Soil functioning evaluation using qualitative and quantitative indexes in agroextractivist system in Oriental Amazonia.

• Grant number: 13/02481-6
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2013
• Effective date (End): July 31, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal researcher: Miguel Cooper
• Grantee: Laura Fernanda Simoes da Silva
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Family agriculture has been charged as been one of the great modifiers of the Amazon forest cover. Although small farmers are responsible for only 30% of the deforestation, the intensity of the degrading practices in the areas occupied by them is greater than those of the great producers. This gradual increase in deforestation has caught attention of the authorities and the scientific community in general, in order to measure the impacts, especially on the soil, and propose alternative uses, management and restoration systems for these ecosystems. However, in the Amazon, few studies have focused on assessing levels of the soil physical quality, especially in areas of family agriculture. The objective of the present study is to characterize qualitatively and quantitatively the functioning of the soil under native vegetation and pasture in an area of family agriculture in Eastern Amazon. The soil attributes obtained from the characterization of the soil functioning will be used for developing hydro-physical soil quality indices, as well as for testing already existing indices, for the assessment of soil degradation and recovery in the study area. The research will be developed in the Praialta Piranheira Agroextractive Settlement located in Nova Ipixuna, state of Pará. Two soil toposequences that present similar characteristics of soil parent material and landscape in the following situations: preserved primary forest and pasture without burning, will be chosen. Pits will be opened in the chosen toposequences according to the main soil types and detailed soil morphological descriptions will be done in each of them. Soils will be sampled by horizon in each pit and a more detailed sampling at the depths of 0-0.05, 0.05-0.10, 0.10-0.20, 0.20 to 0.40 and 0,40 to 0.60m will be done to better characterize the attributes affected by soil degradation and/or recovery. Disturbed and undisturbed soil samples will be collected for routine chemical and physical analysis, soil-water retention curves, soil micromorphological and 2D micromorphometric analysis, structural stability and determination of qualitative and quantitative indices of soil hydro-physical quality. The detailed knowledge of the soil functioning under different land use systems in the Eastern Amazon region will allow to characterize the dynamics of the local land use systems and therefore select and develop the best soil hydro-physical quality indices. The selection and development of the soil hydro-physical indices adapted to the local conditions has the purpose of identifying and measuring the soil degradation and /or recuperation level, so that best management practices are introduced in family agriculture areas for the sustainable use of the soil.