THE INFLUENCE OF THE PERLITE AS A SUBSTRATE FOR IMPROVING ON SOME WATER PROPERTIES ON THE FLUVIAL SOIL WITH AN APLICATION OF RETENTIONAL CURVES
This work is focused on the determination of potential of moisture retaining in perlite and fluvial soil. For assessing this parameter, the method of bar extractors and Porous plate extractors have been explored. The method is applied on 7 different regimes of pressure, (0.1; 0.33; 1; 3; 6.25; 11; 15 bars) in samples composed of perlite and fluvial soil present is different ratios of 20/80, 30/70, 50/50. The major goal of this study is to explore the experimental results of moisture content and to show the effectiveness of the water retention properties of perlite. Water retention curve is the relationship between the water content, and the soil and substrate water potential. This curve is characteristic for different types of soil and substrate, and is also called the soil moisture characteristic. The retention curve reflects the moisture content during a different tension. The date determined in this work are useful to assess the effective zone of the root system. We show that perlite exhibits specific features in respect to the water retention in several types of soils. Because of the good physical properties and the high porosity, the expanded perlite has a significant role in maintaining and improving of the water-airregime in the fluvial soils. In addition, it gives better accessibility of air and moisture for the plants, having a very positive influence on the soil features.