OPENAIRE OpenAire Sygma Recolector de Ciencia Abierta, RECOLECTA DIGITAL.CSIC Crossref European Union Open Data Portal Field Crops Research Open Access 2022-05-23 Project Co-ordinators: Dr. Jose Alfonso Gómez Calero (Instituto de Agricultura Sostenible (IAS-CISC), Dr. Weifeng Xu (Fujian Agriculture and Forest University, FAFU). -- Trabajo desarrollado bajo la financiación del proyecto “Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping Systems” (773903), coordinado por José Alfonso Gómez Calero, investigador del Instituto de Agricultura Sostenible (IAS). The crop-water production function (CWPF) is widely used to quantitatively describe relationships between crop water deficit and yield, and evaluate the effects of different irrigation strategies in agro-hydrological models. In order to reasonably and reliably estimate crop yield and optimize irrigation scheduling, a novel CWPF was proposed by combining the plant water deficit index (PWDI), estimated based on root-weighted soil water availability, with a daily water sensitivity index derived from a sigmoidal cumulative function. Parameterized using data from a two-year winter wheat field lysimetric experiment conducted in the North China Plain and from a previously published two-year spring maize field drip irrigation experiment in Inner Mongolia, China, the CWPFs provided reasonable estimation of different crop yields with different water stress response characteristics under different field environments. Through coupling the genetic algorithm with the integrated simulations of soil water dynamics, PWDI and CWPF in the soil-wheat system, an optimization procedure was developed to determine PWDI threshold combinations to timely trigger irrigation according to pre-designed crop water deficit status. Crop yield and water use efficiency (WUE) of winter wheat were estimated and compared under different optimized constant and variable PWDI threshold combinations. In addition, the effects of climate change on the optimized variable PWDI threshold combinations were investigated using 38 years of historic meteorological data. The results showed that regulated deficit irrigation (RDI) with a variable threshold combination, in which the sensitivity characteristics to water deficit were considered for the crop at different growth stages, was superior to a constant threshold in enhancing crop yield and WUE. Irrespective of the number of irrigation events (1, 2, 3 or 4) during the growing season, the coefficients of variation (CV) of optimized PWDI thresholds for different combinations of irrigation sequence and events were not very large under the same kind of hydrological year (wet, normal or dry), with CV < 0.39 and a median of 0.21. When the mean (MN) of the optimized PWDI threshold combinations for different irrigation sequence and events was used to schedule RDI of winter wheat in terms of various hydrological years, up to 91% of the estimated relative yield was found to be higher than 90% of the corresponding maximum values. Therefore, the MN can be valuable in formulating rational irrigation management strategies of winter wheat to achieve relatively high yields with limited water under changing climatic conditions. This research was supported partly by National Natural Science Foundation of China (U1706211, 51790532), National Key Research and Development Program of China (2017YFE0118100), and the European Union's Horizon 2020 research and innovation programme under Project SHui, grant agreement No 773903. Peer reviewed Winter wheat 2. Zero hunger 0106 biological sciences Root-weighted plant water deficit index 13. Climate action Crop-water production function Cumulative function of water sensitivity index 15. Life on land 01 natural sciences Regulated deficit irrigation 6. Clean water Wu, Xun, Shi, Jianchu, Zhang, Ting, Zuo, Qiang, Wang, Lichun, Xue, Xuzhang, Ben-Gal, Alon, 2022-08-01 journalpaper Project Co-ordinators: Dr. Jose Alfonso Gómez Calero (Instituto de Agricultura Sostenible (IAS-CISC), Dr. Weifeng Xu (Fujian Agriculture and Forest University, FAFU). -- Trabajo desarrollado bajo la financiación del proyecto “Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping Systems” (773903), coordinado por José Alfonso Gómez Calero, investigador del Instituto de Agricultura Sostenible (IAS). The crop-water production function (CWPF) is widely used to quantitatively describe relationships between crop water deficit and yield, and evaluate the effects of different irrigation strategies in agro-hydrological models. In order to reasonably and reliably estimate crop yield and optimize irrigation scheduling, a novel CWPF was proposed by combining the plant water deficit index (PWDI), estimated based on root-weighted soil water availability, with a daily water sensitivity index derived from a sigmoidal cumulative function. Parameterized using data from a two-year winter wheat field lysimetric experiment conducted in the North China Plain and from a previously published two-year spring maize field drip irrigation experiment in Inner Mongolia, China, the CWPFs provided reasonable estimation of different crop yields with different water stress response characteristics under different field environments. Through coupling the genetic algorithm with the integrated simulations of soil water dynamics, PWDI and CWPF in the soil-wheat system, an optimization procedure was developed to determine PWDI threshold combinations to timely trigger irrigation according to pre-designed crop water deficit status. Crop yield and water use efficiency (WUE) of winter wheat were estimated and compared under different optimized constant and variable PWDI threshold combinations. In addition, the effects of climate change on the optimized variable PWDI threshold combinations were investigated using 38 years of historic meteorological data. The results showed that regulated deficit irrigation (RDI) with a variable threshold combination, in which the sensitivity characteristics to water deficit were considered for the crop at different growth stages, was superior to a constant threshold in enhancing crop yield and WUE. Irrespective of the number of irrigation events (1, 2, 3 or 4) during the growing season, the coefficients of variation (CV) of optimized PWDI thresholds for different combinations of irrigation sequence and events were not very large under the same kind of hydrological year (wet, normal or dry), with CV < 0.39 and a median of 0.21. When the mean (MN) of the optimized PWDI threshold combinations for different irrigation sequence and events was used to schedule RDI of winter wheat in terms of various hydrological years, up to 91% of the estimated relative yield was found to be higher than 90% of the corresponding maximum values. Therefore, the MN can be valuable in formulating rational irrigation management strategies of winter wheat to achieve relatively high yields with limited water under changing climatic conditions. This research was supported partly by National Natural Science Foundation of China (U1706211, 51790532), National Key Research and Development Program of China (2017YFE0118100), and the European Union's Horizon 2020 research and innovation programme under Project SHui, grant agreement No 773903. Peer reviewed Crop yield estimation and irrigation scheduling optimization using a root-weighted soil water availability based water production function 10261/276613 https://doi.org/10261/276613 773903