New biotests to measure the biological qualities of composts

To measure the biological qualities of composts, a new set of biotests was developed and evaluated by different institutions using the same compost materials. Per institution the same eight tests with different plants were carried out. As reference a defined standard substrate was used enabling to produce comparable results even under different conditions and with different personal. It could be shown that with the most appropriate combination of tests and test plants it is possible to provide the producers and users of compost a reliable method to measure the biological qualities of composts.