Comparison of Carbon Dioxide Efflux in Different Land Use Typologies

Abstract

Management systems are crucial for soils functioning as a drain or source of greenhouse gas emissions. In this sense, among the alternatives for reducing the precursors of the greenhouse effect are integrated agricultural production systems, particularly Agroforestry Systems. These integrated systems maximize the use of biological cycles, soil, and animal waste, reducing agrochemicals and improving the condition of the rural populations involved. The present study aimed to evaluate the CO2 efflux in different land use types. The study was conducted in four agroecosystems: Forest (FO), Agroforestry Systems (AFS), Mandala (MD), and Degraded area (DA). To quantify the CO2 emanating from the soil, 10 mL of 0.5 N KOH aqueous solution is used and titrated using 0.1 N HCl, phenolphthalein, and 1% methyl orange as an indicator. The CO2 concentration from 5:00 am to 5:00 pm was lower. The lowest CO2 production occurred in FO (82.7 CO2 mg m-2 h-1), statistically differing from the other areas that obtained a CO2 rate higher than 140 mg m-2 h-1. As for kinetics, it was observed in all areas that the greatest release of CO2 during the day occurred at 7:00 am, and this release decreased as the soil temperature increased. The greatest release of CO2 and the highest temperatures occurred in DA, showing that these systems with anthropic modifications can be considered CO2 emitters however, systems closer to the natural ecosystem, such as the AFS, will store carbon in the soil, functioning as a carbon store. Therefore, to reduce CO2 emissions from agricultural activities, it is necessary to use systems that imitate natural ecosystems.