中文摘要：

【目的】研究稻田不同土壤供钾能力条件下，秸秆还田配施钾肥对水稻产量、地上部钾素累积量以及钾肥利用率的影响，为秸秆还田水稻钾肥合理施用提供科学依据。【方法】2011—2012年在鄂中、江汉平原和鄂东地区的10个县（市）选择不同供钾水平田块布置水稻试验。根据湖北省第二次土壤普查制定的速效钾分级标准，本文将土壤速效钾含量〉150mg·kg。的试验点如钟祥和宜城归为高钾供应能力土壤（1级水平），简称为高钾土壤，标记为High—K；土壤速效钾含量100-150mg·kg-1的试验点如团风、仙桃、洪湖和枝江归为中钾供应能力土壤（2级水平），简称为中钾土壤，标记为Middle-K；土壤速效钾含量〈100mg-kg。的试验点如麻城、广水、鄂州和蕲春归为低钾土壤，标记为Low-K。试验共设6个处理，分别为：（1）CK（-K）；（2）＋K；（3）＋s；（4）S＋l／3K；（5）S12／3K；（6）S＋K，其中K和s分别表示钾肥和还田秸秆，以此来考查当前推荐钾肥用量（K2075kg·hm-1）对水稻的增产效果以及轮作模式下麦秆或油菜秸秆还田钾素对钾肥的替代作用。【结果】结果显示cK处理（-K），高钾、中钾和低钾土壤的稻谷产量分别为8372、8710和7767kg．hm-1，施钾和秸秆还田均可以不同程度地增加水稻产量和地上部钾素累积量。与cK相比，高钾、中钾和低钾土壤均以秸秆还田配施钾肥处理的增产效果最显著，增产量分别为633、1098和814kg·hm-1，增幅分别为7．7％、12．6％和12．5％；地上部钾素累积吸收增量分别为40．2、56．5和49．3kg-hm～，增幅分别为t5．9％、21．3％和36．8％。在当前推荐钾肥用量条件下，秸秆还田会造成高钾土壤的钾肥吸收利用率下降，但可明显提高中钾和低钾土壤的钾肥吸收利用率；同时秸秆还田也会显著降低高钾土壤的钾肥农学利用率，但对中钾?

英文摘要：

Abstract： [ Objective ] In order to provide a scientific basis for crop residue management and K fertilization, the effect of straw incorporation plus K-fertilizer on yield of rice, potassium （K20） accumulation amount of shoots and potassium efficiency under different paddy soil potassium levels was studied. [Method] A series of field trials were carried out to study the effect of recommended rate of potassium （K20 75 kg＇hm2） on rice production and whether straw potassium could replace chemical potassium under wheat-rice/rape-rice cropping systems in selected 10 counties in Ezhong, Jianghan plain and Edong regions during 2011-2012. According to the second national soil census in Hubei province, trial sites （available K content 〉150 mg.kgl）, Zhongxiang （ZX） and Yicheng （YC） were classified as high potassium supply capacity soils, marked as high-K; the test points （available K content 100-150 mg.kgl）, Tuanfeng （TF）, Xiantao （XT）, Honghu （HH） and Zhijiang （Z J） were classified as middle potassium supply capacity soils, labeled as Middle-K; the test points （available K content 〈100 mg.kgl）, Macheng （MC）, Guangshui （GS）, Ezhou （EZ） and Qichun （QC） were normalized to low potassium supply capacity soil, labeled as Low-K. The field experiment was carried out in a randomized block design, including six treatments with three replications. The designed treatments were CK （-K）, ＋K, ＋S, S＋I/3K, S＋2/3K, and S＋K, where K and S denoted K fertilizer and straw, respectively. [Result] The results showed that the yield of CK treatment for high-K, middle-K and low-K soil were 8372, 8710 and 7767 kg.hm2, respectively. However, the K-fertilizer and straw returning to field could increase yield of rice and K accumulation amount of shoots at varying degrees. The straw incorporation with K-fertilizer treatment got the best effect compared with CK treatment. The increased yields were 633, 1098 and 814 kg.hm-2, respectively and the yield increase rates were 7.