长期应用养分专家管理模式提高小麦玉米轮作氮肥利用率及土壤有机碳固存

Long-term Nutrient Expert Management Improves Nitrogen Use Efficiency and Enhances Soil Organic Carbon Sequestration in Wheat-maize Rotation System

探究养分专家(NE)管理对小麦玉米轮作体系氮肥利用率和土壤有机碳固存的影响,可为小麦玉米轮作体系培肥增效提供理论基础。2009年开始在华北小麦玉米轮作体系中设置不同管理模式定位试验,将NE管理与农民习惯(FP)管理进行对比,通过9 a田间试验,对不同管理模式下作物产量、氮肥利用率、土壤有机碳含量、固碳速率及固碳效率进行测定和计算,解析长期NE管理在小麦玉米轮作体系中的优越性。结果表明:与FP管理相比,长期NE管理降低了氮肥施用量,但小麦和玉米籽粒产量均无显著差异。NE管理玉米平均氮素累积回收率、农学效率、偏生产力分别较FP管理提高7.4百分点,39.7%,28.4%;小麦分别提高8.0百分点,28.9%,32.8%。9 a后NE管理与FP管理表层土壤有机碳含量均有所提高,但NE管理较FP增长较快,NE处理0~5 cm,5~10 cm,10~20 cm土壤有机质含量年增长速率分别为0.28,0.27,0.34 g/(kg·a),较FP年增长速率提高7.7%,68.8%,126.7%。NE和FP处理秸秆还田年均碳投入量分别为8.5,8.7 t/(hm2·a),固碳速率分别为1.35,0.68 t/(hm2·a),固碳效率分别为18.6%,0.4%(处理间差异显著)。养分专家管理可提高氮肥利用率,增加土壤有机碳固存,长期养分专家管理是小麦玉米轮作体系减肥增效、土壤有机碳库提升的重要措施之一,可保障该体系粮食高产稳产,助力其绿色发展。

In order to explore the effects of nutrient expert(NE)management on nitrogen(N)use efficiency and soil organic carbon(SOC)sequestration in the wheat-maize rotation system and improve its management practices,a long-term experiment was set up in 2009 to compare NE management with farmer′s practice(FP)management.Through 9-years experiment,the crop yield,N use efficiency,SOC content,SOC sequestration rate and SOC sequestration efficiency were measured and analyzed.The advantages of long-term NE management in wheat-maize crop rotation system were evaluated.The results showed that long-term NE management reduced the amount of N fertilizer application rate,compared with FP management,but maintained the crop yields(no significant difference with FP).Compared with FP management,the average accumulative recovery efficiency of N,agronomic efficiency of N,and partial productivity of N in NE management system increased by 7.4 percentage points,39.7%,and 28.4%in maize production system,and increased by 8.0 percentage points,28.9%,and 32.8%in wheat production system,respectively After 9-years experiment,both NE and FP increased the SOC contents,with NE management increased faster than FP.The annual SOC contents rise rates of NE treatment in 0-5 cm,5-10 cm and 10-20 cm soil profile were 0.28,0.27,0.34 g/(kg·a),respectively,which were 7.7%,68.8%and 126.7%higher than those of FP treatment.The average annual carbon input of NE and FP treatment from straw returning were 8.5,8.7 t/(ha·a),respectively,and the SOC sequestration rates were 1.35,0.68 t/(ha·a),respectively,and the SOC sequestration efficiencies were 18.6%and 0.4%,respectively,which shown a significant difference.NE management could improve N use efficiency and increase SOC sequestration.Long-term NE management is one of the important measures for fertilizer saving,efficiency strengthen and SOC pool richen in wheat-maize rotation system.It would play a crucial role in ensuring food security and realizing agriculture green development.