Skip to main content
ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Rangeland Resources & Systems Research » Research » Publications at this Location » Publication #339486
Title: Optimizing ET-based irrigation scheduling for wheat and maize with water constraints

Author
item FANG, Q - Qingdao Agricultural University
item Ma, Liwang
item QI, Z - McGill University - Canada
item SHEN, Y - Chinese Academy Of Sciences
item HE, L - National Meteorological Center
item XU, S - Northeast Agricultural University
item KISEKKA, I - Kansas State University
item SIMA, M - Duke University
item Malone, Robert - Rob
item YU, Q - Northwest Agricultural University

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2017
Publication Date: 12/1/2017
Citation: Fang, Q.X., Ma, L., Qi, Z., Shen, Y., He, L., Xu, S.H., Kisekka, I., Sima, M.W., Malone, R.W., Yu, Q. 2017. Optimizing ET-based irrigation scheduling for wheat and maize with water constraints. Transactions of the ASABE. 60:2054-2065. doi:org/10.13031/trans.12363.
DOI: https://doi.org/10.13031/trans.12363

Interpretive Summary: Deficit irrigation may be more effective in increasing crop water use efficiency (WUE) with better understanding of crop responses to water stress intensity and timing. In this study, the Root Zone Water Quality Model (RZWQM) was first calibrated and validated with measured data from a large-weighting lysimeter from 1998 to 2003 at Yucheng Experimental Station in the North China Plain, for daily ET, soil water storage (0-48 inches), leaf area index (LAI), aboveground biomass, and grain yield. The evaluated model was then used to explore crop responses to various targeted crop evapotranspiration (ETc) levels (40%, 60%, 80%, and 100% ETc) at the selected growth periods of wheat (e.g., planting to before winter dormancy (P-D), Green up to booting (G-B), booting to flowering (B-F), and flowering to maturity (F-M)) and maize (planting to silking (P-S) and silking to maturity (S-M)) under long-term weather conditions from 1958 to 2015, subject to seasonal water availabilities (4/2, 8/4, 12/6, 16/8 inches, and no water limit for wheat/maize, respectively). In general, wheat is more responsive to the targeted ETc levels than maize, while greater influence of weather variation on maize than on wheat was simulated. During the wheat seasons, the highest average WUE was simulated when the highest targeted ETc levels at both G-B and B-F stages were met, with lower targeted ETc levels at the P-D periods. During the maize seasons, lower targeted ETc levels after silking did not significantly affect maize production mainly due to the high seasonal rainfall amounts, but targeted ETc levels higher than 60% ETc before silking were recommended. These results can be used as guidelines for precision irrigation along with real time weather information.

Technical Abstract: Deficit irrigation is proved to increase crop water use efficiency (WUE) in water limited areas, but effective irrigation required better understanding of crop responses to water stress intensity and timing. In this study, the Root Zone Water Quality Model (RZWQM) was first calibrated and validated with measured data from a large-weighting lysimeter from 1998 to 2003 at Yucheng Experimental Station in the North China Plain, for daily ET, soil water storage (0-120 cm), leaf area index (LAI), aboveground biomass, and grain yield. The evaluated model was then used to explore crop responses to various targeted crop evapotranspiration (ETc) levels (40%, 60%, 80%, and 100% ETc) at the selected growth periods of wheat (e.g., planting to before winter dormancy (P-D), Green up to booting (G-B), booting to flowering (B-F), and flowering to maturity (F-M)) and maize (planting to silking (P-S) and silking to maturity (S-M)) under long-term weather conditions from 1958 to 2015, subject to seasonal water availabilities (100/50, 200/100, 300/150, 400/200 mm, and no water limit for wheat/maize, respectively). In general, wheat is more responsive to the targeted ETc levels than maize, while greater influence of weather variation on maize than on wheat was simulated. During the wheat seasons, the highest average WUE was simulated when the highest targeted ETc levels at both G-B and B-F stages were met, with lower targeted ETc levels at the P-D periods. During the maize seasons, lower targeted ETc levels after silking did not significantly affect maize production mainly due to the high seasonal rainfall amounts, but targeted ETc levels higher than 60% ETc before silking were recommended. These results can be used as guidelines for precision irrigation along with real time weather information.