The Kjeldahl method for N determination was used to determine
ear leaf N concentration.7 After weighing 100 mg of leaf tissue,
3.2 g of catalyst (9:1 ratio of K2SO4:CuSO4) and 10 ml of sulfuric
acid (H SO4) were added and mixed with a centrifuge and then placed
in an aluminum digestion block.8 One ml of H202 was added to each
test tube to digest foaming compounds. After that was finished,
another ml was added and the samples were digested for six hours.
Each sample was brought to 75 ml volume with deionized water,
stored in plastic bottles, and analyzed on a Technicon II Auto
analyzer to determine N concentration.

 Ear leaf area, dry weight, and ear leaf N concentration were
typed into a spreadsheet (Quattro Pro9) for manipulation and
transformation on a micro computer. Statistical analysis was
performed for a split-plot experimental design using MSTAT'0.
Harvard Graphics11 was used to plot relationships between changes
in leaf area, dry weight, N concentration, and applied N rates.


 RESULTS
 Crimson clover was one of the cover crops used to determine
the best management practice to optimize factors of corn growth.
Corn ear leaf area, dry weight, and N concentration are distinctly
affected by the various management schemes using clover and varying
amounts of N fertilizer.

 Corn ear leaf area (Table 2 and Figure 1) increased (on the
average) as the amount of N fertilizer increased under all clover
management schemes up to 201 kg N/ha applied N fertilizer. With no
applied N fertilizer (0 kg N/ha) conventional-tillage forage was
the best with a leaf area of 2838 square cm while the fallow
(control) was the worst at 2160 square cm. With no applied N the
management scheme of conventional-tillage forage was 23.9% better
than the fallow scheme. At the maximum amount of applied N
fertilizer (268 kg N/ha) no-tillage mulch was the best method with
a leaf area of 3574 square cm while no-tillage forage was the worst
method with a leaf area of 3286 square cm. Thus, no-tillage mulch
was 8.1% better at that N level. All leaf areas were averaged
according to N level and management scheme. These averages
represented the leaf areas of 20 subplots (Table 2). Thus, on the
average, the leaf area was 26.4% better at the highest level of
applied N of 268 kg N/ha than at the 0 kg N/ha level for all
management schemes.

 Corn ear leaf dry weight (Table 3 and Figure 2) increased (on
the average) as the amount of N fertilizer increased under all
clover management schemes up to 201 kg N/ha applied N fertilizer.
With no applied N fertilizer (0 kg N/ha) conventional-tillage green
manure performed the best while the fallow (control) performed the
worst. In fact, the conventional-tillage performed 30.7% better
than the fallow. At the highest level of applied N fertilizer (268
kg N/ha) no-tillage mulch performed the best with 21.88 g while no-