氮磷钾肥配施对轻镉污染红壤中小白菜生长及镉累积的影响

采用网室盆栽试验方法,研究了氮磷钾(NPK)肥配施对轻镉污染红壤中小白菜生长及镉(Cd)累积的影响.结果表明:与对照比,除第四纪红土红壤中Cd 1.0 mg/kg、N 0.1 g/kg、P0.1 g/kg处理外,其他处理中小白菜体内含Cd量均有降低;缓解镉毒害方面,高P处理优于低P处理;高P和中低量NK肥配施在保证小白菜体内Cd含量最低的同时又能保证其最适的产量,其产量超过实际最高产量的89％.花岗岩红壤和第四纪红土红壤在含Cd 0.5 mg/kg时,NPK肥最佳配比均为N 0.1 g/kg、P 0.3 g/kg、K0.15 g/kg;含Cd 1.0 mg/kg时,花岗岩红壤最佳NPK最佳配比为N0.15 g/kg、P 0.3 g/kg、K 0.15g/kg.

Effects of Combined Application of NPK on Growth of Chinese Cabbage and Cd Accumulation in It Planted in Mild Cd Polluted Red Soil

The effects of combined application of NPK on growth of Chinese cabbage and Cd accumulation in it planted in mild Cd polluted red soil were studied by using net house pot experiment.The results indicated that in comparison with the control,the Cd content in Chinese cabbage all decreased in the treatments except for treatments of Cd 1.0 mg/kg,N 0.1 mg/kg and P 0.1 mg/kg in quaternary red soil;for the effect of reducing the pollution of Cd,the treatments with high P content was better than the treatments with low P content;high rate of P combined with mid-low rate of N and K can ensure the lowest Cd content in Chinese cabbage and the optimum yield of Chinese cabbage,and the optimum yield will exceed the actual highest yield by 89%.The optimum ratio for combined application of NPK was 0.1 g/kg of N,0.3 g/kg of P and 0.15 g/kg of K when Cd content in granite red soil and quaternary red soil all was 0.5 mg/kg;the optimum ratio for combined application of NPK was 0.15 g/kg of N,0.3 g/kg of P and 0.15 g/kg of K when Cd content in granite red soil was 1.0 mg/kg.