TY - GEN
T1 - Impact of irrigation technologies on withdrawals and consumptive use of water
AU - Wilkening, Eric
AU - Heeren, Derek M.
AU - Hallum, Doug
AU - Schellpeper, Jennifer
AU - Martin, Derrel L.
N1 - Funding Information:
The funding for this research was provided by a USGS 104(b) grant from the Nebraska Water Center, Graduate Student Support from the Robert B. Daugherty Water for Food Global Institute at the University of Nebraska, and a grant from the USDA NIFA Agricultural and Food Research Initiative (Award Number 2017-67021-26249). Additional support was received from the Hatch Act (USDA NIFA, Accession Number 1009760) and the Department of Biological Systems Engineering at the University of Nebraska-Lincoln. The authors thank Mr. Mark Schroeder and his team from the University of Nebraska’s Eastern Nebraska Research and Extension Center for their cooperation and help with field operations. We also thank Alan Boldt, Mitchell S. Maguire, Sandeep Bhatti, Jasreman Singh, and Suresh Pradhyun Kashyap for their help in data collection and analysis. We especially want to thank several people for providing input on the concepts presented in this paper: Tom Riley, Director, Nebraska Department of Natural Resources; Dr. Troy Gilmore, Associate Professor, School of Natural Resources, University of Nebraska-Lincoln; and Dr. Dean Eisenhauer, Emeriti Professor, Department of Biological Systems Engineering, University of Nebraska-Lincoln.
Publisher Copyright:
© American Society of Agricultural and Biological Engineers Annual International Meeting, ASABE 2021. All Rights Reserved.
PY - 2021
Y1 - 2021
N2 - Developments in irrigation technologies have subsequently led to increases in irrigation application efficiency, including conversion from surface to sprinkler irrigation, variable rate irrigation (VRI), and low energy precision application. However, while these increases in application efficiency may reduce water withdrawals and/or diversions (from groundwater or surface water), they may not necessarily translate to additional water being available for future or downstream use. Consumptive use of water, water consumed and not returned to the local or sub-regional watershed, is not necessarily impacted by increased application efficiency, but is an important metric in conserving water for other uses. One recent irrigation technology is VRI; while conventional irrigation scheduling methods generally do not consider terrain or root zone available water variability across a particular field site, VRI can account for such spatial variability. This research evaluated several site-years of field VRI research data in an attempt to quantify potential reductions in pumping and consumptive use from irrigation technology. The previously developed consumptive use ratio (change in consumptive use / change in irrigation water applied) provides a useful metric to estimate potential consumptive use reductions for irrigation technologies compared to conventional irrigation. The consumptive use ratio was calculated for different irrigation management scenarios, including VRI (utilizing zone control prescriptions), across four years and two field sites in Eastern and Western Nebraska. Comparing well-managed conventional irrigation scheduling to VRI scheduling, the consumptive use ratio was found to range between 63% and 77%. When VRI does result in reduced water withdrawals, it likely includes some reduction in both consumptive use and deep percolation of irrigation water. Finally, a theoretical approach was presented to model the marginal consumptive use ratio based on both Cobbs-Douglas and polynomial functions. The marginal consumptive use ratio depends on whether seasonal irrigation is in the deficit irrigation, full irrigation, or over irrigation range.
AB - Developments in irrigation technologies have subsequently led to increases in irrigation application efficiency, including conversion from surface to sprinkler irrigation, variable rate irrigation (VRI), and low energy precision application. However, while these increases in application efficiency may reduce water withdrawals and/or diversions (from groundwater or surface water), they may not necessarily translate to additional water being available for future or downstream use. Consumptive use of water, water consumed and not returned to the local or sub-regional watershed, is not necessarily impacted by increased application efficiency, but is an important metric in conserving water for other uses. One recent irrigation technology is VRI; while conventional irrigation scheduling methods generally do not consider terrain or root zone available water variability across a particular field site, VRI can account for such spatial variability. This research evaluated several site-years of field VRI research data in an attempt to quantify potential reductions in pumping and consumptive use from irrigation technology. The previously developed consumptive use ratio (change in consumptive use / change in irrigation water applied) provides a useful metric to estimate potential consumptive use reductions for irrigation technologies compared to conventional irrigation. The consumptive use ratio was calculated for different irrigation management scenarios, including VRI (utilizing zone control prescriptions), across four years and two field sites in Eastern and Western Nebraska. Comparing well-managed conventional irrigation scheduling to VRI scheduling, the consumptive use ratio was found to range between 63% and 77%. When VRI does result in reduced water withdrawals, it likely includes some reduction in both consumptive use and deep percolation of irrigation water. Finally, a theoretical approach was presented to model the marginal consumptive use ratio based on both Cobbs-Douglas and polynomial functions. The marginal consumptive use ratio depends on whether seasonal irrigation is in the deficit irrigation, full irrigation, or over irrigation range.
KW - Consumptive use
KW - Consumptive use ratio
KW - Irrigation water balance
KW - Variable rate irrigation
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U2 - 10.13031/aim.202101114
DO - 10.13031/aim.202101114
M3 - Conference contribution
AN - SCOPUS:85114208950
T3 - American Society of Agricultural and Biological Engineers Annual International Meeting, ASABE 2021
SP - 2536
EP - 2546
BT - American Society of Agricultural and Biological Engineers Annual International Meeting, ASABE 2021
PB - American Society of Agricultural and Biological Engineers
T2 - 2021 American Society of Agricultural and Biological Engineers Annual International Meeting, ASABE 2021
Y2 - 12 July 2021 through 16 July 2021
ER -