Evaluation of Cotton-Based Hydromulches.

Establishment for the vegetation of bare soil often includes some type of hydromulch application.  Most useful for quickly seeding large areas that may have extreme slope, hydromulch materials are made of various mixes of paper, cellulose, or wood fiber.  The hydromulches may also contain poly- acrylamide gels or other tackifiers.  Newer to the market are hydromulches made from cotton-plant based fibers, materials which are a by-product of the cotton ginning process.  The objective of this research was to evaluate the effectiveness of various hydromulches for their ability to produce a stand of vegetation, and to evaluate their water-holding and nutrient retention characteristics.  A series of three experiments were conducted in 2012 and 2013.  First was a series of vegetation establishment studies, where 4 different hydromulches were sprayed at various rates  (2,800 to 3,900 kg ha^-1) to bare soil in which annual ryegrass (Lolium multiflorum Lam.) had been seeded.  Collected data included relative growth and yield of plant tissue.  Second was the determination of water retention in the mulches.  Third, mulch decomposition as affected by carbon (C) to nitrogen (N) ratio was evaluated.  All experiments were performed at least three times over multiple seasons.  Results indicate that all mulches must have supplemental fertilization for best plant establishment, as every mulch was too high in C content for best plant establishment.  Mulches that contained a polyacrylamide gel had significantly higher laboratory water holding capacity, but this did not always translate to a better performing mulch in the field.  For plant establishment, hydromulches made from cotton-plant fibers were more effective than other hydromulches at rapidly producing a stand of ryegrass and/or common bermudagrass (Cynodon dactylon L. Pers.).