Economic analysis of rainwater harvesting and irrigation methods, with an example from China

The purpose of this paper is to evaluate the economic feasibility of agriculture with rainwater harvesting and supplemental irrigation in a semiarid region. The results show the importance of making full use of every open-air hardened surface to collect rainwater and to establish rainwater catchment areas by utilizing unoccupied land. The results also show that the usefulness of the harvested rainwater is enhanced when water saving and prevent seepage techniques are employed. The results indicate that in order to maximize investment it is essential to select crops with a water requirement process that coincides with local rainfall events. Potato was found to be the most suitable crop in the studied region. The economic indices for potato were superior to spring wheat, corn and wheat/corn intercropping. Therefore, potato production using rainwater harvesting and supplemental irrigation is the best alternative for cropping systems in the semiarid region of Gansu, China.