Stratification of soil sampling using spatio-temporal soil and plant mapping technologies: bases for defining the uncertainties and scalability of the assessment (baseline and monitoring) of soil carbon stocks

• Grant number: 24/01979-5
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2024
• End date: June 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Agreement: CNPq
• Principal Investigator: Maurício Roberto Cherubin
• Grantee: Maurício Roberto Cherubin
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 21/10573-4 - Center for Carbon Research in Tropical Agriculture (CCARBON), AP.CEPID
• Associated scholarship(s): 24/11109-8 - Stratification of soil sampling using spatio-temporal soil and plant mapping technologies: bases for defining the uncertainties and scalability of the assessment (baseline and monitoring) of soil carbon stocks, BP.JD

Abstract

Actions to mitigate global warming and consequent climate change are centred on reducing greenhouse gas emissions and increasing the capture and sequestration of atmospheric CO2. In this context, the agricultural and forestry sectors stand out, as they are able to act on both these fronts, particularly in capturing atmospheric CO2 via photosynthesis, and sequestering it in vegetation and soil. There is therefore growing interest in establishing initiatives, programmes and projects that encourage the sequestration of C in the soil of agricultural areas. However, assessing soil carbon stocks to characterise the baseline and then monitoring (MRV - monitoring, registration and verification) the impacts of the management practices adopted is a process that requires intensive soil sampling in the field, making the process time-consuming, expensive and not very scalable. Therefore, finding solutions to optimise field sampling without increasing the uncertainty of ECS measurements has become a technical and scientific challenge that needs to be overcome in the coming years.In this scenario, Precision Agriculture (PA) has emerged as an approach to site-specific characterisation. With the advances in PA over the last few decades, soil characterisation by homogeneous management zones (HMZ) has been highlighted in national and international literature as the new form of localised crop management. Developed using detailed studies of the terrain, soil or plant, the HMZs aim to optimise the resources and inputs needed for agricultural production, from the application of correctives and fertilisers to the variable population of seeds and herbicides. However, despite the fact that research carried out over the last decade points to a growing adoption of this method of managing crop variability, the literature still lacks studies that assess its use for characterising and monitoring ECS.The vast majority of studies are limited to showing the different techniques and technologies used in the delineation of MHZs and do not delve into the benefits (or harms) of their adoption. To this end, the main objective of this research project is to assess whether the design of MHZs allows for adequate stratification of the crop for characterising the soil C stocks (baseline and monitoring), bringing improvements in estimates (reduction of uncertainties) and economic advantages compared to traditional sampling methodologies in dense grids. At the end of this research project, we hope to find (technical and economic) indicators that justify and guide an accurate and reliable diagnosis of the ECS baseline, contributing to the advancement of science in this area. We believe that this project will have a significant impact on the C agenda in national and international agriculture, serving as a scientific basis for establishing evaluation protocols (MRV) for ECS in government programmes, as well as in future C credit initiatives and projects for the voluntary market. (AU)