Project title:
Stabilization mechanisms and possible C gaps in soils from pastures and integrated systems across Brazilian Cerrado

Research theme area:
Soil/Environmental Science, Climate change mitigation

Abstract
Soil C accretion is finite and, under the same management practices and C inputs, soil C stocks in pastures and integrated systems are expected to reach a new equilibrium over the next decades. In areas of Brazilian Cerrado, recent studies showed evidence of limited C sequestration in soils under no-tillage systems. Since some of the Brazilian iNCD commitments relies on soil C sequestration, information regarding the mechanisms of soil organic matter (SOM) stabilization and its persistence is needed to understand and predict the dynamics of soil C stocks and possibly C gaps. In this sense, SOM molecular composition is a key factor in understanding soil C dynamics because soil-atmosphere C fluxes are largely determined by SOM stability. In addition to environmental conditions, SOM stability is depending on the chemistry of the input material and decomposition processes, all of which leave a chemical fingerprint on SOM. Therefore, combining qualitative (chemical composition and stabilization mechanisms) with quantitative (stocks and fractioning) data is considered a key factor in understanding the dynamics of soil C upon pasture recovering and adoption of integrated systems.

Description
The main goal of this proposal is providing a pervasive biome-scale analysis of soil C stock changes and C stabilization mechanisms in pastures and integrated systems in Brazilian Cerrado. Specifically, we aim to (i) quantify the soil C and N stocks, and isotopic composition in livestock areas under the management practices suggested by the ABC Program; (ii) evaluate the SOM composition and how it shifts in sites undergoing pasture recovery and integrated systems; (iii) evaluate the mechanisms of SOM stabilization and infer about possible C gaps and saturation in soils of Brazilian Cerrado; and (iv) assess the contribution of soil C accretion in livestock areas to Brazil achieve iNDC commitments. Several areas with contrasting edaphic conditions will be sampled across Cerrado biome using a cronossequence approach. For each land use, C and N stocks, C contents in soil aggregate fractions and clay-associated, C partitioning (13C) and molecular composition of SOM will be assessed. Besides being critical to Brazil achieve iNDC commitments, such effort would be a useful tool for the evaluation of ABC Program and to encourage decision makers and planners to diffuse sustainable land use strategies and soil management systems in Brazil.

Requirements to fill the position
This project is suitable for a highly motivated candidate with lab experience in soil C analysis (quantification, physical fractioning, isotopic and spectroscopy techniques) and relevant number of scientific publications in the field. Practice on soil C modelling (e.g., DayCent, RothC, MEMS) is desirable. English proficiency is required, as well as experience in R or other similar computer languages. Candidates must have a Doctorate/PhD in Soil Science, Environmental Sciences, Ecology, Agronomy or similar areas.

Funding Notes: This Postdoc Fellowship is funded by FUSP. The fellowship will cover a standard maintenance stipend of R$ 8.479,07 per month.

MORE INFORMATION:
https://www.rcgi.poli.usp.br/opportunities/
Position: Post-Doctoral REF: 22PDR166

https://www.rcgi.poli.usp.br/opportunities-aplication/ AND APPLICATION AT REF 22PDR166 – Post Doctoral