In terms of successful and sustainable development of aquaculture two prospects are most important soil and water quality parameters management and its interaction process understanding. Selection of the site for pond construction soil plays a key role. Soil type, water holding capacity, organic matter, available nutrients and chemical composition of soil these parameters are optimum level is required for aquaculture suitable site. After water filling of the pond water parameters like pH, dissolved oxygen, total alkalinity, total hardness and total ammoniacal nitrogen interact with soil composition. That things are also dependent on climatic conditions and weather patterns.

1. College of Fisheries Science - Veraval
Kamdhenu University
Sub: Soil and Water Quality Management in Aquaculture (AQC-502)
Submitted By
Rajesh V. Chudasama,
M.F.Sc., 2nd Sem. COF-VRL, KU.
Submitted To
Dr. K. H. Vadher,
Associate Professor, COF-VRL, KU.
Department of Aquaculture

2. Soil and Water Interaction:
Physical and Chemical Properties of Soil and Water

3. Introduction
• Successful aquaculture depends on providing animal with a satisfactory environment in
which to grow.
• Good initial condition for aquaculture can be assured by a selecting a site with suitable
soil and a high-quality water supply.
• Soil is a key factor in aquaculture. Pond soil are store house for many substances that
accumulate in the pond ecosystem and chemical and biological process occurring in the
surface layer of pond soil influences water quality and aquaculture.
• Understanding of soil properties and process in soil can be useful in pond aquaculture

4. Pond Soil
 Basic function of pond soil is holding the water.
 Soil plays an important role in regard to the fertility of aquaculture ponds. Types,
characteristics and chemical conditions of soil influences the pond productivity.
 The physico-chemical properties of pond water are more or less a reflection of the
properties of the bottom soil.

5.  The pond bottom is originally made of terrestrial soil and when the pond is filled
with water the bottom becomes wet.
 Mixture of solid materials and with water is called ‘‘mud’’. Solids settle from the
pond water and cover the pond bottom is ‘‘sediment’’.
 Organic matter deposited on the pond bottom is decomposed to inorganic carbon
and released to the water as carbon dioxide and ammonia. Carbon dioxide and
ammonia are highly soluble and quickly enter the water

6. Physical Properties of Soil
• Physical properties of soil include …
I. Soil texture
II. Soil structure
III. Soil color
IV. Soil permeability
• These properties affect processes such as infiltration, erosion, nutrient cycling
and biological activity.

7. Relevant Size of Sand, Silt and Clay
A. Soil Texture
Soil texture refers to the relative proportions of particles of various sizes such
as sand, silt, and clay in the soil.

8. Soil Type Sand (%) Silt (%) Clay (%)
Sandy loam 50-80 0-50 0-20
Clay loam 20-50 20-25 20-30
Silt loam 0-50 50-100 0-20
Silty clay loam 0-30 50-80 20-30
Loam refers to a mixture of sand, silt, and clay.
Source: Handbook of Fisheries and Aquaculture (Khanna, 1966)

9. Soil Texture Important
• Determines water
intake rate,
water storage,
ease of tilling the soil and
fertility of the soil.
• The soil containing at least 30% of clay is ideal for fish pond construction.
Silty clays are excellent for fish pond construction.
• Soil texture is influenced the water turbidity.

10. B. Soil Structure
• Cluster of primary (sand, silt and clay) particles.

11. • The platy types of soil are most suitable for aquaculture.

12. C. Soil Colour
• Soil color gives an indication of the various processes going on in the soil as
well as the type of minerals in the soil.
Soil Color Present Compound
Red soil Iron oxide
Dark soil High organic matter

13. Yellow soil Hydrated iron oxide, Hydroxide
Black soil Manganese oxide
Pale-Yellow soil Low pH, Acid sulphate soil

14. D. Soil Permeability
• The ability of the soil to transmit water and air.
• An impermeable soil is good for aquaculture. (seepage and infiltration is low)
• Pore size, texture, structure - Determines the permeability of a soil.
• Clayey soils with platy structures have very low permeability.
• Permeability is measured: cm/hour, cm/day, cm/sec

15. Chemical Properties of Soil
A. pH
• pH is a measure of acidity in water or soil.
• The ideal pH is 7.5 to 8.5 pond soils.
• pH below 7.5 applied lime
• Soil pH can be reduced most effectively by adding elemental sulfur, aluminum
sulfate or sulfuric acid.

16. B. Phosphorus
• The importance of available phosphorus in soil for increasing productivity is
well recognized.
3 mg/100 g Poor Productivity
3 - 6 mg/100 g Moderate Productivity
6 - 12 mg/100 g High Productivity

17. C. Nitrogen
• Nitrogen in soil is present mostly in organic forms as amino acids, peptides
and easily decomposable proteins.
• The conversion of complex organic forms of nitrogen to simple inorganic
forms is carried out by anaerobic microbes.
• The range of available nitrogen is 50-75 mg/100g of soil relatively more
favorable for pond productivity.

18. D. Organic Carbon
• Compared to the mineral constituents of the soil, organic compounds are
more varied and complex.
• Very high organic content is also not desirable for a pond soil.
• However, organic carbon less than 0.5% may be considered poor, 0.5-1.5% as
average while 1.5-2.5% appeared to be optimal for good production.

19. Pond Water
• When water is added to a pond, it contacts the soil and various reactions occur.
• If the water is acidic and the bottom soil is basic, bases in the soil neutralize acidity in the
water, raising its pH and total alkalinity.
• In cases where both soil and water are acidic, liming is used to neutralize soil acidity and
assure adequate pH and total alkalinity in pond waters.
• Where both soil and water are basic in reaction, liming is unnecessary unless there are
other sources of acidity. A common source of acidity in such aquaculture ponds is
nitrification of ammonium from fertilizers or ammonia excreted by the culture species, and
microbial decomposition of uneaten feed and faces.

20. =
=
Physical Properties of Water
A. Temperature
• Depends on climate, sunlight and
depth of water.
• Decrease in dissolve oxygen
saturation level is directly related to
increase in temperature.

21. B. Turbidity
• Turbidity of water is produced by Dissolved and suspended
substances such as clay particles, humic substances, plankton,
colored compound.
• Turbidity caused by plankton is usually desirable since it
enhances fish production.
• However, turbidity caused due to clay and other colloidal
particles is undesirable since it can choke the gills of fish and
shellfish.

22. • Turbidity is a measure of light penetration in
water.
• Water turbidity in ponds is commonly
measured with Secchi disc.
Turbidity 30 – 40 cm Secchi Disc

23. C. Water Colour
• The colour of water caused by living or non-living substances in suspension and
by extrinsic conditions.
Green water Algal bloom
Reddish brown colour Blooms of dinoflagellates
Bright green water Algae covered depression
Brown colour Abundance of diatoms

24. Chemical Properties of Water
A. Salinity
Freshwater is less than 2 ppt Brackishwater is 2 to 34 ppt Seawater is more than 34 ppt
Salinity is a measure of the concentration of dissolved ions (NaCl) in water
expressed as parts per thousand (ppt).

25. B. pH
• It is a measure of hydrogen ion concentration in water.
• It is being alkaline in mid-afternoon and acidic just before daybreak.
• The limit above or below which pH has a harmful effect is given as 4.8 and 10.8.

26. C. Dissolved Oxygen
• Source of oxygen: Atmosphere, Phytoplankton,
macrophytes and photosynthesis.
• Increasing temperature and salinity, reduce the
saturation point of DO in water.
• Dissolved Oxygen along with temperature control
the metabolism of fish and invertebrates.
• For obtaining good production DO level should be
above 5.0 mg/L.
Dissolve Oxygen v/s Temperature
different water bodies

27. Dissolved Oxygen and Water Temperature Usually Vary Over a 24-Hour Cycle.

28. Stratification can cause dissolved oxygen and temperature to vary at different
depths in the same system.

29. D. Alkalinity
• Bicarbonate (HCO3
-) and carbonate (CO2
3
-) are the major constituent of pond
water and their concentrations are expressed as total alkalinity.
• Calcareous water with alkalinities more than 50 ppm is most productive.
Alkalinity buffers against diurnal
variations in pH.

30. • Waters of low alkalinity (<20 mg/liter) are poorly buffered, and removal of
CO2 during photosynthesis result rapid rise in pH.
• Water with greater than 20 mg/liter alkalinity have greater buffering capacity
and prevent large large fluctuations in pH during photosynthesis.

31. The Form Alkalinity Takes is Linked to pH of the System.

32. E. Hardness
• Hardness is defined as the total of soluble Calcium and Magnesium salts
present in the water medium.
• Bicarbonates of Ca and Mg cause temporary hardness.
• Permanent hardness of water is due to soluble Ca and Mg carbonates and
salts of inorganic acids (CaSO4).

33. G. Ammonia
• Ammonia in water is either unionized ammonia (NH3) or the ammonium ion (NH4)
• Unionized ammonia (NH3) is toxic to fish.
• The total ammonia is depended upon the pH and temperature of water.
• The main source of ammonia in fish ponds is fish excretion. The rate at which fish
excrete ammonia is directly related to the feeding rate and the protein level in
feed.
• The decomposition of this organic matter produces ammonia, which diffuses from
the sediment into the water column.

34. pH and Temperature on Levels of Unionized Ammonia

35. F. Hydrogen Sulfide (H2S)
• Hydrogen sulfide is generated by certain heterotrophic bacteria under
anaerobic conditions and accumulating in pond bottom, bottom soil often
turning black and emanating a rotten smell.
• pH is rises, the percent of hydrogen sulfide decrease.

36. Sulfide Solubility Chart at Different pH
H2S = Hydrogen Sulfide, HS− = Hydrosulfide, S2− = Sulfide di-anion.

37. An Optimum Level of Physico Chemical Properties of Soil and Water
Sr. No. Properties Optimum Level / Type Measurement Technique
1. Soil Texture Clay Loam Soil Glassware
2. Soil pH 7 and a Little above pH Meter / Paper (With Water)
3. Temperature 24° – 30° C Thermometer
4. Turbidity 30 – 40 cm Secchi Disc
5. Water Colour Light or Bright Green Visual Observation
6. Dissolve Oxygen 5 ppm Wrinklers Method
7. pH 7.5 – 8.5 pH Meter
8. Total Alkalinity 75 – 300 ppm Titrimetric Methos
9. Total Hardness 50 – 120 ppm Titrimetric Methos
10. Salinity Depends on Water Body and species Refractometer
11. Hydrogen Sulphide Nil Spectrophotometer
12. Ammonia 0.02 – 0.05 ppm Spectrophotometer

38. Soil and Water Interaction in Aquaculture
Dissociation CaCO3 + CO2 + H2O  Ca+2 + 2HCO3
Hydrolysis Al+3 + 3H2O  Al(OH)3 + 3H+
Neutralization HCO3
- + H+  H2O + CO2
Oxidation NH4
+ + 2O2  NO3
- + 2H+ + H2O
Reduction SO4
+2 + 4H2  S-2 + 4H2O
Complex Formation Cu+2 + CO3
-2  CuCO3
Absorption Absorption of phosphorus on soil colloids
Cation Exchange K (Soil)  K+ (Water)
Sedimentation Soil particles in runoff settle to pond bottom.
Seepage Water carrying dissolved substance seeps downward into the pond soil.

39. Decomposition Microorganisms break down soil organic matter.
CH2O + O2  CO2 + H2O
Photosynthesis Benthic algae produce organic matter release oxygen.
6CO2 + 6H2O  C6H6O6 + 6O2
Diffusion Oxygen diffuses into bottom soil from water above.
Erosion Water current in pond erode the bottom soil.
Suspension Particulate matter eroded from the bottom is suspended in pond water

40. Conclusion
• In terms of successful and sustainable development of aquaculture two prospects are most
important soil and water quality parameters management and its interaction process
understanding.
• Selection of the site for pond construction soil plays a key role. Soil type, water holding
capacity, organic matter, available nutrients and chemical composition of soil these
parameters are optimum level is required for aquaculture suitable site.
• After water filling of the pond water parameters like pH, dissolved oxygen, total alkalinity,
total hardness and total ammoniacal nitrogen interact with soil composition. That things
are also dependent on climatic conditions and weather patterns.

41. • Ayyappan, S., Jena, J. K., Gopalakrishnan, A., Pandey, A. K., & Indian Council of Agricultural Research.
(2006). Handbook of fisheries and aquaculture. New Delhi: Directorate of Information and Publications of
Agriculture, Indian Council of Agricultural Research.
• “Soil Physical Properties and Processes - Minnesota Stormwater Manual.” Retrieved March 23, 2022d.
• “Soil Quality Considerations in the Selection of Sites for Aquaculture.” Retrieved March 23, 2022e.
• Boyd, Claude E. 1995. “Soils in Pond Aquaculture.” Bottom Soils, Sediment, and Pond Aquaculture 1–9.
• Boyd, Claude E., C. W. Wood, and Taworn Thunjai. 2002. Aquaculture Pond Bottom Soil Quality
Management.
• Subhendu, Subhendu, and Datta Datta. 2009. Soil and Water Interaction and Its Importance In
Aquaculture.
References

42. Thank You !!