INVESTIGADORES
ALVAREZ Roberto
artículos
Título:
Predicting average yield and regional production of wheat in the Argentine Pampas by an artificial neural network approach.
Autor/es:
R. ALVAREZ
Revista:
EUROPEAN JOURNAL OF AGRONOMY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2009 vol. 30 p. 70 - 77
ISSN:
1161-0301
Resumen:
A regional
analysis of the effects of soil and climate factors on wheat yield was
performed in the Argentine Pampas in order to obtain models suitable
for yield estimation and regional grain production prediction. Soil
data from soil surveys and climate data from meteorological records
were employed. Grain production information from statistics at county
level was integrated at a geomorphological level. The Pampas was
divided into 10 geographical units and data from ten growing season
were used (1995 to 2004). Surface regression and artificial neural
networks (ANN) methodologies were tested for analyzing the data. Wheat
yield was correlated to soil available water holding capacity (SAWHC)
in the upper 100 cm of the profiles (r2= 0.39) and soil organic carbon (SOC) content (r2=
0.26). The climate factor with stronger effect on yield was the
rainfall/crop potential evapotranspiration ratio (R/CPET) during the
fallow and vegetative crop growing cycle periods summed (r2= 0.31). The phototermal quotient (PQ) during the pre-anthesis period had also a significant effect on yield (r2
= 0.05). A surface regression response model was developed that
account for 64 % of spatial and interannual yield variance, but this
model could not perform a better yield prediction than the blind guess
technique. An ANN was fitted to the data that accounted for 76 % of
yield variability. Comparing predicted vs. observed yield a lower RMSE
(P = 0.05) was obtained using the ANN than using the regression or the
blind guess methods. Regional production estimations performed by the
ANN showed a good agreement with observed data with a RMSE equivalent
to 7 % of the whole surveyed area production. As variables used for the
ANN development may be available around 40-60 days before wheat
harvest, the methodology may be used for wheat production forecasting
in the Pampas.