Soil structural stability shaped by multisource compost amendments: Links to organic matter and microbial processes

Abstract Soil degradation, particularly in arid regions, is a serious challenge to land sustainability, reflecting a continuous need for effective soil management strategies that enhance soil structure and resilience.This study evaluates the effect on soil aggregate stability, organic matter dynamics, microbial biomass and polysaccharide formation of three soil amendments from different origins i.e. cow manure compost, chicken manure compost and brown algae solution.The results showed that chicken manure compost exhibited the highest organic matter mineralization rate (29.24%), followed by cow manure compost (23.05%), while the algae solution showed minimal mineralization (1.88%). Furthermore, the cow manure compost promoted the greatest microbial and fungal biomass, indicating the importance of organic matter recalcitrance in sustaining microbial growth. In contrast, algae solution, despite its limited mineralization, achieved the highest improvement in soil aggregate stability, reaching a mean weight diameter of 2.94 mm after 90 days compared to 1.01 mm for chicken compost and 0.77 mm for cow compost. These findings demonstrate that manure-based composts contribute to rapid nutrient cycling and short-term fertility, while algae-based amendments promote long-term aggregate stability and carbon sequestration. Overall, the study highlights the importance of compost origin and composition in shaping soil biogeochemical processes and provides insights into sustainable soil management strategies in arid agroecosystems.