Compost Use in Plant Nurseries: Hydrological and Physicochemical Characteristics

Abstract

A study was conducted to collect, classify and analyze a large number of compost samples to establish a database for determining the relative quality of different types of composts and their potential use based on their hydrological and physicochemical characteristics. Special attention was devoted to the use of compost for flower growing, which extended the analysis to include substrates, such as peats and organic substrates for pot coltures. Some 64 samples of various composts were collected directly from production plants in northern Italy. Depending on the starting raw materials, compost samples were grouped in six categories: sludge compost; animal manure compost; slaughterhouse waste compost; source separated MSW compost; raw MSW compost and yard waste compost. At the same time, 52 samples chosen from among peats and organic substrates, for professional growers and amateur gardeners, were obtained or bought from greenhouses, garden centres and shops. Hydrological and physicochemical properties of the 116 samples (composts, peats and substrates) were determined including: easily available water (EAW), water buffering capacity, (WBC), air capacity, total porosity, bulk density, real density, pH, specific electrical conductivity, cation exchange capacity, organic carbon and ash