Buffering Capacities in Mediterranean Soils under Different Soil Management

Dryland areas are being seriously affected by degradation processes. The use of organic amendments in ecosystem restoration is an effective technique for accelerating soil regeneration processes in degraded drylands. The goal of this paper is to establish the effect of application of various organic amendments to degraded soil, on soil buffering capacity after 10 years. Buffering capacity is an important indicator, which is evidence of the overall condition of the soil ecosystem and influences a whole range of other soil properties, because buffering in soil is defined as the resistance of the soil to variations in pH. The experiment was carried out at the location called El Pinarillo in the Sierra de Tejeda, Almijara and Alhama Natural Park (southern Spain). The site is located at 470 m a.s.l., in the upper part of an alluvial fan (calcareous conglomerates). The experiment treatments were natural soil, bare soil, hydropolymers, pinus mulch, prescribed burnt, Sewage sludge. Application of hydrogel had the smallest effect on buffering capacity 10 years after application and manifested as just a slight decrease in soil buffering capacity while maintaining or improving other soil properties. The good buffering capacity of this variant also allows further work with the specific soil without greater risk of further degradation. Sludge was identified as the worst variant, whereas soil buffering capacity fell markedly, because sewage sludge may significantly inhibit microbial activity and decomposition of organic matter. This variant is not suitable for further use, because there is a risk of further soil degradation.