Canada: Canadian researchers have completed a project to determine whether variable-rate (VR) fertiliser application techniques can be adapted to manure application or not. Project leader Scott Dick concluded that technique can produce better nutrient utilisation by the crop, higher yields, lower costs and reduce environmental risk of excess nutrients contaminating water supplies. But still, there is need for some refinement in the application of the technology and producers are not yet ready to embrace this precision approach.
During the study, 13 producers provided about two sections of land, a sampling base which represented a cross-section of cropping conditions in the Canadian province. Manure was applied using the drag hose application method. Application rates were varied based on GPS field maps indicating different nutrient requirements for different parts of the fields. Satellite imagery identified zones using different light bands to create a vegetative index of better growing parts of the field. The zones were then individually soil tested to determine the reasons for the variability across zones and establish the optimal nutrient application rate.
Even though the study indicates variable rate manure application isn’t commercially feasible at the present time, information gathered outlines ways producers can use precision farming techniques to increase yields and reduce environmental risks.
For instance, producers can begin by applying a base rate of manure using conventional techniques, then follow up with a variable-rate application of commercial starter fertiliser at seeding time. That scenario allows them time to get accurate manure and soil analyses results back from the lab to provide an accurate match of nutrient applications with crop requirements.
Source: National Hog Farmer