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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #421528
Research Project: Developing Resilient Irrigated Cropping Systems in Concentrated Dairy Production Areas of the Semi-arid West

Location: Northwest Irrigation and Soils Research

Title: Maize silage yield, quality, and crop water productivity functions in the semi-arid northwest U.S.

Author
item Tarkalson, David
item King, Bradley
item Bjorneberg, David

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2026
Publication Date: 5/1/2026
Citation: Tarkalson, D.D., King, B.A., Bjorneberg, D.L. 2026. Maize silage yield, quality, and crop water productivity functions in the semi-arid northwest U.S.. Soil Science Society of America Journal. http://dx.doi.org/10.1002/saj2.70249.
DOI: https://doi.org/10.1002/saj2.70249

Interpretive Summary: Drought and water demands have resulted in the need for data to guide deficit water management in irrigated corn silage production in the semi-arid areas Northwest U.S. The objective of this study was to develop relationships of corn silage yield and quality with corn evapotranspiration (ET) under low and optimum nitrogen (N) input systems. The treatments consisted of two N inputs (0 and 246 kg N/ha/year) and four water input treatments ranging from 25% to 100% of full irrigation. The full irrigation treatment ET was 16% less than the model that predicted ET, indicating that improvements need to be made to better predict corn ET in the semi-arid Northwest U.S. Water production functions (WPF) for corn silage yields were developed for the two N treatments. In general, the silage quality was impacted by water input treatments but not N input treatments. The WPFs were developed using quadratic relationships between ET and maize silage yield, crop water productivity (CWP), and quality measurements. These WPFs are valuable to understanding maize response over a range of water availability and in developing tools to assess future production under water shortages.

Technical Abstract: Drought and water demands have resulted in the need for data to guide deficit water management in irrigated maize (Zea mays L.) silage production in the semi-arid areas Northwest U.S. The objective of this study was to develop relationships of maize silage yield and quality with maize water use (ETc, crop evapotranspiration) under low and optimum nitrogen (N) input systems. The treatments consisted of two N inputs (0 and 246 kg N/ha/year) and four water input treatments ranging from 25% to 100% of full irrigation (based on ET model). Treatments were applied to the same plots for three consecutive years. The full irrigation treatment ETc was 16% less than evapotranspiration model calculated crop use (ETm), indicating that crop coefficients (Kc) may need to be adjusted for maize in the semi-arid Northwest U.S. There were no silage yield response differences between N input treatments in 2017 but during 2018 and 2019, yield water productivity functions (WPFs) were different for the N treatments. In general, the silage quality was impacted by water input treatments but not N input treatments. The WPFs were developed using quadratic relationships between ETc and maize silage yield, crop water productivity (CWP), and quality measurements. The range of maize silage yield across all years and treatments were 4.0 to 19.7 Mg/ha. The range of CWP across all years and treatments were 2.1 to 5.2 kg/m. The ETc at maximum CWPs across all years and treatments was 56% of ETm. These WPFs are valuable to understanding maize response over a range of water availability and in developing tools to assess future production under water shortages.