The use of compost in horticulture, as a soil amendment and nutrient source for plants and the soil microbial community, will contribute to the recycling of waste, and reduce the use of non-renewable artificial fertilisers. For many pot cultures, it will reduce the use of non-renewable peat, compared to other systems. Batches of compost will be tested in North Western, Central Western, and Southern Europe. Specialists in soil microbiology, soil fauna and physiochemical assessments will analyse these compost and compost/soil mixtures.
The general objective of this RTD-proposal is to provide essential information on the safe application of compost in horticulture to provide more sustainable production systems with respect to disease suppression and nutrient management. More specifically, the scientific / technological objectives are:
1. to define composting process conditions that kill plant and human pathogens
2. to predict disease suppressive properties of compost using abiotic and biotic parameters
3. to study the possibility of enriching composts with selected antagonists to increase the disease suppressive characteristics of compost
4. to stimulate the use of compost in the cultivation of pot plants, cut flowers and vegetables by transferring the obtained knowledge to industry and growers.
Progress to Date
Composting conditions needed to kill human and plant pathogens.
Two human pathogens, Escherichia coli and Salmonella choleraesius, and four plant pathogens, Ralstonia solanacearum, Tobacco Mosaic Virus (TMV), Polymyxae betae and Spongospora subterranea, are being studied for their survival in compost heaps. These pathogens are either heat tolerant or difficult to detect and may pose a problem when organic waste materials are contaminated with one or more of these pathogens. S. choleraesius, and even more so TMV, are heat tolerant and temperatures in compost heaps may not reach levels that will eradicate TMV. However, it has been reported that TMV may already be eradicated at temperatures below 50 degrees C, indicating that other factors also play a role in the eradication of TMV during composting. The data show that the eradication of R. solanacearum will usually not be problematic during composting. Experiments on the other pathogens are in progress.
Disease suppression by compost.
Much research has been performed on suppression of root disease by composts. Generally, the suppressiveness of composts is highly variable making it difficult to implement compost in agriculture for the control of root diseases. For practical purposes, the suppressiveness of compost should be predictable by easily measurable parameters, or suppressive properties should be obtained by manipulating the composting process. The project aims to define compost characteristics that are highly related to suppressiveness and to increase suppressiveness by inoculating the compost with biocontrol agents.
A fast assay has been developed to obtain information of the conduciveness of composts to harbour specific biocontrol agents. Several strains of Pseudomonas, Trichoderma, Gliocladium and other species have been tested for their ability to colonise and survive in three different types of compost. The three composts varied considerably in their conduciveness to the tested biocontrol organisms, with one generally being superior to the other two. Experiments will be continued with other composts and a selection of the biocontrol agents that were tested in the first year.
Scientist responsible for the project
Dr DIRK JAN van der GAAG
Kruisbroekweg 5 Box 8
2670 AA Naaldwijk
Netherlands (The) - NL
Phone: +31 174 636885
Fax: +31 174 636835
||Applied Plant Research Research Unit Glasshouse Horticulture
||01 January 2002
||2 071 222 €
|Total EC contribution
||1 574 790 €
|Web address of the project