The Comparative Studing On Use Of Bio-Fertilizer And Fertilizer In Aquaculture In The Small Reservoirs

This paper has studied the effect of the water physical and chemical characteristics,plankton, water primary productivity and silver carp and bighead carp of the smallreservoirs growth using bio-fertilizers(â… ) and fertilizers(â…¡) by comparison method, whichcomprising the difference effect of using the bio-fertilizers and fertilizers to the fishes,and obtained the following results:1. Effect of fertilization on the physical and chemical characteristics ofwinterFertilizer nutritive water body is quicker, the transparency reduces significantly, thetransparency from 0.66m reduced to 0.42m after 3-4 d using fertilizers, but the last time isshorter, the fertilizers effectiveness reduced gradually after 4 d, the transparency alsoraised to 0.59m; but the water transparency of using bio-fertilizers could maintainrelatively stable in 10d. The bio-fertilizers is benefit to improve the water' s dissolveoxygen, after fertilize compares with the comparison reservoir(â…¢)can improve dissolvesoxygen 5.0ï¼…-9.5ï¼…, fertilize does not be benefit to improve the dissolves oxygen but alsoaccelerated the consumption of dissolves oxygen, especially the fertilized level ofdissolve oxygen reduced frequently to the comparison reservoir dissolves below theoxygen level after 3-4 d, lower 1.1ï¼…. Used fertilizers the COD obviously higher, it washigher 29.57ï¼…than used bio-fertilizers as the same time of the day, it was higher 73.38ï¼…than the comparison reservoir, the level of nitrite nitrogen is highest 1 time to 2.9 times.2. Effect of fertilization on the plankton communityBoth bio-fertilizers and fertilizers are helpful to plankton growth, but Fertilizers aremore helpful to phytoplankton growth than bio-fertilizers, bio-fertilizers are more helpfulto zooplankton growth than fertilizers. The advantage zooplankton community of used thebio-fertilizers were mainly the large-scale individual rotifer, the cladocera and thecopepoda, but the small zooplankton the protozoon are fewer; but it was contrary effect ofused fertilizers, the rate of detection of each kind of zooplankton was lower, especially thelarge-scale zooplankton was more lower. Bio-fertilizers was raised 230ï¼…-246ï¼…and385ï¼…-422ï¼…of the zooplankton's quantity and the biomass by used bio-fertilizers than thecomparison reservoir and it was also raised 39ï¼…-85ï¼…and 113ï¼…-200ï¼…than theâ… th reservoir.3. Effect of fertilization on the growth of silver carp and bighead carpBoth bio-fertilizers and fertilizers are helpful to silver carp and bighead carp growth, but Fertilizers are more helpful to silver carp growth than bio-fertilizers, bio-fertilizers aremore helpful to bighead carp growth than fertilizers. Theâ…¡th reservoir bighead carpcondition factor was highest to 2 ages 2.00 and 3 ages 2.15, separately compared to Ithreservoir corresponding age section bighead carp ponderal index high 12.43ï¼…and18.85ï¼…, compared toâ…¢th reservoir corresponding age section bighead carp ponderalindex high 11.86ï¼…and 24.13ï¼….â…¡th reservoir bighead carp the annual accretion quantityseparately compared to the Ith reservoir corresponding age section bighead carp theannual increment quantity high 29.21ï¼…and 72.48ï¼…, compared toâ…¢th reservoircorresponding age section bighead carp the annual increment quantity high 47.08ï¼…andthe 109.27ï¼…,â…¡th reservoir 2 ages bighead carp and3 age bighead carp growth specificspeed to fast respectively was 0.94 and 0.46, butâ… th reservoir only then 0.68 and 0.41,â…¡th reservoir was only 0.66 and 0.34.