Integrated systems are promising strategies to C sequestration and consequently mitigate global warming and climate change, and the implementation of these systems has been funded by public policies such as the Low Carbon Agriculture Plan. The continuous supply of C in the soil can promote significant improvements in the aggregation process and structural quality of the soil, regulating many soil physical processes. Studies have reported that C plays a key role in the process of gaining soil resistance, directly influencing cohesion, compressive properties (strength, elasticity and compressibility), root penetration resistance and tensile strength of aggregates. The purpose of this project is to test the hypothesis that integrated agricultural systems raise the C stock in the soil over time, increasing the mechanical strength and the resilience of the soil in response to the application of external efforts (mechanical stress). The general objective is to evaluate the influence of C and the stability of the soil structure managed under integrated systems on physical and mechanical resistance indicators of soil. For that, soil samples will be collected in scenarios with gradient of C in the soil and consequently different degrees of stability of soil structure. The scenarios will include different phases and times of agricultural systems implementation. Compressive properties and penetration resistance will be measured in undisturbed soil samples submitted to different matric potentials. Additionally, tensile strength tests will be performed on aggregates collected in the field. Total carbon and its respective physical fractions, as well as aggregate stability in water, will be measured and related to the soil strength indicators. It is expected that the C and the agricultural systems conduction time induce structural stability and provide the increase in the soil physical and mechanical resistance indicators. The knowledge and understanding of the role of C in soil strength mechanisms could be a useful tool for constructing, via management, soils more resistant to deformation and rupture, and resilient in events of application of external loads (traffic and animal trampling). Consequently, the soil could become less susceptible to degradation, but with high physical quality for plant growth and development.
News published in Agência FAPESP Newsletter about the scholarship: