Precision irrigation perspectives on the sustainable water-saving of field crop production in China: Water demand prediction and irrigation scheme optimization

There is a global shortage of fresh water to meet the clean production of field crops. Water-saving irrigation can increase the production of field crops, but under certain conditions it can be overly water-saving and unsustainable, particularly in complex terrains in China where there is already a shortage of water resources. In light of the insufficient water resources and partial inequality in China, several investigators in China and abroad have researched irrigation nozzles and pumps, but there is little information on the impact of the environment on crop irrigation. The purpose of this study was to provide a fast and effective crop water demand prediction model to estimate the water requirement during the growth period of crops, to achieve the purpose of applying water according to the demand of the crops, and to optimize the irrigation network to determine the optimal network structure in order to reduce irrigation energy consumption in the process. Specifically, this study analyzed the environmental factors, namely, the soil moisture, soil electrical conductivity, air temperature, and light intensity, affecting the physiological water demand of field crops. Relevant sensors were used in the field, and environmental information was collected. This study used the collected environmental data to build a water demand prediction model based on the back propagation (BP) neural network. It also carried out optimized layout and hydrodynamic analyses of the drip irrigation network and identified the best pipe network arrangement. On the basis of the BP neural network, the remarkable R amount of 0.98963 was obtained for the water demand prediction model. The mean square error (MSE) value was 0.00857724. We also found that the drip irrigation pipe network in the H-shaped arrangement was more suitable for field crop irrigation than the comb-shaped and fish bone-shaped arrangements. This study employed the common field crops in China as the research object, used the wireless sensing technology to obtain the field environment information quickly, and constructed a water demand prediction model with high prediction accuracy. Finally, this study realized the precise control of field crop irrigation, reduced the waste of agricultural water, and achieved sustainable field crop production. (C) 2019 Elsevier Ltd. All rights reserved.