Spatial assessment of soil quality in Brazil and its relationships with Brazilian agricultural expansion, productivity potential and climate change

• Grant number: 23/17876-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2024
• End date: March 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: José Alexandre Melo Demattê
• Grantee: Jorge Tadeu Fim Rosas
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 21/05129-8 - The Brazilian soil quality determined by geotechnologies: mapping, interpretation and agricultural/environmental applications: a legacy for society, AP.TEM

Abstract

The present project aims to map soil quality indicators and apply a method to obtain a map of the soil quality index (IQS) in Brazil, and thus evaluate the relationship with national agricultural expansion, potential soybean productivity and climate change. For this, maps of chemical, physical and biological indicators of the soil will be obtained between 0 and 100 cm depth, and interpreted (scored between 0 and 1) based on soil functions, within the Google Earth Engine platform, using one of the following curves: "more is better", "less is better" and "optimal midpoint". The normalized indicators will be scored using a model developed based on six soil functions. The weights (importance) of the indicators will be assigned in accordance with Karlen and Stott (1994) and Lima et al. (2013), where some indicators will have a greater effect on the final formation of the index. The indicators interpreted and scored by the function will be integrated using an additive model that will be implemented on the GEE platform to obtain IQS maps between 0 and 100 cm depth with 30m spatial resolution. These maps will be validated in pilot areas selected by compartmentalizing the landscape into homogeneous regions using satellite data within the GEE. Furthermore, the maps produced by the thematic project will be evaluated in relation to land use and cover (UCT) maps of Brazil (1985 to 2019) at a scale of 30 m by MapBiomas. They will also be evaluated against future predictions from WorldClim climate data and digital soybean productivity maps. The digital maps obtained by the thematic project with 30 m spatial resolution will be organized within a Geographic Information System on the Web (SIGWEB) for analysis and public consultation. (AU)