Validation and testing of the FAO AquaCrop model under different levels of nitrogen fertilizer on rainfed maize in Nigeria, West Africa
| Autor: | Aondover Tarhule, Uvirkaa Akumaga, A.A. Yusuf |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Atmospheric Science
Global and Planetary Change 010504 meteorology & atmospheric sciences Correlation coefficient Forestry 04 agricultural and veterinary sciences 01 natural sciences West africa Nitrogen fertilizer Agronomy 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Grain yield Soil fertility Agronomy and Crop Science 0105 earth and related environmental sciences Mathematics |
| Zdroj: | Agricultural and Forest Meteorology. 232:225-234 |
| ISSN: | 0168-1923 |
| Popis: | The objectives of this study were to evaluate AquaCrop’s ability to simulate the cumulative grain yield of rainfed maize for different soil fertility levels in the northern Guinea Savanna zone of Nigeria. Seven years (2007–2013) of field experimental data on maize grown under rainfed condition at the Institute for Agricultural Research were used to calibrate (2007 data set) and validate (2008–2013 data set) AquaCrop. We assessed the agreement between model simulated and actual maize yields using correlation coefficient, R2, and the index of agreement, d, as well as the NRMSE. R2 values ranged from 0.82 to 0.99 while values of d ranged from 0.6 to 0.88, indicating a moderate poor agreement to very good agreement. The NRMSE varied between 8% (indicating “excellent” agreement) and 17% (good agreement). On the other hand, in percentage terms the differences between actual and simulated yield range from +19% to −30%. Of the 19 treatments evaluated, 13(68%) are within 10% of each other, generally considered very good, three (16%) are within 20%, considered acceptable; and 3 (16%) are >20%, considered poor. Furthermore, simulated yields systematically over-estimate observed yields a not uncommon result that suggests the need for additional calibration. The grain and biomass yields evaluation results were consistent with other validation studies of the model. |
| Databáze: | OpenAIRE |
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