长期培肥定位试验耗竭阶段各培肥物质对土壤氮库持续效应的研究

试验采用旋转回归设计方法，从１９８６～１９９４年在代表松嫩平原黑土区的东北农业大学试验地内，进行了以农肥、化肥、秸秆、绿肥等培肥物质为试验因素的长期定位试验。试验分两个阶段进行，前一阶段为培肥阶段，到１９９２年结束，后一阶段为耗竭阶段，主要观测各培肥处理对土壤养分的持续效应及产量的影响。建立了耗竭阶段农肥、化肥、秸秆对土壤有机质、全氮、全磷及产量的数学模型。试验表明，随着耗竭试验继续，各处理土壤全氮含量继续下降，在农肥、秸秆、化肥三因素中，以农肥土壤全氮的贡献最大，秸秆次之，化肥最差，土壤碱解氮的变化表明，农肥处理对增加碱解氮作用最大，秸杆次之，化肥最差，在耕作措施处理中，玉米连作和休闲处理增加土壤碱解氮含量不明显。证明利用休闲方式恢复土壤氮库容量是消极的，而绿肥处理后，土壤碱解氮含量有明显地上升趋势。

THE SUSTAINABLE EFFECT OF FERTILIZING MATERS ON SOIL NITROGEN CONTENT DURING FERTILITY EXHAUSTING STAGE OF LONG-TERM LOCATION TESE

Long-term location test of soil fertilizing by farmyard manure, chemical fertilizers, straw and green manure was conducted by rotation regression design in 1986 to 1992 on the filed of Northeast Agricultural University, where is the typical black soil region of Songnen plain The test was divided into two stage The first stage was soil fertilizing, and finished in 1992 The second was fertility exhaustiong stage, and sustainable effect and crop yield affected by different soil fertilizing were observed Mathematical model on crop yield, soil organic matter content, total nitrogen and phosphorus content affected by farmyard manure, chemical fertilizer and straw was established during fertility exhausting stage As the fertility exhausting test continued, the content of nitrogen in soil was decreased in all soil fertilizing treatments According to the test, farmyard manure was the best for increasing the content of total nitrogen and alkaline hydrolytic nitrogen, next was straw and the last was fertilizer In the farming method, succession cropping of corn and fallow field were not distinctness for increasing nitrogen content of soil, which indicated that fallow field was inactive for nitrogen increasing in soil But the nitrogen content of soil was increased remarkably after green manure cropping