摘要
供试土壤按粘土矿物组成分为4组.第1组(土壤7)和第2组(土壤1,2和6)以蛭石和伊利石矿物占优势,具有较高的阳离子代换量.该类土壤,尤其是第1组土壤,具有较高的缓冲钾位势变化的能力和有效钾库;但钾的有效性却较低.相反,以高岭石为主、阳离子代换量较低的第4组土壤(土壤3,8,9和10),其钾位缓冲力和有效钾库均较低;但钾的有效性却较高.而以伊利石为主、高岭石为次的第3组土壤(土壤4和5),其钾素状况则介于上述两者之间.
The status of soil potassium in some cultivated soils were evaluated by Q/I measurement.Soils used could be divided into four groups according to the clay mineralogy.The soils in first(soil 7)and second group(soil 1,2,6)with predorminant vermiculite and illite and higher CEC showed higher potassium buffering capacity(PBC^K) and quantities of labile potassium(ΔK°),but lower potassium availability(AR_e^K).Con- versely,those in forth group(soil 3,8,9,10),consisting of kaolinitic soils with lower CEC, showed lower PBC^K and ΔK°,but highcr AR_e^K,and the others(soil 4,5)with most abun- dant illite and subdorminant kaolinite showed mediate potassium status.
