Assessing impact of tillage and mulch on soil erosion estimated by
Beryllium-7 and on soil moisture, and runoff in Central Benin
Abstract
This study was conducted to assess effect of tillage and mulch on soil
erosion control in typical agroecological conditions of Benin. In
addition, it involved also the assessment of soil moisture and runoff.
The experiment was conducted on two sites in Central Benin during the
short rain season of 2018. The effect of three tillage practices
(contour ridging: CR; slope ridging: SR and no-tillage: NT) and three
mulch doses (0 t.ha-1; 3 t.ha-1; and 7 t.ha-1) on soil erosion under
maize was investigated at small experimental plots (21 m2). The 7Be
method was used to assess the erosion rates, runoff was measured by
total collection and soil moisture content was determined by
thermo-gravimetric method. The results showed a significant decrease in
runoff coefficient and soil loss while increase soil moisture under
no-tillage and contour ridges compared to slope ridges. This effect was
pronounced with greatest. 3 and 7 tha-1. Highest runoff coefficient and
soil loss and the lowest soil moisture were observed under slope ridging
without mulch (i.e. SR0M). The 7Be measurement showed high soil losses
under SR0M (-10.19 t ha-1) at Dan and under NT0M (-7.36 t ha-1) at
Za-zounmè. The treatments NT7M (0.80 t ha-1); SR7M (0.69 t ha-1); IR3M
(2.07 t ha-1) and CR7M (4.05 t ha-1) showed deposition at Dan while SR7M
(0.23 t ha-1) and CR7M (3.93 t ha-1) showed deposition at Za-zounmè.
This study revealed useful information to be taken into consideration
when developing soil and water conservation management strategies in
Benin.