机译:Study on Contribution of Potassium, Nitrogen and Organic Fertilizer to Farmers' Super Rice Production Economy Based on Empirical Study of 690 Rice Farmers in Eight Counties in Liaoning, Zhejiang and Hunan Province钾氮及有机肥投入对稻农超级稻生产经济研究——基于辽宁、浙江、湖南3省8县市690户稻农的实证研究