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Tables 6 and 7 from:


Erickson, B. J., Mishili, F. J., and Lowenberg-DeBoer, J. M. 2005. Value of more uniform nitrogen application across the toolbar. Online. Crop Management doi:10.1094/CM-2005-0714-01-RS.


Table 6. Estimated long term differences in average income for corn following soybeans for differences among grain price, number of acres, and costs of applicators.

Management
situation
(variability
level,a
knife spacing)		 Cost factor
Stand.b $1.50
/bu		 $2.50
/bu		 500
acres		 2000
acres		 $6000
Low
Var.
Applic.		 $18000
Low
Var.
Applic.		 $500
Medium
Var.
Applic.		 $1500
Medium
Var.
Applic.
Low, 30-
or 60-inch		 -1,597 -1,890 -1,304 -1,998   -794 -397 -2,797          
Medium,
30-inch 		   483    234    733    142 1,167           583 383
Medium,
60-inch 		   362    157    568      81    925           462 262
High,
60-inch		  -669   -425   -914   -335 -1,339                    

 a High variability = standard deviation 25 lb/acre; medium variability = standard deviation 9 lb/acre; low variability = standard deviation 0 lb/acre.

 b Stand. = standard 140 lb/acre N rate applied with a conventional manifold in 30-inch spacings, $2.00/bu grain, 1000 acres, $12,000 low variability applicator and $1000 medium variability applicator.

Table 7. Estimated long term differences in average income for corn following corn for differences among grain price, number of acres, and costs of applicators.

Management
situation
(variability
level,a
knife spacing)		 Cost factor
Stand.b $1.50
/bu		 $2.50
/bu		 500
acres		 2000
acres		 $6000
Low
Var.
Applic.		 $18000
Low
Var.
Applic.		 $500
Medium
Var.
Applic.		 $1500
Medium
Var.
Applic.
Low, 30-
or 60-inch 		-1,310 -1,708  -913 -1,855  -221 -110 -2,510        
Medium,
30-inch 		    785     425 1144     292 1770           885 685
Medium,
60-inch 		    640     333    946     220 1480           740 540
High,
60-inch		    -823    -523 -1124    -412 -1646                 

 a High variability = standard deviation 25 lb/acre; medium variability = standard deviation 9 lb/acre; low variability = standard deviation 0 lb/acre.

 b Stand. = standard 170 lb/acre N rate applied with a conventional manifold in 30-inch spacings, $2.00/bu grain, 1000 acres, $12,000 low variability applicator and $1000 medium variability applicator.