Maize grain yield and crop water productivity functions in the arid Northwest U.S.

Increased water demands and drought have resulted in the need to provide data guide deficit management decisions irrigated maize ( Zea mays L.) for grain production. The objective of this study was develop relationships between yield use (ETc, crop evapotranspiration) under low high nitrogen (N) input systems on a soil type (silt loam) common production arid Northwest U.S. treatments consisted two N inputs (0 246 kg ha -1 year , -N +N, respectively) four ranging from 100% 25% full irrigation. irrigation treatment 20% less than evapotranspiration model calculated (ETm), indicating that coefficient (Kc) values may be adjusted There were no response differences 2017 but during 2018 2019 (treatments same plots), ETc versus different +N treatments. Crop functions developed using quadratic yield. range across all years 15.03–7.23 Mg . productivity (CWP) 1.6–2.6 m -3 at maximum CWPs had 60–71% ETm. These are valuable understanding over availability developing tools assess future shortages • Corn developed. ranged 1.6 2.6 ET 60% 71% ET. Full Kc corn