Effect of Micro aod Macro Nutrients Enrich Fertilizer on the Growth Performance of Prawn (Macrobrachium rosenbergii), Rohu (Labeo rohita) and Mola (Amblypharyngodon mola) in a Polycnlture System

Abstract

A six month's experiment was carried out in the earthen ponds to evaluate the effect of micro and macro nutrients on the growth performance of major carps Rohu (Labeo rohita), prawn (Macrobrachium rosenbergii) and mola (Amblypharyngodon mola) in a polyculture system. The trial was conducted into two different treatments and one control each with three replications. In Treatment-I, macro nutrients like urea, TSP and molasses-yeast mixture were applied at the rate of 2.45, 2.45, and 3.09 (g m⁻² week⁻¹), whereas in Treatment-II micro nutrients composition mixer applied at the rate of 4.5 g m⁻² week⁻¹ while no micro and macro nutrients were applied in control. Nine water quality parameters (water temperature, pH, salinity, DO, alkalinity, hardness, nitrate, nitrite and ammonia) were measured from different treatments with comparing control unit by using standard and instrumental methods. The mean value of hardness showed significant difference while other water quality parameters had no significant differences among control and two treatments when one-way ANOVA was performed. The average final mean individual weights of prawn (M. rosenbergii), rohu (L. rohita) and mola (A. mola) in Treatment-I were 24.35, 190.6, 3.67 g and in Treatment-II were 24.7, 182.2, 3.73 g while 22.1, 141.1, 3.36 g were in control. The final harvest weights of mola (A. mola) in Treatment-I and Treatment-II was more or less similar as control. The survival rates of prawn (M. rosenbergii), and rohu (L. rohita) were 73.33, 89.58 and 86.25%, in control 78, 74 and 74% and Treatment-I while mola had 10.67, 15.33 and 15.33% survival rate in T-1, T-2 and control respectively. Perhaps mola (A. mola) fishes were consumed by prawn (M. rosenbergii). There was no significant difference in the survival rates of prawn (M. rosenbergii), rohu (L. rohita) and mola (A. mola) between control and treatments. Production after six months of culture was 351.8, 461.5 and 445.3 kg/ha in control, treatment-I and treatment-II respectively. Significant difference was found in the production of prawn (M. rosenbergii), rohu (L. rohita) and mola (A. mola) among control and two treatments. Fertilizers indirectly played a major role by increasing production of fishes in T-1 and T-2 than control. Use of macro-nutrients enriched Treatment-I gave better overall production of fishes comparing to the Treatment-II with micro-nutrients based commercial fertilizers. However including mola could to maximize the production of prawn and rohu in fertilizer included polyculture system though mola production may be affected by the other fishes. Therefore, inclusion of traditional inorganic fertilizers with the recommended doses of this study might be helpful for carp-prawn polyculture to meet economical and nutritional benefits.