中国农业科学2017，Vol.50Issue(19)：3745-3756,12.DOI:10.3864/j.issn.0578-1752.2017.19.011
秸秆还田条件下不同供钾能力土壤水稻、油菜、小麦钾肥减量研究
Study of Optimum Potassium Reducing Rate of Rice, Wheat and Oilseed Rape Under Different Soil K Supply Levels with Straw Incorporation
摘要
Abstract
[Objective] The experiments were conducted to study the effect of reducing potassium (K) fertilizer rates with straw incorporation on crop yield of cereal and oil, K uptake and K efficiency under different soil K supply capacities of Hubei, in order to provide a scientific basis for K fertilization and soil K management under straw returning.[Method] Field trials in 38 counties (cities) were carried out to study the effect of the substitution of straw incorporation for K fertilizer on rice, winter oilseed rape and wheat. Six treatments were designed: (1) no K fertilization (CK), (2) chemical K fertilization (+K), (3) straw incorporation (+S), (4) straw incorporation with 50% of chemical K fertilization (S+1/2K), (5) straw incorporation with 75% of chemical K fertilization (S+3/4K), and (6) straw incorporation with 100% of chemical K fertilization (S+K). Three soil K supply levels (i.e., HSKS, MSKS, and LSKS) were graded by relative yield (i.e., crop yield in the CK treatment divided by crop yield in the +K treatment) refer to the CK treatment.[Result] Both K fertilization and straw incorporation improved crops yield and K uptake under different soil K supply levels. Total straw incorporation only (+S) would satisfy crops K needs to achieve high yield level (i.e., crop yield in the +K treatment) for the HSKS. For the MSKS, 50% of chemical K fertilization with straw incorporation was needed to reach crop yield level of +K treatment. In case of LSKS, chemical K application rate could reduce 25% for rice and 50% for oilseed rape and wheat under straw incorporation condition, respectively. For the apparent K balance, straw incorporation could offset soil K deficit to some extent. For the seasons of oilseed rape and wheat, straw incorporation to the field could surplus 14.1-152.6 kg K2O·hm-2 and 25.5-95.9 kg K2O·hm-2, respectively. However, soil K balance would still be deficit during the rice season across the sites. The relationship between K fertilization rate and crop yield with straw incorporation was fitted by quadratic and linear-plateau models. The optimum K application rate was obtained from the model under the crop yield of the +K treatment. With straw incorporation, optimum K application rate was 20-33 kg·hm2for the three crops under the HSKS and MSKS levels, where oilseed rape required less K fertilizer than rice and wheat. However, optimum K rate was 45-49 kg K2O·hm-2 for the LSKS level, where oilseed rape needed more K fertilizer than rice and wheat. Compared with current K economic fertilization rate (60 kg K2O·hm-2), chemical K rate could be reduced by 45.0%-66.7% for the HSKS and MSKS levels, and also chemical K fertilizer could be saved by 18.3%-25.0% for the LSKS level.[Conclusion] Chemical K fertilizer could be saved by 18.3%-66.7% while guaranteed crop yields under straw incorporation condition. The reducing rate of chemical K fertilizer should consider soil K supply level.关键词
秸秆还田/水稻/油菜/小麦/供钾水平/钾肥替代/钾肥利用率Key words
straw incorporation/rice/oilseed rape/wheat/soil K supply level/K fertilizer substitution/K fertilizer efficiency引用本文复制引用
张磊,张维乐,鲁剑巍,戴志刚,易妍睿,丛日环..秸秆还田条件下不同供钾能力土壤水稻、油菜、小麦钾肥减量研究[J].中国农业科学,2017,50(19):3745-3756,12.基金项目
国家自然科学基金(41301319)、国家重点研发计划(2016YFD0200108)、耕地保护与质量提升项目 （41301319）
