Projeto e validação teórica de um sistema automatizado para análise da permeabilidade e respiração do solo

Abstract

An essential physical characteristic that controls soil aeration, gas exchange between the soil and the atmosphere, and biological activity in the rhizosphere is soil air permeability (Ka). The precise assessment of this characteristic is fundamental to determine the structural quality of the soil, identify compaction problems, and improve agricultural management practices. However, conventional methods for measuring air permeability in the field are often complex, expensive, and laborious. This study describes the design, theoretical validation, and proposed use of a low-cost, automated pneumatic infiltrometer, conceived to analyze soil air permeability in various situations of structural alteration and initial moisture. The main objective was to propose and detail a device capable of injecting a controlled airflow onto the soil surface and, based on the measurement of the resulting pressure, estimate air permeability. The proposed approach is based on a prototype using the ESP32 microcontroller, a MPXV7002DP differential pressure sensor for permeability analysis, and a carbon dioxide (CO₂) MH-Z19 sensor for soil respiration studies. For the future validation of the prototype, an analysis of the impact of structural disturbance and moisture on permeability is proposed, as well as the quantification of CO₂ efflux. The theoretical analysis indicates that compaction and moisture significantly reduce Ka . It is concluded that the project is an effective and innovative multifunctional platform for research in soil physics and biogeochemistry, offering a rapid and economical method to evaluate the structure and biological activity of the soil in situ.