Question

A border strip irrigation system applies enough water to infiltrate an average depth of 2 inches. PI Losses = 7%. DU = 0.71. Ignore runoff (it is captured, but reused later on another field). How many days should be scheduled between irrigations to match a peak ET rate of ETc = 0.34 in/day?

Answer 1

To match a peak ET rate of ETc = 0.34 in/day, approximately 4 days should be scheduled between irrigations in a border strip irrigation system. This calculation takes into account the application efficiency and the depth of water applied.

Step-by-step explanation:

To determine the number of days that should be scheduled between irrigations to match a peak ET rate of ETc = 0.34 in/day, we need to consider the application efficiency and the depth of water applied.

The application efficiency (AE) can be calculated using the following formula: AE = (DEPTHin - PI Losses) / DEPTHin, where DEPTHin is the average depth of water applied and PI Losses is the percentage of water lost (in decimal form) during the irrigation system.

In this case, the application efficiency is AE = (2 - 0.07 * 2) / 2 = 0.93.

The depth of water that reaches the plant root zone, known as Effective Irrigation Depth (DUE), can be calculated as DUE = AE * DEPTHin

Using the given values, DUE = 0.71 * 2 = 1.42 inches.

Finally, the number of days between irrigations can be calculated by dividing the DUE by the peak ET rate: Number of days = DUE / ETc = 1.42 / 0.34 = 4.18 days.

Therefore, approximately 4 days should be scheduled between irrigations to match a peak ET rate of ETc = 0.34 in/day.