Ionic balance of water and physical-chemical properties of soil from marine shrimp farms of the Jaguaruna interior county, Ceará, Brazil

Abstract

The present work aimed at describing and characterizing the physical-chemical composition and the Na⁺: K⁺ and Ca⁺²: Mg⁺² ratios of well waters used to fill L. vannamei culture ponds, belonging to farms located in Jaguaruana, an interior municipality of the State of Ceará, Brazil. Besides that, the study also sought to describe and characterize the physical-chemical properties of soils from the same shrimp farms. Well water and soil samples were taken in four farms, three located in Jaguaruana (Pasta Branca, Sargento and Poró) and one in the municipality of Aracati, which served as a control. Water samples were analyzed for pH, specific conductance, salinity, total alkalinity, total and calcium hardness, potassium and sodium. Soil samples were analyzed for pH, specific conductance, salinity, potential acidity, phosphorus, organic carbon, total nitrogen, sodium and potassium. The well waters from Aracati, Pasta Branca/Sargento and Poró were classified as euhaline, oligohaline and mesohaline, respectively. The results of pH indicated that liming was necessary in all four farms. All well waters demanded potassium fertilization to compensate for K⁺ deficiency and to adjust Na: K ratio. It has been concluded that, in the productive management of inland shrimp farms, it is important to monitor not only the Na: K and Ca: Mg ratios of the water, but also the absolute concentrations of each ion.
Keywords: Inland shrimp culture. Sodium. Potassium. Calcium. Magnesium. Low-salinity Waters.