Rainfall simulator and plot design for mesoplot runoff studies

Sumner, H.R.; Wauchope, R.D.; Truman, C.C.; Dowler, C.C.; Hook, J.E.

Rainfall simulator and plot design for mesoplot runoff studies

1996

Sumner, H.R. | Wauchope, R.D. | Truman, C.C. | Dowler, C.C. | Hook, J.E.

There is need to evaluate the effects of agricultural production activities on sedimentation, pesticide, and nutrient losses under controlled, simulated rainfall on plots large enough (generally exceeding 50 m2) to incorporate realistic slope lengths and dominant processes that control runoff and sediment yield from "field-size" areas. Therefore, a rainfall simulator system was developed for 600-m2 plots (mesoplots) to evaluate runoff (water and sediment) and agrichemical movement from fields for different tillage practices and chemical applications. The rainfall simulator applies water with irrigation sprinklers spaced 3 m apart on two irrigation laterals arranged 14.6 m apart along the plot length. Runoff and sediment were collected in a V-shaped trough and directed to a flume for measuring and sampling. Simulated rainfall of 25 mm/h with a median drop diameter of 1.52 mm had a coefficient of uniformity of 91 over the plot area. Water was applied and sediment and runoff collected from two mesoplots for six events over a corn-growing season.

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