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长期的定位采样试验研究了近 2 0年锡山市甘露乡土壤表层 ( 0～ 2 0cm)中有机质、全氮、速效氮、速效磷、速效钾等土壤养分的时空变化趋势 ,并分析了土壤养分波动与国家政策、耕作方式、农业投入和单位面积农业纯收益之间的相互关系。结果表明 :2 0年间土壤养分质量总体上呈现先减后增的变化趋势。有机质呈现先减后增的变化趋势 ,且与耕作措施的改变有密切关系。全氮和速效氮呈持续上升趋势 ,上升幅度大于 1 0 0 % ,与氮肥使用量不断上升密切相关。速效磷、速效钾呈持续下降趋势 ,与磷肥、钾肥使用过少有关。国家政策和耕作方式、种植制度对SNQI影响十分明显 ,标准农业投入与土壤养分质量指数呈正相关关系 ,单位面积标准农业纯收益与土壤养分质量指数呈负相关关系
Long-term positioning and sampling experiments were conducted to investigate the temporal and spatial variations of soil nutrients in the soil surface (0 ~ 20 cm) in Xialhan City in the recent 20 years. The soil nutrients including soil nutrients, total nitrogen, available nitrogen, available phosphorus and available potassium were also analyzed. The relationship between fluctuations and national policies, farming methods, agricultural inputs and net agricultural yields per unit area. The results showed that in the 20 years, the soil nutrient quality showed the trend of decreasing first and then increasing. Organic matter showed the trend of decreasing first and then increasing, which was closely related to the change of tillage measures. Total nitrogen and available nitrogen showed a continuous upward trend, with an increase of more than 100%, which was closely related to the increasing use of nitrogenous fertilizer. Available phosphorus, available potassium showed a downward trend, and phosphate fertilizer, potassium fertilizer used too little. National policy and farming methods, planting system has an obvious effect on SNQI. There is a positive correlation between standard agricultural input and soil nutrient quality index. Net agricultural yield per unit area has a negative correlation with soil nutrient quality index