Written by Chloe Dondlinger, Undergraduate Research Assistant in the Department of Agronomy, Horticulture, and Plant Science, under the direction and review of Kristine Lang, Assistant Professor & SDSU Extension Consumer Horticulture Specialist.
Special thanks to Jaelyn Whaley, SDSU Extension Sheep Field Specialist, for peer review of this report.
There are two main ways wool can be used for mulching purposes. The first is raw, unprocessed wool from sheep producers. This method creates an occlusive mat of wool fibers that covers the surface of the soil, which can reduce weed pressure. In addition to its raw form, the more commonly investigated use of wool is in its pelletized form. For this method, pellets of wool are applied to the soil and are either worked into the top few inches or left on the surface. It has been noted that wool pellets can serve as an organic alternative to commercial nitrogen fertilizer for spinach and tomato without compromising yield (Bradshaw & Hagen, 2022).
The purpose of this study was to evaluate both methods of wool mulching and their individual effects on reducing weeds and promoting pepper growth compared to other, more commonly used mulch types. In addition to its effects on peppers, this investigation also sought to capture the mulch types’ effects on their respective soil microbiomes, gaining a broader view of the impact on soil health.
From this preliminary study, Raw Wool appears to be an effective weed management strategy that may help with reducing soil temperature. Multi-seasonal investigation may help further delineate any differences in pepper yield based on these observations.
