Carbon and Nitrogen Content and Stock in No-Tillage and Crop-livestock Integration Systems in the Cerrado of Goias State, Brazil

Abstract

The objective of this study was to evaluate the total organic carbon (TOC) and nitrogen content, and quantify the TOC and nitrogen stocks in land use systems in the Cerrado region of Goiás State, Brazil. A crop-livestock integration system (CLIS) was evaluated - (corn+brachiaria/beans/cotton/soya beans) and a no-tillage system (NTS) - (sunflower/millet/soya beans/corn). The vegetal coverage of the natural Cerrado, adjacent to the NTS and CLIS, was considered as the original soil condition. Soil samples were collected at layer depths of 0.0-10.0 cm, 10.0-20.0 cm, 20.0-30.0 cm, 30.0-40.0 cm, 40.0-50.0 cm, 50.0-60.0 cm, 60.0-80.0 cm, and 80.0-100.0 cm, in a full random experimental design. The CLIS had higher contents of TOC and N than the NTS up to a level of 30.0 cm. Higher nitrogen stocks were observed in the Cerrado. In the CLIS, higher TOC contents were found up to 30.0 cm and nitrogen contents up to 20.0 cm. The sum of stocks up to a depth of 100 cm for TOC and 40 cm for nitrogen was greater in the CLIS when compared to the NTS. Under the CLIS, the stocks of TOC (0.0-30.0 cm) and nitrogen (0.0-20.0 cm) increased in relation to those of the NTS. The CLIS was more efficient in stock accumulation than the Cerrado for the sum of layers 0.0-40.0 cm and 0.0-60.0 cm.