3.2. Soil carbon stocks across different land uses
There were large differences in SOC stocks between sites imple- menting SWC and conventional agricultural practices. These were signif- icant at all sampling depths with the exception of the topmost interval (0 to 0.05 m depth; Fig. 2). On the other hand, semi-natural vegetation sites consistently showed greater amounts of OC in the first 0.05 m of the soil, but these variations were not significant at deeper locations. Convention- al agricultural sites contained about 20 Mg C ha−1 in the soil profile under consideration (0.85 m), while sites with SWC measures and semi-natural vegetation stored above a third more. Overall, the average SOC contained in the first 0.3 m of the soil accounted for roughly half of that stored in the studied soil profile (Fig. 2; Table A2).
3.3. Soil properties across different land uses
Soil textural analyses showed no significant differences across the different land uses (Table 3). However, SOC contents and C/N ratios under conventional agriculture were lower than those of sites having SWC structures and those sustaining semi-natural vegetation. The same observed differential pattern also applied for SOC stocks, while soil nitrogen stocks were higher in semi-natural ecosystems than in cropped sites (Table 3). There was a similar variation in δ13C values along the soil profile for the three land uses (Fig. A1). These exhibited a noticeable increase in δ13C values within the first 0.3 m depth below which they remained relatively constant. From that depth down, the