Subsoil Dynamics of POM and MAOM in Continuous Living Cover Cropping Systems

Abstract

This research investigates the dynamics of particulate organic matter (POM) and mineral-associated organic matter (MAOM) in the subsoil (30-60 cm) under continuous living cover cropping systems. While previous research has largely focused on topsoil, this project explores how these systems impact POM and MAOM in deeper soil layers, which are crucial for long-term carbon storage and soil sustainability. Using soil samples collected over five years (2020-2024) from two agricultural sites with annual and perennial crop rotations, the samples were analyzed for organic carbon content. Results revealed that POM remained relatively stable, sustained by continuous plant residue inputs, while MAOM showed greater variability, likely due to interactions with soil minerals and environmental factors. Soil texture played a significant role, with sandy soils favoring POM accumulation and finer-textured soils supporting greater MAOM content. These findings highlight the importance of considering both management practices and soil physical properties to optimize carbon sequestration and enhance overall soil health.