ABSTRACT

Melioration with regard to pond fisheries is applied not only to the pond itself but to the territory surrounding the fish farm. Melioration of fish ponds is directed along two lines—care of water and care of soil. The close interaction between water and soil determines the qualitative assessment of the entire complex of biological and physicochemical phenomena occurring in a fish pond. Measures directed toward the improvement of ponds of different categories include the creation of hydrochemical conditions essential for the fish under culture, control of aquatic plants to preclude harmful overgrowth, checking of excessive siltation, estivation, lime application, and techno-cultural measures. The mechanical aerators used in the USA are quite effective, increasing the oxygen content to such an extent that fish production has been improved by 29.7%. When the ponds are annually filled with water, even with application of organic manures and inorganic fertilizers, estivation is nonetheless important—just as crop rotation is in agriculture—because soil structure is very significant.