应用~(32)2P研究在石灰性土壤上提高过磷酸钙利用率的施用方法

<正> 过磷酸钙中的有效成分是水溶性的磷酸一钙Ca(H_2PO_4)_2·H_2O],易被作物吸收,但当过磷酸钙施入石灰性土壤后,水溶性的磷酸离子(H_2PO_4~-)扩散系数很小,而且在扩散过程中又与石灰性土壤中的 C_a~(+2)、M_g~(2+)离子结合,而转化成含水磷酸二钙、无水磷酸二钙和磷酸八钙等中间产物,最后经水解作用形成作物难以吸收利用的性质稳定的磷灰石,从而大大降低了过磷酸钙的肥效。许多试验研究指出,当季作物对磷肥的利用率不到10%,以后各季作物甚至更低。而磷肥的不同施用方法在很大程度上又影响着磷肥的利用率。本文通过应用含有~(32)P 的过磷酸钙以不同的施用深度和方法探讨作物对磷素的吸收利用能力及对作物生长的影响。

RESEARCH ON THE METHODS OF APPLICATION OF SUPERPHOSPHATE FOR INCREASEING THE UTILIZABLE EFFICIENCY BY MEANS OF 32P ON CALCIUM SOILS

This article deals with the influence of the depths aud methods of appli- catcion of superphosphate marked with ~(32)P on P absorption and growth of the spring wheat in calcareous soils with the pot cultural experiment.The re- sults obtained are summerized as follows: 1、In calcareous soils,the effect of concentrative applying with superphos- phate fertilizer is better than that of disperse applying.Under the condi- tion of the same amount of P fertilizer,the amount of dry matter either above or below ground of young Plants with concentrated application is more than that of it with disperse applying.Concentrative deep application is better than concentrative shallow application. 2.Concentrated application of manure may impove the P nutrition of the young plants,advance the development of root system and increase the effi- ciency of P utilization.