Estimated Mineralization Rates, Nitrogen Credits for Legumes and Ammonia Conservation Factor For Organic Nitrogen
Source: University of Maryland Cooperative Extension, 1993
Regulatory Citation: COMAR 15.20.08.05
Estimated mineralization rates are based on latest available data in Mid-Atlantic region,
recommended by the University of Maryland Cooperative Extension Service and accepted by the
Maryland Department of Agriculture. The following factors shall be used by all nutrient
management consultants as basis for calculation of available nitrogen from different forms and
sources of the organic wastes for the first year and from previous years of applications.
Manure Mineralization Rates
| Manure Sources and Types |
% of Nitrogen Availability for Organic N Mineralization in Each Year |
|
This Year |
Last Year |
3rd Year |
4th Year |
| Cattle (Dairy & Beef) all types |
35 |
18 |
9 |
5 |
Poultry
a. Caged layers (Deep pit storage)
b. All other (Flor) |
60
50 |
10
15 |
5
8 |
3
4 |
| Swine (all types) |
50 |
15 |
8 |
4 |
| Horse |
20 |
10 |
5 |
3 |
| Sheep |
30 |
15 |
5 |
3 |
Sludge Mineralization Rates
Current year mineralization
rates and previous year Km factors for sludge applied
(Km units: Lbs N mineralized per ton
of sludge applied per % organic N)
| Sludge Type |
Mineralization
rates for
current
application |
1
yr ago |
2 yrs ago |
3 yrs ago |
4 yrs ago |
5 yrs ago |
6 yrs ago |
7 yrs ago |
8 yrs ago |
9 yrs ago |
| Unstabilized |
0.40 |
2.40 |
0.96 |
0.44 |
0.24 |
0.24 |
0.24 |
0.11 |
0.11 |
0.11 |
Lime
Stabilized or
Aerobically
Digested |
0.30 |
2.10 |
0.90 |
0.42 |
0.32 |
0.30 |
0.30 |
0.30 |
0.30 |
0.30 |
Anaerobically
Digested |
0.20 |
1.60
|
0.72 |
0.42 |
0.38 |
0.38 |
0.38 |
0.36 |
0.36 |
0.17 |
| Composted |
0.10 |
0.90 |
0.50 |
0.50 |
0.48 |
0.46 |
0.46 |
0.44 |
0.42 |
0.42 |
I-C1
Nitrogen Credits for Legume Crops
|
| Crop |
Lbs.
N/Acre |
Perennial Crops
Alfalfa
Ladino clover
Red clover
Birdsfoot
trefoil |
100 - 150a
60
40
40 |
Winter Annual Crops
Crimson clover
Hairy vetch
Austrian winter
peas |
50 - 100b
75 - 150b
75 - 150b |
Summer Annual Crops
Lespedeza
Soybeans |
20
15 - 40c | |
a. Depends on stand;- if stand is good (>4 plants per sq ft), credit 150 lbs;
- if
stand is
fair (1.5 to 4 plants per sq ft), credit 125 lbs;
- if stand is poor (<1.5 plants per sq ft), credit 100
lbs.
b. Depends on planting date
(biomass production), kill date
and
subsequent tillage.
c. A minimum of 15 lbs and may be
as much as 1 pound per
bushel if
soybeans up to 40 lbs. maximum
|
Ammonia (Nh4) Conservation Factors
| Day Incorporated |
Conservation
Factor |
Injected
1
2
3
4
5
6 |
1.00
0.80
0.64
0.48
0.32
0.16
0.00 |
I-C2
Maryland Nutrient Management Manual
|
