Sl. No

Parameter

Advisory

1.

pH  

      2-6.5

Lime application is required/ follow our blog- Determination of lime requirement and methods.  (https://aquabeats.in/pages/blogdetail.php?blogId=23)

     6.5-7.5

Ideal pH. No amendment required

     7.5 and above

The soil is under anerobic condition and may contain hydrogen sulphide and sulphates/sulphur, and it can turn to acidic on drying which will demand hydrogen sulphide. Better to maintain as such and go ahead with culture following the principles of bioremediation.

2.

Eh (Milli Volts)

+50 to 0

Low organic matter and anaerobic conditions have not been set in. Pond productivity may be low and required organic manure application may be resorted to have phytoplankton blooming.

0 to - 100

Reduction status increases corresponding to the decrees in Eh indicating more microbial activity. Situation is favorable as sufficient organic matter is available for supporting phytoplankton production. Can undertake culture without amendment.

-100 to -150                    

The system has set in with anaerobiosis and nitrate respiration has been getting completed sliding it to sulphate/Sulphur respiration. If detritus bioremediation protocols are implemented the system can be protected from further sliding down to lower Eh. Estimate sediment oxygen demand and hydrogen sulphide production potential and report to Aquabeats for further support.

-150 to -200

Sulphate/Sulphur respiration has set in and hydrogen sulphide production has commenced. Protocols for bioremediation of organic matter and hydrogen sulphide have to be resorted. Estimate sediment oxygen demand and hydrogen sulphide production potential and report to Aquabeats for further support.

-200 and below

The system as such is unsuitable for stocking and for improvement follow the protocols for organic matter and hydrogen sulphide bioremediation. Make sure that hydrogen sulphide emanation does not take place to the water column. Protocols for bioremediation of organic matter and hydrogen sulphide have to be resorted before stocking and make sure that the hydrogen sulphide does not get emanated to water column.

3

Total organic carbon % w/w

0 to 1%

Mineral soil with low organic matter content. Organic fertilizers can be added to attain productivity.

1-3%

Mineral soil, moderate organic matter content, best range for aquaculture. No need to add any organic matter.

3.0 to 15

Mineral soil, high organic matter content. Bioremediation to reduce organic matter has to be resorted. Do not dry the pond if the Eh happens to be < 150mVolts as acid formation may take place.

>15

Organic soil, not fit for aquaculture as such. Removal of top soil is recommended and layering with soil having lower organic carbon. Alternatively, drying, tilling application of lime and bioremediation with organic matter degrading bacteria have to be resorted to bring down the organic carbon to 3%.

4

Total organic nitrogen (mg/100g)

0 to 50

Minimal (need not add any more nitrogenous organic matter)

5 to 75

Optimal (need not add any more nitrogenous organic matter)

75 to 100

Higher (There is the chance of generating ammonia under anaerobic conditions) Bioremediation has to be resorted

100 to 150

Highest (Possibilities of producing ammonia under anaerobic condition is more). Bioremediation has to be resorted

150 and above

Lethal – as large quantity of ammonia will get emanated to the water column. Appropriate steps must be undertaken to eliminate the nitrogenous matter before stoking what are the appropriate steps we advise?

5

Total phosphorous

<3mg/100g soil

Poor productivity is expected. Supplementation with rock phosphate recommended

3 to 6mg/100g soil

Average (No further amendment required) no further amendment means?

6 to 12 mg/100g soil

High productivity is expected. Excess bloom can be expected and hence addition of manure can be avoided.

> 12 mg/100g soil

Excess. Very high bloom can be expected. Accordingly manuring has to be avoided.

6

Soluble sulphur

% (w/w)

< 0.3

Low risk in the sense that hydrogen sulphide production potential is low what do we suggest?

0.3 to 0.5

Moderate risk as under anaerobic conditions Hydrogen sulphide may be formed

0.5 to 0.8

Moderate to high risk as hydrogen sulphide will be formed till Sulphur respiration gets completed, and hence bioremediation protocols have to be undertaken

> 0.8

High to unacceptable as there is threat of formation of hydrogen sulphide and morality

> 1.0

Unacceptable as hydrogen sulphide formation will take place under anaerobic condition and subsequent mortality. Better to remove the top soil and replace with soil containing low sulphate

7

Cation exchange capacity (Mol (+)/Kg

2-6

Lower CEC suggest low buffering capacity and need of frequent liming to maintain pH. Moreover, the soil has less nutrient holding capacity also

6-10

Ideal CEC suggest adequate buffering capacity demanding less frequent liming more nutrient holding capacity and slow release

10-20

8

General appearance of soil

Whitish sandy

Having more sand content and less organic matter. Productivity is likely to be less. Less iron content and thereby lesser iron sulphide. In case hydrogen sulphide is formed likely to be released in to water.

Brown loamy

Comparatively less sand and more organic matter, with moderate productivity.  Less iron content and thereby lesser iron sulphide. In case hydrogen sulphide is formed likely to be released in to water.

Dark brown

Comparatively more organic matter and less iron because of which hydrogen sulphide is likely to be released in to water in case got generated under anaerobic conditions.

Light black

Indicates formation of iron sulphide due to the trapping of hydrogen sulphide formed. Indicates high organic matter content

Dark black

High organic matter, higher iron content and hydrogen sulphide production potential

9

Texture

Sandy

Not ideal for culture as it does not hold nutrients and leads to low productivity. What should he do? We cant expect him to not do culture if the texture is sandy?

Loamy

Consists of nearly equal parts of sand, silt and clay, robust combination nutrient rich what do we advice?

Clayey

Stabilized the bottom and binds large quantity of nutrients and releases slowly what do we advise?

10

Seepage

Yes

Must take care of lowering of water level unexpectedly

No

Need not worry about seepage water, but evaporation loss will lead to salinity increase

11

Does the pond fit with sluice gate

Yes

Lift the lowest plank to allow water in and the top most one for letting water out

No

Water exchange has to be through pumping and appropriate capacity pumps have to be fitted to take in sufficient water during a period of time

12

If no how do you propose to allow water in

Pumping from creek

AS the water quality of the creek may change, a knowledge on the same is required while pumping water to the pond.

Pumping from back water

Pumping must coincide with the tide with respect to the salinity requirements

Pumping from river/stream

River/stream water is ever changing in quality and hence care must be taken to avoid pumping of undesirable quality water.

Pumping from sea

Water quality remains more or less stable, but the salinity increase in the pond must be addressed on pumping sea water

Pumping from borewell

Borewell water may contain toxic compounds including hydrogen sulphide. Hence direct pumping to the culture pond must be avoided, instead it can be brought through a guard pond.

13

How do you propose to filter water

Bagnet

Use Bagnet of not less than 2-meter length of 100 micrometer pore size. Frequent change of the net is required as the clogging possibilities are higher. Tie it to the outlet of the pump.

Screens

Suited for sluice gates. Three-layer independent screens are better. The outer one having 1mm pore size, middle 0.05 mm pore size and the inner 0.1 mm pore size. They must be vertically placed in the sluice gate and as the clogging chances are higher intermittent replacement is required with washed and cleaned ones.

14

Height of the bund from ground level

30cm

Lower – possibility of flood water entry high

30-60

Moderate – Possibility of flood water entry exist

60-90

Ideal

15

Width of the bund

< 60cm

Insufficient what repercussions if he still performs stocking?

> 60cm

Most ideal would be 90 cm

16

Slope of the bund to the pond

10 degree

Very less

15 degree

Moderate

18 degree

Optimum