不同质地土壤钾肥分布规律研究

A Study on The Laws of Potassium Fertilizer Distributing in Different Texture Soils

研究表明，不同质地的土壤，施钾后钾的分布规律不一样，土壤保持钾的能力，在低施钾时〔＜６００ｍｇ／ｋｇ（以每公斤土含Ｋ２Ｏ量表示，下同）〕，容量因素（△Ｑ）是：△Ｑ壤＞△Ｑ粘＞△Ｑ砂，中量施钾时（６００～８００ｍｇ／ｋｇ），△Ｑ壤＝△Ｑ粘＞△Ｑ砂，在高施钾时（＞８００ｍｇ／ｋｇ），△Ｑ粘＞△Ｑ壤＞△Ｑ砂。钾缓冲因素变化规律与容量因素一致。施钾在土壤液相和固相的分布规律符合Ｙ＝Ｃ－ａｂｘ方程。建议一次施钾量的最佳点应是△Ｂ≈２．０，砂、壤、粘分别为１５０。

The potassium instantaneous potential buffer characteristics is vary in different texture soils.The capability of the soil keeping potassium,the capacity factor (△Q) is: △Q loam >△Q clay >△Q sand under lower level of K 2O application (<600 mg·kg -1 ),△Q loam =△Q clay >△Q sand under middle level of K 2O application (600～800 mg·kg -1 ), △Q clay >△Q loam >△Q sand under higher level of K 2O application (>800 mg·kg -1 ).The change laws of the buffer of the potassium are the same as the capacity factor.After applying K 2O,the law of potassium distributing in the liquid phase and solid phase of different texture soils accords with equation Y=C-ab x . It is suggested that the best amounts of potassium application once should be △B≈2.0, the sandy soil loamy soil and clayey soil should be 150,390 and 360 mg·kg -1 resp.