Question

Given: A solid set irrigation system with 30 feet x 40 feet spacing applies water with a DU = 0.72. ETc = 0.26 in/day, PI Losses = 9% and LR = 0. MAD = 35%. AWHC = 1.74 in/ft and RZ is 5 ft. With perfect timing, how much gross water (inches) needs to be applied to refill the soil profile?

Answer 1

To determine the amount of gross water needed to refill the soil profile, you need to calculate the available soil water (ASW) and the minimum allowable depletion (MAD). However, the question does not provide the soil water content (SWC), so the exact amount of gross water cannot be determined.

Step-by-step explanation:

To determine how much gross water needs to be applied to refill the soil profile, we need to calculate the available soil water (ASW) and compare it to the minimum allowable depletion (MAD).

First, calculate the ASW by multiplying the Available Water Holding Capacity (AWHC) by the root zone depth (RZ). In this case, ASW = AWHC x RZ = 1.74 in/ft x 5 ft = 8.7 inches.

Next, calculate the MAD by multiplying the ASW by the MAD percentage (35%). In this case, MAD = ASW x MAD = 8.7 inches x 0.35 = 3.045 inches.

To refill the soil profile, the amount of gross water needed would be the difference between the MAD and the soil water content (SWC) which can be calculated by multiplying the spacing (30 ft x 40 ft) by the application depth.

However, the information provided does not include the SWC, so it is not possible to determine the exact amount of gross water required to refill the soil profile.