Calibration of EPIC for the Simulation of Wind Erosion Damage to Pearl Millet in West Africa
K. Michels, K.N. Potter and J.R. Williams
Abstract
Sandblasting and burial of young pearl millet seedlings by
blown sand can be an important production constraint for this major staple crop in the
West African Sahel. Attempts to simulate plant production under these conditions are
scarce. The objective of this study was a calibration and preliminary first evaluation of
the EPIC simulation model to simulate pearl millet production, and sandblast damage to
millet seedlings for the environmental conditions of the Sahel.
Several modifications were made had to be done in EPIC in
order to simulate the extremely low soil phosphorus contents and the short sand storms on
days with low average wind speeds. To simulate crop damage caused by erosive wind storms,
attempts were made to integrate simple mathematical empirical functions were incorporated
into the wind erosion subroutine. Abrasion damage was calculated as a reduction in actual
leaf area with a linear relationship to the amount of eroded soil. Burial damages were
simulated when a threshold amount of eroded soil was exceeded during one storm.
The modified EPIC gave reasonable results in simulating
millet growth under the semiarid conditions in Niger. The simulation results reflected
well the low average yields under low-input conditions. Plant stress due to high soil
temperatures as well as surface crusting may be important features to include in future
modeling work. |
