对虾养殖池塘氮磷收支的实验研究

EXPERIMENTAL STUDIES ON NITROGEN AND PHOSPHORUS BUDGETS OF SHRIMP CULTURE POND

用六个面积２５ｍ２，不同对虾放养水平：５２０００、６００００、７５２００尾／ｈｍ２的池塘围隔进行了本实验研究。结果表明：实验中投放的饵料、肥料分别占氮总输入的４９．７％～５４．５％和４７．５％～５０．１％；占磷总输入的３０．０％～３４．７％和６５．１％～６９．９％。在支出项目中，收获对虾占氮磷总输入百分比分别为９．０６％～１１．５％和３．０２％～３．９４％。沉积氮磷量为其主要支出项目，分别占总输入的１９．４％～６４．６％和２１．７％～９５．９％。底泥中氮磷的渗漏只占其支出的很小部分，分别占其输入的５．０％和０．５％左右。

Nitrogen and phosphorus budgets of shrimp culture pond were studied in six enclosuresstocked with Penaeus chinensis at three levels,i.e,52 000 ind./hm 2, 60 000 ind./hm 2 and 75 200 ind./hm 2,respectively.The main results were as follows:The largest percentages of N and P input were feed and fertilizer,49.7%～54.5% and 47.5%～50.1% for N,30.0%～34.7% and 65.1%～69.9% for P. Among the items of N and P outputs,the shrimp harvest comprising 9.06%～11.05% of total N input and 3.02%～3.94% of total P inputs.Uptake by muds represented the major loss of N and P, comprising 19.4%～64.6% of N input and 21.7%～95.9% of P input, while the loss through seepage only comprising small percentage of the total inputs of N and P,i.e, 5.0% for N and 0.5% for P.