Durability of selected mulches, their ability to control weeds, and influence growth of loblolly pine seedlings

Abstract

Several mulc hes of natural, synthetic, or blends of natural and synthetic fibers were tested around newly planted loblolly pine (Pinus taeda L.) seedlings on a sheared and windrowed site in central Louisiana, U.S.A. The vegetation was primarily winter annuals, some residual grasses and forbs, and sparse woody regrowth. Study 1 was rotary mowed just prior to planting in March 1992, and 35 mulches and an untreated check were established. In Study 2, 15 mulches and an untreated check were established in a 1-year-old rough in March 1993. In both studies, a single loblolly pine seedling formed each plot established in a randomized complete block design, with 10 blocks as replicates. Each block was planted with a separate open-pollinated loblolly pine family.

Nearly all mulches had deteriorated to some extent after three growing seasons. Synthetic mulches were generally more durable than the natural or natural/synthetic mulches. Mulching eliminated the established vegetation and germinants, and vegetation did not readily reestablish following the deterioration of a mulch. The soil seed bank apparently was not sufficient to regenerate areas that were once covered with mulch, and many of the natural materials deteriorated into a fibrous cover that acted like a natural litter layer. Both of these residual weed control effects—insufficient soil seed bank and formation of a fibrous cover—were important in stopping vegetation from reestablishing after a mulch had deteriorated. After three growing seasons, the loblolly pine seedlings generally grew better if mulches were used.

Citation

Haywood, James D. 1999. Durability of selected mulches, their ability to control weeds, and influence growth of loblolly pine seedlings. New Forests. 18: 263-276