许多八十年代开挖建成的池塘,经过十多年的高密度养殖,在饲养管理中施放大量有机粪肥,投放许多精饲料和青饲料,加之,养殖鱼类排泄的粪便,池水中死亡的生物体和每年塘埂坍塌冲刷流入塘中泥砂相混合,在鱼塘底 Many of the ponds excavated in the 1980s have been heavily dedusted for more than a decade to produce large amounts of organic manure and many fine feeds and fodder. In addition, manure excreted by farmed fish, dead organisms in pond water And the annual pond slump scouring infiltration pond mixed with mud, pond bottom