Stock and indices of carbon management under different soil use systems

Abstract

The aim of this study was to evaluate the stock of total organic carbon (TOC) and to perform the physical-granulometric fractionation of soil organic matter (SOM) in different management systems (MS). Three MS and one reference area of Native Forest (NF) were studied, and the three systems were sugarcane (SC), permanent pasture (PP) and no-tillage system (NTS). Soil samples were collected in the 0–0.05, 0.05–0.10, 0.10–0.20-m layers. Soil density (Sd), TOC, stratification index (SI), carbon stock (StockC), variation in StockC (∆StockC), carbon content of particulate organic matter (C-POM) and mineral organic matter (C-MOM), carbon stock index (CSI), lability (L), lability index (LI), and carbon management index (CMI) were determined. The MS presented higher Sd than the NF area. The NF area had higher TOC contents in the first layers, reaching 25.40 g kg-1 in the 0–0.05-m layer, with the PP area having higher values than the NF in the 0.10–0.20-m layer. The NF area showed the highest levels of C-POM (15.25 g kg-1) and C-MOM (10.15 g kg-1) in the first layer. In the 0.10–0.20-m layer, the PP and NTS systems were superior to the others. Regarding the C-MOM content, SC and PP showed higher levels in the 0.10–0.20-m layer. The highest CMI values were observed in the NTS and PP areas in the 0.10–0.20-m layer. The MS increased the Sd and reduced the TOC levels. The different MS modified the POM fraction, and the MOM fraction was most impacted by the SC area. The lability of the SOM was altered by the MS in the most superficial layers.

Modeling future carbon stock in melon cultivation agroecosystems under different climate scenarios

“…The melon cultivation agroecosystems composed of green manures and with no tillage over the years provided greater C stocks in the soil than the Caatinga (Figure 1), mainly due to the increased biomass input in these systems and maintained soil structure (Zhang et al, 2019;Morais et al, 2021). The vegetable cocktail with a greater predominance of legumes had a higher C stock when compared to the other green manures through the biological nitrogen fixation (BNF) process.…”

Humic substances and oxidable fractions of organic matter in different environments in Amazônia Maranhense

“…Most studies on SOM emphasize the in uence of different management practices on carbon (C) levels and stocks in the soil, and the most speci c way of evaluating such changes is related to a greater understanding of the stability of C in the soil. (Machado et al 2019, Morais et al 2021).…”