Modeling precision agriculture for better crop productivity and environmental quality.

摘要

Adoption of precision agriculture requires delineation of stable management zones so that site specific management practices can be applied to improve crop productivity and environmental quality. A quantitative approach was developed to delineate the zones by using the map overlay capability of a Geographic Information System (GIS) for the soil type, topography and crop yield data layers based on field data from 1996 through 1999. The study was conducted on a 22-ha tile drained maize (Zea Mays)-soyabean (Glycine max) rotation field, located in central Iowa, USA. The integration of data layers showed that low yield zones were consistent from year to year and were affected by the interaction of soil type and topographic attributes. Simulations with the calibrated and validated Root Zone Water Quality Model (RZWQM98) for this field showed that the maize yield response function reached a plateau when N-application rate exceeded 200 kg ha-1 in 1996 and 170 kg ha-1 in 1998. These results suggest that the RZWQM can be used to simulate the yield response function for each zone delineated on the basis of long-term yield data to move a step forward in the adoption of a precision agriculture system..