在江苏淮北地区土地平整后形成的生土上,对水稻小麦水稻、水稻油菜水稻、水稻绿肥水稻3种种植模式不同施肥条件下的氮、磷、钾产投比及与土壤肥力关系进行试验分析.结果表明:随着种植季数的增加,氮、磷的产投比有很大的提高.3季种植后,有机质投入量与土壤有机质净增量,总投氮与土壤全氮、碱解氮,总投磷量与土壤速效磷,总投钾量与速效钾均呈显著正相关,肥料投入对生土土壤肥力演变起决定性作用. In the native soil formed after land leveling in Huaibei area of ​​Jiangsu Province, the experiment was conducted to test the relationship between N, P, K ratio and soil fertility under different fertilization conditions under the three cropping patterns of rice wheat, rice Rape rice and rice green manure rice The results showed that the ratio of input and output of nitrogen and phosphorus increased greatly with the increase of planting seasons.After planting in the third season, the input of organic matter and the net increment of soil organic matter, total nitrogen and soil total nitrogen, There was a significant positive correlation between nitrogen and total phosphorus content and soil available phosphorus, total potassium input and available potassium, and fertilizer inputs played a decisive role in the evolution of soil fertility.