Origin, molecular composition and fate of dissolved organic matter in intensive grazing and integrated livestock-forest systems

• Grant number: 21/08362-5
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: November 01, 2021
• End date: April 30, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Ladislau Martin Neto
• Grantee: João Vitor dos Santos
• Supervisor: Patrick G Hatcher
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil
• Institution abroad: Old Dominion University (ODU), United States
• Associated to the scholarship: 20/04938-7 - Quantification and spectroscopic characterization of dissolved organic matter in soils under pastures and integrated production systems, BP.MS

Abstract

Brazil plays a globally important role being the largest exporter of beef and the second largest bovine producer in the world. The biggest challenge for the country has been to increase the productive capacity of Brazilian soils based on the concept of sustainable agriculture. Within this scenario, conservation practices have shown both high productivity and sustainability in the agronomic world, highlighting both management, intensive grazing, and integrated livestock-forest systems. Dissolved organic matter (DOM) is an important reactive carbon pool in soils participating in many biogeochemical processes. Despite its importance to soil function, studies focused on its dynamics in Brazilian soils are scarce. Soil DOM contains molecular and stable isotopic signals from inputs derived from surface vegetation, as well as from the subsurface biotic and abiotic processes. Accordingly, to appreciate the role of soils inglobal productivity it is necessary to understand the connectivity between the various environmental processes that play a role in molding soil organic matter into an important global carbon reservoir. Considering the fact that studies have already commenced in Brazil, in long-term field experimental areas, the goal of this project is to investigate the origin, molecular composition and fate of soil DOM.These studies will take place in intensive grazing and livestock-forest systems, from the surface through the subsurface, using traditional Stable Isotope Analysis (´ 13C and ´ 15N), along with advanced molecular-level characterizations using Tetramethylammonium Hydroxide Thermochemolysis - Gas Chromatography/Mass Spectrometry (TMAH-GC x GC/MS) and Electrospray Ionization coupled withFourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI-FT-ICR-MS). The research group of Professor Patrick Hatcher has significant internationally recognized experience in the area of environmental chemistry and geochemistry. The achievement of these experiments under supervision of Dr. Hatcher, specialist in the techniques proposed, will facilitate the understanding and interpretation of results, allowing a better understanding of how pastures under different managements, including integrated systems, affect soil biogeochemistry.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DOS SANTOS, JOAO VITOR; BENTO, LUCAS RAIMUNDO; BRESOLIN, JOANA DIAS; MITSUYUKI, MILENE CORSO; OLIVEIRA, PATRICIA PERONDI ANCHAO; PEZZOPANE, JOSE RICARDO MACEDO; BERNARDI, ALBERTO CARLOS DE CAMPOS; MENDES, IEDA CARVALHO; MARTIN-NETO, LADISLAU. The long-term effects of intensive grazing and silvopastoral systems on soil physicochemical properties, enzymatic activity, and microbial biomass. CATENA, v. 219, p. 11-pg., 2022-09-11. (19/18267-0, 17/20084-5, 20/04938-7, 21/08362-5)