不同稻田土壤钾素丰缺水平下施用钾肥的效应及对土壤肥力的影响

Effects of Applying Potassium Fertilizer to Paddy Soil with Different Levels of Potassium and Impact of Applying Potassium Fertilizer on Soil Fertility

采用田间小区试验，选择三个土壤钾素丰缺不一致的稻田，研究施用钾肥对水稻产量和土壤养分含量的影响。结果表明：在三个土壤钾素丰缺不同的稻田中，施用钾肥都可以提高水稻产量，各施钾处理比不施钾增产4．08％～25．88％。在速效钾中低含量和高含量水平下，钾肥（K2O）的经济施用量为80kg／hm2和45kg／hm2；而速效钾低含量水平下，早稻的经济施钾量是100kg／hm2，晚稻是60kg／hm2。不同钾肥施用量对收获后稻田土壤的有机质、氮素、磷素和钾素含量的影响不显著。

Three paddyfields with different levels of potassium were chosen to study the effects of applying potassium fertilizer on rice yield and soil nutrient content through field plot experiment. The results indicated that with different contents of available K, the application of potassium fertilizer with each fertilizer rate all can increase rice yield, and the rice yield in each treatment all increased by 4.08%-25.88% than that in control （no potassium fertilizer applied）. With middle-low and high content of available K, the best economical potassium （K20） fertilizer rate was 80 kg/hm2 and 45 kg/ hm2, respectively; however, with low content of available K, the best economical potassium （K20） fertilizer rate was 100 kg/hm2 in early rice and 60 kg/hm2 in late rice. The contents of organic matter, nitrogen, phosphorus and potassium in paddy soil after harvest were not significantly affected by different potassium fertilizer rates.