Characterization of pH, organic carbon and redox potential in pond soils of semi-intensive culture of marine shrimp Litopenaeus vannamei

Abstract

Pond soils of semi-intensive culture of marine shrimp Litopenaeus vannamei were studied in relation to pH, organic carbon (%) and redox potential (mV), and the mathematical relationship between them was also investigated. The mean values of the characteristics were as follows - pH: 6.73 ± 0.49 (6.0 to 7.8; n=255), organic carbon: 1.51 ± 0.53% (0.45 to 2.85%; n=255), and redox potential: í 283.51 ± 64.4 mV (-29 to -523 mV; n=1,215). It was verified that pH is directly proportional to redox potential (R² = 0.52; p < 0.01) and inversely proportional to the percentage of organic carbon (R² = 0.30; p < 0.05). No significant relationship was found between percentage of organic carbon and redox potential in pond soil (p > 0.05). It was concluded that the studied pond soils are highly reduced and slightly acid, but with appropriate amount of organic carbon for productivity.