Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2004
Publication Date: 9/1/2004
Citation: Pote, D.H., Grigg, B.C., Blanche, C.C., Daniel, T.C. 2004. Effects of pine straw harvesting on quantity and quality of surface runoff. Journal of Soil and Water Conservation. 59(5):197-203.
Interpretive Summary: Marketing pine straw is a multi-million dollar industry because of its value as a soil mulch, but the loss of those mulching benefits from pine forests has raised concerns about effects on soil erosion and runoff in watersheds where pine straw is harvested. Research was conducted to determine whether such concerns are justified, and evaluate harvesting practices to minimize any problems found. This study showed that pine straw harvesting did increase runoff, soil erosion, and some nutrient losses; but these effects were decreased by less-frequent harvesting schedules. These results are of interest to scientists, watershed managers and extension personnel because they provide information for better management of pine straw harvesting to help producers control soil and water losses while maintaining high levels of production.
Technical Abstract: Pine needles (straw) are an attractive mulching material that protects the soil surface against erosion, conserves soil moisture, moderates soil temperature, and inhibits weed growth. Because pine needles tend to interlock, pine straw stays in place better than most mulches, yet it retains a loose, open structure that allows air, fertilizer, and water to easily penetrate the soil surface. Such characteristics have made pine straw a valuable commodity, but the loss of those mulching benefits from pine forests has raised concerns about effects on watersheds where pine straw has been harvested. For example, pine straw absorbs the impact of rain drops and slows the speed of runoff flows, so its removal may increase soil erosion and nutrient losses, and decrease water-holding capacity of the forest floor. To test this hypothesis, three pine-straw harvesting practices and a control treatment (no straw harvest) were compared to determine harvesting effects on water, soil, and nutrient losses in runoff. Plots were constructed in an established (16 yrs) pine stand that had tree spacing of 3.0 m by 1.5 m, and basal area of 41.3 square meter/ha. Each plot (2 m X 1 m) had 4% slope, aluminum borders, and a runoff collector. Simulated rainfall was applied (5 cm/hr) to produce 20 minutes of runoff from each plot. Results showed that pine straw harvesting increased runoff, soil erosion, and some nutrient losses; but these effects were mitigated by less-frequent harvesting schedules.