Table 9 Estimated leaf area with minimum amount of fertilizer
nitrogen to reach 2.70% sufficiency level
 ESTIMATED LEAF AREA
 (square cm)
COVER CROP MANAGEMENT AT 2.70% SUFFICIENCY LEVEL
Crimson CT-Forage 3299
clover CT-Green manure 3076
 NT-Mulch 3106
 NT-Forage 3311
 Fallow (control) 3174

Rye CT-Forage 3115
 CT-Green manure 2957
 NT-Mulch 2924
 NT-Forage 2832
 Fallow (control) 2915


 At this sufficiency level the estimated leaf areas under the
crimson clover and rye management schemes varied only slightly and
were all statistically equal (Table 9).

Table 10 Estimated ear leaf dry weight with minimum amount of
fertilizer nitrogen to reach 2.70% sufficiency level
 ESTIMATED DRY
 WEIGHT (g)
COVER CROP MANAGEMENT AT 2.70% SUFFICIENCY LEVEL
Crimson CT-Forage 20.19
clover CT-Green manure 17.92
 NT-Mulch 15.46
 NT-Forage 19.54
 Fallow (control) 18.58

Rye CT-Forage 20.88
 CT-Green manure 19.02
 NT-Mulch 18.09
 NT-Forage 19.25
 Fallow (control) 18.87


 The estimated dry weights at the sufficiency level, however,
varied far more than the leaf areas (Table 10). The estimated dry
weight of the conventional-tillage forage scheme under clover was
20.19 g at the 2.70% N sufficiency level6 while the no-tillage
mulch weighed 15.46 g. That means that conventional-tillage forage
weighed approximately 23.4% more than no-tillage mulch at the same
sufficiency level. However, the farmer might receive greater
benefit using no-tillage mulch because it costs less to reach the
sufficiency level. Although the dry weight may be less at that
level, it costs the farmer under conventional-tillage forage $57.42
($0.66 per kg N) more than the no-tillage mulch to reach the
sufficiency level.