Spatial Prediction of Soil Aggregate Stability and Aggregate-Associated Organic Carbon Content at the Catchment Scale Using Geostatistical Techniques

摘要: The association of organic carbon with secondary particles (aggregates) results in its storage and retention soil. A study was carried out at a catchment covering about 92 km2 to predict spatial variability soil water-stable aggregates (WSA), mean weight diameter (MWD) (OC) content macro-(> 2 mm), meso-(1–2 micro-aggregate (< 1 mm) fractions, using geostatistical methods. One hundred eleven samples were collected the 0–10 cm depth fractionated into macro-, meso-, micro-aggregates by wet sieving. OC determined for each fraction. greater percentage found micro-aggregates, followed meso-aggregates. Aggregate greatest meso-aggregates (9 g kg−1), (7 while least macro-aggregates (3 kg−1). Although significant effect (P = 0.000) aggregate size on found, however, our findings did not support model hierarchy. Land use had 0.073) content. coefficients variation (CVs) contents associated fraction indicated as most variable (CV 71%). Among lower CV value 27%. WSA ranged from 15% 84% micro-aggregates. Geostatistical analysis showed that measured variables exhibited differences their patterns both magnitude space relative nugget variance aggregate-associated properties than 45%. range variogram almost similar (about 3 km) three studied classes. km 6.5 Kriged maps predicted WSA, MWD fractions clear patterns. However, close similarity (co-regionalization) observed between MWD.