晋西黄土区果农间作土壤养分空间分布

为了研究黄土区农林复合系统土壤养分的空间分布及效应，对山西吉县残塬面核桃×花生、核桃×大豆和核桃×玉米3种典型果农间作类型下0～100 cm土层中土壤有机质、全氮、速效磷和速效钾进行了测定和分析。结果表明：1）3种间作类型土壤养分的空间分布特征具有一定的相似性。在垂直方向上，土壤养分含量随土层深度的增加而减少，并且距果树越远，土壤养分的垂直递减梯度越小；在水平方向上，离果树越近，土壤养分越少。2）效应分析结果表明，间作系统中果树与作物存在竞争，间作系统中作物土壤养分的综合效应优劣说明间作作物以花生为最佳、大豆其次、玉米最差。根据研究结果提出了研究区果农间作系统减少土壤养分竞争的相关建议：加强水肥管理、增加果树和作物的间作距离、设置根障。

Spatial distribution of soil nutrient in fruit-crop intercropping in Loess Plateau of west Shanxi Province

The objective of this study was to investigate the spatial distribution of soil nutrient and inter-effects under different types of fruit-crop intercropping system in the Loess Plateau of west Shanxi Province. Organic matter, total nitrogen, available phosphorus (p) and available potassium (k) in 0-100 cm soil profile were measured and analyzed under three typical fruit-crop intercropping types, i.e., walnut-peanut, walnut-soybean and walnut-maize. The results of this paper showed as follows: Spatial distribution characteristics of soil nutrient in walnut-crop intercropping types showed certain similarity. In vertical direction, soil nutrient was decreasing with the increase of soil depth, and decrease gradient of soil nutrient in vertical direction was decreasing with the increase of the distance from the walnut tree. In horizontal direction, soil nutrient was decreasing with the decrease of the distance from the walnut tree.There were competition for soil nutrient between walnut and crop in walnut-crop intercropping system.?The competition was the weakest in the peanut and walnut type, and the strongest in the maize and walnut type. In order to decrease soil nutrient competition between walnut and crop in walnut-crop intercropping system, the following measures should be taken. Enhancing the management of irrigation and fertilization for intercropping system. Increasing the distance of crops from the tree row, and setting root barrier between crops and walnut.