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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。
The active ingredient in the superphosphate is water-soluble calcium phosphate [Ca (H 2 PO 4) 2 · H 2 O], which is easily absorbed by the crops. However, when the superphosphate is applied to the calcareous soil, the soluble phosphate ions (H 2 PO 4 - ) Diffusion coefficient is very small, and in the process of diffusion and calcareous soil C_a ~ (+2), M_g ~ (2+) ion binding, and into aqueous dicalcium phosphate, anhydrous dicalcium phosphate and phosphoric acid eight Calcium and other intermediate products, and finally by the hydrolysis of the formation of crops is difficult to absorb the use of stable properties of apatite, thus greatly reducing the fertilizer effect of superphosphate. Many pilot studies point out that seasonal crops use up less than 10% of the phosphate fertilizer and the subsequent seasons are even lower. The different methods of application of phosphate fertilizer to a large extent affect the utilization of phosphate fertilizer. In this paper, the effects of crop uptake and utilization of phosphorus and their effects on crop growth were investigated by using different application depths and methods with ~ (32) P superphosphate.