Abawi, G.S., and T.L. Widmer. 2000. Impact of soil health management practices on soilborne pathogens, nematodes and root diseases of vegetable crops. Applied Soil Ecology 15: 37–47.

Allison, F.E. 1973. Soil Organic Matter and Its Role in Crop Production. Amsterdam: Elsevier Scientific Publishing. In his discussion of organic matter replenishment and green manures (pp. 450–451), Allison cites a number of researchers who indicate that there is little or no effect of green manures on total organic matter, even though the supply of active (rapidly decomposing) organic matter increases.

Björkman, T., R. Bellinder, R. Hahn, and J. Shail, Jr. 2008. Buckwheat Cover Crop Handbook. Geneva, NY: Cornell.

Cornell University. Cover Crops for Vegetable Growers. URL.

Hargrove, W.L., ed. 1991. Cover Crops for Clean Water. Ankeny, IA: Soil and Water Conservation Society.

MacRae, R.J., and G.R. Mehuys. 1985. The effect of green manuring on the physical properties of temperate-area soils. Advances in Soil Science 3: 71–94.

Miller, P.R., W.L. Graves, W.A. Williams, and B.A. Madson. 1989. Cover Crops for California Agriculture. Leaflet 21471. Davis: University of California, Division of Agriculture and Natural Resources. This is the reference for the experiment with clover in California.

Pieters, A.J. 1927. Green Manuring Principles and Practices. New York: John Wiley.

Power, J.F., ed. 1987. The Role of Legumes in Conservation Tillage Systems. Ankeny, IA: Soil Conservation Society of America.

Sarrantonio, M. 1997. Northeast Cover Crop Handbook. Soil Health Series. Kutztown, PA: Rodale Institute.

Smith, M.S., W.W. Frye, and J.J. Varco. 1987. Legume winter cover crops. Advances in Soil Science 7: 95–139.

Sogbedji, J.M., H.M. van Es, and K.M. Agbeko. 2006. Cover cropping and nutrient management strategies for maize production in western Africa. Agronomy Journal 98: 883–889.

Summers, C.G., J.P. Mitchell, T.S. Prather, and J.J. Stapleton. Sudex cover crops can kill and stunt subsequent tomato, lettuce, and broccoli transplants through allelopathy. CaliforniaAgriculture 63(2): 35-40.

Sustainable Agriculture Network. 2007. Managing Cover CropsProfitably, 3rd ed. Handbook Series, No. 9. Beltsville, MD: USDA Sustainable Agriculture Network. sare.org. An excellent source for practical information about cover crops.

Weil, R., and A. Kremen. 2007. Thinking across and beyond disciplines to make cover crops pay. Journal of the Science of Foodand Agriculture 87: 551–557.

Widmer, T.L., and G.S. Abawi. 2000. Mechanism of suppression of Meloidogyne hapla and its damage by a green manure of sudan grass. Plant Disease 84: 562–568.