摘要
土壤有机质与粮食安全和气候变化等重大问题密切相关,也是目前国内外研究热点。通过分析黄淮海平原10个小麦玉米长期定位试验资料,在不同施氮量下建立土壤有机质积累与碳投入的数学模型,探讨了土壤有机质积累与碳氮投入的关系。结果表明:土壤有机质积累与碳投入的关系受氮肥用量的影响显著,无论低量施氮(长期定位试验中的常规施肥量,化肥氮量≤330kg/(hm.2a))还是高量施氮(长期定位试验中的高量施肥量,化肥氮量>330kg/(hm.2a)),秸秆根茬碳还田量与土壤有机质变化量之间均呈极显著正相关关系(P<0.01);利用土壤有机质积累与碳投入的数学模型计算的维持土壤有机质平衡的碳投入量(MSC),高量施氮时为7254kg/(hm.2a),低量施氮为1297kg/(hm.2a),前者是后者的5.6倍。因此,大量施用氮肥降低了投入碳的积累,不利于土壤有机质的提升。
Soil organic matter plays a crucial role in soil fertility,environmental protection and sustainable development of agriculture.Inventory of soil organic carbon is necessary for the development of strategic policies regarding to the global agricultural production and environmental change.Carbon sequestration is very important not only to improve soil quality and increase economic crop production,but also to increase soil carbon storage for carbon trading and mitigating CO2 emissions from the soil profile.Much attention has been paid to global carbon cycle because of the emergence of a series of environmental problems such as the increase in atmospheric CO2 concentration and global warming.More than twice as much carbon is held in soils as investigation,and changes in soil carbon content can have large effects on the global carbon budget in the atmosphere.Thus,increasing soil organic matter content is of great importance for the sustainable development in China and the entire world.Various management practices on agriculture land can have an impact on soil carbon content.Agricultural practices that affect soil carbon include tillage system,cropping system,N fertilization,and many others.Agricultural management practices such as tillage,rotation and fertilization influence soil organic matter dynamics after long term cultivation to a large extent.Nitrogen application can have a significant effect on soil organic carbon pools and plant biomass production,but it is not convincingly clarified whether nitrogen fertilizers increase or decrease soil organic matter at certain agricultural conditions.The objective of this paper was to explore the relationship between carbon-nitrogen application and the accumulation of soil organic carbon.The experimental data were mainly obtained from in ten long-term fertilization trials at different locations.This paper evaluated the change of soil organic matter in relation to input of straw-stubble organic carbon and nitrogen amendment.All long-term trials were located in an important g
出处
《生态学报》
CAS
CSCD
北大核心
2010年第13期3591-3598,共8页
Acta Ecologica Sinica
基金
科技部支撑项目(2006BAD05B04)
国家重点基础研究发展计划(973)项目(2009CB118608)
农业部公益性行业专项(200803030)资助
关键词
氮肥施用
秸秆和根茬输入
土壤有机质
黄淮海平原
nitrogen amendment
straw and stubble input
soil organic matter
Huanghuaihai Plain
