Sustainable irrigation based on co-regulation of soil water supply and atmospheric evaporative demand

Authors

Jingwen Zhang, University of Illinois at Urbana-Champaign
Kaiyu Guan, University of Illinois at Urbana-Champaign
Bin Peng, University of Illinois at Urbana-Champaign
Ming Pan, Princeton University
Wang Zhou, University of Illinois at Urbana-Champaign
Chongya Jiang, University of Illinois at Urbana-Champaign
Hyungsuk Kimm, University of Illinois at Urbana-Champaign
Trenton E. Franz, University of Nebraska - LincolnFollow
Robert F. Grant, University of Alberta
Yi Yang, University of Illinois at Urbana-Champaign
Daran R. Rudnick, University of Nebraska - LincolnFollow
Derek M. Heeren, University of Nebraska - LincolnFollow
Andrew E. Suyker, University of Nebraska - LincolnFollow
William L. Bauerle, Colorado State University
Grace L. Miner, USDA-ARS

Comments

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Abstract

Irrigation is an important adaptation to reduce crop yield loss due to water stress from both soil water deficit (low soil moisture) and atmospheric aridity (high vapor pressure deficit, VPD). Traditionally, irrigation has primarily focused on soil water deficit. Observational evidence demonstrates that stomatal conductance is co-regulated by soil moisture and VPD from water supply and demand aspects. Here we use a validated hydraulically-driven ecosystem model to reproduce the co-regulation pattern. Specifically, we propose a plant-centric irrigation scheme considering water supply-demand dynamics (SDD), and compare it with soil-moisture-based irrigation scheme (management allowable depletion, MAD) for continuous maize cropping systems in Nebraska, United States. We find that, under current climate conditions, the plant-centric SDD irrigation scheme combining soil moisture and VPD, could significantly reduce irrigation water use (−24.0%) while maintaining crop yields, and increase economic profits (+11.2%) and irrigation water productivity (+25.2%) compared with MAD, thus SDD could significantly improve water sustainability.