Hydrologic Redistribution and Rhizosphere Biology of Resource Islands in Degraded Agro-ecosystems of the Sahel

Principal Investigator:

Richard Dick: Project Director and Professor, School of Environment and Natural Resources
Amanda Davey: Project Coordinator, School of Environment and Natural Resources


Institut Sénégalais de Recherches Agricoles (Senegal’s Agricultural Research Institute)
Research Institute for Development (IRD), France
IRD’s Laboratory of Tropical Microbial Ecology, Senegal
University of California-Merced
University of Thies, Senegal
Central State University, Ohio


October 1, 2010 - September 30, 2018 (Estimated)


The $2.6 million, 5 year project funded by National Science Foundation (NSF) is investigating the unique interactions between shrubs and crops as a basis for developing sustainable agricultural practices in the ecologically fragile Sahel region of Africa. The project director is Richard Dick, Professor of Soil Microbial Ecology in the School of Environment and Natural Resources. Amanda Davey (SENR) coordinates project logistics, purchasing, reporting, student preparation for living and working in Senegal, and budget management.

The Sahel is experiencing serious landscape degradation and desertification that significantly reduces food security in the region.  A potential key for restoring these landscapes are two unrecognized shrub species that can coexist with crops and have the ability to  lift water from wet sub- to dry-surface soil and improve soils. Fundamental hydrology and rhizosphere microbiology research will contribute towards the development of optimized shrub-crop systems that reduce crop water stress and stimulate microbial enhancement of nutrient availability (e.g. nitrogen fixation) and plant growth (e.g. plant hormones, disease suppression). This knowledge will provide a basis for the logical design of agricultural systems that will restore currently degraded landscapes and help develop effective and sustainable agricultural systems in the Sahel.  This will benefit all countries in the Sahel which, together, have >15 million ha of semi-arid land currently farmed by similar destructive agricultural practices.

Recent Developments:

During 2014, Matthew Bright, a candidate in the School of Environment and Natural Resources specializing in soil science who is being advised by Dr. Dick, Spencer Debenport, a PhD candidate in the Department of Plant Pathology who is being advised by Dr. Brian McSpadden-Gardner, and Chelsea DeLay, a soil science research associate in the School of Environment and Natural Resources under the direction of Dr. Dick completed their two year field work in Senegal. They are investigating the microbiology of shrub rhizosphere, and associated interactions with crops. This includes studying beneficial bacteria and fungi, particularly mycorrhizal fungi. Additionally, University of California Merced PhD candidate, Nathaniel Bogie, under the supervision of UC Professor Teamrat Ghezzehei, investigated the hydrologic aspects of the shrub-crop system.

In May the second advanced training course in tropical soil microbiology, called MicroTrop took place in Senegal. The intensive one-month course brought together PhD students and post-doctoral researchers from the United States and African countries of Benin, Burkina Faso, Cameroon, Ivory Coast, Kenya, Madagascar, Senegal, and Zimbabwe. Participants received cutting-edge lectures and lab training on the full range of microbial ecology topics. The course capstone was a research project pairing U.S. participants with African participants. Each group designed a project that included experimental and analytical procedures, data analysis, write-up, and presentation. Aside from the scientific training, participants engaged in numerous cultural and interpersonal interactions to expose participants to the culture, agriculture, and environmental challenges of Senegal that are representative of much of West Africa.