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北京近郊池栽小区试验发现 ,北京近郊小麦 玉米轮作体系土壤有效硫含量具有明显的季节变化 ,其中表层 (0～ 2 0cm )土壤的变化幅度最大 ,2 0～ 4 0cm土层次之 ,4 0～ 6 0cm土层最小 ,主要与大气、降水、灌水、植物吸收、淋溶等因素有关。小麦生育期内土壤剖面中有效硫含量呈从上层向下递减的趋势 ;玉米生育期表层土壤有效硫呈下降趋势 ,收获时成为三层中最低的一层 ,说明土壤有效硫在剖面中有明显的淋洗现象。北京远郊的小麦 玉米轮作体系中土壤表层有效硫变化趋势与近郊的相似 ,但变化幅度比近郊土壤小
The experiment of suburban pond planting area in Beijing found that the soil available sulfur content of wheat and wheat rotation system in the suburbs of Beijing had a significant seasonal variation, of which the surface soil (0 ~ 20 cm) had the largest change range, the soil layer varied from 20 cm to 40 cm, 6 0cm soil layer is the smallest, mainly with the atmosphere, precipitation, irrigation, plant absorption, leaching and other factors. The effective sulfur content of soil profiles decreased from the upper layer in wheat growth stage. The available sulfur in surface soils decreased during maize growth and became the lowest layer in the three layers during harvest, indicating that the soil available sulfur was obviously in the profile Leaching phenomenon. The trend of available sulfur in surface soil of wheat-wheat rotation system in the outer suburbs of Beijing was similar to that of the suburbs, but the change range was smaller than that of the outer suburbs