Agricultural Land Management practices and their influence on microbial community composition and biological activity in soil

Aims: Land management practices are among the most crucial factors influencing soil properties. Integrated amplicon sequencing and biological properties analysis can provide contextual insights into how management practices shape soil microbial communities. Methods: We conducted a completely randomized sampling study at Agricultural University, Plovdiv, to assess the impact of Lavender Cultivation, Wheat-based Rotation and Unmanaged land, on soil microbial community structure and properties. Results: Taxonomic assessment indicated a clear distinction in microbial community composition. Unmanaged soils were dominated by reduced and less diverse but dominant microbial groups, possibly driven by selection pressure from limited resources. In contrast, cultivated soil supported diverse microbial community of r and k strategists. Enzymatic activity increased significantly (p≤0.05) in managed soil. Land management significantly influenced the pH, EC, Basal Respiration, and Soil Moisture content (p≤0.05). Higher soil respiration (CO2) was observed in uncultivated soil, indicating role of substrate quality in microbial substrate utilization efficiency. Proteobacteria (54.75%) was the dominant phyla in unmanaged land, followed by Bacteroidota (16.45%). In Lavender cultivation, Actinobacteriota (34.20%), Proteobacteria (20.56%), and Acidobacteriota (20.11%) were the most abundant. Similarly, in Wheat based rotation, diverse proportion of Acidobacteriota (28.73%), Actinobacteriota (19.97%), Proteobacteria (17.5%) and Bacteroidota (10.64%) was observed. Alpha diversity indices such as Shannon and Simpson index was higher in cultivated soil. Beta diversity analysis showed a distinct dissimilarity between uncultivated and cultivated soil. Conclusions: Our findings indicate that interaction between factors such as cropping system, fertilization, and moisture content, distinctly shape the microbial community. Long term monitoring would help understand sustained effect on soil health.