Author(s)

Sidy Diakhaté^1,2,6*, Ndeye-Yacine Badiane-Ndour¹, Hassna Founoune-Mboup¹, Sally Diatta¹, Abdoulaye Fofana Fall¹, Rebecca R. Hernandez³, Laurent Cournac², Richard Dick⁴, Lydie Chapuis-Lardy⁵

¹National Research Laboratory for Crop Production (LNRPV/ISRA), Dakar, Senegal.
²LMI IESOL, International Laboratory for Ecological Intensification of Cultivated Soil in West Africa Dakar, Senegal.
³Land Air and Water Resource Department, University of California-Davis, Davis, CA, USA.
⁴School of Environment and Natural Resources, Ohio State University, Columbus, OH, USA.
⁵French National Research Institute for Sustainable Development (IRD), Montpellier, France.
⁶IRD-ISRA Research Center, BP1386, Dakar, Senegal.

Drought stress strongly affects soil biota and impairs crop production, which under climate change will be exacerbated in semi-arid cropping regions such as the Sahel. Hence soil management systems are needed that can buffer against drought. In West Africa, field studies have found intercropping of millet with the native shrub Piliostigma reticulatum improves soil-plant-water relations, microbial activity and diversity, and suppress parasitic nematodes, which can significantly increase crop yield. However, little information is available on its beneficial or negative effects on soils or crops during water stress. Therefore, the objective was to investigate the impact of P. reticulatum in moderating water stress effects on soil properties and pearl millet (Pennisetum glaucum [L.] R. Br.) productivity. In the greenhouse, soil chemical and microbial properties and millet growth were investigated with a factorial experiment of varying levels of soil moisture (favorable, moderately stressed, or severely stressed water conditions) that was imposed for 55 days on soils containing sole P. reticulatum or millet, or millet + P. reticulatum. The results showed that the presence of P. reticulatum did not buffer soils against water stress in relation to soil chemical and microbial properties measured at the end of the experiment. Severe water stress did significantly decrease the height, number of leaves, and aboveground biomass of millet plants. Additionally, respiration, nematofauna trophic structure and abundance decreased as water stress increased. Lastly, bacterial feeders and plant parasitic nematodes were the most sensitive to severe water stress while fungal feeding nematodes remained unaffected. The results suggested that the intensity of water stress had more negative effects on soil basal respiration rather than soil microbial biomass.

Sub-Saharan Africa, Shrub-Based Cropping System, Pennisetum glaucum (L.) R. Br., Water Stress, Climate Change, Nematode, Basal Respiration, Greenhouse Experiment

Diakhaté, S. , Badiane-Ndour, N. , Founoune-Mboup, H. , Diatta, S. , Fall, A. , Hernandez, R. , Cournac, L. , Dick, R. and Chapuis-Lardy, L. (2016) Impact of Simulated Drought Stress on Soil Microbiology, and Nematofauna in a Native Shrub + Millet Intercropping System in Senegal. Open Journal of Soil Science, 6, 189-203. doi: 10.4236/ojss.2016.612018.