免耕覆盖下土壤水分、团聚体稳定性及其有机碳分布对小麦产量的协同效应  

Synergistic Effects of Soil Moisture,Aggregate Stability and Organic Carbon Distribution on Wheat Yield Under No-Tillage Practice

作　　者：郑凤君 王雪 李生平[1] 刘晓彤 刘志平 卢晋晶 武雪萍[1] 席吉龙 张建诚 李永山[3] ZHENG FengJun;WANG Xue;LI ShengPing;LIU XiaoTong;LIU ZhiPing;LU JinJing;WU XuePing;XI JiLong;ZHANG JianCheng;LI YongShan(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081;People’s Government of Fangshan District Liulihetown,Beijing 102403;Institute of Cotton,Shanxi Agricultural University,Yuncheng 044000,Shanxi;Institute of Resources and Environment,Shanxi Agricultural University,Taiyuan 030031)

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081 [2]北京市房山区琉璃河镇人民政府,北京102403 [3]山西农业大学棉花研究所,山西运城044000 [4]山西农业大学资源环境学院,太原030031

出　　处：《中国农业科学》2021年第3期596-607,共12页Scientia Agricultura Sinica

基　　金：国家重点研发计划(2018YFD0200408,2016YFD0300804);国家科技支撑计划(2015BAD22B03);中央级公益性科研院所基本科研业务费专项(1610132019033)。

摘　　要：【目的】基于山西运城8年(2008—2015)长期定位试验,研究免耕覆盖下土壤团聚体稳定性、团聚体活性有机碳分布特征、冬小麦水分利用效率和产量变化特征,分析土壤水分、土壤团聚体稳定性及其有机碳组分对小麦籽粒产量的协同关系,为选择适宜黄土高原旱作农业区最佳耕作模式提供理论依据。【方法】选取传统耕作秸秆翻耕还田(CT-SP)和免耕秸秆覆盖还田(NT-SM)两种耕作措施,在冬小麦收获期,利用干筛法测定土壤团聚体各粒级质量分数;测定各粒级土壤团聚体有机碳(SOC)及活性有机碳(可溶性有机碳,DOC;易氧化有机碳,EOC;微生物量碳,MBC)含量;测定土壤水分(土壤体积含水量,qv;播种前贮水量,SB;收获后贮水量,SA;生育期耗水量,ET;降水利用效率,PUE;水分利用效率,WUE)和作物产量等关键指标。【结果】(1)与CT-SP处理相比,NT-SM处理显著提高0.25—2 mm团聚体含量、>0.25 mm团聚体含量(R0.25)和几何平均直径(GMD),分别提升13.9%、8.8%和9.6%。(2)与CT-SP处理相比,NT-SM处理中全土SOC、>2 mm和0.25—2 mm粒级团聚体SOC与MBC含量分别提升17.7%与23.6%、18.4%与18.2%和22.4%与39.2%。0.25—2 mm粒级团聚体对SOC和MBC的贡献率,分别提升18.4%和28.4%。(3)与CT-SP处理相比,NT-SM处理提高了SA、PUE、WUE和小麦产量,分别提升17.7%、8.92%、14.98%和8.92%,并且SOC、WUE、R0.25、MWD和GMD等指标与小麦产量相关系数均达到0.9以上。(4)通过结构方程模型分析发现,土壤团聚体DOC和EOC通过协同效应影响MBC的变化,MBC含量对SOC的总效应为0.88,是影响SOC变化的主导因子。(5)土壤贮水量、土壤团聚体稳定性及其有机碳分布协同影响小麦产量,并且土壤团聚体稳定性对小麦产量表现为极显著正效应。【结论】在黄土高原旱作农业区,免耕秸秆覆盖还田可改善土壤团聚体结构,增加土壤水分含量,提高小麦水分利用效率,显著增加耕层土壤有机�【Objective】Based on an 8 year(2008-2015)long-term field experiment in Yuncheng,Shanxi Province,the characteristics of stability and active organic carbon contents in soil dry aggregate,water use efficiency and winter wheat yield under no-tillage with straw mulching were studied,and the synergistic effect among soil moisture,the stability and organic carbon components of soil aggregates and wheat grain yield were analyzed,so as to provide a theoretical basis for the best tillage practice in the dry farming area of the Loess Plateau in China.【Method】In this study,two tillage treatments in the long-term field experiment were selected,including CT-SP(convention tillage with straw plowing)and NT-SM(no-tillage with straw mulching).During the winter wheat harvest period,the soil aggregate fractions were measured by dry-sieving method,the contents soil organic carbon(SOC)and active organic carbon(dissolved organic carbon,DOC;easily oxidized organic carbon,EOC;microbial biomass carbon MBC)in soil dry aggregates were determined,and soil moisture(soil volumetric water content,qv;soil water storage before sowing,SA;soil water storage after harvesting,SB;water consumption during growing period,ET;precipitation use efficiency,PUE;water use efficiency,WUE)and crop yield were investigated too.【Result】(1)Compared with CT-SP treatment,NT-SM treatment significantly increased the proportions of aggregate 0.25-2 mm,the contents of macro-aggregates(R0.25)and geometric mean diameter(GMD)by 13.9%,8.8%and 9.6%,respectively.(2)Compared with CT-SP treatment,the contents of SOC and MBC in bulk soil,>2 mm and 0.25-2 mm in NT-SM treatment,increased by 17.7%and 23.6%,18.4%and 18.2%,22.4%and 39.2%,respectively.The contribution rates of 0.25-2 mm soil aggregate-associated carbons to SOC and MBC increased by 18.4%and 28.4%,respectively.(3)Compared with CT-SP treatment,NT-SM treatment increased the SA,PUE,WUE and wheat yield by 17.7%,8.92%,14.98%and 8.92%,respectively,and the Pearson correlation coefficients between yield and SOC,WUE,R

关 键 词：免耕覆盖 土壤团聚体 活性有机碳 土壤贮水量 水分利用效率 小麦产量 结构方程模型 

分 类 号：S152[农业科学—土壤学] S512.1[农业科学—农业基础科学]