Application Of Pig Manure Treated By Effective Bacteria In Fish Farming

In view of the regional situation under which pig production is high and the integrated system of pig and fish production is carried out in Xingan County,Jiangxi Province,this thesis aims to analyze the feasibility of applying pig manure treated by effective bacteria to fish farming in small reservoirs by comparing the effect of three different treatments of pig manure,i.e,direct use(Ⅰ),use of the residual of pig manure after fermenting as methane production(Ⅱ) and use after treatment by effective microbe(Ⅲ) with a control(no use of pig manure,Ⅳ),on water quality,plankton community and the growth of stocked filter feeding silver and bighead carp.The main results are as follows:1.Effects of three different treatment of pig manure on water physio-chemical index.The reservoir could maintain the fair water quality suitable for fish farming after use of the pig manure treated by effective microbe.The SD was relatively constant around the 40 cm and the dissolved oxygen was increased 4.79%～19.28%compared to the control waterbody(no input of pig manure as fertilizer).pH is stable with small daily change from 7.2 to 7.8.Meanwhile in the waterbody in which fresh pig manure was put in directly,SD was always lower and sometimes was as low as 25 cm and the dissolved oxygen was decreased as much as 27.08%compared to the control waterbody,pH had a larger daily variation from 6.5 to 7.8.COD,ammonia nitrogen and nitrite nitrogen were 42.62%. 76.48%and 107.14%higher than that in the waterbody input the pig manure treated by effective microbe.The reservoir in which use of the residual of pig manure after fermentation as methane production had the medium values between the treatmentsⅠandⅢ.2.Effects of three different treatment of pig manure on plankton communityAfter input of the pig manure treated by effective microbe,the phytoplankton community was mainly composed of these species which are digestible for the filter feeding fish,such as dinoflagellate,euglena and diatom and zooplankton was mainly consisted of cladocerans and copepods.While in the waterbody in which fresh pig manure was put in directly,the species composition of phytoplankton was largely chlorella and cyanophytes and the species composition of zooplankton was mainly protozoan.The number density and biomass of phytoplankton is nearly equal between the treatmentⅠand treatmentⅢ,but the number density and biomass of zooplankton in the treatmentⅢwere 55%～85%and 112%～143%higher than treatmentⅠ,respectively,and 28%～36%and 44%～83%higher than treatmentⅡ. 3.Effects of three different treatment of pig manure on growth of silver and bighead carpIn the treatmentⅢ,the growth rate,survival and yield of silver and bighead carp were highest among the four treatments.The annual growth increment,survival rate and yield of stocked silver carp which initial size were 3 cm and 0.2 kg/fish were 37.4%and 9.50%,13.3%and 8.6%48.2%and 15.9%higher than treatmentⅠ,respectively.The annual growth increment,survival rate and yield of stocked bighead carp which initial size were 3 cm and 0.3 kg/fish were 70.61%and 49.01%,9.3%and 6.0%,67.5%and 34.8% higher than treatmentⅠ,respectively.In treatmentⅡ,both silver carp and bighead carp had the medium growth,survival and yield.Taking into account the water quality,growth and yield of stocked silver carp and bighead carp,Ⅰconclude that use of pig manure after treating by effective microbe has better productive and ecological benefits than direct use of fresh pig manure and use of the residual of pig manure after fermenting as methane production and is worth popularizing.