Stock and indices of carbon management under different soil use systems

Diego Henrique de Oliveira Morais,Paulo Guilherme da Silva Farias,Leandro Marciano Marra,Carla Aparecida da Silva,Jefferson Matheus Barros Ozório,Jean Sérgio Rosset,Camila Beatriz da Silva Souza,Selene Cristina de Pierri Castilho

doi:10.5327/z21769478867

Diego Henrique de Oliveira Morais, Paulo Guilherme da Silva Farias + Show 6 more

Open Access

https://doi.org/10.5327/z21769478867

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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.

Highlights

The conversion of natural areas into production systems can, in addition to modifying the landscape, change the edaphic quality when not properly handled (Freitas et al, 2018)
Regarding the Soil density (Sd), it can be observed that the three managed areas had higher values than the area of Native Forest (NF) in the 0-0.05-m layer, being similar to each other, ranging from 1.35 to 1.52 Mg m-3, whereas the area of NF presented a value of 1.08 Mg m-3 (Table 2)
In the 0.10–0.20-m layer, the areas of SC and permanent pasture (PP) had the highest values of Sd, and the area of no-tillage system (NTS) was similar to the NF (Table 2)

Summary

Introduction

The conversion of natural areas into production systems can, in addition to modifying the landscape, change the edaphic quality when not properly handled (Freitas et al, 2018). The different uses and managements directly influence soil attributes, such as carbon (C) (Lal, 2018; Ozório et al, 2019), besides causing changes in physical (Sales et al, 2018; Falcão et al, 2020), chemical (Souza et al, 2018; Assunção et al, 2019), and biological attributes of the soil (Borges et al, 2015; Barbosa et al, 2018). One of the methods for evaluating SQ is the analysis of C compartments of the physical fractions of the SOM (Cambardella and Elliott, 1992). With the data of physical fractionation, it is possible to obtain the carbon management index (CMI), developed by Blair et al (1995), which is a useful tool to analyze the effects of different management systems, as it analyzes the effects of the systems on the quality and quantity of SOM in the same index (Ghosh et al, 2019) Those are divided into two fractions, the particulate organic matter (POM), a fraction with high potential to indicate SQ in a short period of time (Bayer et al, 2002; Bongiorno et al, 2019); and the mineral organic matter (MOM), which is the most stable fraction of the SOM, being less sensitive to changes in a short period of time (Cambardella and Elliott, 1992).

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