TOBACCO STALKS AND STEMS FERTILITY VALUE AND USE
ISSUED: 1-64
REVISED: 4-79
J.H. Smiley and W.O. Atkinson
On the average, a ton of burley leaf
will yield about 1,500 pounds of stalk, or a ratio of 4 to 3. In dark air-cured
and dark fire-cured tobacco, a ton of leaf yields about 660 pounds of stalk,
or a ratio of 3 to 1.
Tobacco stems are available in limited
quantities in areas where tobacco re-dryers are located. Since farmers
purchase the stems, good conservation practices are usually followed in
using them. However, tobacco stalks accumulate on the farm where the tobacco
was grown and cost the farmer nothing. Hence their value is not always
realized, and the stalks are not always handled properly.
Value
Table 1 shows the average amounts of
nitrogen, phosphorus, potassium, calcium, and magnesium found in tobacco
stalks and stems from a number of samples analyzed by the Kentucky Agricultural
Experiment Station.
Table 1. Average Composition of Burley Tobacco Stalks and Stems
Material |
Total Pounds per Ton
|
N |
P* |
K* |
Ca |
Mg |
Stalks |
56 |
5 |
75 |
36 |
5 |
Stems |
50 |
5 |
145 |
70 |
8 |
*Values for phosphorus (P) can be converted to P205
by multiplying by 2.29 and potassium (K) can be converted to K20
by multiplying by 1.2.
Since dark tobacco, both fire- and air-cured,
is not fertilized at the same high rates as burley tobacco, the nutrient
content of the stalks and stems is somewhat lower.
Tobacco stems are included in the above
table since farmers in areas where redryers are located are interested
in their value. These data refer to burley tobacco stems only. Flue-cured
tobacco stems, also a byproduct of re-dryers in Kentucky, contain about
27 pounds of nitrogen, 5 pounds of phosphorus, and 110 pounds of potassium
per ton.
Table 2 indicates the average total
nutrients in burley tobacco stalks and stems that are available for crop
growth during the first year after they are applied to fields.
Preserving Tobacco Stalks
The Kentucky Agricultural Experiment
Station found that 61 percent of the nitrogen, 38 percent of the phosphorus,
83 percent of the potassium, and 41 percent of the organic matter may be
lost from tobacco stalks if they are piled outside the barn and exposed
to rainfall during the winter months (Fig. 1 ). Thus, the greatest value
is obtained when the stalks are kept under shelter until they are spread
on lawns, gardens, or fields.
Table 2. The Average Amounts of Various Nutrients in Burley Stalks
and Stems That Are Available the First Year of Application
Material |
Total Pounds per Ton |
N |
P* |
K* |
Ca |
Mg |
Stalks |
30 |
4 |
62 |
15 |
3 |
Stems |
27 |
4 |
116 |
50 |
6 |
*Values for phosphorus (P) can be converted to P205
by multiplying by 2.29 and potassium (K) can be converted to K20
by multiplying by 1.2.
If you must pile stalks outside through
the winter, do not leave them under barn eaves where excess water will
run through them. Stack the stalks in deep piles and cover them with straw
or other crop residues to reduce leaching.
Whole tobacco stalks make acceptable
bedding material in loafing sheds and feed lots under cattle and horses.
The animals will break up the stalks so that they can be handled in manure
spreaders and easily plowed under. However, stalks are not satisfactory
in stalls that must be cleaned often. When used in dropping pits for poultry,
the stalks should be cut or shredded.
Using Tobacco Stalks and Stems
If you spread tobacco stalks in winter,
put them on lawns, pasture, meadow, or small grain fields where a living
root system will pick up nutrients as they leach from the stalks. Fewer
nutrients will be lost if stalks are spread on such fields in the spring.
Loss of nutrients should also be small when stalks are spread in the spring
and plowed under on land going into a cultivated crop. Whole stalks may
interfere to some extent with tillage and harvesting operations before
they rot.
Caution
Tobacco stems should not be used on
tobacco land unless they are sterilized at the re-dryer.
If a mosaic susceptible variety of
tobacco is being grown, the stalks should not be used on tobacco beds or
fields.
Stalks from black shank infested fields
should not be used on tobacco land, but may be used on other field crop
and pasture land provided water from these fields does not drain on to
tobacco land.