[Combined construction of rainwater catchment techniques with methane pool and greenhouse]

A combined structure of rainwater catchment, methane pool and reformed greenhouse was constructed to improve water use efficiency. The results showed that the combination of rainwater catchment, reserving techniques and water saving measures was efficient to resolve the problem of water deficiency in the semi-arid region with precipitation of 250-550 mm. The combined structure of water catchment engineering, greenhouse and methane pool redistributed light, temperature, water and heat to develop higher benefits economic crops, and improved water use efficiency, which made it possible to develop high yield, and best quality agriculture in this region. Through optimizing the ecological factor in greenhouse, the water use was reduced by 50%-70%, and the soil temperature and night temperature were raised. This combined construction also improved productivity in greenhouse, and efficiently controlled plant diseases and insect pests. Methane pool provided CO2 and part energy source. The shady area back of the greenhouse was exploited by growing shady crops and epiphyte, which contributed to exchange energy and CO2 between light and shady house. This model could be used as water catchment agricultural development model in the region, and some other new approaches to water catchment agriculture in semi-arid region were discussed in this paper.