北美保护性耕作及对中国的意义

Conservation tillage systems in North America and their significance for China

由土壤侵蚀、荒漠化及盐碱化导致的耕地地力退化 ,严重威胁着中国的农业生产和生态环境 .为了阻止耕地地力的持续下降和生态环境进一步恶化 ,土壤管理方式必须由传统的耕作方式转向保护性耕作 .纵观 2 0世纪有关治理耕地水土流失的技术方法 ,没有哪一项技术可与由美国提出并加以完善的保护性耕作相比 .美洲的农业实践证明 ,保护性耕作可以控制土壤侵蚀 ,减少劳动量 ,节省时间和能源 ,改善土壤耕性 ,增加土壤有机质 ,改善水和大气质量 ,增加土壤生物多样性 .通过回顾保护性耕作的发展历史和应用现状 ,强调了该耕作技术在保持水土和改善土壤性状上的价值和采用保护性措施时应该注意的关键问题 ,如保护性耕作农机具、化学除草和转变观念等 ,同时总结了农民在采用保护性耕作时应该采取的具体步骤 .总之 ,面对中国耕地土壤水土流失严重和地力持续下降以及生态环境恶化的严酷现实 。

Soil degradation through erosion and desertification reduces soil productivity, and is a serious problem in agricultural production of China. To avert our arable land from further degradation, soil management must be shifted from degrading tillage to conservation practices. Over viewing the technology used in the 20th century for controlling soil degradation from erosion, conservation tillage developed in the United States and adopted in South America and Africa is one of the most successful measures to overcome soil degradation problems. This paper reviewed the historical development and the current situation of conservation tillage systems used in North and South America, with special reference to their effects on soil erosion control and soil quality. The increasing adoption of conservation tillage systems in North and South America and Africa followed an enhanced awareness of the increasing risk of soil erosion and the high cost of fuel associated with conventional tillage. Many crucial points for successfully adopting conservation tillage systems were emphasized, such as equipment/tool development and chemical weed control. Adopting conservation tillage could provide China with low-priced means of reducing soil degradation and improving soil and water quality.