5" day - Central Institute of Brackishwater Aquaculture

Though excen mom! of dily daompc80lc m e mnUu may uust
problems, but in W i pad* r high livel of alpnic mrtta is always
binbk. It is porrible to m e the soil fix produaivity bucd on the ap.nk urban
wnlmL The d l which has ap.nic urban mraH ka than 0.5% is low pmdudive.
0.5 to 2% medium poduction ud .bovt 2% high prcdu&m.
13A Crklmm urbollate (CKO,)
This is r pramelm which gives r fiir idea rbaa the free MOY c m of Ihc
soil. Thc soil with no WO, emtent will show ridk d o n . Such soil can be
lmpmvcd to neutral soil pH or alkaline by the agpliution of lime. By doing so, the
harmful action of ccrhh subarnca like sulpida md acids can be nduccd The soil
rich in CaCOj content pmmotes bwlogiul pmductivity rs it enhncts the brukdom
of organic subsunc+r by bfterL crating a more hvounbk oxygen and carbon
nmr. It procipiutw nupcndcd or mlublc apmic moPr*L darcuw BOD and
cnhwxa nidflution dw &tho rsquhmom of&chrm by nitrlt'yln~ orpninu The
productive wil should have ulcium urbcnnc more thrn 5%.
1.2.5 Soll ulslty
Saline mils arc wlly bvrrn but potml~lly productive soils. Thew soils do
not supporl pht mwth prinutily kuwe of excesrive ah in the $oil solution. In
excer~of dium ih dd axart akpninic effsts on the absorption offalcium and
m.pneoium. RKII uihle wllo commonly occur in uid md miuid mgionr and
ams nur to sea. The ulinity of mil increawr with the henme in mnr salinity
Salinity plays an imponant role in the tnnrfmation of nitrogen, both native as
well as added In the form of fertilized. The available nitmgen content in water
Increases with the increase in salinit). However. at higher salinity greater amount of
nltrogcn IS held In the soil wmplex and nibifmtion rate become slow. Rate of
decompontion of organic manurc is also affected under diffmt water salmity levclr
Decompothion ntc of D.M. is comparatively lower under hiber water rrlin~r?
leveia.
1.2.6 Redox potenHal
Oxypn is required for the decomp~ition of organic waste. In sediments. when
lnpuu of organic matter e d the supply of oxygen, anaerobic condition deveiops.
This reducing condition can k muwed as the redox potentirl. Rcdox potential IS
m p d u Eh which indlwr whaha the .ma or 1011 is in reducad condition or
oxldlud tbndltlon. Ne)nlw (-) Rbdca vdw lkour nduclrq~ condition and mirive
(+) value show aerobic condition of the pond bottom rsdimems/mud. Thc opdmum
range of soil chMcteristics suitable for shrimp fuming with minimum ud maximum
vllucr arc mentioned in Table 3.
Trbk 3. Sdl ebanctrrbtia 8mit.k fw bncbhrrtcr aqunhn
hnMtrrr 1 Mhhma - - M.emm I Wsmm Raue
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