An experimental hardwood plantation was established in an abandoned field to test the effects of
straw and plastic mulches on the growth and nutrition of seedlings of butternut (Juglans cinerea L. ),
white ash (Fraxinus americana L. ) and bur oak (Quercus macrocarpa Michx. ). The plantation followed
a randomized block design, where the factors were the species (three), the treatments (straw
mulch, plastic mulch and control) and three replications (three blocks), for a total of 27 experimental
units. Mulching significantly influenced soil temperature and humidity. Black plastic gave the highest
values for soil temperature (34.7°C in July), whereas straw mulch produced the lowest (24.8 C in
July ). White ash and bur oak responded significantly and positively to the mulch treatments: butternut
did not respond. Foliar nutrient contents revealed significant differences between species, and
butternut had the highest foliar concentrations of N (34.6 and 26.9 mg g-l) of the three hardwood
species in 1987 and 1988. These differences in nutrient requirements may be responsible for the different
growth performances of the three species on the site. The findings will help in prescribing the
appropriate species to be used in conjunction with mulches in hardwood plantations.