Ground Cover Supplement : GC Supplement - Precision Agriculture 2005
GROUND COVER PRECISION AGRICULTURE 10 CROP BIOMASS IMAGING CROP PLANTS THEMSELVES are the greatest indicator we have of how they feel about the varied environment they live in. They actually integrate for us the complex interactions that are occurring in the soil (physical, chemical and bio- logical) as well as above-ground factors (humidity, temperature, sunlight hours, aspect etc). Therefore, knowing the crop response can tell us a lot about the crop's growing environment and how farmers could improve it. Silverfox, working as part of the GRDC PA Initiative, has been looking at crop biomass images that show normalised difference vegetation indices (NDVIs), a measure of how crops are responding to their growing environment. We use up to 10 years of historical NDVIs to determine zones of poor per- formance (unhappy plants -- red in the analytical image), average performance (life's OK) and high performance (very happy plants -- blue in the image) in dif- ferent parts of a paddock (or across a whole farm). Then we look to see if different crop plants respond consistently within those zones; whether it is a wet year, district average (decile 5), or a dry year. If the plants always respond the same (low, average, or high compared with the pad- dock average biomass) within a zone no matter what the season, then the pattern of performance is consistent/stable and therefore predictable. In this case, forecasting the future crop growth (and yield) based on history can be done with some confidence. It is from these stable zones linked with soil test Plants don't lie IAN MALING OF SILVERFOX SOLUTIONS EXPLAINS THE VALUE OF CROP BIOMASS IMAGES Happy plants, unhappy plants High NDVI, Blue, Site B, Deep Duplex Low NDVI, Red Colour, Site A, Shallow Duplex Depth of sample cms 0-10 10-20 20-30 0-10 10-20 20-30 Texture Loamy sand Loamy sand Loamy sand Loam Clay Clay pH 5.6 6.8 6.4 6.9 7.9 8.5 OC% 0.7 0.3 0.2 1.2 0.6 0.4 P9 3 2 3 0 8 3 Reactive Fe 355 508 689 559 685 710 K 75 97 111 165 235 341 S 6.9 7.5 10.3 12.6 32 79 EC 0.06 0.06 0.03 0.24 0.49 0.44 Root Depth 50-60cm 10-20cm The deep duplex soil noted as site B in the table below.
GC Supplement - Nutrient Management 2006
GC Supplement - Grain Storage 2005