Application of the feedback model in the recovery of degraded soils of pastures in the Central Amazon

Abstract

The removal of primary forest leads to the loss of the topsoil and a decrease in the level of nutrients available to the plants, in addition to increasing the risk of clearings caused by falling trees. Forest recovery can take up to 175 years, depending on previous land use and management. This project proposes to study the rhizosphere microbiota of tree species used in the recovery of deforested areas in Central Amazonia, applying the "plant-soil feedback" model in the establishment of native or economically important forest species in degraded pasture soils. At first, the feedback will be determined in a greenhouse in microcosms simulating the transition of the soil between pasture and establishment of four tree species affected or not by the Amazon Dark Earth and, in another study, it will be determined under natural conditions of the field the dynamics of microbial communities in the rhizosphere of these plants in degraded soils, under the effect or not of this "feedback" in comparison with a control soil. The evaluation will include next-generation sequencing techniques and statistical and bioinformatics analyses. It is expected to obtain answers on how microorganisms and plants interact in Amazonian soils and propose improvements in the recovery of deforested and/or degraded areas, through the provision of microbial communities with positive functional actions focusing on soil quality and plant development, determined via functional metagenomic analysis. This research responds to one of the proposals of the FAPESP-supported project "Plan-to-soil feedbacks in the Amazon Forest and agricultural systems in the State of Amazonas" (Proc. 2020/08927-0) that the CENA/USP Cellular and Molecular Biology Laboratory is developing together with the team from EMBRAPA-Amazônia Central and the INPA-National Institute for Research in the Amazon, through the so-called FAPEAM-FAPESP. (AU)