Quantitative analysis on technological characteristics of different conservation tillage patterns in major agricultural regions of China

Based on the basic principles of "Three-Min and Two-High"(minimum soil disturbance, minimum land-surface bareness, minimum field pollution, high resource conservation and high economic efficiency), an indicator system was developed for quantitatively analyzing the characteristics of conservation tillage (CT), and 28 patterns of CT in five regions (Northeast and North of China, Loess Plateau, Farming-Pastoral Transitional Zone and Yangtze River Basin), covering 10 provinces in China were studied in this article. The result shows that: the key patterns of CT in China have a high degree of conservation. The values of comprehensive "conservation degree"(Cd) of 27 patterns out of 28 patterns are higher than 10.0. Compared with traditional tillage patterns, most of the CT patterns increase the land cover degree, reduce the soil disturbance, improve soil water, soil nutrition and prevent soil loss, and add the economic benefits as well, but have weak performance in "minimum field pollution"; CT in five regions has different characteristics. CT in Northeast China shows high benefits in improving soil water, soil nutrition and soil preservation and reducing soil disturbance, but increases the application rate of chemical fertilizer and pesticides. In Loess Plateau, the CT indicates higher land cover degree, but lower economic benefits. Higher land cover and higher economic benefit were observed in Farming-Pastoral Transitional Zone. In Yangtze River Basin, CT has higher economic benefit but consumes more labor force. Part of the conservation tillage in North China Plain increases soil water and nutrition, but there are no significantly effects on reducing soil disturbance or increasing economic benefits; based on the evaluation results, the model and technology of CT suited for different regions should be further improved in order to build a Chinese characteristic conservation tillage system.