Triggering effect of hydrogen peroxide on composting and a new method for assessing stability of composts in a thermally insulated microcosm system

In laboratory scale experiments using a microcosm thermally contained system, hydrogen peroxide exerted a triggering effect on the composting process. Upon treatment with hydrogen peroxide the temperature in the composting mass increased at a significantly faster rate than in the control. Similar triggering effects were observed in all cases of compostable materials examined. Among these were: immature orujo compost, orujo co-composted with alpechin, cotton gin trash alone or mixed with olive pulp (de-stoned by centrifugation fraction of de-oiled alpeorujo); mushroom straw compost; and spent mushroom compost. Compost quality is an intricate topic and its precise definition is often controversial. In general terms compost quality is the summation of the numerous characteristics of compost that are recognised to play a role in sustaining soil quality and contributing to plant health and yield. Although there may be disagreements on quantitative measures, this definition implies response of a soil ecosystem including its plant constituents to a particular compost treatment. This definition makes sense only if it is used in reference to a particular compost attribute and type of application. Moreover, most agree that important characteristics of compost, such as suppressiveness against soil borne root pathogens, are closely linked to the composting process. The observed triggering effect of hydrogen peroxide on composts can be successfully exploited for the assessment of an important aspect of compost quality, i.e. its stability, through the development of a more sensitive modification of the self-heating test.