Dynamics of soil properties and pathogen levels in Pacific white shrimp ponds during a production cycle: Implications for aquaculture management

Abstract

This study examines the temporal and spatial variations in soil properties and microbial populations in Pacific white shrimp ponds throughout a production cycle in Phuket Province, southern Thailand, aiming to refine shrimp farming methodologies and enhance pond soil management. We collected soil samples from four ponds across two aquaculture sites at six different stages of the production cycle—Before Sediment Flushing (BSF), After Sediment Flushing (ASF), and during each month of the four-month cycle (M1 to M4). These samples were analyzed from both central and peripheral pond zones at three soil depths (0–5 cm, 5–10 cm, and 10–15 cm). The results indicated negligible variation in soil characteristics and microbial loads across all stages. Nevertheless, a significant finding was the fluctuation in levels of easily decomposable organic matter (EDOM), which is critical for maintaining soil and water quality and affects both shrimp growth and disease incidence. EDOM levels decreased to their lowest after ASF, then progressively increased, reaching a peak at M4 (p < 0.05). The study suggests that effective sediment flushing post-cultivation not only mitigates the accumulation of deleterious residues, but also reduces the necessity for prolonged pond desiccation, thereby offering a sustainable strategy to maintain the ecological balance of shrimp ponds over successive farming cycles.