长期保护性耕作对土壤有机碳和玉米产量及水分利用的影响  

Effects of long-term conservation tillage on soil organic carbon,maize yield and water utilization

作　　者：王碧胜 蔡典雄[1] 武雪萍[1] 李景[1] 梁国鹏[1] 于维水 王相玲[1] 杨毅宇[1,2] 王小彬[1] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所耕地培育技术国家工程实验室,北京100081 [2]山西农业大学,山西太谷030801

出　　处：《植物营养与肥料学报》2015年第6期1455-1464,共10页Journal of Plant Nutrition and Fertilizers

基　　金：国家科技支撑计划课题(2015BAD22B03);国家"863"计划课题(2013AA102901);公益性行业(农业)科研专项(201203077;201203030)资助

摘　　要：【目的】通过研究保护性耕作对旱地春玉米土壤有机碳(SOC)、产量及水分利用的影响,分析保护性耕作的增产机制,为旱作农田耕作技术应用提供理论和技术支持。【方法】采用2003~2013年连续11年的田间定位试验,设传统耕作(CT)、少耕(RT)和免耕(NT)3种耕作措施,分析土壤0-20 cm和20-40 cm土层有机碳含量、土壤0-20 cm含水量、作物耗水量、玉米产量和水分利用效率的年际变化和耕作处理间的差异,并对玉米产量与影响因素的相关性进行分析。【结果】1)保护性耕作能有效提高土壤有机碳含量,少耕、免耕处理0-20 cm土层有机碳含量11年平均值较传统耕作分别提高了11.2%和3.4%;至2013年少耕、免耕20-40 cm土层有机碳含量分别较传统耕作增加了5.53和3.29 g/kg;土壤0-20 cm有机碳储量净增加速率分别为C 0.365和0.754t/(hm2·a)。2)保护性耕作具有明显的增产效果,少耕产量最高,增产效果最好2003~2013年均产量为5.83t/hm^2,较传统耕作提高了14.7%;免耕次之,年均产量为5.39 t/hm^2,较传统耕作增产6.1%。3)各耕作处理玉米产量与土壤0-20 cm土层含水量之间存在显著的二次方程关系,与作物耗水量之间具有显著的乘幂方程关系。4)保护性耕作可以增加土壤水分减少玉米生育期内的耗水量,提高水分利用效率,其中免耕土壤0-20 cm土层水分含量最高2003-2013年平均含水量为15.2%,较传统耕作和少耕提高了1.90和1.66个百分点,且生育期耗水量最少2003~2013年均耗水量为403.5 mm,较传统耕作和少耕减少了16.1 mm和7.6 mm;少耕、免耕的水分利用效率较传统耕作分别提高了16.1%和10.2%,降水利用效率较传统耕作提高13.9%和5.8%。【结论】长期保护性耕作可以有效地提高土壤有机碳含量、增加土壤水分、减少作物耗水量,从而显著提高了玉米产量和水分利用效率,3种耕作措施中以少耕效果最好,免耕次之在旱作农田推广少、免[Objectives]Conservation tillage is widely used in dry farmlands of northern China in recent years.A long term field experiment（2003-2013） was conducted to explore impact of the conservation tillage on soil organic carbon（SOC）,spring maize yield and water utilization.We demonstrated the cause of yield improvement in the conservation tillage further,and then provided theoretical and technical support for dry farmland tillage.[Methods]There were three treatments,conventional tillage（CT）,reduced tillage（RT） and no-tillage（NT）.Annual variations of SOC（0-20 cm and 20-40 cm）,soil moisture at 20 cm depth,crop water consumption,maize yield and water use efficiency were analyzed,and effect of the three tillage methods on above factors was also analyzed.Correlation analysis between maize yield and above factors was done in our study.[Results]1） The conservation tillage can improve soil organic carbon（SOC） content,the annual SOC（0-20 cm） contents of the RT and NT treatments were increased by 11.2%and 3.4%compared with CT respectively,and the SOC（20-40cm） of the RT and NT treatment were increased 5.53 and 3.29 g/kg.The increased rates of 0-20 cm SOC stock of RT and NT were C 0.365 and 0.754 t/（hm^2.a） respectively.2） The conservation tillage significantly increased crop yields：the average annual yields of 2003-2013 of the RT and NT treatments were 5.83 t/hm2 and 5.39t/hm2 respectively,which are 14.7%and 6.1%higher than that of CT.3） The maize yield under the tillage had significant quadratic relationship with the soil 0-20 cm layer water content,and had significant power equation relationship with crop water consumption.4） The conservation tillage can increase soil moisture,reduce water consumption during maize growth and improve water use efficiency（WUE）：compared with the CT and RT,NT increased the average moisture contents of 2003-2013 by 1.90 and 1.66 percentage points,whereas decreased annual water consumption by 16.1 mm and 7.6 mm;compared with CT,RT and NT increas

关 键 词：保护性耕作 有机碳 玉米产量 水分利用 

分 类 号：S513[农业科学—作物学] S153.6