Evaluating ceres-maize model using planting dates and nitrogen fertilizer in Zambia
Date
2015-02-15
Authors
Sichingabula, Henry
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Agricultural Science
Abstract
A field experiment was conducted during the 2013/2014 season to evaluate the performance of CERES-maize
model in simulating the effect of date of planting, nitrogen fertilizer and root-zone soil water profile on growth
and yield of maize (Zea mays L.) at the Field Research Station of the School of Agricultural Sciences, University
of Zambia, Zambia (15o23.6859′S, 28o20.226′E; 1,261 m.a.s.l). The experimental design was a split plot with
three replicates, three planting dates (November 24, December 8, and December 22) assigned to main plots and
two nitrogen fertilizer rates (112 and 168 kg N ha-1) assigned to sub-plot. Phenological stages and aboveground
biomass were used for model evaluation and these were observed at vegetative and reproductive stages. Soil
water profiles were monitored using the Diviner 2000 Probe. Planting date significantly affected grain and
biomass yield at P < 0.05. The coefficients of variation for grain and biomass yield were below 12% and
considered efficient. The Generalized Likelihood Uncertainty Estimation (GLUE) programme was used to
estimate the genetic coefficients for the CERES-maize model. The model’s prediction of plant emergence (±1
days), time to anthesis (≥ −3 ≤ ±1 days) and maturity (≥ −4 ≤ 6 days) was good. Simulation of biomass
(RMSE=1135 kg/ha, d=0.96, EF=0.86) was reasonably accurate while leaf area index (d = 0.54, EF = −0.65) was
simulated with less accuracy due to poor d-stat and forecasting efficiency. The model’s simulation of grain yield
was fair (NRMSE = 21.4%) while soil root water availability demonstrated that substantial potential yield may
have been lost due to water stress. The results showed that the model can be used to accurately determine
optimum planting date, biomass yield and nitrogen fertilizer rates with reasonable accuracy.
Keywords: biomass, calibration, CERES-maize, fertilizer application rate, GLUE, tops weight
Description
Journal Article
Keywords
Biomass , Fertilizer application rate