【摘要】 测定黄绵土、黑垆土及(土娄)土钾素含量及土壤供钾状况Q/I曲线的结果表明,黄绵土的全钾、缓效钾及速效钾含量最低;土壤供钾强度AR °,黑垆土>(土娄)土>黄绵土;供钾容量△k°,黑垆土与(土娄)土相近,但均明显高于黄绵土;供钾的缓冲能力PBC(土娄)土最大,黑垆土与黄绵土相近。连续8年施用氮磷化肥后,蝼土缓效钾较8年前下降7.3%～10.2%,速效钾下降11.8%～17.1%;AR°下降34%～61%,△k°下降近1倍;施用足量有机肥可以维持并提高土壤钾素含量和供钾水平。更多还原

【Abstract】 This research had measured the contents and quantity-intensity (Q/I)relationships of potassium in loessial soil, orthoheilu soil and lou soil, which were the main agiculturl soils on the loess plateau. The results showed that the contents of potassium in loessial soil was lowest among the three soils. The levels of AR°of potassium was orthoheilu soil > lou soil> loessial soil, the contents of △k in ortholeilu soil was similar with that in lou soil, and the PBC~k of lou soil was biggest among the soils, the PBC~k of orthoheilu soil was similar with loessial soil; Although the levels of potassium in lou soil was high, there were significant decreases of nonexchangeable K and exchangeable K in soil after the application of N and P fertilizers for 8 years, arid the percent of decrease of nonexchangeable K and exchangeable K was 7.3%～10.2%, 11.8%～17.1%, respectively; the levels of AR°decreased 34%～61%, and the decrease of △k was almost 50%. Also, the application of manure increased the levels of potassium in lou soil significantly.更多还原