The accuracy of farm machinery for precision agriculture: A case for fertilizer application

Abstract

Work quality, capacity and reliability are important criteria for design and evaluation of farm equipment. With the introduction of precision agriculture, the ability to adapt to spatially variable soil and crop conditions, becomes an additional aspect. A calculation method is developed to find the precision of site specific fertilizer application. The variance between the required rate, RR, and the applied rate. AR, is used as a measure for precision. The theory of geo-statistics is used for variance calculation. Spreading patterns are evaluated for different levels of field variability, positioning accuracy and resolution of the required application rates. The shape of spreading patterns had small influence. The effect of the accuracy of positioning systems depends on the resolution of the required application rates and of the working width of independently controlled sections of the spreaders. The study shows how machine design depends on the resolution of field information.