油菜秸秆还田对水稻增产及供钾的效果

Effects of Rapeseed Straw Returning on Increment of Yield and Supplying Capacity of Potassium in Rice

在湖北省应城、孝昌、汉川、荆门布置油菜秸秆还田对后季水稻产量及钾素吸收量影响试验,分析油菜秸秆还田对水稻的增产和供钾效应的影响。结果表明,应城、孝昌和荆门三个试验点施钾效果明显,在此条件下秸秆还田(NP+S)比不还田(NP)处理稻谷产量与稻草生物量平均分别增加725和669 kg/hm2,增幅分别为10.21%和8.36%。四个试验点施钾和秸秆还田均可提高水稻地上部钾素吸收量,与NP处理相比,NP+S、NPK(施钾)和NPK+S(施钾配合秸秆还田)处理地上部钾素吸收量分别增加了20.2、48.3和58.3 kg K2O/hm2;进一步分析表明,水稻钾素吸收量增加的主要原因是生物量的增加,而各处理的钾含量差异不显著。种植水稻后各处理的土壤速效钾含量均呈不同程度的下降趋势,但油菜秸秆还田的两个处理(NP+S和NPK+S处理)的下降幅度明显低于相应的不还田处理(NP和NPK处理)。油菜秸秆还田具有提高后季水稻产量和稻草生物量、增加钾素的供应和缓解土壤钾素亏缺的作用。

The effects of rapeseed straw returning on yield and potassium uptaking of rice were studied in the four counties including Yingcheng Xiaochang,Hanchuan,and Jingmen of Hubei province.Potassium fertilization had significant effects in Yingcheng,Xiaochang and Jingmen site.The yield and straw biomass of rice averagely increased 725 and 669 kg/hm^2 in the straw returning with treatment （NP＋S） compared with no potassium fertilization （NP） with the increase rate of 10.21% and 8.36%.The K uptaking was improved by applying potassium fertilization or straw returning over all sites.Compared with NP treatment,the K uptake increased 20.2,48.3 and 58.3 kg K2O/hm^2,in the NP＋S,NPK and NPK＋S treatments.The increase of rice potassium uptaking was due to the increase of biomass.The differences of K content were not significant among the treatments.Soil available K content declined in all treatments among the sites after planting rice.The decline was significantly lower in the treatment of straw returning compared with treatments without straw returning.It is indicated that rapeseed straw returning can improve the yield of rice grain and straw,enhance the K supplying and relieve the deficiency of soil potassium.