Drip Irrigation in the Sustainable Garden
Large-scale, commercial vegetable, fruit, and flower growers have long recognized the economic and resource-saving benefits of using drip irrigation systems. With the large range of low-cost, easy to install, DIY, drip irrigation systems now available, nearly every grower and home gardener can take advantage them.
Traditional overhead sprinkler systems have significant drawbacks. When an automatic sprinkler system activates in windy conditions, much of the water sprayed may be blown away from the intended target area, leaving the soil short of needed water.
In calmer conditions, there may be substantial water loss through evaporation because the water remains exposed on the plant or soil surface. Additionally, leafy plants restrict the amount of water that can get through to the underlying soil, depriving the root system of moisture.
Because sprinkler systems are normally set to activate once or twice each day, there is a constant cycle of dampening followed by drying out. This cycle can cause stress and encourage disease.
When plants are on sloping ground, the plants at the top of the slope may be further under-watered, because gravity will naturally draw any water downwards. The water available to plants on a slope will vary, with those at the bottom always having more water than those at the top. This can cause unwanted color and size variations.
Drip irrigation systems overcome many of the problems faced by overhead sprinkler systems and have several other advantages. They are designed to frequently deliver moisture to the root system. Obviously, plants can manage water resources better via their root systems. When the roots have the right amount of moisture, the plant can distribute water and nutrients up through the leaves, and to the fruit or flowers of the plant.
Because most drip irrigation systems are installed on or below the soils surface, loss of water through evaporation is minimized. Using a drip system efficiently prevents the root systems and soil from drying out. On slopes, drip systems can be tailored to ensure that plants at all points receive the required amount of water.
In addition, preventing water from contacting the leaves helps to inhibit microbe growth, and minimizes the travel of many surface fungi, bacteria, and other disease-causing microbes to other plants or into the soil. Most systems can also be closely and accurately controlled and monitored, largely preventing over-watering which is a major cause of many problems including many diseases and nutrient deficiencies.
Provided they are setup, maintained, and used correctly, drip irrigation systems require much less water (and work) than overhead systems. On average, water consumption is reduced by 20-40%. And many can be easily automated saving valuable time, energy, and resources. The water savings is so substantial that recognizing the superior efficiency of drip irrigation, many water companies allow continued use of these systems during drought conditions.