冬种绿肥和稻草全量还田对单季稻田土壤理化性质的影响

摘要

采用田间定位试验,研究了冬闲期种植绿肥和稻草全量还田对江汉平原单季稻田土壤理化性质和水稻产量的影响.试验设置稻草不还田水稻不施肥(CK)、稻草不还田单施化肥(NPK)、稻草原位焚烧还田+化肥(RSB+ NPK)、稻草全量还田+化肥(RSM+ NPK)、稻草不还田单独种植绿肥+化肥(GM+ NPK)以及稻草全量还田+种植绿肥+化肥(RSM+ GM+ NPK),共6个处理.结果表明,与不还田的CK及NPK处理相比,RSM+ NPK、GM+ NPK和RSM+ GM+ NPK处理模式均有利于改善土壤物理性状和提高耕层土壤养分及有机质含量,其中多以RSM+ GM+ NPK处理增幅最大.RSB+ NPK处理较CK处理显著提高土壤pH值、土壤有效磷和速效钾含量,但对土壤有机质、全氮和碱解氮含量影响不大.GM+ NPK处理与RSM+ GM+ NPK处理稻谷产量近似,分别较NPK处理显著增加6.9％～11.7％和6.0％ ～ 13.4％,3年平均增加9.1％和8.7％,而RSM+ NPK和RSB+ NPK处理的稻谷产量3年里与NPK处理无显著差异.综合考虑,在江汉平原单季稻作条件下,以冬闲期稻草条带覆盖还田与种植绿肥配合还田为宜,可以改善土壤理化性质,显著提高水稻产量.%A three-year field experiment was conducted to examine the effects of green manure planting during the winter fallow season and rice straw retention on soil physical and chemical properties and rice yield from a mono-rice cropping system of Jianghan Plain,central China.The experiments comprised of six treatments,viz.,no rice straw return with only chemical fertilizers (NPK),rice straw burning in situ and chemical fertilizer (RSB + NPK),rice straw mulching and chemical fertilizer (RSM + NPK),green manure planting without rice straw return and with chemical fertilizer (GM + NPK),rice straw strip mulching with green manure planting and chemical fertilizer (RSM + GM + NPK) and a control (CK) with no straw return and chemical fertilizer application.Results revealed that RSM + NPK,GM + NPK and RSM + GM + NPK treatments improved the soil physical properties,and increased soil organic matter,total nitrogen,available nitrogen,available phosphorous and available potassium compared with CK and NPK.The RSB + NPK treatment significantly increased the soil pH and triggered the available phosphorous and available potassium,but had no effect on soil organic matter,soil total nitrogen,available nitrogen.The minimum bulk density,maximum total porosity,soil organic matter,soil total nitrogen,and available potassium were observed in RSM + GM + NPK treatment.The RSM + GM + NPK and GM + NPK were statistically similar with each other for grain yield,but these two treatments recorded significantly higher grain yield than NPK treatment during the 3-year experiment.Conpared with NPK,the mean of 3 year rice grain yield in RSM + GM + NPK and GM + NPK were significant increased by 9.1％ and 8.7％,respectively.The RSM + NPK and RSB + NPK were statistically at par with NPK for grain yield.In conclusion,the RSM + GM + NPK treatment can be an effective way to improve the physico-chemical properties of soil,ultimately enhancing the soil fertility and rice yield.