旱地长期施肥对土地生产力和肥力的影响

本文总结了半干旱黑垆土区 1 990～ 1 999年长期定位施肥的试验结果 .有机肥在提高旱地生产力和土壤肥力方面起着主导作用 .在施入等量氮磷养分下 ,平均有机肥增产 4 6 6% ,有机肥 +化肥增产4 4 8% ,化肥增产 2 2 4 % .施肥后效和土壤肥力均随施肥量的增加而提高 .后效的增产率在 3年内的约占原施肥处理的 1 / 4～ 1 / 3.

Effect of long-term fertillization on land productivity and soil fertility in dryland

The experimental results of long term fixed fertilization from 1990 to 1999 in dark loessal soil in semiarid were summarized. The organic manure plays an important role for improving dryland productivity and soil fertility.Under the condition of fertilizing the equal N and P, the yield was increased by 46 6% by organic manure alone, 44 8% by the combination of organic manure and chemical fertilizer, 22 4% chemical fertilizer alone. In addition, soil fertility was improved along with the increment of fertilization. The aften effect of fertilization could contribute 1/4 to 1/3 of the yield increment ratio in the next 3 years.