Edaphic breath in soil use and management systems

Abstract

In Brazil, soil use and occupation is largely responsible for greenhouse gas emissions, and one of the ways to monitor disturbances to ecosystems is through edaphic breathing, result of root breathing and the activity of microorganisms present in the soil. Given the above, the objective was to evaluate the microbial activity of the soil through edaphic respiration in four soil use systems. The research was carried out in four soil use systems: forest remnant area (F); agroforestry system (AFS); mandala (M) and pasture (P), belonging to the Universidade Federal da Paraíba (UFPB), Campus III, located in the municipality of Bananeiras - PB. Three samples composed of soil were collected at a depth of 0-20 cm, in each system of use, for chemical and physical analysis in order to characterize the study areas. To quantify carbon dioxide, the methodology described by Grisi was used and the CO2 captures occurred at night and during the day, for 8 months. A completely randomized design was used in a 4 x 2 factorial scheme. The lower temperatures during the night favored a higher CO2 emission; the pasture system and the AFS showed higher CO2 release in the two evaluation shifts, the forest remnant area showed less release of carbon dioxide. The microbial activity of the soil is more efficient at night; and the pasture area has higher CO2 emissions due to the lack of vegetation cover.

Comparison of Carbon Dioxide Efflux in Different Land Use Typologies

“…After being removed from the field, the containers were immediately closed and taken to the CCHSA/UFPB Post-Harvest Laboratory for chemical analysis. The absorbed CO 2 was determined according to the methodology proposed by Gomes et al (2022). The absorbed CO 2 was determined using the equation: ACO 2 = (A-B) x 2 x 2.2, in mg, A'ACO 2 = ACO 2 x (4/3 x 10,000/h + S), in mg m -2 h -1…”

Basal soil respiration in land use and cover systems in a caatinga enclaves moist forest

“…To prevent gas exchange, the bucket rim was buried in the ground. The absorbed CO 2 was determined according to the method proposed by Gomes et al (2022).…”

“…However, within the daytime period, the greatest release of soil CO 2 occurred in the pasture use system (113.8 mg m -2 h -1 ), followed by mandala agriculture (93.9 mg m -2 h -1 ), agroforestry (84 mg m -2 h -1 ), and forest (74.9 mg m -2 h -1 ) (Figure 2). This difference in the concentration of daytime CO 2 between the systems can be attributed to inherent characteristics of the soil in each area and the form of use or management adopted, which, associated with environmental stimuli such as moisture and surface temperature, influence the metabolic processes of soil organisms (Gomes et al, 2022).…”

“…surface temperature, influence the metabolic processes of soil organisms (Gomes et al, 2022). The balance between the input and output of carbon (C) from the soil has strong influences on atmospheric CO 2 concentrations, and the form of land occupation and management can affect this natural process by modifying the flow of CO 2 from the soil to the atmosphere (emission) or from the atmosphere to the ground (sequestration).…”