Carbon, Nitrogen, and Natural Abundance Of Δ13C and Δ15N of Soils Under Agroforestry Systems

ABSTRACT The aim of this study was to evaluate changes in C and N levels and in the natural abundance of δ15N and δ13C of a Inceptisol in an agroforestry system (AFS). Soil samples were collected from eight depth levels from 0.0-1.0 m in each studied area. The experiment was carried out in a completely randomized 2 × 8 (2 forest areas and 8 depths) split-plot design with three replications. Except for the topsoil (0.0-0.10), the area of this AFS has preserved content of C and increased level of N (0.2-1.0) compared to the Forest. Both areas showed signs of natural abundance of δ13C in plants with C3 photosynthetic pathway, and the forest area presented higher values of δ15N in the superficial layers (0.0-0.20), indicating greater decomposition of organic matter.