Impacts of Intensified and Integrated Systems on C Stock, Dynamics and Structure of Soil Organic Matter: Assessments with Spectroscopies and Microscopy.

• Grant number: 24/14266-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2024
• End date: September 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Ladislau Martin Neto
• Grantee: Vitor da Silveira Freitas
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil
• Associated research grant: 23/02444-5 - Understanding intensified and integrated production systems: from the quantum world to low-carbon agriculture, AP.PFPMCG.TEM

Abstract

The Brazilian agricultural sector has the potential to further expand food production and meet growing demand from the country and abroad, but its sustainability is essential for production in these systems to be adaptable to the needs of the population and the broader environmental context, including achieving the goals of international treaties related to global climate change. Therefore, it is necessary to intensify the use of resource-saving technologies with low greenhouse gas (GHG) emissions. Pigeon pea (Cajanus cajan) has been used in consortium with grasses and legumes because it has the potential to reduce GHG emissions due to the reduction in the production of enteric methane by ruminants, biologically fix nitrogen (N) in plants, and also increase carbon (C) sequestration in the soil. Experiments with integrated ILPF systems also provide favorable conditions for increasing SOM, including in depth, and have demonstrated the possibility of increasing SOM content in relation to traditional management systems. The source of residues in the ILPF systems under study is very diverse, with grasses (pastures and corn), trees (eucalyptus), and animal waste. Therefore, it is essential to evaluate the dynamics of soil organic matter (SOM) and C and N stocks in this type of plant consortium and ILPF systems. In this context, this proposal aims to quantify C and N stocks in soils, including quantification of soil organic carbon (SOC) and attempted quantification of soil inorganic carbon (CIS), and to evaluate the structural differences of SOM in production systems with grass and legume consortium, and new data from ILPF systems after 5 years of the last analyses, which are of great interest to evaluate any quantitative and qualitative changes in SOM. Analyses will be performed with intact soil samples and with physical and chemical fractions of SOM. To this end, a physical and chemical soil fractionation method will be used, as well as isotope analyses, with spectroscopic techniques and confocal fluorescence microscopy, with the aim of generating unprecedented scientific data and supporting agronomic recommendations and the ABC+ Plan. Thus, this project is expected to obtain important information regarding the transformation process and chemical composition of MOS in tropical climates under the consortium of grasses and legumes over time, and with ILPF systems, in addition to separately evaluating the contributions of COS and CIS to soil C stocks, considered a very important topic in the context of sustainable agriculture, climate change and one of Brazil's important strategies for decarbonizing agriculture.