Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2005
Publication Date: 9/1/2005
Citation: Holt, G., Buser, M., Harmel, D., Potter, K., Pelletier, M.. 2005. Comparison of cotton-based hydro-mulches and conventional wood and paper hydro-mulches--Study 1. The Journal of Cotton Science. 9:121-127. Interpretive Summary: The use of a mulch to control erosion resulting from rain events is not uncommon. In the past, mulches were applied in various ways ranging from hand application to mechanical broadcasting. In more recent times, the application of mulches using a hydro-mulcher has been practiced on steep slopes or in residential neighborhoods. A hydro-mulcher is a tank where a mulch and water slurry is mixed and then sprayed, under high pressure, onto the soil. The most common hydro-mulches are made of wood and paper. In this study, cotton gin byproducts that have been processed using USDA's patented COBY process were evaluated for their effectiveness at controlling soil erosion and promoting grass seed germination. Tests were conducted at the USDA-ARS Cotton Production and Processing Research Unit in Lubbock, TX. The study consisted of evaluating seven different mulches (3-COBY products, paper hydro-mulch, wood hydro-mulch, cottonseed hulls, and wheat straw) at two application rates (1000 and 2000 lb/acre). The results indicate that both the cottonseed and COBY mulches performed equal to, or better, than the conventional wood and paper hydro-mulches at reducing soil erosion from a 2.5 in/hr rain. However, the coverage factor obtained with the wood and paper mulches was higher than either the cottonseed hull or COBY products, thus indicating additional work is needed in the area of coverage for the cotton-based material.
Technical Abstract: Soil erosion from steep slopes, bare soil, or construction sites is a problem that can create on-site gullies and revegetation difficulty and can adversely affect downstream water bodies and aquatic ecosystems. Mulches have been widely used to mitigate the effects of erosion. One common type of mulch, "hydro-mulch", uses shredded wood and paper that is mixed with water and applied with an applicator gun. In this study, conventional wood and paper hydro-mulches were compared to cottonseed hulls and three types of processed cotton gin by-products. The mulches were applied at two rates, 1121 and 2242 kg/ha (1000 and 2000 lb/acre). The following comparisons were made: 1) time to runoff, 2) sediment loss, 3) percent of mulch washed off, 4) mulch coverage (C-Factor), and 5) grass seed establishment. Results indicate the cotton-based mulches (cottonseed hulls and cotton gin by-products) performed equal to, or better, than conventional wood and paper mulches in reducing soil loss in a simulated 6.35 cm/hr (2.5 in/hr) rainfall intensity event. Likewise, a lower percentage of the cotton-based mulches washed off than occurred with the conventional wood and paper hydro-mulches. However, the coverage factor and the time to runoff associated with the wood and paper mulches was higher than for any of the cotton-based mulches. Overall, the cotton-based mulches showed great promise in erosion control applications.