Soil Health and Cover Crops

Soil Health and Cover Crops

Soil is a foundational resource to farming, conservation and health in the 21st century. Soil health, also referred to as soil quality, is defined as the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. Key concepts of soil health and ecological soil management include protecting soil habitat; managing more by disturbing less; keeping soil covered, diversifying food and carbon sources for soil microorganisms; diversifying plant and animal communities; and growing living roots throughout the year. This topic page will focus on how to build soil health for improved soil function and better crops.

Definition: Soil health is the capacity of a soil to maintain its function and flow of ecosystem services given a specific set of physical, chemical and environmental boundaries. (USDA-NRCS 2013; Doran et al., 1994)

  • Crop productivity
  • Nutrient storage and cycling
  • Physical stability
  • Water holding capacity and flow
  • Filtering and buffering capacity
  • Degrading or detoxifying pollutants
  • Biodiversity
  • Management
  • Soil properties
  • Crops
  • Soil biology
  • Environment

Managing for Healthy Soil Processes

Soil processes include nutrient availability, pH, cation exchange capacity, aeration, drainage, water infiltration and holding capacity, microbial activity and diversity, nutrient mineralization, soil organic matter decomposition and accretion.

  • Keep soil covered year-round
  • Minimize soil disturbance (e.g., physical, chemical, and biological)
  • Maximize living roots
  • Energize the soil ecosystem (Use plant and livestock diversity to increase and energize diversity in the soil!)
  • Rapidly increasing world population,
  • Increased food supply requirements
  • Continued loss of prime farmland to development
  • Improved long-term sustainable agriculture production
  • Enhanced economic viability
  • Improved environmental resilience
  • High-performing productive soils are needed
  • Production costs can be reduced
  • Profits can be improved
  • Natural resources are critically important and need to be protected
  • Water quality is improved due to reduced nutrient and sediment loads
  • Biodiversity and wildlife habitat are enhanced

Why Minimize Soil Disturbance?

Good soil biology begins with practices that enhance and promote soil as a habitat and an ecosystem.

  • Destroys soil structure
  • Accelerates decomposition of organic matter
  • Increases erosion
  • Disrupts habitat of soil organisms
  • Can cause compaction
  • Collapses soil lattice structure which is foundational to soil pore space, which critical for air and water flow
  • Disturbs and cuts up the carbon and micronutrient trading network of the mychorrhizal fungi
  • Disrupts and can destroy the infrastructure of the soil habitat

What are the benefits of healthy soils?

The benefits of healthy soils include better soil function, consistent crop productivity, improved nutrient storage and cycling, increased resilience against drought and other stresses, enhanced water holding capacity, and greater microbial and habitat diversity.

Soil cover in the form of cover crops, living mulches, crop and forage residue provides armor for the soil to prevent and reduce wind and water erosion, evapo-transpiration, extreme surface temperatures, and crusting.

  • Adding new organic matter (crop and forage residues) every year is the most important way to improve and maintain soil health
  • Bare soil is susceptible to wind and water erosion, evapo-transpiration, extreme surface temperatures, and crusting
  • At temperatures above 110+ degrees soil microorganisms begin to shut down activity
  • Increases the decomposition of woody surface residues
  • Reduces diseases the next year
  • Suppresses weed pressure
  • Maintains biological activity longer in the season
  • Increases Nitrogen (N) and Carbon (C) mineralization
  • Enhances nutrient cycling
  • Organic matter and soil structure
  • Legumes and nitrogen (N) production
  • Nutrient enrichment
  • Soil microbial activity
  • Water conservation
  • Weed suppression
  • Pest management
  • Cool Season Grasses
  • Cool Season Broadleaves
  • Warm Season Grasses
  • Warm Season Broadleaves

What are we watching and learning about soil health?

Soil Health: What are we reading?

  • Ackerman-Leist, P. 2013. Rebuilding the foodshed: How to create local, sustainable and secure food systems. A community resilience guide. White River Junction, VT: Chelsea Green.
  • Albrect, W. 1938. Soils and Men: Yearbook of Agriculture. Washington, DC: USDA.
  • Brady, N.C. and Weil, R.R. 2008. The nature and properties of soils, 14th Edition.
  • Clark, A. (Ed.). 2012. Managing cover crop profitably, 3rd. Edition. USDA Sustainable Agriculture Research and Education Handbook 9. Accessed at http://www.sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitably-3rd-Edition
  • Cornell Soil Health Assessment Training Manual. (PDF)
  • Evanylo, G. and R. McGuinn. 2009. Agricultural management practices and soil quality: Measuring, assessing, and comparing laboratory and field test kit indicators of soil quality attributes. (PDF)
  • Fleming, C. and W. Thomason 2015. Virginia Cover Crops Fact Sheet Series No. 1: Beneficial Uses of Cover Crops. Accessed at http://pubs.ext.vt.edu/CSES/CSES-120/CSES-120.html
  • Fleming, C. and W. Thomason 2015. Virginia Cover Crops Fact Sheet Series No. 2: Cover Crop Performance Evaluation in Field and Controlled Studies. Accessed at http://pubs.ext.vt.edu/CSES/CSES-121/CSES-121.html
  • Gliessman, S.R. 2015. Agroecology: The ecology of sustainable foods systems. 3rd Edition. Boca Raton, FL. CRC Press.
  • Hodges, S., Schonbeck, M., Dorn, S., and D. Westfall-Rudd. Sustainable farming practices: Soil management In Virginia Whole Farm Planning: An educational program for farm startup and development. Virginia Beginning Farmer and Rancher Coalition. (In Press)
  • Howard, A. 1972. The soil and health: A study of organic agriculture. Schocken Books
  • Karlen, D.L. 2012. Soil health: The concept, its role and strategies for monitoring. In D.H. Wall et al. (eds.) Soil Ecology and Ecosystem Services. (pp. 331 – 336). Oxford University Press.
  • Killham, K. 1994. Soil ecology. Cambridge University Press.
  • Lal, R. 2014. Societal value of soil carbon. Journal of Soil and Water Conservation. Vol. 69. No. 6: 186 – 192. doi:10.2489/jswc.69.6.186A
  • Magdoff and Van Es. 2009. Building soils for better crops, 3rd Edition.
  • Marschner, H. 1997. Mineral nutrition of higher plants. 2nd Edition. New York, NY: Academic Press.
  • Soil and Water Conservation Society (SWCS). 2000. Soil Biology Primer. Rev. ed. Ankeny, Iowa: Soil and Water Conservation Society.
  • Sylvia, D.M., Fuhrman, J.J.,   Hartel, P.G., and D.A. Zuberer. 2005. Principles and applications of soil microbiology, 2nd Edition.
  • Thistlethwaite, R. 2012. Farms with a future: Creating and growing a sustainable farm business. White River Junction: Chelsea Green Publishing.
  • USDA – NRCS Soil Health Fact Sheets
  • USDA-NRCS’ Soil Quality Indicator Sheets on Biological, Chemical and Physical Properties.
  • Virginia NRCS Cover Crop Planning Manual 1.0
  • White, C., and M. Barbercheck. 2012. Managing soil health: Concepts and practices.  Agroecology In Practice Fact Sheet EE0026.  The Pennsylvania State University. (PDF)

Featured Publications

Contacts

Eric Bendfeldt
ebendfel@vt.edu

Greg Evanylo
gevanylo@vt.edu

John Galbraith
john.galbraith@vt.edu

Wade Thomason
wthomaso@vt.edu

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