pond dynamics and whatnot. Flashcards
what does pH control for pond dynamics?
phisiology
enzyme reactions
O2 loading of blood
NH3 toxicity
what three things can pH change result from?
i) respiration
ii) photosynthesis
iii) nitrification
what are the 2 main limes?
Dolomite CaMg(CO3)2 Calcite/Calcium Carbonate CaCO3
when carbon dioxide is removed by photosynthesis, the equilibrium shift left. What happens to calcite and dolomite?
they may precipitate
What happens to carbonates and pH in sediments?
they change.
what are sediments?
primarily clay and organic debris
adding carbon dioxide to ponds with cations exchanges what?
clays, other cation exchanges also occur. Al+3 most important.
what happens to pH in newly flooded ponds?
they have a lower pH over a short time.
Photosynthesis:
- during the day CO2 is removed and what increases?
- during the night CO2 is added and what drops?
pH
During photosynthesis, when all the CO2 is used, what levels can pH get to?
8.3,
as much as 10, using CO3 as a carbon source.
if alkalinity is low, what will stop as carbon limiting?
photosynthesis
For nitrification, what enters water via N2 Fixation?
N
N becomes what in aquatic organisms?
Protein
Protein de-aminated puts what in water?
NH3
If NH3 is not incorporated in plants, what happens to it?
oxidized by bacteria
What are the three reasons for liming?***
i: kill soil pathogens
ii: increased buffering capacity
iii: provide C for photosynthesis
regarding the extent of effects, what occurs with high or low alkalinity?
dramatic effects with low, no effect with high
when observing alkalinity levels, when would you choose to lime?
when less than 20ppm
when would dramatic effects occur in regards to alkalinity levels?
dramatic effects when less or equal to 5ppm. less as it approaches 20ppm
name the 4 types of limes
calcite,
dolomite
calcium hydroxide
calcium oxide
What must you keep in mind for purity amongst limes?
that limes ay not be pure and this must be accounted for.
what is the efficiency rating of limes based on?
particle size. Smaller is more efficient, particles <1/4mm are 100% efficient
what are the four categories of particle sizes for lime, and on what size mesh can they be retained on?
> 1.7mm, 10mesh screen
1.69-0.85mm, 20 mesh screen
0.84-0.25mm, 60 mesh screen
<0.24mm, pass 60 mesh screen. 100% efficiency
to estimate the application rate of lime, you must account for what 3 factors? ***
i: neutralizing value
ii: purity
iii: efficiency
how deep would you sample mud for acidity sampling, and why?
the top 15cm, because limes react up to this depth
how many mud samples would you take for a pond 1ha? ( i think, double check with jer)
1ha = 24 samples
if you add manures, what should you add with it? why?
add with calcite.
elevated CO2 helps solution.
would you drain the pond before fertilizing?
if possible
3 general steps for applying lime
spread evenly
disc into bottom
more caustic CaO + CaOH - for sterilization
fertilizing pond, chemically, are rated by the content of what three nutrients? ***
nitrogen, phosphorus, and potassium content
how would you read the numbers ‘20,20,20’? ***
20% nitrogen, 20% phosphorus, 20% potassium content. the rest usually made up of calcium carbonate
what are the three most easily used forms of nutrients used by plants?
Ammonia and ammonium
Orthophosphate
Potassium salts
Solubility of lime is controlled by what 5 factors?
i: water depth
ii: particle size
iii: solubility constant of salts
iv: temperature
v: sinking rate
what are organic fertilizers?
manure, plant processing waste, chapped plants.
how do organic fertilizers compare to chemical?
low nutrients and high water content. usually only one nutrient lacking. Productivity increase goes down as you successively add more fertilizer
Graph the relation between productivity and increased fertilizer
ok :D
Usually _______ phytoplankton blooms at one time
only one
What occurs when nutrient levels change in regard to fertilization and phytoplankton blooms? (images on notes)
later second species will bloom as nutrient levels change
big phytoplankton: _______ need high nutrients
small phytoplankton: _________ need low nutrients
diatoms
flagellates
what type of phytoplankton bloom has the lowest concentration of N?
blue green
In FW, what has the first limiting nutrient? what has the second?
P is first, N is second
if P is > 2ppm in high oxygen water, what may happen?
form calcium phosphate and precipitate out
what are the chemical fertilizer application amounts for P, N?
3-9kg phosphate/ha
1-3kg ammonia N /ha
every 2-3 weeks,
if no bloom results, check alkalinity. C may be limited
3 methods of assessing productivity:
- monitoring Chlor A - florometry
- dark bottle/light bottle methods
- secchi disc: 20-30cm depth ideal
what is the ideal depth for secchi disk?
20-30cm
Why is neutralizing value?
Amount of acidity removed per unit weight of the lime
How does the neutralizing value change from calcite to calcium oxide?
It increases 1.00-1.79
