摘要： 用室内模拟和生物耗竭的方法研究了土壤中钾素的变化,试验结果表明,淹水可以减少土壤对外源钾素的固定,淹水比20%田间含水量钾素的固定减少2～29mg/kg。当土壤经过干湿以后,土壤会发生明显的固定钾作用,土壤含钾量越高,固定钾能力越强。棉花吸收的钾素中有80%来自于土壤非交换性钾,盆栽生物耗竭与连续种植10年棉花的田间土壤,具有相同的结果,土壤交换性钾在下降到一定程度后不再下降,而1mol/LHNO₃不能提取的钾(层间钾)一直在下降。

关键词: 耗竭土壤, 固钾, 棉花

Abstract: The change of soil potas sium was s tudied by indoor simulation and bio-depletion methods. The study showed that humid soil may reduce soi-l fixed potassium from potassium fertilizer. Inundated soil reduced the fixed potas sium by 2-29 mg/ kg than that of soil containing 20% water.The soil potassium fixation was increased after dry and humid alternation. Soil with higher potassium content had a higher fixation ability. Eighty percent of the potassium taken up by cotton was from non-exchangeable potas sium of the soil. Both the pot and the field experiment showed a same result that the c ontent of soi l non-exchangeable potassium will no longer decrease when it reached a certain level, while non-extractable potassium with 1 mol / L HNO₃will continue to decline.

Key words: Depletion soil, Fixed potassium, Cotton

中图分类号: 

• S158.3