Importance and trees management of Senegalia senegal on soil fertility and yield of associated crops in northern Senegal
Résumé
Trees are usually eliminated in field due their possible competition with crops for water and
nutrients. Our work aimed to investigate how to manage S. senegal trees to optimize their as-
sociation with crops. A field trial was conducted under natural conditions in a S. senegal plan-
tation 10 years old. Investigations were conducted during two years to evaluate the effect of
S. senegal trees management on gum arabic yield, associated cowpea yield, soil mycorrhizal
fungi spores density and enzymes activities reflecting soil fertility such as fluorescein diacetate
(FDA), acid phosphatase and dehydrogenase. Four treatments of pruning were applicated
(control, shoots, roots, shoots and roots pruning) and tapped in november. Soil samples were
collected during dry and wet seasons at 0-25 cm layer. Cowpeas were sown at the begin-
ning of rainy season in rows 0.5 m apart. Results showed that shoots pruning significantly
increased gum arabic while a negative effect of roots pruning was noted. The presence of
S. senegal increased soil fertility and cowpea yield. Any significant effect of treatments was
noted on pods yield during the first year. However, shoots pruning, shoot and roots pruning
increased significantly pods yield during the second year. Shoots and roots pruning seemed to
decrease FDA and spores density depending on the season. Our results showed that shoots
and roots pruning increased the positive effect on soil fertility and the association of S. senegal
with annual crops.