Fertigation is a landscaping and gardening practice in which water-soluble materials are added to the water used for irrigation. Classically, fertigation supplies nutrients in the form of fertilizers, although it can also be used to deliver soil amendments and a variety of other materials, including agricultural chemicals to cope with crop pests and plant diseases. In commercial agriculture, fertigation is in wide use, and the concept began to spread to residential landscaping and hobby gardening in the early 2000s.
A basic system simply has a tank attached to the water outlet, allowing the user to add chemicals to the tank as needed. Typically, local codes require the installation of a backflow valve, which prevents materials in the tank from traveling up the water line, thereby eliminating the risk of contamination. Permits may also be required for particular agricultural chemicals, especially those which pose a risk to human and animal health if poorly managed.
When crops are fertigated, the water-soluble materials in the tank are delivered to the plants along with the water they need. This delivery system allows the plants to absorb more than they can through classical topical applications, which means that less fertilizer and other materials are needed. Furthermore, this system reduces the risk of leaching and runoff, which benefits the surrounding environment. It is also easier to manage the system when compared with a typical topical fertilization and plant-care regimen.
One distinct disadvantage of fertigation is that it does not allow farmers and gardeners to deliver solid soil amendments such as compost, humus, and similar materials. This can lead to imbalances in the soil quality, especially if the method is used for an extended period of time to manage crops. These systems can also reduce the amount of time spent inspecting crops, because people don't need to be in the fields as much, and this can mean that the early signs of problems in the fields are missed.
There certainly are lots of reasons to use a fertigation system, or to integrate it into an existing system of landscaping and gardening. Regular fertigation can help plants develop large, healthy roots, leading to healthier and happier crops and ornamental gardens. Before installing this system, however, it is a good idea to check on local codes to confirm that the system is legal, and to see which chemicals will be permitted for use with a fertigation tank.