低盐基土壤K、Ca、Mg的交互作用对水稻生长与养分吸收的影响

本文研究了我国南方的低盐基土壤施用Ｋ、Ｃａ、Ｍｇ对水稻生长，养分迁移和养分吸收的影响，结果表明，在低盐基土壤ＮＰ基础上施Ｋ，随Ｋ用量增加到一定量，水稻生长受阻，生长量和产量下降的趋势。ＮＰＫ肥基础上施Ｍｇ生长量随之增加；ＮＰＫ肥基础上Ｃａ，Ｍｇ一起补给，产生协同作用，使水稻生长量明显增加。阳离子交换树脂模拟试验表明，Ｋ－Ｍｇ、Ｋ－Ｃａ和Ｍｇ－Ｃａ在养分向根迁移过程中即存在正的交互作用。盆载试验表明

EFFECT OF INTERACTIONS OF K, Ca AND Mg APPLIED TO SOILS WITH LOW BASE CONTENT ON GROWTH AND NUTRIENT UPTAKE BY RICE PLANT

Effects of potassium, calcium and magnesium fertilizers applied to soils on rice growth, nutrient migration and nutrient uptake by rice plants in soils with low base content in southern regions of China were investigated. Results showed that on the basis of NP fertilizers with the increase of K, the rice growth was retarded and its biomass decreased, Applying Mg on the basis of NPK fertilizers increased the rice biomass. Applying Ca, Mg on the basis of NPK fertilizers resulted in the synergistic effect to make the biomass remarkable increase. It is suggested that the triangular interactions of K-Ca-Mg are positive interactions. Simulation experiments using ion-exchange resin showed the positive interactions between K-Mg, K-Ca and Mg-Ca in the process of nutrient migration to roots. Pot culture experiment showed an antagonistic effect between K-Mg and Mg-Ca in the process of nutrient uptake by rice plant. However, combinative use of K-Ca-Mg increased the total uptake of nutrient, showing a synergistic effect It is mainly due to the promotion of rice root growth. In addition, the possibility of decreasing the requirement of K by the triangular interaction of K-Ca-Mg was also discussed.