Dr Cassandra Schefe, Cameron Grant, Peter Dahlhaus, Nathan Robinson, Ryan Walker, Les Janik, Dean Jones, Ben Fleay.
Site 3, Yarrawonga, VIC
The aims of the PA component of the GRDC Stubble project were to:
• deliver a pilot project to understand how soil parameters, including PAW, vary across a paddock and understand
whether current PA datasets can correlate with PAW
• connect variations in soil moisture with nitrogen supply
• demonstrate the use of NDVI to inform variable rate applications of nitrogen
• determine the economic value of variable rate nitrogen application across paddocks, based on zones
• Electromagnetic (EM) zoning was strongly related to differences in pH at 10–30cm depth in two out of three paddocks.
• All three paddocks showed variability in chemical properties, with the EM zoning showing good separation of chemical properties between zones. This provides confidence that the zoning was suitable.
• Variability in plant growth needs to be examined ‘holistically’ rather than just focussing on one variable. While a paddock may show variation in plant available water (PAW), it may be that sodicity or subsoil acidity is the key limiter in plant performance, not water availability per se.
• Existing precision agriculture (PA) datasets, in conjunction with selected chemistry sampling, can be used to indicate relative change in PAW across paddocks, but not the actual volume of water storage.
|Lead research organisation||
|Host research organisation||
|Trial funding source||GRDC RPI00009|
This work was carried out as part of the PA component of the GRDC investment into the Maintaining profitable farming
|Other trial partners||University of Adelaide, School of Agriculture, Food & Wine; Centre for eResearch and Digital Innovation; Federation University Australia; Australian Precision Ag Laboratory; Precision Agriculture|
|Sow date||Not specified|
|Harvest date||Not specified|
|Plot size||Not specified|
|Plot replication||Not specified|
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.