Integrated dryland agriculture sustainable management in northwest China

Abstract

Dryland agricultural area of China generally refers to the regions with average annual rainfall of 250-550 mm to the northeast of the Tibet Plateau. The dryland agricultural area accounts for 33 % of total arable lands, and affords 32 % of total population for the country. In this region, the major landscape is dominated by low hilly and scattered small plains. Locally, the winter is cold and dry and the summer is warm and rainy. As a general trend, local inter-annual precipitation fluctuates greatly, leading to low and unsteady field productivity. Terrace building practice has a history of nearly 2000 years. With the popularity of agricultural machinery, the size and quality of terraces significantly increased over the past 20 years. Currently, the terrace establishment acts as a fundamental role in soil and water conservation, which help improve farmland productivity, and has become a major base of crop production and livestock development. Increasing crop yield per unit area proves to be the critical pathway to overcome poverty and achieve prosperity for local people, and the fundamental condition to increase land vegetation cover and biodiversity. As a result of years of exploration, various farming patterns of furrow-ridge with plastic film mulching in terms of maize, potato, wheat and other crops have been developed, which play important roles in local development. Particularly, summer crops such as maize and potato, whose growth rhythms match with the dynamics of rain and thermal distribution, have been chosen to extend for planting in large areas due to their great yield potentials and fine market value. Therefore, the two crops are preferable to meet the demand of local social-economic and natural conditions. With the extension and application of furrow-ridge with plastic mulching technologies, yield potential of crops has been continuously improved. Since the beginning of twenty-first century, food shortage has been largely solved in most of dryland agricultural region, which has lasted for last centuries. With the increases in the productivity of field maize and the suitability area of maize cultivation, there have been a large amount of additional maize straw resources available to be used for silage fermentation. This turned to become one of major sources of livestock forage, which had been the major restriction for local livestock development in the past. Artificial grasslands not only act as supplemental sources of local livestock forage, but in the meanwhile, they could exert important effects on the restoration of local ecological vegetation restoration, and the control of serious soil erosion. According to the principle of efficiently utilizing natural rainfall, vegetation coverage and biodiversity tended to be gradually increased in dryland agricultural area of China, while there has been synergetic development in coupled natural and human system through incorporating food crops and cash crops into artificial grassland and livestock husbandry system. This sort of integrated management paradigm is thus developed on the basis of sustainable development in dryland agricultural area of northwest China.