CSLB C-27 Landscaping ContractorIrrigation SystemsMedium
A C-27 contractor is preparing to install a new irrigation system for a client in a region with clay soil. The design calls for pop-up spray heads in a turf area. To minimize runoff and ensure proper absorption, which of the following adjustments or considerations is most appropriate during the design and installation phase?
- ADesign for multiple, shorter watering cycles with 'soak' periods in between.
- BInstall a single, long watering cycle daily to deeply saturate the soil.
- CIncrease the operating pressure of the spray heads to ensure wider coverage.
- DSpecify high-flow rate nozzles to reduce overall watering duration.
Show answer & explanationAnswer & explanation
Correct answer: A. Design for multiple, shorter watering cycles with 'soak' periods in between.
Clay soil has a slow infiltration rate, meaning it absorbs water slowly. Applying water too quickly or for too long can lead to significant runoff. Designing for multiple, shorter watering cycles with 'soak' periods (known as 'cycle and soak') allows water to gradually infiltrate the soil, preventing runoff and ensuring deeper absorption.
Why the other options are wrong
- B. A single, long watering cycle would result in significant runoff in clay soil, as the soil's absorption rate would be exceeded quickly.
- C. Increasing operating pressure can lead to misting and water loss through evaporation, and does not address the slow infiltration rate of clay soil.
- D. High-flow rate nozzles would apply water faster than clay soil can absorb, leading to increased runoff.
Cycle and Soak Watering
An irrigation technique where the total watering time is broken into multiple shorter cycles, separated by 'soak' periods, to allow water to infiltrate slowly into the soil and prevent runoff.
- Especially effective for sloped areas and soils with low infiltration rates (e.g., clay).
- Reduces water waste by minimizing runoff and promoting deeper root growth.
- Programmed into smart irrigation controllers or manually set.
Memory trick: Clay soil drinks slow, so give it sips, not a flood flow.