Author(s)

M B Almendro Candel, J Navarro-Pedreño, I Gómez Lucas, M M Jordán Vidal, E García-Sánchez & J Mataix-Solera

Abstract

Movement of Fe, Mn, Cu and Zn in a sewage sludge-treated soil M.B. Almendro Candel, J. Navarro-Pedreno, I. G6mez Lucas, M.M. Jordan Vidal, E. Garcia-Sanchez & J. Mataix-Solera Departamento de Agroquimica y Medio Ambiente, University Miguel Hernhandez, Elche, Alicante, Spain. Abstract Restoration of degraded soils with organic wastes could be a feasible practice to minimise erosion in the Mediterranean area. Today the use of sewage sludge to improve the nutrient contents of a soil is a common practice. In order to study the mobility of some elements through the soil, we have designed an experiment that tries to reproduce the behavior of metals in the soil as a part of the non- saturated zone. A controlled experiment in a greenhouse using soil columns was used. A calcareous soil from the south-east of Spain was amended with 30000, 90000 and 180000 kg sludge/ha. Iron, manganese, cupper and zinc were analyzed in soil samples at intervals of 15 cm of depth, during four months. Total, available, exchangeable and soluble forms of these micronutrients were analyzed. Positive effects of organic wastes application have been observed. We found that the use of sewage sludge as fertilizer of this calcareous soil increases the bioavailability of iron, copper and zinc. There are not important displacements and movement of the micronutrients along the soil profile. 1 Introduction During the last years, much research on the use of wastes in agriculture and for recovery of degraded soils have been developed. Sewage sludge is one of these wastes, because it practically contains all the nutrients necessary for plants. The application of sludge on agricultural soils is a method which offers important benefits: first, the transport and application costs are quite low (mostly if it is about dehydrated sludge) in the case of agricultural soils located near the

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