Numerical modelling and economics of agricultural land degradation in the Maltese Islands

Abstract

The study applies a new GIS-based numerical modelling approach to calculate the economic burden agricultural land owners suff er through soil erosion land degradation. Numerically modelled soil erosion volumes in Maltese agricultural areas were estimated at 766 278 m3/yr costing 7.98M€/yr to replace. The model calculates that the average owner incurs 1170€/0.01km2/yr on soil replacement and soil improvement requirements. With average yearly economic revenue of 1720€/0.01km2/yr, this cost benefi t imbalance may force agricultural land owners to not replace eroded soils. Over time, as a result of soil erosion, an increasingly large proportion of agricultural land may no longer suitable for agricultural purposes. Over 50 years, 1.53km2 (0.5% of Maltese area) of agricultural land may be depleted of soil, incurring an average national agricultural revenue loss of 0.26M€ per year. Soil erosion rates, and associated economic implications, may be mitigated with cost e ffective management practices. Two such practices include conservation tillage, which o ffers various economic advantages to farmers, and the restoration of breaches in slope-facing rubble walls in areas subject to soil erosion. The latter may require an investment of 11.94M€ at the National scale or €1,600 by the average agricultural land owner. Both measures contribute towards the sustainable use of Maltese agricultural areas and maintaining key associated ecosystems services.