华北农田不同耕作方式的固碳效益评价

Evaluation of tillage treatments on soil carbon sequestration in North China Plain

为研究长期耕作措施下农田土壤碳储量以及潜在碳成本的情况,在中国科学院石家庄栾城生态系统试验站进行了长期耕作定位试验,设置免耕(NT)、旋耕(RT)和翻耕(CT)3个处理,并对各处理的固碳效益进行了评价。结果表明在秸秆还田、化肥投入的条件下各处理碳储量均呈现增长趋势,2004—2010年各处理间碳储量平均值由37 867.06增长到48 316.33kg/hm2,SCS的大小为CT>NT>RT;潜在碳成本NT、RT与CT分别为499.50,516.91和564.84kg/(hm2.a);通过效益评价可知,NT的生态效益最好,各处理间差异显著。RT的经济效益最好,与NT间差异不显著,但RT显著高于CT。建议华北麦玉两熟区农田优化当前农艺措施,提高机械覆盖面积,提升免耕作物经济产量,在此区域适当推广少免耕技术。

The study was established at the Luancheng Agro-Ecosystem Experimental Station with three tillage practices under winter wheat growing season; conventional tillage （CT）, rotary tillage （RT）, and no-tillage （NT）, Farmland soil carbon storage, hidden carbon cost （HCC） and benefit evaluation in long-term tillage practice were studied. The results showed that： SCS was increased with times in the condition of straw back and fertilizer input. The average value of SCS was increased from 37 867.06 to 48 316.33 kg/hm2 from 2004 to 2010. The amount of SCS fotlowed the order：CT〉NT〉RT. HCC of each treatment （NT,RT and CT） was 499.50,516.91 and 564.84 kg/（hm^2·a）. Ecological benefit was the highest under NT, Economic benefit was the highest under RT, differences of economic benefit index values between NT and RT were not significant, it is better to adopt minimum and no tillage in North China Plain.