关键词: 冬小麦, WOFOST作物模型, 减产风险

Abstract: Spatial variations in soil fertility parameters of the soil (0-50 cm) of cropland in the North Canal basin of Beijing were analyzed using geo-statistics and geographical information system (GIS). Soil fertility parameters included pH, bulk density, organic matter, total nitrogen and available phosphorus. The results revealed a significant spatial variation in the five soil fertility parameters. Available soil phosphorus had the largest coefficient of variation (68%). The coefficient of variation ranged from 6% to 22% for soil pH, bulk density, organic matter, and total nitrogen. The semi-variograms of the five soil fertility parameters were best described by the Gaussian model. Soil pH and bulk density had a relatively strong spatial correlation, which was caused by structural factor. In contrast, soil organic matter, total nitrogen and available phosphorus had moderate spatial correlations, which were related to both structural and random factors. Using a Kriging method, spatial distribution maps of the soil fertility parameters were made and the areas of graded lands were counted. Meanwhile, the spatial variations of soil fertility parameters were analyzed. We argue that the analysis of spatial patterns of soil fertility parameters in the North Canal basin is essential for precision agriculture.

Key words: WOFOST crop model, winter wheat, yield reduction risk