Spatial and Temporal Distribution of Soil Microbial Properties in Two Shrub Intercrop Systems of the Sahel

The Sahel is an ecologically vulnerable region where increasing populations with a concurrent increase in agricultural intensity has degraded soils. Agroforestry offers approach to remediate these landscapes. A largely unrecognized agroforestry resource the are native shrubs, Piliostigma reticulatum , and Guiera senegalensis that varying degrees already coexist row crops. These shrubs improve soil quality, redistribute water from deep surface (hydraulic lift), can crop growth. However, little information available on whether affect spatial temporal dynamics of microbial communities. Therefore, objective this study was determine composition activity wet dry seasons the: shrub rhizosphere (RhizS), inter-root zone (IntrS), outside influence (OutS) for both G. P. Senegal. 3 × 2 factorial field experiment imposed at two locations (490 700 mm annual rainfall respectively), had sampling treatments three (RhizS, IntrS, OutS) (wet dry). Soils were analyzed for: diversity (DGGE bacterial 16S or fungal 28S rRNA gene sequences phospholipids fatty acid, PLFA); enzyme activities; biomass carbon (MBC); nitrogen (N) mineralization potential. For DGGE profiling, community responded more effect, whereas, sensitive season. PLFA, MBC, activities inorganic N significantly higher RhizS. presence maintained communities during This represents paradigm shift semi-arid environments logically it would be expected have no extended In contrast shown not case rather roots season most likely due hydraulic lift root exudates. implications when cropped fields decomposition nutrients proceed Thus, enabling accumulation plant uptake by crops rainy