yield forecasting of Australian Sugar Cane and Peanut Crops using Remote Sensing and GIS Dr Andrew ROBSON Kingaroy, Queensland, Australia, 4610 Ajrob720@yahoo.com.au b.h. 07 41600735. mob. 0417322137
Importance of accurate yield forecasting: At a regional level: provide essential pre-harvest information to support decisions regarding harvesting, transporting, marketing and forward selling. - At the farm level: provide information to growers that support improved management strategies that optimise productivity (i.e. PA).
Sugarcane
Most suitable source of imagery: Regional Scale SPOT5 : 10 m spatial resolution 4 band spectral resolution cost ~ $1/ km2 2-3 revisit day improved possibility of capture 3600 km2 tile encompasses the majority of crops in each region. Full GIS layers of every crop provided by mills Bundaberg and Isis Herbert Burdekin
Most suitable source of imagery: Paddock Scale IKONOS : Due mainly to cost 3 * 50km2 (~$22/ km2) 3.2 m spatial resolution, 0.8 m PS 4 band spectral resolution (NIR, red, green, blue) Identify sub metre constraints such as weeds, soldier fly, rat, cane grub, land forming etc. Poor irrigation Insect Weed infestation Differing Cultivar
Optimal timing of imagery capture Imagery captures between January to early March generally restricted by cloud cover, for all regions. This limits the opportunity to implement alternative management strategy within the same season of imagery capture due to size of cane and growth stage limiting its capacity to respond. However, remote sensing was identified to be highly effective for identifying differences in crop vigour, assisting with coordinated plant and soil sampling to identify the likely driver of reduced production. This information was then used to coordinate remedial action for the following season.
At the Crop scale: Indentifying variability Vegetation Index (VI) (plant structure/ pigment/ water content etc) False colour image- IR, Red, Green VI- highlights variation in crop vigour Classified VI image
Development of Yield maps from sampling points False colour image of a cane crop with sample points Correlation between GNDVI and TCH (Tonnes of Cane Per Hectare) In crop sampling Average GNDVI = 0.61 Predicted Yield = 77.9 TCH GNDVI (NIR-Green)/(NIR+Green) Surrogate yield map derived by correlation algorithm
Development of generic SPOT5 Yield algorithm Entire Cane blocks where the average GNDVI value was extracted. 600ha. Average crop GNDVI Vs Yield from 2008 (n = 39) and 2010 (n= 112).
Validation of generic algorithm at the in- crop level. Classified yield map from in crop samples Classified yield map from generic algorithm Selected point locations within Bundaberg crops. Accuracy of prediction
Production of surrogate yield maps: Farm Scale 61 blocks predicted average yield 90 TCH, Act. 93.4 TCH (97%) cv. Q208 Pred. 47 tch Act. 51 tch 93% cv. Q208 Pred. 82 tch Act. 89 tch 92% cv. Q208 Pred. 72 tch Act. 71 tch 101% cv. Q200 Pred. 71 tch Act. 70 tch 102% cv. KQ228 Pred. 112 tch Act. 108 tch 104% cv. KQ228 Pred. 97 tch Act. 107 tch 91% cv. Q138 Pred. 94 tch Act. 97 tch 97% cv. KQ228 Pred. 91 tch Act. 101.5 tch 90% cv. KQ228 Pred. 99 tch Act. 105 tch 94% cv. MXD Pred. 75 tch Act. 65.5 tch 114% cv. KQ228 Pred. 101 tch Act. 113 tch 89% cv. MXD Pred. 81 tch Act. 85.5 tch 95% cv.Q208 Pred. 70 tch Act. 64.5 tch 110% cv. Q135 Pred. 70 tch Act. 71 tch 99% cv. Q208 Pred. 50 tch Act. 50 tch 100% cv. Q200 Pred. 87 tch Act. 85 tch 103%
Regional Prediction of Sugarcane Yield Bundaberg/ Isis/ Herbert growing regions Using 2008/ 2010 algorithm : Yield = 3.1528 * EXP (5.6973 * GNDVI) - 2010 Nth Bundaberg (3544 crops): Pred. 79.7 TCH, act. 81.8 TCH (97%) 2010 ISIS (2772 crops): Pred. 84 TCH, act. 84 TCH (100%) - 2011 Nth Bundaberg (3824 crops): Pred. 80.1 TCH, act. 73.3 TCH (109%) - 2011 ISIS (4205 crops): Pred. 98.4 TCH, act. 83.3 TCH (118%) - 2012 Nth Bundaberg (3217 crops): Pred. 88 TCH, act. 88.9 TCH (99%) - 2012 ISIS (4000 crops): Pred. 92.5 TCH, act. 96 TCH (96%) - 2011 Herbert (6481 crops:): Pred. 56.9 TCH, act. 55 TCH (103%) - 2012 Herbert (15463 crops): Pred. 75 TCH, act. 72 TCH (104%) * TCH- Tonnes of Cane Per Hectare
Bundaberg: Comparison of years 2010 ave. GNDVI: 0.567 2011 ave. GNDVI: 0.5697 2012 ave. GNDVI: 0.584
Generation and Distribution of Yield Maps at the Regional Scale. Can be used to identify sub- regional seasonal and temporal trends
Peanut
Development of Yield maps from sampling points In crop sampling Correlation between (NDVI) and Yield (Tonnes Per Hectare) False colour image of a peanut crop with sample points NDVI (NIR-Red)/(NIR+Red) Surrogate yield map derived by correlation algorithm
Pod yield vs NDVI (n=352) data from 6 growing seasons and 8 varieties Development of generic algorithm for predicting yield Pod yield vs NDVI (n=352) data from 6 growing seasons and 8 varieties
South Burnett 5000km2 coverage Identifying where the Crops are. South Burnett 5000km2 coverage Assigning blocks as peanut crops Classification of peanut ‘pixels’ False colour image Example: Predicted area 6000 ha Ave. NDVI: 0.55
Predicting Average and Total Yield. Average NDVI extracted = 0.55 2.4 t/ha 0.55 Correlation between NDVI and crop yield Predicted average Yield: 0.2717*EXP (3.9659*0.55) = 2.4 T/ha Predicted total yield: 2.4 T/ha * 60000 ha = 14,400 t peanut
Yield Predictions: Crop scale NDVI images of dry land peanut crops overlayed on a false colour image. 1500 m Dryland crop (cv. Walter) Area=317 ha Predicted 849 t : Delivered 874 t (97%) Crop locations within Australia Dryland crop (cv. Walter) Area=18.9 ha Predicted 76.6 t: Delivered 77.4 t (99%)
Yield Prediction at the Block Scale Total area of Peanut (143.6 ha) average predicted yield = 3.43 t/ha: Actual average yield = 3.39 t/ha total predicted yield = 492.3 tonnes; Actual total yield = 487 tonnes Pred. yld 4.3 t/ha (Act. 4.1 t/ha) Pred. yld 6.87 t/ha (Act. 5.3 t/ha) Pred. yld 4.3 t/ha (Act. 3.9 t/ha) Pred. yld 4.0 t/ha (3.6 t/ha) Pred. yld 1.2 t/ha (act. 1.8 t/ha) Pred. yld 4.3 t/ha (act. 4.4 t/ha) Pred. yld 3.6 t/ha (act. 2.9 t/ha) Pred. yld 2.1 t/ha (act. 1.8 t/ha)
Production of Peanut Yield Maps at the regional Level.
Surrogate maps provide can assist with harvest segregation for quality based on pod maturity and aflatoxin risk.
Correlation between NDVI and pod maturity (% Black kernel) Maturity: Case Study Total area 17.61ha Total Yield 101.27t Ave t/ha 5.75t/ha Correlation between NDVI and pod maturity (% Black kernel)
Soil temperature variability across zones Tiny tag sensor Soil temperatures measured at strategic locations Portable weather station
the predicted crop maturity date was 158 days using ambient temperature. Substitution of soil temperature data measured over the three week period a predicted maturity range of 2 days between the black and red colour zones (155-157 days from sowing) extrapolated for the entire pod-filling period, a maturity range of 7 days between the black to red colour zones (138- 145 days from sowing) APSIM thermal time model 1/t = (T-Tb)/θ where, 1/t is the development rate T is daily mean temperature (°C) Tb is base temperature (°C) below which the rate is zero θ is a constant identifying the thermally modified time for each development stage.
Opportunity for Harvest Segregation Based on Aflatoxin Risk. The optimum conditions for aflatoxin production are low soil moisture, as well as high soil temperature (25C to 32C). Stressed plants/ less shading are likely to be exposed to a longer period of high aflatoxin risk. R2: 131.94476, -14.62327 X2: 131.93914, -14.63059 X3: 131.94083, -14.63234
Tree Crops
Avocado- Field sampling based on NDVI maps False colour image of Avocado block sampling locations overlayed Classified NDVI image of Avocado block sampling locations overlayed
Development of commercially relevant maps Correlation between N1/RENDVI and % commercial yield Map of %commercial yield generated from the correlation between N1RENDVI.
Avocado: Regional Forecasting Predicted Avocado pixels (SAM Classification) Derived yield maps (Avocado blocks) 1,383 ha * Predicted average yield of 13.1 TPH = 18,117 tonnes Predicted Avocado blocks (Polygons)
Mapping orchard constraints at the tree level ‘Geo tagging’ individual trees so in field assessments and measurements can be spatially linked (i.e. with a PDA). Can be performed at low cost using GoogleEarth, with points then exported into ArcGIS/ Excel for further analysis.
Mapping Disease Ciba Geigy Avocado tree health rating scale False colour image of Avocado orchard with Geo-tagged trees Derived tree health map following field survey Ciba Geigy Avocado tree health rating scale
Conclusions: - Imagery is an effective and efficient TOOL for: - For identifying within crop/ Orchard variability. Assist with the adoption of PA, fertigation, disease and pest monitoring. - Within season yield forecasting at the Block/ Farm and Regional level. - Useful for multiple applications but only as good as the data collected. Requires involvement from all facets of farming (i.e. grower, agronomist, seed and fertilizer reps, research bodies etc) to ensure maximum use, feasibility and adoption. GoogleEarth provides a very effective method for image distribution.