Table 11a. Fertilization (kg/ha/week) with inorganic fertilizers
based on secchi disk reading |
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Secchi
disc (cm) |
Nitrogen |
Phosphorus1 |
Urea |
Triple
super phosphate (50%) |
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20�25 |
0 |
0 |
0 |
0 |
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25�30 |
0 |
0 |
0 |
0 |
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30�354 |
5 |
2 |
11 |
4 |
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35�40 |
10 |
2 |
22 |
4 |
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>403 |
20 |
2 |
44 |
4 |
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Source: Adapted from, Boyd and Tucker (1998); Boyd
(2005); Fox (2008b) |
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1P as P2O5 (Boyd,
2003c). Phosphorus is generally limiting in algae production. |
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2Maximum theoretical
photosynthesis: 8 kg N and 0.8 kg P/ha/d (Fox, 2008b). |
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3Fertilization may
be suspended below 35 cm, especially where feed rates are higher. |
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Table
11b. Some inorganic and organic fertilizers used in shrimp aquaculture. |
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Inorganic
Fertilizer |
Nitrogen % |
Phosphorus % (as P2O5) |
Kg4,5 to get 20 kg N/ha� |
Kg4,5 to get 1 kg P/ha (as P2O5) |
Fertilization1 in kg/ha to
add based on available nitrogen in the soil (12.5 mg/100 g soil) |
Fertilization in kg/ha to
add based on available nitrogen in the soil (25 mg/100 g soil) |
Fertilization in kg/ha to
add based on available nitrogen in the soil (50 mg/100 g soil) |
Fertilization in kg/ha to
add based on available phosphorus in soil (1.5 mg/100 g soil) |
Fertilization in kg/ha to
add based on available phosphorus in soil (3 mg/100 g soil) |
Fertilization in kg/ha to
add based on available phosphorus in soil (6 mg/100 g soil) |
Urea |
45 |
0 |
44 |
|
100 |
50 |
25 |
� |
� |
� |
Ammonium
nitrate |
33�35 |
0 |
59 |
|
132 |
66 |
33 |
� |
� |
� |
Ammonium
sulfate |
20�21 |
0 |
95 |
|
214 |
107 |
54 |
� |
� |
� |
Ammonium
phosphate |
11 |
48 |
182 |
2 |
409 |
205 |
102 |
40 |
20 |
10 |
Diammonium
phosphate |
18 |
48 |
111 |
2 |
250 |
125 |
63 |
40 |
20 |
10 |
Calcium
nitrate |
15 |
0 |
133 |
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300 |
150 |
75 |
� |
� |
� |
Sodium
nitrate |
16 |
0 |
125 |
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281 |
141 |
70 |
� |
� |
� |
Super
phosphate |
0 |
18�20 |
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5 |
� |
� |
� |
100 |
50 |
25 |
Triple
super phosphate |
0 |
44�54 |
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2 |
� |
� |
� |
38 |
19 |
10 |
Gypsum |
0 |
0 |
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� |
� |
� |
� |
� |
� |
NPK(S)6 (e.g.
15�15�15) |
Variable (15) |
Variable (15) |
133 |
7 |
300 |
150 |
75 |
127 |
63 |
32 |
Mono
ammonium phosphate |
11 |
48 |
182 |
2 |
409 |
205 |
102 |
40 |
20 |
10 |
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Nutrient content (%) |
Organic carbon in
soil (1 000 mg/100 g soil)7 |
Organic carbon in
soil (500 mg/100 g soil)7 |
Organic carbon in
soil (250 mg/100 g soil)7 |
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Organic
fertilizer |
Nitrogen |
Phosphorus |
Potassium |
Sulphur |
Moisture |
Amount of organic manure
(kg/ha) to add |
Amount of organic manure
(kg/ha) to add |
Amount of organic manure
(kg/ha) to add |
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Cow
dung (fresh) |
0.5 |
0.15 |
0.5 |
� |
60 |
500 |
1000 |
2000 |
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Cow
dung (decomposed, dry) |
1.2 |
1 |
1.6 |
0.13 |
35 |
208 |
417 |
833 |
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Poultry
manure |
1.9 |
0.56 |
0.75 |
1.1 |
55 |
167 |
333 |
666 |
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Sheep,
fresh |
1.4 |
0.2 |
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77 |
179 |
357 |
714 |
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Compost |
0.75 |
0.6 |
1 |
� |
40 |
333 |
667 |
1333 |
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Adapted from Knud�Hansen et al. (1998); CIBA
(1994, 2003) |
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See also FAO (1987a) for a more detailed table on
inorganic fertilizers
(http://www.fao.org/docrep/field/003/ab468e/AB468E03.htm)� |
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1Available nitrogen in soil
at 250 to 750 mg/kg (ppm) is good for aquaculture (Boyd, 2003b). |
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2Available phosphorus above
60 ppm in the soils is good for aquaculture (Boyd, 2003b). |
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3Organic carbon of
1.5 to 2.5 % is good (Boyd, 2003b). |
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4Minimum nitrogen
and phosphorus concentrations to stimulate eutrophication are 0.01 to 0.1 mg
P/Iitre and 0.08 to 0.8 mg N/litre (Boyd, 2003b). |
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5Fox (2008b),
"Typical ratio (N:P) for brackishwater ponds is around 12-20:1";
Phytoplankton: 50 % C, 9 % N, 1 % P. |
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6N, nitrogen, P, phosphorus, K, potassium, S, sulphur. In
100 kg of 15-15-5, you�ll have 15 kg N, 15 kg P2O5 and 5
kg of K2O. |
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7For example, if the
soil organic carbon level is 500 mg/100 grams of soil sample, 417 kg of
decomposed dry cow dung is sufficient as an organic matter application. |
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