Effects of Amendment of Calcimagnesic Soils With Olive Husk Compost In Tunisia

Abstract

The amounts of olive husks produced in Mediterranean countries are very significant. Their treatment and disposal are becoming serious environmental problems. Increasing attention has been paid to finding a use for olive husks. A technological treatment is available to reduce their pollutant effects and to transform them into valuable products. The most suitable procedures are recycling instead of the detoxification of these wastes. It is possible to transform olive husks into organic fertilizers (composts) by composting with poultry manure. The compost has no phytotoxicity and may improve soil fertility and plant production. The composting process involves the microbial degradation of the polluting load of the solid wastes. Results of experiments using olive husk composts in crop production have shown that yields obtained with organic fertilization are similar, and sometimes higher, than those obtained with classic manure. Their bioavailability may be linked to the soil humic complexes originated by these organic fertilizers and to mineral components (active lime and clay). The composition of vegetable leaves improved similitude between compost and manure, normal concentrations but with deficiency in nitrogen, phosphorus and potassium.