Spatio-temporal mapping of organic carbon stock

• Grant number: 22/13995-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: July 31, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: José Alexandre Melo Demattê
• Grantee: Bruno dos Anjos Bartsch
• 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

Soil is the largest terrestrial carbon reservoir. Soil organic carbon (SOC) is critical to soil quality and crop productivity, being directly associated with climate change mitigation and food security. Brazil has an expressive agricultural production area and a great potential for SOC sequestration. Even so, the spatio-temporal distribution of the SOC stock in the territory is little known, making it difficult to implement public policies for low-carbon agriculture. The objective of this research is to map the space-time distribution of SOC (present, past) in Brazilian soils with detailed resolution for layers 0-5, 5-15, 15-30, 30-60 and 60-100 cm deep, and to identify the main factors that control its dynamics through the use of different covariates derived from remote sensing and modeling strategies. Three mapping approaches will be tested for each 5-year period in the present and past: 1) Calibration and validation of SOC predictive model for each period; 2) Calibration of a model in the recent period (2019-2023), which will be used to predict the SOC of each period; 3) Calibration of a single model, which will be used to predict the SOC of each period. Several static (soil and relief attributes) and dynamic (land use and cover, vegetation indices, reflectance of exposed soil and vegetation and frequency of exposed soil) covariates will be tested over time, derived from remote sensing. Final maps will be validated with existing maps and sampling points. It is expected to obtain and make available unpublished maps, with detailed resolution, of the SOC stock with a time interval of 5 years between 1984 and 2023 for the study area which covers approximately 2,574 km², which comprises the municipalities of Piracicaba, Charqueada, Iracemápolis, Saltinho , Rio das Pedras, Mombuca, Rafard and Capivari, in the State of São Paulo, Brazil, and thus serve as an incentive in the elaboration of public policies.