Evaluation of Synthetic Mulches on the Establishment and Growth of Cottonwood

ABSTRACT

Soil microclimatic conditions created by various weed-control mulches and the resulting survival, diameter, and height growth of cottonwood seedlings were studied in central Kansas. The treatments compared the effects of six synthetic plastic mulches often used in horticultural practices with the effects of cultivation or a herbicide. One-year-old seedlings were planted with either clear plastic, blue and yellow waste plastics, black or gray/black polyethylene, or polypropylene fabric weed barrier; cultivation; or herbicide weed-control treatment. After five years, sapling survival was more than 85% for all mulch types except the clear plastic (82% survival). Differences among weed-control treatments were significant for survival, height, stem diameter, and biomass. Sapling growth was best with sulfometron methyl herbicide, slightly less for cultivation, and nearly the same for all other materials for weed control. Stem temperature had no relationship to first year height growth. Soil temperature and moisture had a slight relationship to second year height. Use of herbicides or cultivation was clearly less expensive than synthetic mulch for weed control.

KEYWORDS:

• Herbicide
• mulch
• polyethylene
• polypropylene
• Populus deltoides
• weed control