摘要
在利用长期定位试验的实测土壤有机碳（SOC）数据,验证DNDC（脱氮-分解作用）模型在黄土丘陵沟壑区应用的可行性基础上,应用DNDC模型来研究黄土丘陵沟壑区坡耕地农田土壤碳库储量动态变化及碳循环特征。结果表明：施肥可提高作物残体与根系分泌物的外源C携入量,也能提高土壤异氧呼吸对内源C的消耗,且施用有机肥后提高效果显著。总体上,单施有机肥、有机肥配施氮肥均能显著提高0-30 cm土层SOC含量,40年后各处理SOC分别比初始值提高了90.29%、86.46%。不施肥和单施氮肥,SOC含量总体都呈现下降趋势,40年后各处理SOC分别比初始值降低了3.52%、0.38%。依据DNDC模型模拟结果,在黄土丘陵沟壑区坡地上,为保持和提高土壤肥力,增加碳库储量,以施用有机肥为主,配合施用一定量的氮肥将是非常有效的措施。
Based on the feasibility of DNDC（denitrification-decomposition） model in the hilly-gully areas of the Loess Plateau,which was verified by the 8-year soil organic carbon（SOC） data derived from long-term experiment,continuous SOC changes and carbon cycle features on the slope land were studied by using DNDC model.The study not only provides scientific basis for increasing the region＇s agricultural soil fertility and farm production,but also makes a corresponding contribution to scientific reducing,therefore it is of great practical significance.The results,derived from the combination data of validation simulation and 40-year long-term simulation,indicated that fertilizer application could increase the amount of input exogenous carbon,which was brought into soil such as crop residues and root exudates,while fertilization could increase consuming endogenous carbon by soil heterotrophic respiration;the effect of the only manure or compound manure and chemical fertilizer applications were significant.On the whole,the content of SOC in the 0-30 cm soil layer of the only manure or the compound manure and nitrogen applications were 90.29% or 86.46% higher significantly than the starting values 40 years ago,respectively.However,the content of SOC in the control treatment or in the chemical nitrogen application treatment were 3.52% and 0.38% lower than the starting values 40 years ago,respectively.According to the simulating results of DNDC model on the slope land in hilly areas of the Loess Plateau,applying manure mainly with a certain amount of nitrogen fertilizer will be an effective measure for maintaining improved soil fertility,increasing the amount of storage of the organic carbon pools in soil.
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2010年第4期668-676,共9页
Journal of Natural Resources
基金
中国科学院重要方向项目(KZCX2-YW-443-3)
中国科学院西部行动项目(KZCX2-XB2-05-01)
国家科技支撑项目(2006BAD09B07)
