Han Bin, Kong Fan-Lei, Zhang Hai-Lin, Chen Fu
Ministry of Agriculture Key Laboratory of Farming System, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Ying Yong Sheng Tai Xue Bao. 2010 Jan;21(1):91-8.
By the methods of field experiment, laboratory analysis, and in situ investigation, this paper studied the effects of different tillage conversion on the carbon sequestration capability of farmland soil doubled cropped with wheat and corn. Compared with conventional tillage (CTA), conservation tillage practices benefited the accumulation of soil organic carbon, among which, no-tillage plus straw returning (NTS) increased the organic carbon accumulation in 0-5 cm soil layer by 18.0%, rotary tillage plus straw returning (RTS) increased this accumulation in 0-5 and 5-10 cm soil layers by 17.6% and 25.0%, respectively, and conventional tillage plus straw returning (CTS) increased the organic carbon in 10-30 cm soil layer by 31.8%. After the conversion from CTA to NTS, the carbon emission from farm operations decreased by 54.3 kg x hm(-2) x a(-1); while the conversion from CTA to CTS and RTS resulted in an increase of this emission by 46.9 kg x hm(-2) x a(-1) and 34.4 kg x hm(-2) x a(-1), respectively. Considering of the accumulation of soil organic carbon and the carbon emission from farm operations, it could be concluded that the conversion from CTA to conservation tillage changed this farmland soil from carbon source to carbon sink, and the RTS among the three conservation tillage modes resulted in the highest soil carbon sequestration (1011.1 kg x hm(-2) x a(-1)).
通过田间试验、实验室分析和实地调查等方法，研究了不同耕作方式转变对小麦玉米复种农田土壤固碳能力的影响。与传统耕作（CTA）相比，保护性耕作有利于土壤有机碳的积累，其中，免耕秸秆还田（NTS）使0-5厘米土层有机碳积累量增加18.0%，旋耕秸秆还田（RTS）使0-5厘米和5-10厘米土层的有机碳积累量分别增加17.6%和25.0%，传统耕作秸秆还田（CTS）使10-30厘米土层有机碳增加31.8%。从CTA转变为NTS后，农事操作的碳排放减少了54.3千克·公顷⁻¹·年⁻¹；而从CTA转变为CTS和RTS分别使该排放量增加了46.9千克·公顷⁻¹·年⁻¹和34.4千克·公顷⁻¹·年⁻¹。综合考虑土壤有机碳积累和农事操作的碳排放，可以得出结论：从CTA转变为保护性耕作使该农田土壤从碳源转变为碳汇，三种保护性耕作模式中RTS土壤固碳量最高（1011.1千克·公顷⁻¹·年⁻¹）。
