摘要
草甸土是辽宁地区的主要农业土壤,但是草甸土中含有大量的2∶1型黏土矿物,这些矿物具有固钾能力,受这些矿物的影响,草甸土具有较强的固钾能力,较大程度上限制了外源钾素的发挥。采用连续流动法研究了腐殖酸对浑河流域发育的草甸土钾素固定与释放的影响,结果表明,施用腐殖酸能够降低土壤对钾素的固定量。腐殖酸对土壤固钾率的影响与腐殖酸和钾的施入顺序有关,在外源钾(800 mg kg-1)存在时腐殖酸提前于钾素一天施入,与未加腐殖酸相比能引起溶液钾的显著增加,其中胡敏酸增加41.8%,富里酸增加56.3%;腐殖酸与钾素同时加入,也能引起溶液钾的增加,但增加幅度降低,其中胡敏酸增加7.3%。富里酸增加26.2%;腐殖酸后于钾素加入,引起的溶液钾变化较小,其中胡敏酸增加5.5%,富里酸增加9.8%。三种施入方式对交换钾变化影响不大。不同施入方式下土壤的固钾率表现为:未加腐殖酸>后加腐殖酸>同时加入>先加腐殖酸。
Meadow soil is one of the major agricultural soils in Liaoning Province. It contained a large amount of 2：1 clay minerals which have strong capacity for potassium （K） fixation. So meadow soil also has strong capacity to fix K, which lowered the utilization rate of K. The continuous flow method was used to investigate the effect of humus acids on fixation and release of K in this study. The results showed that the application of humus acids reduced the K fixation in meadow soil, and the K fixation rate was depended on the order of humus acids added into soil. When humus acids was added before K, the content of K in soil solution was increased markedly than no humus acids, and was increased about 41.8% and 56.3%, respectively, by the addition of humic acids and fulvic acids. The addition of humus acids and K at the same time also increased the content of K in soil solution, and humic acids increased about 7.3% and fulvic acids about 26.2%. And the addition of humus acids after K induced little change in the content of K in soil solution, and humic acids only increased about 5.5% and fulvic acids about 9.8%. Rate of K fixation was in the following order： no humic acids 〉 the addition of humic acids after K 〉 the addition of humic acids and K at the same time 〉 the addition of humic acids before K. The addition order of humic acid had no significant impact on exchangeable K.
出处
《土壤通报》
CAS
CSCD
北大核心
2016年第4期949-953,共5页
Chinese Journal of Soil Science
基金
国家重点研发计划(2016YFC0501205)资助
关键词
草甸土
钾素
固定
释放
Meadow soils
Potassium
Fixation
Release
