| With the rapid development of tilapia aquaculture,integrate agriculture-aquaculture(IAA) is becoming the main tilapia aquaculture mode in southern China. Due to its breeding density, impact on water environment and disease, IAA mode is queried by many people. In this paper, there are three ponds of two modes,in every month around2012, we measure the water quality factors(temperature, pH, dissolved oxygen(DO), ammonia nitrogen(NH3-N), phosphate(PO4-P) and nitrite(NO2-N)), the streptococcus disease incidence in tilapia, the heavy metal content(copper (Cu), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb)) in sediment, water and tilapia muscle.Result shows that there is no streptococcus disease break out in two kinds of ponds during the aquaculture. There is no obviously difference between the temperature, pH, DO and NH3-N of the two mode. The NO2-N average content of P1, P2and P3are0.45mg/L,0.38mg/L and0.35mg/L, and are higher than monoculture pond Mi, M2and M3(0.24mg/L,0.3mg/L and0.24mg/L).The PO4-P content of P1, P2and P3are3.14mg/L,1.29mg/L and0.27mg/L, only M1is detected PO4-P in three monoculture ponds, and the average content is only0.11mg/L. The heavy metal results show that:in the two kinds of mode, Cu, As and Pb in water, sediment and fish have no significant differences (P>0.05), but the Cr content in the sediment in IAA ponds P1, P2and P3are225.78mg/kg,50.23mg/kg and243.78mg/kg are higher than monoculture ponds M1, M2and M3(35.77mg/kg,20.65mg/kg and24.87mg/kg)(P<0.05). The Cd content in sediment of P1, P2and P3are2.13mg/kg,3.53mg/kg and3.93mg/kg, and are also higher than three monoculture ponds M1,M2and M3(0.87mg/kg,2.27mg/kg and0.88mg/kg)(P<0.05). This study also shows that, in addition to the Cd content in sediment and the Cu in water of two modes and the Cr in sediment of IAA exceed national standard, the other heavy metal content in water, sediment and fish of two kinds of mode ponds are all accord with national standard. |
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