Effect of different organic amendments on soil properties of a citrus orchard

Abstract

Soil properties and heavy metal contents in soil were studied after seven years of application of several organic amendments (ovine manure: 12 t/ha/y, anaerobically-digested sewage sludge: 12 and 24 t/ha/y and MSW compost: 12 and 24 t/ha/y). The changes observed in the soil properties depended on the considered parameter, treatment and sampling depth. The use of sludges and compost led to an increase of heavy metal contents in 0-20 cm depth samples, but not in those obtained at 20-40 cm