The precision variability study of wheat yield in Xiaoqing River drainage area

This paper took the wheat field of alluvial soil in Xiaoqing River drainage area as the research site, aimed to the spatial pattern of wheat yield. With the help of DGPS, 104 observing points were made in a wheat field approximate 3hm² located in Xiaoqing River drainage area in Jinan of Shandong province in 2007. Geostatistics combined with geographical information system (GIS) was applied to reveal the spatial variability of wheat yield. Research results indicated the average wheat yield was 4739.1kg/ha, the high value was 6450.8kg/ha, the low value was 2016.3kg/ha. Model prediction were employed in this paper, the range, nugget and sill were calculated, Semivariogram model of wheat yield was established, the interpolation methods were decided, the optimal interpolation by ordinary Kriging was selected, and the spatial distributing map of wheat yield was drawn. It is shown that the semivariogram structure of wheat yield was spherical, the Nugget/sill of it was 0.623 and belonged to middle intensity, there is high wheat yield in the southeast and south of the field, the spatial correlation distance of wheat yield was 171.62m, a geostatistical analysis indicated that random factors(irrigation status, fertilizer utilization, environmental pollution, cultivation measures, management etc.) were the main factors of the spatial correlations of wheat yield, the ratio is 62.3% .