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sur le développement des zones arides et semi-arides

Accueil du site → Projets de développement → Projets de recherche pour le Développement → 2021 → SHRUB-CROP-MICROBIOME INTERACTIONS : A NOVEL RHIZOSPHERE ALLIANCE TO MITIGATE IN-SEASON DROUGHT IN THE SAHEL

United States Department of Agriculture (USDA) 2021


Drought Sahel

United States Department of Agriculture (USDA) National Institute of Food and Agriculture


Identification : 1026605

Pays : Etats Unis

Durée : START : 01 JUN 2021 TERM : 31 MAY 2023

In the Sahel, the semi-arid region containing our study site in Senegal, millet is a staple crop and is produced by subsistence farmers without externally purchased inputs or irrigation. However, the UN reports that this area is a "climate change hotspot" with change occurring about 50% more quickly than other parts of the world. Erratic rainfall and drought decrease crop production and will further exacerbate food insecurity in this region. In Senegal, 47% of the population is already food insecure, and the United Nations estimates a nearly 600% increase in population by the year 2100, potentially forcing this country to rely on international aid. Therefore, local and biologically based systems are needed to promote plant resilience to drought. The goal of this work is to find such solutions for subsistence farmers and policy makers in the Sahel, and one such solution is intercropping millet crops with the native woody shrub Guiera senegalensis. This work builds on a twenty-year field study in the Sahel on the interactions between G. senegalensis intercropping and millet growth.We plan to collect soil from well characterized plots in Senegal, ship this soil to the US, and grow millet. The soils are obtained from intensively intercropped and intensively monocropped plots, and we aim to subject millet plants grown under each of these treatments to an early-season drought to characterize the effect of soil type (and therefore, management practice) on millet stress and the microbiome. We also include a treatment in which we add Guiera residues (leaves and small stems) into these treatments to mimic the effect of tilling these residues into the intercropped fields, a management practice our research group is also studying. These soil samples will be used to characterize structure and function of the microbial community by analyzing the DNA, RNA, phospholipid fatty acid profiles, and extracellular enzyme activities. Soil samples will also be used to characterize the nutrient content and carbon content of soils at the beginning and end of the drought. Plant samples will be analyzed for stress-related proteins and physical manifestations of stress.

The overarching objective is to determine the impact of intercropping millet crops with Gueira senegalensis on the metagenomes of soil microorganisms that have linkages to millet drought resilience. Specifically, the objective of the proposed work is to elucidate the impact of the microbial community on mitigating millet drought stress decoupled from influence of G. senegalensis and hydraulic redistribution. We plan to do this by growing pearl millet (Pennisetum glaucum) in soils that have been heavily intercropped and soils that have been heavily mono-cropped and subjecting them to a ten-day drought. Soils will also be treated with organic matter from G. senegalensis to mimic in-field conditions.Specific objectives:Test the impact of shrub presence on microbial community composition and gene expression, with emphasis on beneficial organisms that promote plant growth and confer drought resistance to plants, via a range of methods to profile community composition, metabolic potential, biomass, extracellular enzymes, and production of some known plant signaling molecules.The greenhouse-grown millet will be characterized for a range of physiological indicators of plant stress such as nutrient content, above and below ground biomass, and production of stress-related proteins and sugars.

Financement total : $101,820

Performing Institution : OHIO STATE UNIVERSITY
Investigator : Mason, L.

Présentation : USDA (NIFA)

Page publiée le 1er décembre 2021