Abstract
Soils with high organic carbon content, such as those with A horizon, occur in different regions of Brazil. This study aimed to determine the quantitative and qualitative characteristics of organic matter regarding the humic A horizon under different land uses in Bom Jardim, in Rio de Janeiro State, Brazil. Samples from forest, pasture, Eucalyptus plantation, coffee cultivation, olericulture, and also passion fruit soils were sampled and analyzed. In October 2011, undisturbed samples from humic A horizons, were collected for soil density analysis. In addition, disturbed samples were collected for the determination of organic carbon (C-org) content, total carbon, humic substance fractions contents and natural abundance of (13)Carbon (delta C-13). Low C-org contents were observed in areas under olericulture, pasture and passion fruit cultivation. The fulvic acid fraction was higher than other fractions, regardless of land use. The small variability in delta C-13 indicated maintenance of original C-org and suggest high resistance of Soil Organic Matter in humic A horizons.
Highlights
Mountain farming systems are very common worldwide
Disturbed samples were collected for the determination of organic carbon (Corg) content, total carbon, humic substance fractions contents and natural abundance of 13Carbon (δ13C)
The fulvic acid fraction was higher than other fractions, regardless of land use
Summary
Mountain farming systems are very common worldwide. generally small-scale and family-run systems ensure food security for thousands of people, as well as protect the environment, in other words, beautify rural landscapes, these systems provide various ecosystem services (Kohler & Romeo, 2014). Some soil classes are more resilient to organic matter loss owing to agricultural interventions and low-temperature effects (Buol & Eswaran, 2000) Cultural practices, such as no-tillage farming, crop rotation and agroforestry, stabilize macroaggregates in the soil and reduce carbon loss. According to the Brazilian Soil Classification System, the humic A horizon is a thick, dark-colored layer with high organic carbon content and low base saturation (Santos et al, 2018) These unique characteristics are a reflection of soil formation, landscape evolution and cultural practices (Volkoff et al, 1984; Benites, 2002; Dias et al, 2003; Dalmolin et al, 2006; Silva et al, 2007; Calegari, 2008; Fontana et al, 2010, 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
