不同施肥条件下红壤旱地磷素形态及有效性分析

磷素是红壤地区农业生产的最重要的限制因素，因此红壤磷素形态与转化问题的研究，对红壤地区农业生产具有重要意义。用Hedley方法对不同施肥条件下红壤旱地土壤磷素形态进行了研究，结果表明：施磷肥能明显增加红壤各形态无机磷含量和大多数形态有机磷含量；红壤中，对植物最有效的树脂磷和碳酸氢钠磷含量很少，铁铝结合态磷和残留磷含量很多；对有效磷（Bray磷）贡献最大的磷素形态是碳酸氢钠无机磷、铁铝结合态无机磷和存在于土壤团聚体内表面的有机磷。这对于了解不同施肥条件对红壤旱地磷素有效性的影响、探索磷素消长规律、指导红壤旱地磷素管理等都有一定的理论和实践意义。

EFFECT OF FERTILIZATION ON PHOSPHORUS FORMS AND ITS AVAILABILITY IN UPLAND RED SOIL

Phosphorus(P) is the limiting factor for agricultural production in red soil regions,so the study about P forms and transports can be meaningful to agricultural production in red soil regions.The forms and contents of phosphorus by upland red soils different in fertilization were studied with the P fractionation method proposed by Hedley.The results show: 1) All the inorganic P and most of the organic P are always lower in soil not fertilized with inorganic or organic phosphorus than in soil fertilized with phosphorus.2) Resin-P and NaHCO_(3)-P that can be utilized by plant easily are tiny,but P combined with ferric and(aluminium) and Residual-P are the greatest parts in upland red soil. So the P availability in red soil is low.3)NaHCO_(3)-P_(i),P_(i) combined with ferric and aluminium,P_(o) existed in soil aggregates are the most contributive forms to available P(Bray-P).In a word,these results guide us to research on P availability and transformation of phosphorus by upland red soils different in fertilization.And then,they can be theoretical and practical guidance for phosphorus managment in upland red soil.