Why should residential homeowners care about irrigation management?
Water costs money. Someone who does a good job of irrigation management will have a greener lawn, better landscaping, and a lower water bill than someone who doesn’t. Poor irrigation management also has an environmental impact because water is a limited resource. The more we use, the less water is available for alternate uses. Water is also the primary vehicle that moves fertilizers and pesticides off of landscapes and carries them into our streams and water bodies where they can cause environmental damage.
What are the environmental and health consequences of poor irrigation management?
Water is the primary vehicle for moving fertilizers and pesticides out of the soil where they are needed and useful into groundwater, streams, and water bodies. Drinking fertilizers and pesticides that are pumped out of wells from the groundwater can have negative health effects.
Fertilizers help plants grow. In streams and water bodies, excessive fertilizers and nutrients will promote aquatic vegetation and algae to the point that they choke out other native plant species and consume so much of the water’s oxygen that fish and other aquatic animals are negatively impacted. When too much irrigation water is applied, water will either run off or move down through the soil past the bottom of the root zone where the plants can no longer reach it. When this happens, it can cause erosion and/or move nitrogen and soluble phosphorous with it.
When do I turn my water on in the spring?
It depends on your location, the weather, and how much precipitation (water) was stored in the soil over the winter as snow melt and rain.
How long do I leave it on?
Leave the water on just long enough to fill the root zone up to field capacity. In order to know this, you will have to have a good idea of your sprinkler application rate or drip irrigation system.
What kind of irrigation system should I put in? What kind of sprinkler heads? Can I design it, or should I have a professional do it?
I am assuming you are talking about an automated irrigation system. Pop-up sprinklers are the most popular. The sprinkler heads depend on your system’s operating pressure, flow rate, and area that you want covered. You will be slightly more efficient with sprinklers with larger drops, and those that don’t throw the water long distances.
Watering lawns and flower beds with drip irrigation is a very efficient way to irrigate, but it will cost a little bit more to set up. If you plan to put in a drip irrigation system for a lawn, it should be installed before the grass is established. Otherwise, you will end up digging up the entire lawn to put it in.
As far as designing it, you may not want to do things the way that I do, which is to try to figure it out by yourself and ending up spending much more time and money on it than if you had it professionally designed in the first place. But if you are adventurous, there are pamphlets and books on how to design and install your own sprinkler system (check your library). Sometimes there are trained people in hardware stores who will design your irrigation system for you if you buy your components there. It helps to remember what motivates people, and a hardware store designer may not give you the low-cost, most efficient solution.