Land spreading of solar-dried citrus peel to control runoff and soil erosion

Marginal areas of southern Italy are often characterised by steep slopes and scarce vegetal coverage, which induce relevant runoff and soil erosion phenomena. On the other hand, the agricultural system of some Italian regions is characterized by the presence of many citrus industries, producing high amounts of by-products and wastewater. The possibility to spread over land orange peel could represent an alternative solution for a more sustainable biomass disposal and, at the same time, against the risks soil erosion in Mediterranean areas. This paper reports the results of an experimental research activity aimed at evaluating the hydrological effects of land spreading of solar-dried citrus peel over steep plots (remodelled at 100%-slope), containing bare soil or covered by vegetation and exposed to natural rainfalls. The comparison of hydrological observations to those performed on not treated soils (“control”) highlighted that the addition of citrus peel to soil induced an appreciable reduction of runoff and particularly of sediment yield, due to the improvement of the soil properties, which encourages establishment and development of vegetation.