Soil Structure and Moisture Constants Changed by Tobacco Waste Application in a Clay Textured Field

Abstract

In this study, effect of tobacco waste (TW) application on soil structural parameters and water holding capacity were determined in a clay field. Tobacco waste was applied into a clay soil surface (0 - 15 cm) with 4 different rates (0, 2, 4 and 6%) and three replications in a randomized plot design. After eight months, changes in soil organic carbon content, bulk density (BD), total porosity (F), gravimetric (W) and volumetric (θ) water content, air filled porosity (Fa) and relative saturation (RS) values were determined in clay soil for each treatment. TW application rates significantly increased organic C contents and F values while they significantly decreased bulk density values of the clay soil. Although the W values significantly increased over the control, the θ and RS values decreased with increasing the F values by the application of TW. The high application rates of TW (4 and 6%) increased moisture content at permanent wilting point (PWP) more than at field capacity (FC). Thus, AWC values in higher rates of TW were lower than the AWC values in 2% rate of TW and control treatments. Increasing Fa is important for plant root respiration and microbial activity especially in the clay soils. The high rates of TW increased F values but decreased the AWC of clay soil over the control treatment.