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Step 6. Liquid waste nutrient -
This
worksheet estimate the nutrients in containment ponds.
Example Information:
| Estimated nutrients in containment pond, which
consists of 80% supernatant and 20% sludge and
based on an annual precipitation of 13 inches.
It is estimated only 30% of the 13 inches has
the potential to runoff, which creates 3.9 ac-in
(32.5% Ac-Ft) or 105,900 gallons of runoff. |
Nutrient content Supernatant
Sludge
(NRCS Ag Waste Management Handbook, Table 4-10)
|
|
|
N
= |
1.67
lb/1000 gal |
51.66
lb/1000 gal |
NH4-N
= |
1.50
lb/1000 gal |
|
P
= |
|
17.5
lb/1000 gal |
K
= |
7.5
lb/1000 gal |
14.17
lb/1000 gal |
|
Supernatant |
Nitrogen in Supernatant
| 1. |
Calculate amount
of organic N in manure per 1000 gal
lb total N – (lb ammonium N
+ lb nitrate N) = lb organic N/1000
gal |
1.67 – (1.5 + 0) =
0.17 lb/1000 gal |
| 2. |
Calculate amount of organic
N in manure available:
lb organic N/1000 gal. x mineralization
factor* = available organic N/ton |
0.17 x 0.3 (mineralization factor) =
0.05 lb N |
| 3. |
Calculate amount of plant-available
N in manure:
available organic N + ammonium N +
nitrate N = lb plant available N/1000
gal |
0.05 lb + 1.50 lb + 0 = 1.55 lb available
N/1000 gal |
| 4. |
Calculate amount of plant-available
N in runoff:
lb plant available N/1000 gal x runoff
= lb plant available N/1000 gal of runoff |
1.55 lb x 105.9 (1000 gal) = 164 lb
N |
| 5. |
Adjust for volatilization:
Volatilization from application = 1/3
loss |
164 lb x .66 = 108.4 lb N |
| 6. |
In this example 80% is supernatant
Available Nitrogen in supernatant |
80% supernatant x 108.4 = 86.6
lb available N 50
lb/ac is applied to perennial grass
that will produce 2 ton/ac
| 86.6 lb |
= |
50 lb |
| x ac |
|
1 ac |
| x |
= |
1.7 ac |
Therefore 1.7
ac needed to apply supernatant
from holding pond. |
|
| Available Phosphorus in
supernatant - No available phosphorus
in supernatant |
Available Potassium
in supernatant
| 1.
|
Calculate
amount of K in runoff:
lb plant available
K/1000 gal x runoff = lb plant available
K/1000 gal of runoff |
7.5
lb x 105.9 (1000 gal) = 794.25 lb K |
| 2. |
In this example
80% is supernatant
|
794.25 x 80%
= 635.4 lb K
|
| 3. |
Convert K to K2O
(divide by 0.83). |
635.4 lb divided
by 0.83 = 765.5 lb K2O |
|
Sludge |
In this example 20% is sludge
(figures added to land application)
|
Nitrogen in Sludge
| 1. |
Calculate
amount of organic N in manure available:
lb organic N/1000
gal. x mineralization factor* = available
organic N/ton |
51.66 lb N x 0.3
(mineralization factor) = 15.5 lb N |
| 2. |
Calculate
amount of plant-available N in runoff:
lb plant available
N/1000 gal x runoff = lb plant available
N/1000 gal of runoff |
15.5
lb N x 105,900 gal = 1641 lb N
|
| 3. |
In this example
20% is sludge
Available N in sludge |
1641 lb x 20%
= 328 lb N |
|
Phosphorus in sludge
| 1. |
Calculate
amount of P in runoff:
lb P/1000 gal
x runoff (1000 gal) = P/1000 gal of
runoff |
17.50 lb x 105.9 (1000 gal) = 1853 lb.
P
|
| 2. |
In
this example, the nutrients in
the containment pond consist of 80%
supernatant and 20% sludge. Therefore,
multiply by 20% to determine the available
P from sludge. |
1853 x 20% = 370.7 lb
P
|
| 3. |
Convert P to P2O5 (divide
by 0.44) |
370.7 lb P divided by 0.44
= 842 lb P2O5 |
|
Potassium in sludge
| 1. |
Calculate
amount of K in runoff:
lb P/1000 gal
x runoff (1000 gal) = P/1000 gal of
runoff |
14.17 lb x 105.9 (1000 gal) = 1500.6
lb K
|
| 2. |
In
this example, the nutrients in
the containment pond consist of 80%
supernatant and 20% sludge. Therefore,
multiply by 20% to determine the available
K from sludge. |
1500.6 x 20% = 300 lb
K
|
| 3. |
Convert K to K2O
(divide by 0.83). |
300 lb divided by 0.83
= 362 lb K2O3
|
|
|
