Corn ear leaf dry weight (Table 6 and Figure 5) increased (on
the average) as the amount of N fertilizer increased under all rye
management schemes up to the 201 kg N/ha applied N fertilizer.
With no applied N fertilizer (0 kg N/ha) no-tillage mulch, the
best, performed 35.6% better than fallow, the worst. At the
highest level of applied N (268 kg N/ha) no-tillage mulch performed
the best with a weight of 20.83 g while no-tillage forage was the
worst at 19.12 g although the difference between the two was only
8.2%. On the average, the dry weight was 47.0% better at the
highest level of applied N that at the 0 kg N/ha level for all
management schemes. On the average, the dry weight at the 67
kg N/ha and 134 kg N/ha level of applied N were the same (Table 6).

 Corn ear leaf N concentration (Table 7 and Figure 6) decreased
(on the average) from the 0 kg N/ha to 67 kg N/ha levels of N
fertilizer and increased (on the average) from the 67 kg N/ha all
the way to the 268 kg N/ha level of applied N fertilizer for all
rye management schemes. With no applied N fertilizer, no-tillage
mulch had the best ear leaf N concentration of 2.48% while fallow
had the worst of 1.77%. Thus with no applied N, no-tillage mulch
was 28.6% better than the fallow. In fact, at this level, no-
tillage mulch is only 0.22% N concentration under the 2.70%
sufficiency level6. At the 268 kg N/ha level of applied N
fertilizer no-tillage mulch had the best N concentration of 3.18%
while no-tillage forage was the worst with 2.96% N although both
were above the sufficiency level and there existed only a 6.9%
difference between the two. On the average, the N concentration
was 28.2% higher at the highest level of applied N fertilizer of
268 kg N/ha than at the 0 kg N/ha for all management schemes. On
the average, the N concentration was 7.7% higher at 0 kg N/ha than
at 67 kg N/ha for all management schemes (Table 7).

 DISCUSSION
 A 2.70% sufficiency level of N concentration in the ear leaf
of a corn plant is required for a healthy plant.6 Different cover
crops can be sacrificed and different management schemes utilized
to try to help provide the required N to the corn. In any event,
applied inorganic N fertilizer must be used in some amount to reach
this level. The amount of inorganic N fertilizer required to reach
this sufficiency level is critical for economic reasons (Table 8).

 For crimson clover, no-tillage mulch required only 57 kg
N/ha, the least N fertilizer, while no-tillage forage required 179
kg N/ha, the most (Table 8). That means no-tillage forage required
68% more N fertilizer than no-tillage mulch to reach the same
sufficiency level of 2.70% N6. For management schemes under the
rye cover crop, conventional-tillage forage required the least N
fertilizer (143 kg N/ha) while no-tillage forage required the most
(230 kg N/ha). That translates to 37.8% more inorganic N
fertilizer required for no-tillage forage than for conventional-
tillage forage to reach the 2.70% N sufficiency level6.