Development of Sustainable Agriculture on Sloping Lands in China

摘要

When farming on sloping lands in China, farmers generally plant their crops up-and-down the slope and cultivate their land with minimal concern for soil erosion. This causes loss of not only topsoil but also plant nutrients. Since sloping lands cover vast areas in China and are being encroached upon and cultivated every year, it is imperative that appropriate technologies for managing these lands be introduced to farmers to minimize damage to the lowland areas and avoid farmers slipping into poverty because of degraded soils. As a model for development of sustainable agriculture on sloping lands in China, on-farm trials, funded by the Potash and Phosphate Institute of Canada (PPIC), were conducted in farmers' fields in Sichuan, Guizhou, and Yunnan provinces. In the trials, alley cropping and application of balanced fertilizer were employed as the technology to reduce soil erosion and increase crop yields, in comparison with the farmers' practice. Day lily, pears, and Chinese prickly ash were used as hedgerow crops and corn, soybean, and sweet potatoes as alley crops in the alley cropping technique whereas K application was emphasized in the balanced fertilizer treatment. Results showed that K increased crop yields significantly when compared with the farmers' practice, which received no K. Increase in corn yield as high as 13% and wheat + barley yield as high as 31% was obtained from K application. With proper plant population density, K plus dolomite and B increased corn yield at the Yunnan site by 115% when compared with the farmers' practice. Soil loss was greatly reduced by alley cropping, ranging from 60%-80%, Economic analysis indicated higher net return from the application of K and alley cropping than that of the farmers' practice. Currently, the project is extending this technology to farmers. Responses to the extension are positive from both farmers and government officials.