Vol. 51—1997 - NorthEastern Weed Science Society

Waggoner December 24, 1994
143
1.5
2 2.5
3
3.5
4
4.~
).,Ị
.
J
1.~
2 2.5
4
I
./4.5
y
Fig 10. The c ntours of yield on a map where herbicide
increases eas ward or right from 0 to 2 kg/ha and fertilizer
increases nor hward or toward the to from 0 to 250 k /ha.
A critic marc ing to the drummer of fertilizer and pesticide
fallout imput s high exchange rates of environmental currency
to a kg of ch mical--but zero environmental currency to a
hectare of la d cropped. The critic might set exchange rates
of 200 for he bicide and 1 for fertilizer but 0 for land. The
ridge of risi g yield in Fig 10 becomes a valley of
environmental economy in Fig 11 because the higher yields
shrink hectar s land to grow the specified 5 tons, causing kg
of chemicals 0 increase less than the rates kg/ha.
Nevertheless, high exchange rates for chemicals and zero for
tilling land uts minimum expense in the southwest corner
where no chem'cals are applied over many hectares.