Soil Loss, Runoff, and Water Quality of Seeded and Unseeded Steep Watersheds Following Prescribed Burning

Abstract

Seeding of steep slopes (37 to 61%) after burning on the Edwards Plateau in central Texas reduced soil losses 78 to 93%. Moreover, the major impact of burning on soil losses was significantly reduced in 3 months on burned and seeded watersheds, but not for 15 to 18 months on unseeded watersheds. Stability (soil losses comparable to pretreatment levels) was reached in 6 months on burned and seeded watersheds. Soil loss rates stabilized when cover (live vegetation plus litter) reached 64 to 72% during normal to wet years or 53 to 60% during dry years. Thus, amount of precipitation and cover are closely tied to soil losses. Overland flow stabilized in 4 to 5 years on unseeded watershed and in 1 to 2 years on seeded watersheds. Water quality, lowered slightly by burning, returned to preburn levels within 2 years after seeding. Without seeding it took 4 years to reach preburn levels. Overall, water quality change following burning was not considered to be serious.