406 Organic waste reuse and recycling: technology and management
Table 8.7 Nutrient uptake rates for selected crops, kg/(ha-yr) (adapted from U.S. EPA
1981 and local agricultural offices of Asian countries)a
Nitrogen Phosphorus Potassium
Forage crops
Alfalfaa
Bromegrass
Coastal bermudagrass
Kentucy bluegrass
Quackgrass
Reed Carnarygrass
Rye grass
Sweet clovera
Tall fescue
Orchargrass
Field crops
Barley
Corn
Cotton
Grain sorghum
Potatoes
Soya beans
Wheat
Rice
Non sensitive to light
Sensitive to light
Mustard
Cabbage
Carrot
Onion
Tea
Orange
Coffee225-540 130-
225 400-675
200-270
235-280 335-
450
200-280
175
150 – 325
250 – 350125
175 – 200
75 – 110
135
230
250
160110
60
60
210 – 240
180 – 190
120 – 170
120
330
11022-35
40-55
35-45
45
30-45
40-45
60-85
20
30
20 – 5015
20 – 30
15
15
20
10 – 20
1540
40
40
35 – 40
20 – 30
20 – 30
45
240
20175-225
245
225
200
275
315
270-325
100
300
225 – 31520
110
40
70
245 – 325
30 – 55
20 - 4540
40
20
300 – 345
325 – 445
120 – 140
N.A.
250
125
a Legumes will also take nitrogen from the atmosphere. These are data for temperate
climates where the growing season is usually once a year. For tropical areas where there
are more than one growing season in a year, the unit of nutrient uptake rates can be
changed to kg/(ha-growing season)
N.A. = not available
The nitrogen application rate should be determined from a nitrogen balance on
the system. The important processes involved in nitrogen removal from wastewater
applied to the land are ammonia volatilization, crop uptake and removal, soil
adsorption of ammonia, incorporation into the soil organic fraction, and
denitrification. With the slow rate process, nitrogen management is principally due
to crop uptake with some denitrification. The proper application rate will be that
which, when crop uptake and denitrification are considered, maintains the nitrogen