TITLE:
Impact of Simulated Drought Stress on Soil Microbiology, and Nematofauna in a Native Shrub + Millet Intercropping System in Senegal
AUTHORS:
Sidy Diakhaté, Ndeye-Yacine Badiane-Ndour, Hassna Founoune-Mboup, Sally Diatta, Abdoulaye Fofana Fall, Rebecca R. Hernandez, Laurent Cournac, Richard Dick, Lydie Chapuis-Lardy
KEYWORDS:
Sub-Saharan Africa, Shrub-Based Cropping System, Pennisetum glaucum (L.) R. Br., Water Stress, Climate Change, Nematode, Basal Respiration, Greenhouse Experiment
JOURNAL NAME:
Open Journal of Soil Science,
Vol.6 No.12,
December
6,
2016
ABSTRACT: 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.