Chemical control of a tall fescue sod (Festuca arundinacea
Schreb.) using glyphosate and simazine improved early tree growth of black walnut (Juglans nigra
L.) more than either deep ripping or irrigation on an upland old field site in southern Illinois. Growth of trees with irrigation and grass control was less than with grass control only; however, irrigation alone to maintain soil moisture levels above -0.5 atmospheres had no effect in the absence of grass control. Planting germinated seed at the intersection of the 30 inch deep ripping furrows was beneficial with grass control, but had no effect without grass control. None of the treatments significantly altered long-term soil mineral composition in the upper 24 inches. The study supports the conclusion that black walnut can be managed for nuts above a 9 foot long veneer log on marginal agricultural lands with shallow siltpans or fragipans using agroforestry practices.
chemical weed control
Juglans nigra L.
Van Sambeek, J.W.; McBride, F.D. 1991. Grass control improves early growth of black walnut more than either deep ripping or irrigation. In: Garrett, H.E. "Gene", ed. Proceedings of the 2nd conference on agroforestry in North America; 1991 August 18-21; Springfield, MO. Columbia MO: University of Missouri, Columbia, The School of Natural Resources: 42-57.