간척지에서 수도 및 기타작물의 내염성에 관한 연구 (제7보) 염분간척지에서 수도의 N 세포의 변동에 따르는 P와 K의 반응에 관하여

Study on the Salt Tolerance of Rice and Other Crops in Reclaimed Soil Areas (Ⅶ) On the Optimum Ratio of Phosphate and Potash to N Fertilization for Rice Plant in the Reclaimed Salty Areas

The rice variety, Nongkwang was used in two factorial experiments with the combination of 15 kg and 20 kg of N per 10 a, 3 levels of P2O5 (0, 4 and 8 kg per 10 a) and 4 levels of potash(0, 2, 4 and 8 kg per 10 a) in the reclaimed soil areas containing 0.48% on the average salt content throughout the year(0.67% at the end of April). The absorption of N, K and Ca was accelerated by increased N applications. The absorption of P itself was not enhanced by the increased application of P2O5 but the absorption of K2O reduced the absorption of Mg was affected. The increased application of K2O reduced the absorption of Si and seemed to increase the content of carbohydrate in the rice plants. Twenty kg of N and 4kg of P2O5 per 10 a produced satisfactory yields of rough rice, potash applications are ineffective in this experiment on rice grain production.