System management of irrigation under climate change conditions for determining the crop water demand and solutions for the water-saving

Abstract

When droughts occur and temperatures rise, water demand increases when growing crops. For these conditions, system management of irrigation is proposed as a system approach, which ensures the efficient use of water resources and their savings. A method for estimating the increase in water resources under climate change is proposed. The method is based on a comparison of water balance deficits, ranked by estimated moisture supply of the year, at two time intervals: in recent 30 years and in past decades before (1960–1990 and 1991–2021). System management of irrigation combines instrumental and calculative methods. Instrumental methods using an automated tensiometer and Watermark provide feedback on the daily soil moisture status in the field. According to the calculative methods, irrigation forecasting is carried out using Internet weather services and optimal control is carried out on a sliding interval. An algorithm of the instrumental-calculative method is proposed within system irrigation management. When the algorithm is combined with biologically optimal irrigation regimes, the effective use of available water is achieved. When using the parameters of water-saving irrigation regimes, water resources are saved up to 30%, which is important in a changing climate.