Towards Development of Eco-Agriculture of Rainwater-Harvesting for Supplemental Irrigation in the Semi-Arid Loess Plateau of China

The semi-arid Loess Plateau is a central zone of Chinese rain-fed farming. Drought and soil erosion are the two major obstacles to restrict economic development in this semi-arid Loess Plateau. The traditional conservation agriculture and runoff agriculture have been developed for several decades, which have reduced water and soil loss and improved rainwater utilization efficiency to a certain extent. However, its regulative role in rainwater is very much limited, and problems of agriculture production, such as severe seasonal drought and water shortage, low agriculture productivity, fragile ecological environment, and low yield-invest ratio, are still going on. Supplemental irrigation of harvested rainwater is an important form of rainfall regulation and utilization on the basis of sophisticated technologies and theories of conservation agriculture and runoff agriculture, which not only promotes fulfilling rainfall harvesting in spatial location like the conservation agriculture and runoff agriculture measure but also gets at true rainfall harvesting in time distribution by principle of superposition and also decreases invalid evaporation for rainfall runoff. Agriculture productivity will be highly increased by using rainwater harvesting for supplemental irrigation. It not only brings about the integration of ecological reconstruction with economic development, but also provides a new approach to the agriculture sustainable development and overcomes two of the biggest obstacles (drought and soil erosion). It is suggested that this technology will become a strategic measure and comprehensive development model in semi-arid Loess Plateau of China.