潮土肥力演变与施肥作用的长期定位试验初报

１９８９－１９９４年在河南封丘潮土上，对几种主要肥料的效益。以及不同施肥条件对土壤养分供应能力的影响进行了长期定位试验，试验结果表明；潮土的生产潜力很大，贫瘠的潮土单施Ｎ肥或Ｐ肥收效甚微，只要Ｎ，Ｐ肥配合施用，其交互增产作用极显著，如一旦停止施肥，产量又将急剧下降到很低水平，在富Ｋ的潮土上，连续五年不施Ｋ肥和有机肥，对小麦产量尚不构成影响，然而耕层土壤中的速效Ｋ以每年３．８ｍｇ／ｋｇ的速度下降，已

A PRELIMINARY REPORT ON LONG-TERM STATIONARY EXPERIMENT ON FERTILITY EVOLUTION OF FLUVO-AQUIC SOIL AND THE EFFECT OF FERTILIZATION

A long-term stationary experiment was designed to determine crop responses to several major fertilizers in fluvo-aquic soils and the effect of fertilization models on soil nutrient supply. Results showed that fluvo-aquic soil had a great production potential. But on infertile fluvo-aquic soil, crop response to single N or P fertilizer was very limited. When they were applied in combination, the effect of their interaction on crop yield became significant. Once fertilization stopped, crop yield dropped down drastically to a very low level. On K-rich fluvo-aquic soil, the practice of no application of K and organic manure for 5 years did not cause any threat to crop yield. However, the readily available K in the plowed layer decreased at a rate of 3.8 mg/kg per annum, approaching the critical level. The long-term experiment also showed that the cumulative recovery rates of N and P fertilizers in the 5 years, 57.2% and 43.8% repectively, were much higher than the results in a single cropping experiment. With the current fertilization models and crop yield level, little surpluses of N and P nutrients and organic metter exited in most fluvo-aquic soils, whereas K deficit occurred in almost all the fluvo-aquic soils.