An overview of the physical and chemical properties of substrates used in horticulture at southern Brazil

Abstract

The cultivation in greenhouse and containers culminated with the necessity to use substrates with formulations as well as distinguished chemical and physical characteristics, the last ones assuming a key role in cultivation of horticultural plants. The aim of this study is to present results of physical and chemical analyses of substrates forwarded to an commercial laboratory (Laboratório de Substratos para Plantas - UFRGS) for the last three years, aiming to establishing a panorama of the substrates area and comparing them with reference values cited in the literature. In this period were performed 307 physical and 479 chemical analyses, which were the basis for this study. Physical analyses performed were the density in dry basis and the water retention curve (total porosity, air space, available water and remaining water). Chemical analyses were the electrical conductivity (EC) and the pH. The main results concerning physical characteristics, demonstrate that the substrates present wide range of density in dry basis and may be used for different sized containers; however most substrates analyzed is out of ideal range for the other physical characteristics of the substrate. For the chemical characteristic the substrates in cultivation in southern Brazil are mostly alkaline and the electrical conductivity of the substrates in cultivation is very diverse, with considerable number of samples above the recommended.