Weed suppression with hydramulch, a biodegradable liquid paper mulch in development

Abstract

AbstractCost-effective, laborsaving, and environmentally sound weed management practices are needed for sustainable vegetable production. Organic production, in particular, precludes the use of synthetic herbicides and requires that organic farmers utilize practices that reduce harmful environmental impact. Although polyethylene film mulch is used extensively in vegetable production in Florida, its use has a number of drawbacks, among which is the susceptibility of opaque polyethylene mulch to penetration by yellow and purple nutsedge. Appreciable labor and disposal/environmental costs are associated with its removal. A durable mulch material that would effectively control nutsedge and other weeds but with no associated environmental and disposal costs is highly desirable. Hydramulch, a paper-like material applied as a slurry consisting of cotton waste, newsprint, gypsum and a proprietary adhesive, was tested as a biodegradable alternative to polyethylene mulch during the spring of 2003. Experiments were conducted in southeastern and north-central Florida to compare the effects of three hydramulch formulations, polyethylene mulch and a no mulch control on soil temperature, soil moisture and weed infestation. Soil temperature under hydramulch was 1–4°C lower than that under polyethylene. In the absence of rain, the use of hydramulch resulted in soil moisture levels that were 1–4% lower than with polyethylene mulch. Higher soil moisture with hydramulch than polyethylene was coincident with rainfall. Hydramulch remained intact on most beds and suppressed broadleaf weeds and grasses, particularly at the north-central site where the mulch was applied at a greater thickness. However, purple nutsedge readily penetrated hydramulch. Therefore, hydramulch may be applicable for use for the suppression of broadleaf weeds and grasses at sites with little or no nutsedge pressure in fall or in crops for which cooler soils are desirable or crops that are rainfed or overhead irrigated.