ABSTRACT
Pond fertilization to increase fish yields has long been practiced throughout the world. It is a well-known tradition in China to utilize animal manures and human excreta as major sources of pond inputs for polyculture of the major Chinese carps (Ling, 1967; Wohlfarth and Schroeder, 1979). The uses of inorganic fertilizer were introduced more recently in temperate regions (Mortimer, 1954; Gooch, 1967). There is voluminous literature on pond fertilization, documenting many conflicting and inconsistent results based on various types of fertilizer, rates of input, and methods and frequency of application (Coleman and Edwards, 1987). Those controversial viewpoints may actually reflect the differences in the physical and chemical environments of experimental ponds as well as variations in cultured fish species and stocking densities. Some of the problems have also stemmed from the lack of proper statistical designs with sufficient replication and common protocols for pond fertilization experiments.
