Soil Organic Matter Fractions Under Eucalypt Plantation in Reform Management

Abstract

Harvesting and reform in eucalyptus can lead to changes in soil organic matter (SOM). The objective of this work was to evaluate the changes in total organic C (TOC) and N (NT), C and N in humic acid (HA), fulvic acid (FH), light organic matter (LOM) and microbial biomass (MB), in Ultisol of eucalypt stands over one, two and four years of renovated areas in Rio Grande do Sul state. After the first year of eucalyptus reform, there were 78% of increases in TOC (0.0-1.0-m soil layer). After two years, there was an increase in TN and an average reduction of 52% in LOM-C (0.0-0.1-m soil layer). FA-C, HA-C, and HU-C presented mean reductions of 43 Mg ha -1 (0.0-1.0-m soil layer) after four years of reform. The litter contribution of previous crop and the crop residues from the harvest resulted in increments of the SOM fractions. However, there is a negative effect in later years.

Carbon stocks and lability in land use and management systems in southwestern Goiás, Brazil

“…This large carbon fixation by eucalyptus plants can contribute to increases in the carbon stocks in the 0-0.1 m soil layer. Soares et al (2019) found an increase of 128 % in the carbon stocks in areas managed with eucalyptus for 13 years, after one year of a new planting, when compared to an area with native vegetation. These studies corroborate the results found in the present study, which showed the highest carbon stocks for areas cultivated with eucalyptus and under intensive grazing.…”

Best tillage practices for eucalyptus growth and productivity: A review on the Brazilian experience

“…In eucalyptus plantations under reform management, additional soil disturbance arrives from mechanical tillage for the new planting. Such disturbances are related to soil compaction and disintegration, and the incorporation of organic residues and horizons into the soil mass of the tilled profile (Soares et al, 2019). In a third rotation Eucalyptus grandis plantation, Gatto et al (2003) observed that the tillage systems adopted caused small changes in soil physical properties.…”