annual report - Central Institute of Brackishwater Aquaculture

AQUACULTURE ENGINEERING AND ENVJRONMENT DIVISION
soil and w m q~;lllty md productivily
Soil and wakrquality and biolw
prom-gement
for sustainable shrimp dudivity in elation to ~~ p e e s
f- (AEEDW)
The soilandwater quality and biological
productivity was studied in relation to
Madras : B. P. GupLa
culture practices in a commercial farm at
Joseph K' Kri*nani7 M' and Venkannapalem, Nellore (A.P.). The data
P.S. Sudeesh
recorded
~ ~
during - the culture phase in both
semi-intensive and extensive types of culture
Kakdwip : R. K. Chakraborti
svstems is presented in Table 2. Soil conditions
were also noted during pond prepara-
Nnhual productivity and its enhamement tion and after harvest. There was a significant
by application of diffe~nt manures and increw in organic carbon in both systems
fedilizera from culture to harvest period (Table 2).
Mud reducing conditions were comparatively
higher in semi-intensive culture (Eh
'To understand the natural productiv- -180 mV) than extensive culture (Eh-120
ity and its enhancement in culture Systems, a ,,,v),
series of yard experiments were conducted
using different organic and inorganic ma- Changes in soil-water interface due to acnurcsvu.,
cattle dung@; 196, poultry manure cumulated organic matter
ti)0.3%, urea @! 50 kdha and single superphosphate
@! 330 k~h:, added singly or in
combination lo filtered scawatcr held in 1 ton
In order to study thi changes in soilcapacity
cement tanks with a 10 cm layer of water interface due to accumulation of orsaline
mil at thc bottom and the effect on ganic matter, a yard experiment was initiated
plankton and benthos production was aa- using cement tanks (1 ton capacity) holding
sesscd before nnd after rc;lrin# postl:Iw;le CII filtered seawater with a 10 cm layer of saline
P, monodon (ilverage weight 0.3~) (ri R soil at the bottom. Different size groups of
nc>./m2. 'Ihc water and u~il quzllit) ~n tlie shrimp^)^., 0.3 g, 7.0 g and 16 g werc stocked
tank was ani~lvscd 211 weekly intcnitl.; lor a in thc tanks @; 8 no.im2 and fed with suitable
periodc)1?9dziysprior tocl~x.kingthc shrimp. Iced provided in starter, grower and finishcr
'Ihe ammonia (0.iNN - 0.018 ppm), nitrite grades @ 8%, 5% and 3% of body weight
(0.005 . 0.01 pprn), ('01) (5.0 - 17.6 pprn), rcspcctively. At the cnd of a period of W
B01) (2.8 - 6.0 pprn) and 112S (I3D1.) wcrc days, the values ol Eh and orjianic carbon
found to be within acccptilhle Icvcls with dif- wcrc found to bc highcr with finisher feed
lercnt types (ir mznurc and frrtilF~rr trr;hc- (Ch-130 mV, orgi~nicarhon 0.19%) though
mCnls. lIil~('~cr thc soil ~lhitsc regiitvrrd ;I with~n acceptable limits, than with starter
reducing conditi(>n (I:h -7(1 to -120 m\') ern (I:h - 100 mV, organic carbon ().lhq,) or
treatment with manures. Ilighcr producti\- power feeds [E:h .115mv, organic carbon
ity was noticed with,cornhincd trciitnlc~~t\ 0.16?4). The concen~ri~tio~ of ammoniii
(I 14.5 - 277.0m~'im."hr) At thc rnd ollhc (O.(K)S ppm) and nilr;tc ((1,019 ppm) werc
pcrir~d the shrimp wcrc intnxluced for rear- also higher with finishcr leetl colnpilred to
ing with and without supplemcnti~ry feed tor startcr and gclwer feeds (0.002 0.(~)5
a period of 120 days. The experiment iq in ppm respectively for starter feed ,!nd 0.003
progresr.
and 0.07 ppm respectively for power feed).
21