management conditions, such concerns appear to be
unfounded. Cutter and Garrett (1993) reported that
height, diameter and specific gravity were greater for
alley cropped walnut trees than for trees grown
under woodlot-like conditions. Furthermore, based
upon growth during the first 17 years, 50-60 year
veneer log rotations are projected for alley cropped
trees compared with a customary 80-100 years for
conventionally-grown trees.
Numerous economic assessments have been conducted
on agroforestry alley cropping with typical
internal rates of return ranging from 4 to 11% (Kurtz
et al., 1984). In general, returns tend to increase with
management complexity and site quality. Moreover,
tree species which yield especially high-value wood
products and fruit or other marketable products have
obvious advantages over low-value species which
produce only wood products. Assessments made of
alley cropping on marginal quality farm land have
shown that alley cropping produces land expectation
values comparable to those of traditional agricultural
systems (Lottes, 1985). Furthermore, the planting of
valuable hardwood species with nitrogen-fixing
woody and herbaceous types has been demonstrated
to be an economically viable alternative to conventional
row crops on these sites (Gordon and Dawson,