Agronomy and Horticulture, Department of
ORCID IDs
C. S. Wortmann https://orcid.org/0000-0001-9715-8469
Z.P. Stewart https://orcid.org/0000-0003-4058-8526
Document Type
Article
Date of this Version
2021
Citation
Liben FM, Wortmann CS, Yang H, et al. Nitrogen response functions targeted to technology extrapolation domains in Ethiopia using CERES-maize. Agronomy Journal. 2021;113:436–450. doi:10.1002/agj2.20439
Abstract
The profitability of fertilizer-N use can be optimized using N response functions specific to climate-based technology extrapolation domains (TED). Crop growth simulation can complement field research for targeting of response functions. The objective of this study was to target maize (Zea mays L.) N response functions to seven TED in Ethiopia through CERES-Maize simulation of continuous maize over 30 yr. The complete factorial set of treatments included seven levels of N in 25 kg ha−1 increments under no-till (NT) and conventional tillage (CT) systems. The CERES-Maize simulated experiments were done for two or three sites per TED. Nitrogen response functions were generated for each TED with tillage-specific functions for three TED with tillage × N interactions. The N rate responses for all TED fit curvilinear to plateau functions but with differing magnitudes and shapes of response. The mean yield with NT was 6% less than with CT, but the difference declined with increased N rate. The economically optimum N rate (EONR) ranged from 65 to 179 and 103 to 243 kg ha−1 for high and low-cost fertilizer-N, respectively. The EONR was 6% less and the profit cost ratio was 11% higher with CT compared to NT, indicating greater fertilizer-N need with NT than with CT. The application of N for maize was highly profitable for all TED. The EONR from CERES-Maize were higher than past field research results. This suggests that the CERES-Maize N response functions were most appropriate for well-managed crop production situations in Ethiopia.
Included in
Agricultural Science Commons, Agriculture Commons, Agronomy and Crop Sciences Commons, Botany Commons, Horticulture Commons, Other Plant Sciences Commons, Plant Biology Commons
Comments
Copyright © 2020 F. M. Liben, C. S. Wortmann, H. Yang, T. Tadesse, Z. P. Stewart, D. Wegary, and W. Mupangwa. Agronomy Journal © 2020 American Society of Agronomy. Published by John Wiley & Sons Inc. Used by permission.