Evaluation of PRS® probe technology and model for variable rate fertilizer application in hummocky fields in Saskatchewan
Greer, J., E. Bremer and J. Burns. 2012. IPCA
Abstract
Increasing net returns from variable-rate fertilizer application requires efficient
use of reliable knowledge about fertilizer response variation within a field. Based
on PRS® probe technology developed at the University of Saskatchewan,
Western Ag Lab provides growers with a simulation modeling tool, the PRS® Nutrient Forecaster, that allow growers to assess the cost-benefit of a particular
fertilizer and/or cropping decision on a field-by-field basis. The potential to
increase net returns by varying fertilizer application within a field was evaluated
in two fields in Saskatchewan in 2004. Fertilizer prescriptions were developed at
a grid spacing of 12 m using PRS® measurements and estimated moisture at
selected topographic positions within a field. An algorithm was developed to
deliver four nutrients with two machine-compatible blends: nutrients were applied
within 5% of the optimum rate. Evaluation based on backcast yield estimates
indicated that this approach increased net returns by $25 to $125 per hectare.
Key Words
simulation model, optimization, logistic
