Disease Suppression of Potting Mixes Amended with Composted Biowaste

W. J. Blok¹, A. J. Termorshuizen¹, T. G. C. Coenen¹, V. de Wilde² and A. H. M. Veeken²

Abstract
Peat mining destroys valuable nature areas and contributes to the greenhouse effect. This warrants the search for alternatives for peat in potting mixes. Composted biowaste could provide such an alternative. An additional advantage of (partially) replacing peat by compost is the increased disease suppressiveness.

In this study, nine commercial composted biowastes were tested for disease suppressiveness using the pathosystems Pythium ultimum-cucumber, Phytophthora cinnamomi-lupin and Rhizoctonia solani-carrot.

Increased disease suppression was found in compost-amended potting mixes for all three pathosystems. The level of disease suppression ranged from slight stimulation of disease to strong suppression. Suppressiveness against one disease was not well correlated with that against the other diseases. The CO2 production, a measure of general microbial activity, was the parameter most strongly correlated with the level of disease suppression.

Wetsieving the biowaste with tap water over a 4-mm sieve prior to composting yielded a compost with an 2.4-fold increase in organic matter and a twofold decrease in EC and Cl--concentration of the compost. The latter reductions allow for an increase of the amount of peat that can be replaced by compost.

A linear relation was found between the amount of compost added to the potting mix and the level of disease suppression indicating the potential for increasing disease suppressiveness of potting mixes by replacing peat by high-quality composted biowastes.

Source
Köpke et al (Eds) (2005): Researching Sustainable Systems. Proceedings of the First Scientific Conference of the International Society of Organic Agriculture Research (ISOFAR). ISOFAR / IOL / FiBL, Bonn and Frick; ISBN 3-906081-76-1

Author Locations and Affiliations
(1) Biological Farming Systems Group, Department of Plant Sciences, Wageningen University, Marijkeweg 22, 6709 PG Wageningen, The Netherlands
(2) Department of Environmental Technology, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands

Paper copy and PDF version may be ordered from FiBL (see FiBL shop at https://www.fibl.org/shop/index.php); FiBL order number 1394. A PDF version is available free of charge for ISOFAR members via the member area of www.isofar.org

en français


	Organic Sci. Cluster	About Us	Top 10	Français
	British Columbia	Alberta	Saskatchewan	Manitoba
	Ontario	Québec	Atlantic	Donate
Research Extension Courses Consumers -------------------------- Virtual Tours Student & Job Opportunities News Articles Standards -------------------------- Market Information Events Issues Animal Welfare Strategic Plans -------------------------- Links Award-winners Site Map	Disease Suppression of Potting Mixes Amended with Composted Biowaste W. J. Blok¹, A. J. Termorshuizen¹, T. G. C. Coenen¹, V. de Wilde² and A. H. M. Veeken² Abstract Peat mining destroys valuable nature areas and contributes to the greenhouse effect. This warrants the search for alternatives for peat in potting mixes. Composted biowaste could provide such an alternative. An additional advantage of (partially) replacing peat by compost is the increased disease suppressiveness. In this study, nine commercial composted biowastes were tested for disease suppressiveness using the pathosystems Pythium ultimum-cucumber, Phytophthora cinnamomi-lupin and Rhizoctonia solani-carrot. Increased disease suppression was found in compost-amended potting mixes for all three pathosystems. The level of disease suppression ranged from slight stimulation of disease to strong suppression. Suppressiveness against one disease was not well correlated with that against the other diseases. The CO2 production, a measure of general microbial activity, was the parameter most strongly correlated with the level of disease suppression. Wetsieving the biowaste with tap water over a 4-mm sieve prior to composting yielded a compost with an 2.4-fold increase in organic matter and a twofold decrease in EC and Cl--concentration of the compost. The latter reductions allow for an increase of the amount of peat that can be replaced by compost. A linear relation was found between the amount of compost added to the potting mix and the level of disease suppression indicating the potential for increasing disease suppressiveness of potting mixes by replacing peat by high-quality composted biowastes. *Source* Köpke et al (Eds) (2005): Researching Sustainable Systems. Proceedings of the First Scientific Conference of the International Society of Organic Agriculture Research (ISOFAR). ISOFAR / IOL / FiBL, Bonn and Frick; ISBN 3-906081-76-1 *Author Locations and Affiliations* (1) Biological Farming Systems Group, Department of Plant Sciences, Wageningen University, Marijkeweg 22, 6709 PG Wageningen, The Netherlands (2) Department of Environmental Technology, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands Paper copy and PDF version may be ordered from FiBL (see FiBL shop at https://www.fibl.org/shop/index.php); FiBL order number 1394. A PDF version is available free of charge for ISOFAR members via the member area of www.isofar.org en français
Top

Disease Suppression of Potting Mixes Amended with Composted Biowaste

Top