【摘要】 根据我们对我省不同土壤交换性钾和非交换性钾的测定以及棉花的钾肥试验,初步确定我省白土类型土壤,沿江沙土和沙壤土,徐淮地区沙土为缺钾土壤(交换性钾含量10—20斤/亩,非交换性钾65—200斤/亩),苏州地区黄泥土钾的供应也不充足(交换性钾18—24斤/亩,非交换性钾60—80斤/亩),里下河地区湖积物发育的土壤和滨海地区土壤钾的供应丰富(交换性钾40—70斤/亩)非交换性钾200—300斤/亩)。三年棉花钾肥试验指出,当土壤交换性钾含量低于25斤/亩时,施用钾肥有显著增产效果。土壤含钾水平愈低,钾肥增产效果愈显著。钾肥能减轻红叶茎枯病,防止早衰。钾肥能减轻苗期病害,保证壮苗全苗。钾肥能增加铃重,促使棉铃吐絮畅,棉花品质好。蕾期田间棉株钾素营养诊断,可作为棉花追施钾肥的参考。更多还原

【Abstract】 From the determination of exchangeable and non-exchangeable potassium ofthe different soils in Jiangsu Province and the experiments of potash fertilizationon cotton,it was preliminarily established that bleached whitish soils in ChenjiangDistrict,the sandy and sandy loom soils along the Yangtze River and the sandysoils in Xuzhow-Huaiying District are deficient in available potassium(exchange-able K 10—20 jin/mu,non-exchangeable K 65—200 jin/mu),the K supply ofthe permeable paddy soils in Suzhow Distriet is also low(exchangeable K 18—24jin/mu,non-exchangeable K 60—80 jin/mu),and the soils in The Lower RiverBasin and along the coast line are rich in K supply(exchangeable K 40—70 jin/mu,non-exchangeable K 200—300 jin/mu).The results from the cotton potash fertilizaton during 1973—75 had shownthat when the amounts of exchangeable K were less than 25 jin per mu,theapplication of potash fertilizer had a marked eliect in increasing cotton yield.Potash fertilization lessened the wilting disease and prevented the prematurity.Potash fertilization lessened the root diseases during the seedling stage toensure the stand in the field.Potash fertilization increased the boll wight,promoted boll opening and im-proved the fibre quality.The diagnostic technique of potassium on cotton during the square stage wasa very useful tool to decide whether the potash fertilizer should be side-dressed.更多还原