摘要
利用紫色水稻土不同耕作制度下的长期定位试验数据,结合DNDC模型来探讨长期不同耕作措施下土壤有机碳变化趋势。选取常规平作(CK)、垄作免耕(水稻—冬水)(T1)、垄作免耕(水稻—油菜)(T2)、水旱轮作(水稻—油菜)(T3)4种处理,分析了15年来土壤有机碳的变化特征,并用DNDC模型模拟了长期试验点15年和100年有机碳变化趋势。结果表明:经过15年的耕种,4种耕作制度的土壤有机碳含量都较原始有机碳含量有所上升。T2处理的土壤有机碳增幅最大,分别为CK,T1和T3处理的131%,142%,153%。T3处理的有机碳含量最低。DNDC模型的模拟结果与田间实测结果大致相同。模拟值与实测值的RMSE值都小于10%,且相关系数都达到0.01水平下的极显著关系,这表明4种耕作制度的DNDC模拟效果极好。对试验地土壤有机碳变化趋势的长期模拟结果显示,只要保持现有的耕作制度和种植模式,100年间4种处理的土壤有机碳都会持续稳定地增加。
A long-term experiment and DNDC model were conducted to study the effects of different tillage systems on accumulation and mineralization of organic carbon in purple paddy soil.The 15-years pre-set experiment included four tillage treatments that conventional tillage with rotation of rice and winter fallow system（CK）,no tillage and ridge culture with rotation of rice and winter fallow system（T 1）,no tillage and ridge culture with rotation of rice and rape system（T 2） and conventional tillage with rotation of rice and rape system.（T 3）.The trend of soil organic carbon in the long-term experiment was simulate by DNDC model with two time scales from 1990 to2004 and 1991 to 2099.The results were as follow： with a time frame of 15 years,the contents of soil organic carbon under different treatments were higher than the primitive soil content.The content of soil organic carbon in T2 was the highest,and it increased by 131% and 153% compared to that in CK、T 1 and T 3,respectively.The lowest occurred in T 3 was observed.The analog value of DNDC model were same as measured values of different treatments.The RMSE（root mean square error） values between the analog values and measured values were smaller than 10%,and the correlativities of all treatments were extremely correlativity in 0.01 notable level.It indicated that the simulates effect of four kinds cultivation system by DNDC model were extremely well.As displayed by the long time stimulant results： if keeping present cultivation system and cultivate pattern,soil organic carbon contents of four kinds treatment would stablly increase during 100 years.
出处
《农机化研究》
北大核心
2013年第1期38-42,共5页
Journal of Agricultural Mechanization Research
基金
中国科学院资助项目(XDA05050506)
水体污染控制与治理科技重大专项(2012ZX07104-003)
重庆市自然科学基金资助项目(CSTC
2009BB1108)
重庆市环境保护局环保科技项目(环科字2010第26号)
中国博士后科学基金项目(20090460716
201003306)
