Qualidade do ambiente edáfico em sistemas de uso e cobertura do solo

Abstract

The concept of sustainability has led agricultural research to a growing search for alternative and sustainable models for agriculture, with the understanding of the dynamics of the edaphic environment, above all, the soil-litter interaction, the decisive starting point for understanding the functioning of agroecosystems. The present work aimed to evaluate the quality of the edaphic environment in different land use and cover systems. The study was conducted in four land occupation systems, namely: forest remnant, agroforestry system (SAF), agricultural mandala and pasture. Thus, this dissertation was divided into three chapters in a scientific article format. The first evaluated the effects of agricultural landscape intensification on the decomposition of phytomass of Azadirachta indica and Gliricidia sepium. In this chapter, the decomposition rate was estimated using nylon (litter bags), containing 20 g of leaves of each species, which were placed on the soil surface of each system for a period of 108 days. Both species showed rapid decomposition rate in the period evaluated, considering all systems. Land use and land cover systems influenced the decomposition of A. indica and G. sepium leaf phytomass. The second chapter aimed to assess the edaphic breathing in each system in the night and day periods. The microbial activity was estimated by quantifying the carbon dioxide (CO2) given off in the edaphic respiration process, from the soil surface, and captured by a KOH solution. The production of CO2 was greater at night than during the day, regardless of the systems analyzed. Among the areas evaluated, the forest was the one with the lowest CO2 emissions, being considered as a CO2 receiver in contrast to the pasture area that functioned as a CO2 emitter. The third chapter aimed to assess the quality of the edaphic environment and ecosystem services from sustainable indicators of participatory diagnosis. The agroforestry system showed similarities in the quality of the edaphic environment and ecosystem services when compared to the native forest area. Edaphic temperature, soil water content and quality of plant residues are factors that strongly influence decomposition and release of CO2 by edaphic organisms. It is recommended that soil conservation management practices be adopted in systems with greater human intervention, such as pasture and agricultural mandala.