Factors Influencing Infiltration and Sediment Production of Semiarid Rangelands in Nevada

Simulated rainfall was used to study infiltration rates and sediment production of28 plant communities and soils of five watershed areas in central and eastern Nevada. Two antecedent moisture conditions were used: soil initially air dry and initially at field capacity. InfiltratIOn rates and sediment production of the various soils are largely controlled by extent and surface morphology of dune interspace soils. Vesicular horizons are unstable in dune interspace surface soils. These horizons seldom occur in coppice dunes or in well-aggregated dune interspace soils. Infiltration rate is negatively related, and sediment production positively related to the occurrence and morphology of vesicular horizons. More sediment is produced from soils with antecedent moisture initially at field capacity than from'initially dry soil because of the instability of vesicular horizons when the soils were saturated.