长期浅耕与秸秆还田对关中平原冬小麦-夏玉米轮作土壤钾素含量及层化比率的影响  

Effect of long-term shallow tillage and straw returning on soil potassium content and stratification ratio in winter wheat/summer maize rotation system in Guanzhong Plain,Northwest China

作　　者：师江澜[1] 李秀双[1] 王淑娟[1] 李硕[1] 李有兵[1] 田霄鸿[1] 

机构地区：[1]西北农林科技大学资源环境学院/农业部西北植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《应用生态学报》2015年第11期3322-3328,共7页Chinese Journal of Applied Ecology

基　　金：国家科技支撑计划项目(2012BAD14B11);中央高校基本科研业务费专项(QN2013075)资助

摘　　要：采用土壤分层采样和钾素化学形态分组方法,探讨连续13年秸秆全量还田与浅耕对关中平原冬小麦-夏玉米轮作体系土壤各形态钾素含量及层化比率的影响.结果表明：采样区土壤速效钾和非交换性钾均有显著的表聚现象和层化效应,速效钾及其组分表现尤为突出,且15-30 cm土层亏缺严重,已低于缺钾临界值;速效钾及其组分的土壤表层（0-5 cm）与5-15 cm和15-30 cm耕层土壤的比值（SR1与SR2）之间呈显著性差异,非交换性钾与矿物钾的比值则差异不显著.连续秸秆全量还田对维持冬小麦-夏玉米轮作体系土壤钾库平衡有积极贡献,但应高度关注有效钾素表聚和层化对土壤钾肥力的负面效应.Soil stratified sampling method and potassium chemical fractionation analysis were used to investigate effects of long-term shallow tillage and straw returning on soil K contents and stratification ratios in winter wheat / summer maize rotation system in Guanzhong Plain of Northwest China. The results showed that after 13-year continuous shallow tillage and straw returning,surface accumulation and stratification effect obviously occurred for soil available K（ SAK） and nonexchangeable K（ NEK）,which was particularly remarkable for SAK and its fractions. Serious depletion of SAK occurred in 15-30 cm soil layer,and the SAK value was lower than the critical value of soil potassium deficiency. Meanwhile,significant differences were found between SR1 and SR2values of SAK and its fractions,SR was obtained by values of topsoil layer（ 0- 5 cm） divided by corresponding values of lower soil layers（ 5- 15 cm layer,SR1,or 15-30 cm layer,SR2）. However,no significant difference was observed between SR values of NEK and mineral K. In conclusion,returning of all straw over 10 years in the winter wheat / summer maize rotation system contributed greatly to maintaining soil K pool balance,while special attention should be paid to the negative effects of surface accumulation and stratification of SAK on soil K fertility.

关 键 词：浅耕 秸秆还田 土壤钾素 层化比率 冬小麦-夏玉米轮作体系 关中平原 

分 类 号：S512.11[农业科学—作物学] S513