Ferramentas moleculares para avaliação da saúde do solo em sistemas agroflorestais da reserva natural Vale.

Abstract

Healthy soils are the basis of sustainable agriculture and climate change protection on the planet. The study of microbial functional diversity through the application of molecular techniques in different soil managements can contribute to the assessment of soil health. This research demonstrates how molecular tools contribute to the assessment of soil health in agroforestry systems at the Vale Natural Reserve. The study was carried out in the Vale Natural Reserve, located in the municipality of Linhares, in the state of Espírito Santo. Five cropping systems were selected, namely, agroforestry system under implementation (SAF); cocoa plantation under thinned native forest (CAB), also called cabruca; consortium of rubber trees and cocoa (SC); pasture (PAS) and native forest (MN), which was used as a reference. Metagenomic approaches (Metabarcoding and Shotgun) and metaproteomics were used to access microbial diversity and its functions. Metagenomics revealed the functional potential and diversity of microbial communities. On the other hand, metaproteomics pointed out the biological processes that occurred in an environment, through the proteins expressed by microorganisms. The results indicated a greater similarity between the areas of CAB and SC, showing a greater diversity of microorganisms, genes and proteins that participate in carbon fixation, contributing to soil health. Green manure provided a greater abundance of processes related to the transformation of nitrogen in the soil in the area of the agroforestry system under implementation, but proteins related to carbon fixation (C) are more present in more mature AFS areas (SC and CAB). More conservative managements are associated with greater C fixation over time. It was possible to demonstrate that integrated molecular tools provide a deep diagnosis on the functional state of the soil. Genes and proteins related to the carbon and nitrogen (N) cycles can incorporate advanced indices of soil health and direct management to increase productivity, improve diversity metrics and increase C fixation in the soil.