LINCOLN, Nebraska, USA, May 13, 2019 – In a new study published in Environmental Research Letters, researchers from the Daugherty Water for Food Global Institute (DWFI) and the University of Nebraska–Lincoln (UNL) found that about a third of producer fields studied were successful in achieving high yields within irrigated water requirements. This shows that achieving nearly full yield potential and staying below irrigation water requirements are compatible goals when applied to actual fields in the state. Irrigation water requirements are the seasonal amount of irrigation water required to achieve full yield potential. Yield potential is the maximum yield attained when water and fertilizers are not limited. Authors note that in the case of U.S. corn, reaching 80% of yield potential is a reasonable goal.
Researchers collected real data from Natural Resources Districts and through producer surveys. They then developed a framework to diagnose current irrigation water use in relation with grain production in producer fields. While previous related studies have relied primarily on data from simulations or research farms, the new study used actual producer data from more than 500 corn and soybean producer fields in Nebraska.
A striking finding was that yield did not differ between fields using different types of irrigation scheduling. One type of scheduling included technologies that enable more efficient irrigation, such as soil water balances, soil moisture sensors, or irrigation-aid computer tools such as CornSoyWater. Another type involved “soil feeling,” or visual assessment of plant status. The last type included rudimentary methods like fixed calendar dates or basing irrigation off of a neighbor’s schedule. Actual yield averaged 86% of full yield potential across all three scheduling methods. However, fields that used best available technologies to schedule irrigation saw very little water surplus, especially compared to the other two methods, but only represented 22% of the total fields. This finding indicates large room to save irrigation water and potentially increase farm profit through adoption of new technologies.
Researchers also found actual irrigation in fields to be similar to estimated irrigation water requirements in over half of the fields. According to lead researcher and author Kate Gibson with DWFI, this means producers are doing quite well at achieving high yields with little water surplus. But, there is still a lot of potential for reducing water use in the remaining half of the fields studied.
Author Patricio Grassini of UNL’s Agronomy and Horticulture Department adds, “Potential irrigation water savings are greatest in years with above- or near-average precipitation.” Further, farm net profit can be increased by reducing current water surplus through education and cost-effective technologies to track soil water status.
Author Justin Gibson, also with DWFI says, “Flexible irrigation equipment can help deliver water right on time and in the right amount.” These tactics would also reduce unnecessary water use by excess irrigation, which can have adverse impacts on water quality, contribute to greenhouse gas emissions, and burden agricultural producers with unneeded costs.
Funding for the work presented in the new publication came from the Daugherty Water for Food Global Institute, Nebraska Corn Board, and Nebraska Soybean Board.
Full article available at https://doi.org/10.1088/1748-9326/ab17eb.
Video recap available at https://www.youtube.com/watch?v=ElDGsaO0vW8&t=19s
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The Robert B. Daugherty Water for Food Global Institute at the University of Nebraska was founded in 2010 to address the global challenge of achieving food security with less stress on water resources through improved water management in agricultural and food systems. We are committed to ensuring a water and food secure world while maintaining the use of water for other human and environmental needs.
The University of Nebraska has invested in four interdisciplinary, University-wide institutes — including the Robert B. Daugherty Water for Food Global Institute — that leverage talent and research-based expertise from across the University of Nebraska system to focus on complex state, national and global challenges.
Learn more at waterforfood.nebraska.edu.
Contact: Molly Nance, Director of Communications and Public Relations
Daugherty Water for Food Global Institute at the University of Nebraska
mnance@nebraska.edu | (+1) 402.472.5512