Impacts of Grazing on Watersheds: A State of Knowledge.
Date
1982
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Texas Agricultural Experiment Station
Abstract
Livestock grazing affects watershed hydrologic properties by removing
protective plant cover and by trampling. Reductions in the
vegetation cover may: (a) increase the impact of raindrops, (b) decrease
soil organic matter and soil aggregates, (c) increase surface
crusts, (d) decrease infiltration rates, and/or increase erosion. Resultant
impacts may include increased overland flow, reduced soil water
content, and increased erosion. Bacteria and/or nutrients as potential
pollutants from livestock grazing do not appear to be a problem on
areas not included on riparian zones.
Existing studies show no hydrologic advantage to grazing a watershed
lightly rather than moderately. Some studies show no difference
in soil loss, infiltration capacity, or soil bulk density between light.
moderate, or ungrazed pastures. Little information supports claims for
specialized grazing systems. To evaluate hydrologic impacts adequately,
additional studies, both intensive and extensive, should be
conducted.
Description
36 pg