施钾对紫色土稻麦产量及土壤钾素状况的影响

EFFECTS OF LONG-TERM POTASSIUM APPLICATION ON YIELD AND SOIL POTASSIUM IN RICE-WHEAT CROPPING SYSTEM IN PURPLE SOIL

通过 9年定位试验 ,研究了水稻—小麦轮作中 ,连续施用钾肥对紫色土钾素形态、含量变化及钾肥产量效应的影响。结果表明 ,长期施钾明显提高稻麦产量 ,维持紫色土有效钾库的平衡 ,提高并保持土壤的持续供钾能力 ;在每年 75 0 0kghm- 2 稻秆还田的基础上 ,每季配施 70kghm- 2 (K2 O)左右的化学钾肥是维持紫色土土壤钾库平衡的有效措施。

Summary Effects of long term K application on crop yield and soil K content and forms in rice wheat rotation were studied. The results showed that long term K application markedly increased crop yield, the balance of the available K in purple soil was maintained and the ability of soil to supply K was raised. A joint application of rice straw (7 500 kg hm -2 a -1 ) and chemical K fertilizer (about K 2O 140 kg hm -2 a -1 ) is recommended to keep the balance of K in purple soil.