Effects of spatial variability of nitrogen supply on environmentally acceptable nitrogen fertilizer application rates to arable crops

Abstract

Current N recommendation schemes are based on the Maximum Economic Yield (MEY), as obtained at "economic optimum' fertilizer application rates. Environmental standards for the amount of mineral N left in the soil at harvest time will soon restrict fertilizer rates to obtain an Environmentally Acceptable Production (EAP). For MEY, but especially for EAP, spatial variability of N supply in a field which is managed as if it were a homogeneous unit should be taken into account. Degree of spatial variability in N supply should be explicitly taken into account in future discussions of the conflict between environmental and production targets. -from Authors