Spatial variation of aggregates stability and carbon stock in archaeological dark earths under cocoa cultivation

Abstract

The archaeological dark earth occur in ancient indian settlements, and its striking characteristics presence of ceramic artifacts and dark color with large stable deposit of organic carbon and may make on average six times more carbon than not anthropogenic soils, appearing therefore as a large reservoir of organic carbon. So the aim of this study was to evaluate the spatial variation of aggregate stability and carbon stock in area archaeological dark earth under cocoa cultivation in the municipality of Apuí, AM. A mesh was defined in an area with archaeological dark earth under cocoa cultivation, with dimensions of 42 × 88 m, with spacing of 6 × 8 m, totaling 88 sampling points collected at these sites were sampled at depths of 00.0-0.05; 0.05-0.10; 0.10-0.20 and 0.20-0.30 m. Soil density bulk analysis, geometric mean diameter, weighted mean diameter, total organic carbon and carbon stock. The results were submitted to descriptive statistics and geostatistics analysis. Soil attributes studied presented spatial dependence, spherical and exponential models and range from 20 m. Soil density, geometric mean diameter and mean weight diameter presented themselves dependent on the amount of organic carbon and carbon stock in soil ADEs. The high carbon content correlated with soil bulk density and aggregation rates in TPAs soils.