Conservation agriculture in rainfed areas of China

Abstract

Conservation agriculture (CA) is now widely recognized as a viable concept for practicing sustainable agriculture. Grouped under the title “conservation agriculture,” an inter-related and synergetic set of principles and practices have been developed to combat land degradation, falling soil fertility, rapidly declining production levels, inefficient use of scarce water resources, and desertification. China is an ancient agricultural country, its agriculture dates back at least 8000–9000 years. It has a long history of practices of soil and water conservation. Presently—due to a wide range of soil types and climate, and the cropping systems practiced in China—diverse CA systems exist in different agroecological regions of China. However, modern conservation tillage (CT) is fairly new. The total area under CT in China exceeded 6.67 million ha in 2012 with a ten-fold increase in past 10 years. A 13-year case study on the Loess Plateau showed that no-till with stubble retention (NTS) improved grain yield significantly. With NTS, water stored in surface layers is more available for crops than that in deeper layers; surface (0–10 cm) soil water content under NTS improved up to 90 % when compared with conventional tillage. Soil organic carbon improved. Crops under NTS had better growth and yield. Soil quality, water use efficiency, and nitrogen use efficiency improved, and soil erosion significantly decreased. Profitability improved under NTS within two rotation cycles of spring wheat–field pea; total profitability of NTS was 81, 38, 75, 165, and 66 % higher than that of conventional tillage (T), no-till without stubble retention (NT), conventional tillage with stubble incorporated (TS), conventional tillage with plastic mulch (TP), and no-till with plastic mulch (NTP). Therefore, NTS is the best CA practice for improving crop productivity and sustainability. Although the importance of CA has been increasingly recognized, there are many barriers to its widespread adoption including traditional intensive agriculture attitude, small farm sizes, lack of suitable machines, lack of diverse CA technologies, and the high opportunity cost of straw/residues. Therefore, further investment into technical research, machine design, demonstration and extension, and substitutes for fuel and forage are important for a breakthrough on CA adoption in China.