Abstracts Biological Sciences

The influence of sodium chloride and gravel treatments on infiltration.

by William Riley,1943- Powers

During the summer of 1967, two experimental sites (Atterbury and Santa Rita) were fenced, and 12 runoff plots were installed at each site. A modified Purdue Sprinkling infiltrometer was used to determine the infiltration capacities of all plots. After calibration, four treatments were applied, and the infiltration capacities were determined for treatment effects. Each of four treatments (control, sodium chloride, gravel mulch, and a sodium chloride and gravel mulch) were replicated three times. Runoff from natural rainfall events was recorded for correlation with infiltration events. Analyses of variance and covariance analyses were utilized to evaluate treatment effects upon infiltration. For the system used, no significant treatment effects upon infiltration capacities were found. All plots showed an increase in infiltration capacity after treatment. A decrease in bulk density caused by insect activity and latent root growth of spring annuals might be the cause for increased infiltration capacities. The drop size classification of the simulated rainfall showed that 8l.67 of the drops were less than 1.167 irnu. With this drop size, soil disturbance could be minimal, and the effects of the above treatments would tend to be nullified. Simulated raindrop size, natural, and system variation caused lack of significant results.