Dear Friends:

Jacky Foo [foo@SWIPNET.SE] asked
> In table 2, manure-fed pond received a stocking of fingerlings at 167.30
> kg/mu while in the digested_pig_slurry-fed pond it had 85 kg/mu
>
> Q: why do you use two significantly different stocking rates for the
> fingerlings in the two ponds ?
> Q: what is the general stocking rate for fish polyculture that is used by
> fish farms in Jiangsu Province ?

In Table 2 indicated different stocking density in manured pond and slurry
pond. As I understand, the manured fishpond was a fishpond of certain
production unit, and the researchers could do nothing to change it whereas the
stocking density was lower in test pond. Even though the fish yield was higher
than manured fishpond.

The general stocking density depends on the production target, the dominant
species and the main feeds in polyculture e.g. the target 500 kg/mu, the
dominant species grass carp, the main feed input terrestrial grass (rye grass
and sudan grass).

The stocking density could be grass carp 80 kg, bream 7.5 kg, silver carp 8
kg, bighead carp 2 kg, common carp 1 kg, crucian carp 0.5 kg, and tilapia i
kg. The total 100 kg.

The gross weight harvested was about 600 kg and the net weight harvested will
be 500 kg/mu.

> chicken manure+grass fed pond had input of 30.645 t/ha and grass of 0.93
> t/ha while  digested_pig_slurry-fed pond of only 1090.8 t/ha
>
> Q: why is the chicken manure input 30 times higher

No, the slurry input about 30 times higher because the main content is the
moisture in slurry.

Li Kangmin