Soil Greenhouse Gases: Relations to Soil Attributes in a Sugarcane Production Area

Abstract

The production of the main soil greenhouse gases (GHG: carbon dioxide [CO 2 ], methane [CH 4 ,] and nitrous oxide [N 2 O]) is influenced by agricultural practices that cause changes in soil physical, chemical, and biological attributes, directly affecting their emission to the atmosphere. The aim of this study was to investigate the infield soil carbon dioxide emissions (F CO2) and soil CO 2 , methane, and nitrous oxide production potentials (P CO2 , P CH4 , and P N2O , respectively) under laboratory conditions and their relationship to soil attributes in a mechanically harvested sugarcane area. Soil carbon dioxide emissions presented an infield average emission value of 1.19 µmol CO 2 m-2 s-1 , while GHG production in the laboratory was 2.34 µg C-CO 2 g-1 soil d-1 and 0.20 ng N-N 2 O g-1 soil d-1 for P CO2 and P N2O , respectively. No significant production or oxidation was observed for CH 4. Factor analysis showed the formation of two independent processes that explained almost 72% of the total variance observed in the data. The first process was related to F CO2 transport and its relation to soil physical attributes such as microporosity, macroporosity, the C/N ratio, soil moisture, and soil bulk density, showing the dependence between F CO2 and soil porosity. The second process was related to soil CO 2 and N 2 O production potentials under laboratory conditions and their relation to soil chemical attributes such as the sum of bases, pH, and available phosphorus, which affect microbial activity and contribute to GHG production. Although presented as independent, these processes are coupled and occur simultaneously in the soil, in addition to providing information about their variability and showing if the infield emissions are due to gas transport processes or soil carbon levels and their quality.

CO2, N2O and CH4 Emissions and C Storage in Eucalyptus Forests with Different Managements of Harvest Residues

“…Another factor that may explain the higher CO 2 -F observed in the planting rows compared to the inter-rows is the lower bulk density (Ds) found in this position in all soil layers evaluated (Figure 3). High Ds, and the consequent decrease in soil porous space, limits the diffusion of gases [52,53] After harvest, there was a signi cant increase in Ds in the 0-10 and 60-100 cm layers in the inter-rows (Figure 4). The same did not occur in the planting rows, since machine tra c occurs predominantly in the inter-rows [54].…”

Emissão de gases de efeito estufa do solo em áreas de Blowdown na Amazônia Central

“…A compactação dos solos também contribui similarmente, devido à ausência de continuidade porosa do perfil solo (Bicalho et al, 2017;Van Horn et al, 1995). Borges et al (2015) notaram que solos com aporte de carbono, emissões mais elevadas de CO2 foram encontradas em áreas com textura argilosa, se comparados com solos de textura arenosa em condições tropicais, similarmente às condições temperadas (Dilustro et al, 2005).…”