Get Your Drip On: The Advantages of Drip Irrigation
There are many ways to water a garden, each with their pros and cons. One common watering method is drip irrigation, a relatively inexpensive approach that is great for water conservation. Drip irrigation involves installing hoses or tubes to deliver water to the garden, which many growers find better for the health of the plants, the health of the soil and the preservation of other physical features of their properties.
Controlling the amount of water your thirsty plants are able to imbibe requires more effort than simply turning on the hose and sprinkler. Using just a hose and sprinkler and nothing else to water your plants can lead to plants fluctuating between being too wet and too dry.
The most effective and efficient method of watering plants is drip irrigation, and setting up a system for a garden of any size or shape is a relatively easy and inexpensive investment.
What is Drip Irrigation?
Any system consisting of hoses or tubes with micro-perforations or larger holes to uniformly deliver water along the length of the hoses or tubes can be considered a drip-or-trickle irrigation system. These are low-pressure systems, with a pressure of usually 5-15 lbs. per square inch (PSI), which deliver water evenly along the root zones of plants.
In a drip-irrigation set-up, the drip tape or tubes are placed on either side of the plants or along the rows. Water seeps through small emitters that permit water to flow out of the pipe, tape or hose at a slow rate.
There are two main types of emitters you can get for your drip irrigation system: pressure-sensitive and pressure-compensating. Pressure-sensitive emitters deliver more water at each emitter at higher water pressures. Pressure-compensating emitters provide the same flow over a wide pressure range. Both types of emitters can be directly attached to the mainline or placed on the ends of smaller, micro-tubes.
Installing a drip system is not overly taxing and does not require a landscape contractor. Advice on installation can usually be obtained at the point of purchase. Most systems snap or slide together quite easily. Emitters can then be spaced at desired locations along the line or at pre-selected locations.
A simpler method of drip irrigation is to run lengths of soaker hoses along and around your plants and then connect to a hose spigot. Both approaches to drip irrigation can run on a timer if desired. No matter what method is selected, a filter should be used to collect any sediments that could potentially clog any of the emitters. Check for clogs often.
Advantages of Drip Irrigation
Many people believe the advantages of a drip-watering system far outweigh the disadvantages. The overall consensus is that drip-watering is better for the health of the plants, the health of the soil and the preservation of other physical features of the property.
The biggest benefit of drip irrigation systems is that less water is used to irrigate plants and it is used more efficiently. The water is delivered uniformly at the soil level to the roots, where it is needed. Overhead or sprinkler irrigation systems are subject to wind drift and the watering pattern may be uneven, whereas drip irrigation avoids this issue.
Overhead watering creates wet leaves, which could lead to potential mold and disease problems that do not occur with drip irrigation. Some gardeners also experience less weeds when using drip irrigation since only the desired plants are being watered, not the weeds that grow in between rows.
Your house and other structures adjacent to your garden could also benefit from drip irrigation. Overhead watering can cause mold on siding. Drip irrigation does not. Many fungal diseases that can occur in your mulch will be reduced or eliminated with drip irrigation, and pavement that would have been subject to continual irrigation will last longer as well.
Drip irrigation systems are better for the soil and the environment because there is less potential soil erosion with drip systems and nutrient runoff is reduced as well. This also makes drip systems ideal for sloped gardens, where the irrigation water is absorbed by the soil instead of being lost as runoff.
Pesticide use is also reduced with drip irrigation. Not only are there often fewer problems to treat, but any pesticides that are used will have to be reapplied less often as they are not getting washed off like with other watering methods.
Drip-irrigation systems are versatile and can be powered by many different sources. There are systems that run on batteries, ones that plug into an outlet and even ones that can be powered by solar energy. You could also simply turn on your hose spigot when you think your plants need a drink.
These systems can be customized into zones as well, so if you have plants with higher or lower water needs, those specific issues can be addressed. The addition of a timer can also help with this. As your plants grow and your garden areas expand, a drip irrigation system can be moved or expanded.
Another major advantage to drip irrigation is the time using automatic irrigation frees up for you. Not only can you do whatever you want to do in the time you would have spent watering, you can still work in the garden while plants are being irrigated instead of having to wait for the sprinkler to run its course.
Disadvantages of Drip Irrigation
Drip irrigation is not always perfect and any potential disadvantages should be considered before investing time and money into a system. For example, a drip system of any size will cost more than a garden hose and sprinkler, and especially more than a watering can. Consult your certified public accountant to perform the necessary cost-benefit analysis. This is obviously an exaggeration, but be sure to consider the value of your time.
A drip system will also take time to install, which will directly correlate to the size and shape of your planting area. These factors, along with the maturity of your plants and crop types, will dictate how much drip tube and how large of a system you will need to set up. Regardless of a drip irrigation’s size requirements, it’s going to take longer to install than setting up a lawn sprinkler. There are also maintenance issues, which may be the biggest drawback to drip irrigation systems. For example:
- Emitters can clog and need to be cleaned out.
- Rodents may chew through the lines.
- Drip tape needs to be periodically replaced.
- Filters may be needed, which will need to be cleaned or changed.
- The lines may be trip hazards if they are above ground.
- The lines can accidently be cut with a wayward shovel strike if they are buried and not marked.
Even if your system works perfectly, your landscape will inevitably change. Your plants will grow, or you may want to make some landscape renovations. In each of these cases, you will have to modify your drip system to accommodate these changes. But with the potential environmental benefits and improved performance by your plants, these drawbacks may be a small price to pay for the overall benefits of a drip-irrigation system.
Tips & Tricks for Installing Drip Irrigation Systems in Your Garden
It is no secret plants need large quantities of water for growth. Water typically makes up 80-95% of the mass of growing plant tissues. The water content of mature, woody plant tissue ranges from 45-50%, while the water content of herbaceous plants ranges from 70-95%. Water moves through plants by a process known as transpiration—the loss of water from plants by evaporation.
Plants use most of the water absorbed by irrigation for transpiration, but about 5% of the water is used during photosynthesis to produce the sugars necessary for plant growth. The rate of transpiration depends on the amount of water available within the plant and surrounding soil, as well as the plant getting enough energy to vaporize water.
Most energy used by the plant to support transpiration comes directly from the sun. Sunny, hot weather increases the rate of transpiration in plants and increases the risk of wilting if adequate water is not available.
The temperature of irrigation water should be checked before it is provided to plants. Water that is too hot can burn foliage and roots, while water that is too cold can shock roots. A black hose on a sunny day can deliver scalding, hot water to plants unless it has been allowed to run for a few minutes. The optimal temperature of outdoor water is 50-70°F. Indoor watering should be done with room-temperature water.
Always use an appropriate rate of water based on what is being watered. Seeds that have yet to germinate should get a light, evenly dispersed soaking so they don’t become dislodged. This rule also rings true for seedlings in the cotyledon stage of development. Established plants can withstand heavier amounts of watering. Last but not least, no matter what method of irrigation you ultimately choose, water the soil whenever possible, not the foliage.
Written by Chris Bond | Certified Permaculture Designer, Nursery Technician, Nursery Professional
Chris Bond’s research interests are with sustainable agriculture, biological pest control, and alternative growing methods. He is a certified permaculture designer and certified nursery technician in Ohio and a certified nursery professional in New York, where he got his start in growing.