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Evaluating Management Zone Optimal Nitrogen Rates with a Crop Growth Model
Author(s) -
Miao Yuxin,
Mulla David J.,
Batchelor William D.,
Paz Joel O.,
Robert Pierre C.,
Wiebers Matt
Publication year - 2006
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2005.0153
Subject(s) - yield (engineering) , mathematics , crop simulation model , crop , zea mays , calibration , fertilizer , hybrid , agronomy , crop yield , field corn , simulation modeling , statistics , environmental science , biology , materials science , metallurgy , mathematical economics
Determining MZ (management zone)‐specific optimal N rate is a challenge in precision crop management. The objective of this study was to evaluate the potential of applying a crop growth model to simulate corn ( Zea mays L.) yield at various N levels in different MZs and estimate optimal N rates based on long‐term weather conditions. Three years of corn yield data were used to calibrate a modified version of the CERES‐Maize (Version 3.5) model for a commercial field previously divided into four MZs in eastern Illinois. The model performance in simulating corn yield for two hybrids (33G26 and 33J24) at five N levels in two independent years was evaluated. Economically optimum N rates (EONRs) were estimated based on 15 yr of simulation (1989–2003). The model explained approximately 59 and 93% of yield variability during calibration and validation, respectively. The model performed well at non‐zero N rates, with most of the simulation errors being <10%. Model‐estimated EONR varied from 70 to 250 kg ha −1 . Economic analyses indicated that applying N fertilizer at year‐, hybrid‐, and MZ‐specific EONR had the potential to increase net return by an average of US$49 (33G26) or US$52 (33J24) ha −1 over a URN (uniform rate N) application at 170 kg ha −1 . Applying average hybrid‐ and MZ‐specific EONRs across years did not consistently improve economic returns over URN application; however, applying the hybrid‐ and MZ‐specific N rates that maximized long‐term net returns would improve economic return by an average of US$22 (33G26) and US$14 (33J24) ha −1