The trends of crop yield responses to conservation tillage in China

Chinese. 明确中国目前开展的保护性耕作研究的产量效应以及具体分布情况。收集公开发表的涉及保护性耕作的研究论文，对有关数据进行整理和分析。研究发现，中国保护性耕作研究具有明显的地域特色：少耕研究集中在东北地区，免耕研究集中在长江下游及东南地区，秸秆处理和综合型措施的研究以西北地区最多。中国保护性耕作的产量研究结果多为增产，但也有10.92%的减产数据见诸于各地的报道，其中黄淮海、华北平原、西北内陆、青藏高原、黄土高原区的减产概率比较高；少耕和免耕处理的减产概率较高；小麦减产概率最高，玉米减产概率最小。不同区域、不同作物对保护性耕作措施的反应不同：小麦在黄淮海、华北平原及西北地区的减产发生频率较高，少耕处理的减产概率最大，但在西南地区的稳产性能较好；水稻在西南地区减产概率高，在长江中下游和东南地区的稳产性能较好，秸秆处理减产概率高，而免耕稳产性能较好。少、免耕和秸秆处理相结合的综合型保护性耕作措施减产概率很低，且在所有区域对所有作物的表现相同，值得重点研究。保护性耕作是实现农业可持续发展的重要手段，但保护性耕作措施的选择应因地制宜，根据生产条件采用最具生产价值的耕作模式。本研究的结果能够为我国保护性耕作的稳产丰产研究和推广应用提供指导。

English. Conservation tillage (CT) also can be referred to as resource-efficient/resource effective agriculture. It hase become one of the most important measures of sustainable agriculture development, and it is a relatively new concept but widely adopted in China and has considerable benefits. This paper reviewed the historical development and the current situation of conservation tillage research in China, with special reference to their effects on crop yield, especially reduction of output. Many crucial points for successfully adopting conservation tillage systems were emphasized. Research advances in the conservation tillage of China in recent years were reviewed in this paper. Based on papers published, the current research progress on conservation tillage (CT) of crop production in China were summarized and analyzed. All these aspects were reviewed and the detailed information of conservation tillage from China were studie. It was discovered that the characteristics of conservation tillage research in China was distinct: reduced tillage was predominantly in northeast of China, no-tillage was centralized in lower reaches of the Yangtse Rive and southeast of China, and a large proportion of research in northwest was straw mulching and composition treatment. Most of the reports showed production increased with CT, only 10% showed reduction in output but distributed in all regions of China. There was a high probability reduction of output in Huanghuaihai plain and northwest of China in adoption of conservation tillage, treatment of reduced tillage and no-tillage, wheat had the highest probability than rice and maize when planted with conservation tillage. The responses to CT were different: the wheat yield in Huanghuaihai plain or northwest of China and adopted reduced tillage or no-tillage showed a high probability in decreas of yield, but the yield was stable in southwest of China; rice yield in southwest of China showed more higher probability in decrease of yield, however, the yield in the middle and lower reaches of the Yangtse Rive and southeast of China was stable, straw mulching showed more higher probability reduction of output. There was a very interesting thing about combination of no-tillage and straw mulching, it is worth to investigate since its effects on crop yield are stable. Conservation tillage is a key technique of sustainable agriculture, and carrying out research of application and extension of conservation tillage in China is of profound significance. It is necessary to strengthen the study of key techniques, to enhance research strength and level for improving and promoting sustainable agriculture, and change the traditional idea of farmers so as to accelerate the application of conservation tillage in China.