摘要
以湖北省武穴市和荆州市长期定位试验为对象,利用X射线衍射、选择性浸提以及室内模拟等方法,研究秸秆还田下水稻土中黏土矿物组合的差异及钾素的释放。结果表明,长期秸秆还田,土壤中伊利石和高岭石增加,蛭石和1.4 nm过渡矿物(HIV)减少;长期秸秆还田配施氮磷钾肥,土壤中高岭石、蛭石和HIV增加,伊利石和绿泥石减少。长期秸秆还田,土壤中全钾、非交换性钾和交换性钾含量均增加,且土壤各形态钾素与伊利石含量呈显著正相关,与高岭石和HIV含量则呈显著负相关。0.05 mol L^(-1)草酸浸提下,土壤钾素的释放量和释放速率较大,且随浸提次数的增加,钾素的释放速率逐渐降低并保持稳定。土壤钾素的释放量与土壤非交换性钾和全钾含量呈显著正相关,伊利石和HIV是影响供试土壤钾素释放的主要黏土矿物,且二者间存在相互转化的关系。长期秸秆还田可以增加土壤的供钾能力。
The compositions of clay minerals and release of potassium (K) in paddy soils under straw returning from long-term experiments in Wuxue and Jingzhou were investigated by the methods of X-ray diffraction, selective extraction and laboratory simulation and so on. The contents of illite and kaolinite increased while those of vermiculite and 1.4 nm transition minerals (HIV) decreased in the straw returning treatments. Straw returning with nitrogen (N), phosphorus (P) and K fertilizers increased significantly the contents of kaolinite, vermiculite and HIV, but decreased those of illite and chlorite. The contents of soil total K, non exchangeable K and exchangeable K increased in the long-term straw returning treatments. There were significant positive correlations between various forms of K and illite content in soils, and significant negative correlations between kaolinite and HIV contents. The release quantity and the release rate of K were maximum after K extracted with 0.05 mol L-1 oxalic acid, and the release rates of K were gradually reduced and then kept a stable value with the extraction times. The release quantities of K were positively correlated with the contents of non-exchangeable K and total K in soils. Illite and HIV were the main clay minerals that affected the release of K in soil and the reciprocal transformation between them. Straw returning can increase the K supplying capacity for soil.
作者
刘智杰
黄丽
李峰
李小坤
鲁剑巍
LIU Zhi-jie;HUANG Li;LI Feng;LI Xiao-kun;LU Jian-wei(Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China)
出处
《土壤通报》
CAS
北大核心
2018年第6期1390-1396,共7页
Chinese Journal of Soil Science
基金
国家自然科学基金(41271252)
公益性行业专项基金(201503123)资助.
关键词
秸秆还田
水稻土
黏土矿物
钾素释放
Strawreturning
Paddy soil
Clay mineral
Potassium release
