Composting carbon-rich residues like wood and timber by-products with high moisture, and nutrient-rich wastes like manures, biosolids and food processing wastes holds promise as a source of high-quality compost for the horticulture industry, and as an environmentally and economically sound means to process and reuse by-products. 

Potential savings could be realized from reduced fertilizer, pesticide and irrigation water use. The costs associated with compost acquisition and application may be offset by reducing or eliminating the need for a cover crop fallow period and by a shortened crop production cycle. 

Objectives of current UW research
We are investigating the use of composts in field nursery crop (woody ornamentals) production, comparing compost and conventional production practices to determine the benefits of each system. 

The project evaluates the effects of adding moderate to high rates of decomposed organic matter (compost) on soil physical, chemical and biological properties and growth and health of woody ornamentals. By measuring both soil and plant parameters, we can relate changes in soil properties to plant growth, disease incidence and overall marketability.

Full Research Proposal   Effects of compost on soil chemical, physical and biological properties in field nursery crop production

The Importance of Soil Organic Matter in Nursery Crop Production - A powerpoint presentation

See also Effect of Feedstocks on the Composting Process and Finished Products   (Abstract)

Web Resources
Bio Cycle - Journal of Composting & Recycling on-line 
Composting News on-line

Print Resources and References

The Composters Answers Book. Volume 1. 1999.

Composting Manure for Value-Added Products. 2001.

Hendricks, W. 1993. Using compost on liner beds. Combined Proc. Int. Plant Prop. Soc. 43: 455-456.

Hoitink, H.A.J., M.A. Rose and R.A. Zondag. 1997. Composted biosolids: an ideal organic amendment for container media supplying both nutrients and natural suppression of root rots. p. 58-61.

Maynard, A.A. 1998. Using MSW compost in nursery stock production. Biocycle 39: 63-65.

Quarles, W. and J. Grossman. 1995. Alternatives to methyl bromide in nurseries: disease suppressive media. IPM Practitioner 17:1-13.

Press, C.M., W.F. Mahaffee, J.H. Edwards and J.W. Kloepper. 1996. Organic by-product effects on soil chemical properties and microbial communities. Comp. Sci. & Util. 4:70-80.

Raymond, D.A., C. Chong and R.P. Voroney. 1998. Response of four container grown woody ornamentals to immature composted media derived from waxed corrugated cardboard. Compost Sci. Util. 6: 67-74.

Tripepi, R.R., M.W. George, A.G. Campbell and B. Shafii. 1996. Evaluating pulp and paper sludge as a substitute for peat moss in container media. J. Environ. Hort. 14: 91-96.

Widmer, T.L., J.H. Graham and D.J. Mitchell. 1997. Potential use of composted municipal solid waste for management of Phytophthora root rot of bearing citrus. Proc. Fla. State Hort. Soc. 110: 46-50.

Widmer, T.L., J.H. Graham and D.J. Mitchell. 1996. The effect of composted municipal solid waste as a soil amendment on the growth of young citrus trees and Phytophthora nicotianae. Soil and Crop Sci. Soc. Fla. Proc. 55: 32-36.