It has been widely It has been widely recognized thecrucial role of soil monitoring in assessing the effectivenessof the soil measures and agro-environmentschemes passed by Regional and local administrationin complying the EU’s Common Agricultural Policy tosoil protection. The costs of soil monitoring howeverare substantial and the reliability of the results oftenquestionable. A reason is that the monitoring activitycommonly consists of a network of sampling pointswhich are then spatialized through different inferencemodels. This methodology does not often enable areliable estimation at the fi eld scale, that is the scalewhere the measures are foreseen and fi nanced. Theorganic carbon content of the ploughed layer is an importantsoil feature, which regulates many soil functions.It is therefore considered in Organic Farming(OF) and contemplated in many agro-environmentschemes. The adoption of OF is expected to improvesoil organic carbon content (SOC) of the fi elds asa whole. Nevertheless, the improvement might showlocal variations, because of the interaction betweencrop management and other factors, for instance, soilerosion. Aim of this work was to check the variationsin SOC and stock between and within fi elds where CAwas or not applied, using combined soil proximal sensors,namely γ-ray and Vis-NIR spectroscopy.The research work was carried out in four areas inwestern Sicily (Italy). Two adjacent arable fi elds weresurveyed for each area, comparing OF (green and organicmanure, 20-30 cm rotary tilling, chiselling, orploughing, crop rotation) lasting from 3-10 years, withcontinuous traditional farming (TF, no rotation, mineralfertilization, 40-50 cm ploughing). The lithologywas either clayey and calcareous-clayey fl ysch, orclays, silty-clays and marls, but the soils were similarand characterized by toposequences of Calcisols,Regosols, Cambisols, and Vertisols. The γ-radiometricsurvey was performed by “The Mole” sensor, made by“Medusa Systems”, while the Vis-NIR spectroscopyused Fieldspec 3Hi-res with the ASD Contact probefor Vis-NIR region (0.350-2.5 µm).The soils had similar texture, common vertic properties,presence of secondary carbonates, and loworganic matter, but gravel content was very variable.The carbon stock (upper 30 cm) of the whole fi eldsunder OF resulted signifi cantly higher than in TF (onaverage of 36.0 versus 33.2 Mg. ha-1). In addition,TF fi elds showed very heterogeneous SOC, with veryhigh and very low values, as a consequence of soilerosion, while in OF SOC was much more homogeneous,thus refl ecting both higher organic matter accumulationand lower soil loss from water erosion insimilar morphological positions.
|Number of pages||1|
|Publication status||Published - 2014|