在玉米大豆耕作制度下两种湿润热带老成土中的钾Ⅰ．管理Ｆ．Ｒ．Ｃｏｘ，Ｅ．Ｕｒｉｄｅ作物对钾肥的效应通常是与交换性Ｋ相关的（Ｇｒｅｅｌａｎｄ，１９８５）。在巴西的热带高原草原，当土壤里的交换性钾含量低于０．１５ｃｍｏｌ／ｋｇ时，钾肥效应才出现。在巴西的... Potassium in two humid tropical soils under maize soybean farming system Ⅰ. Management R. Cox, E. The effect of Uride crops on potash fertilizer is usually related to exchangeable K (Greeland, 1985). In the tropical prairies of Brazil, the potash effect occurs when the exchangeable potassium content in the soil is below 0.15 cmol / kg. In Brazil ...