LOJKA B. , SPAAN W., HOOGMOED W. , POSTHUMUS H.
Abstract
The influence of different barriers on soil conservation and thus on sustainable crop yields in semi-arid zone of Burkina Faso was evaluated. A predictive computer model SCUAF was used to simulate four scenarios of different farming management to predict soil loss and crop yields over a period of 28 years. The simulation was based on the results of a field experiment assessing the effect of vegetation barriers Andropogon gayanus (perennial grass), Ziziphus mauritiana (shrub) and stone rows. The model predicted that vegetation and stone barriers significantly reduce soil losses compared to the control without barriers, and that higher soil losses occur in years with high rainfall. When additions are not applied sorghum yields decline over time in all four treatments. This is due to a decreasing amount of available nutrients in the soil due to nutrient mining, combined with loss of soil organic matter. Application of organic manure has a larger positive effect on the crop yields than inorganic fertilisers.
Key words:
Andropogon gayaus, erosion, soil conservation, Sorgum, Ziziphus maritiana.