作物种植前后土壤有机质及养分因子的空间变异性分析

Abstract

The soil organic matter and nutrient factor space evolution for before and after planting crops was discussed, based on data of tested soil and household survey over the years. Results could provide the theoretical basis for reasonable input of crop nutrient and planting structure adjustment to divisional guidance in different regional.The spatial variability of soil factor before and harvest after crops was analyzed by using Moran' s I index analysis, Pearson correlation coefficient analysis,and Kriging interpolation diagram. Results suggested that three methods can interactly examine and complemente. Moran's I index was proved to the great different of nutrient factor of all kinds with the enlarged area coverage,. The correlation degree among all kinds was tested through Pearson correlation. The feature of space distribution in different area could be directly reacted by Kriging interpolation.. The characteristics of used nutrient was showed as following: 1) The soil organic matter and nitrogen was a very close relationship with water,and they had a high content in the water resource district. Results resulted from the accelerated the transformation of nitrogen by water. 2) The a period of time was needed to degradation of a plethora of nutrients in the soil after input nutrient,and this process was closely related with the regional natural environment condition. 3) The calculated result showed a significant correlation between the content of P and K Because of mainly using the compound fertilizer. The content of P and K of soil were higher after harvest crops than before planting crops,which was contributed to the used compound fertilizer with fixed ratio of P and K by farmers. In addition,another reasons is the slower degradation rate of P and K. For the same crop,nutrient inputs by farmers was differend in different regional,but it was correlations in quantitative in the area for different crop. Input nutrient in the same area was the relatively small differences between in conventional rice crop and in scale management grape. However,input nutrient was bigger different for other crops. Spatial analysis results was basically agreed with the peasant household survey results. Nitrogen input should be properly controlled in high mountain,suburban vegetable growing areas,and pot source river downstream zone due to high input nitrogen. The high content of soil P was also properly needed to control in Mountain surrounding. The content of input K is usually not high. Although the the K content in some areas is higher,it is mainly distributed in the high mountains areas,which may be related to the trees.