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

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

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，生长量和产量有下降的趋势。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，在水稻养分吸收过程中K－Mg和Mg－Ca通常表现为颉颃作用，但K－Ca－Mg的结合施用，增加养分的总吸收量，显示协同作用。这可能是由于K－Ca－Mg的结合促进了稻根生长和养分吸收之故。另外，本文还探讨了利用K－Ca－Mg的三角交互作用减少K的需求量的可能性。

Effects of potassitim, 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 inveshgated.Results showed that on the basis of NP fertilizers with the increase of K, the rice growth was reeded and its biomass decreased, Applying Mg on the basis of NPK fenilizers increased the rice biomass. Applying Ca Mg on the basis of NPK fertilizers resulted in the synergishc 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 interactuions betWeen K-Mg, K-Ca and Mg-Ca in the process of nutrient Angration to roots. Pot culture experiment showed an antagonistic effect between K-Mg and Mg-Ca in the process of nutrient uptake by rice plane 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.