Interesting Data

Last month I attended ProGreen Expo here in Denver, a week of classes and seminars (plus a big trade show) for landscape professionals. One of the classes I attended was an overview of irrigation system basics and, more importantly, water management practices. It was exciting to get some hard data that I can now apply to a concept I’ve been familiar with for many years now: water cycling.

The basic idea of cycle and soak irrigation is to match the precipitation rates (water output) of your sprinkler to the infiltration (absorption) rates of your soil. In soils that absorb water slowly (or if you are watering on a slope), you will have to apply water for shorter periods of time to prevent runoff (and waste). Multiple water applications (cycling) may then be necessary to meet the water needs of the plants. Here is the data that gives us a clearer idea of how long to run those sprinklers before runoff occurs:

Clay soil: rotor head = 18-24 minutes, spray head = 6-8 minutes.
Loam soil: rotor head = 36-42 minutes, spray heads = 12-14 minutes.
Sandy soil: rotor head = 60-72 minutes, spray heads = 20-24 minutes.

With a bit of research and some basic math you can become super efficient and “green” with your water use.