Landscape Architect Articles

LSMP Irrigation November 200512-29-05 | News

Fertigation:

An Automated Way to Grow

By Tom Strong, Strong Enterprises

A similar fertigation set up also attaches the fertilizer tank to the backflow prevention device. Note the spigot on the right side of the tank?EUR??,,????'??+it lets maintenance crews mist plants for the foliar (through leaf) feeding that many species enjoy.

With the advent of drip irrigation, how do you fertilize plant material? Amid the continuing concern over water shortages, it appears that many groundskeepers, as well as homeowners, are either initially installing, or converting to, drip irrigation.

But this change poses yet another dilemma. How do you fertilize the plant material? If utilizing a drip irrigation system in order to conserve water, as well as saving time and money, no longer can you broadcast dry granular fertilizer onto the soil surface and expect it to be leached into the soil by overhead watering where the plant?EUR??,,????'???s roots can pick-up the nutrients. Therefore, the fertilizer must be dispensed directly into the irrigation system.

Recognizing there was a real need to not only conserve water by utilizing more and more drip irrigation, but also to fertilizer the plant material, Strong Enterprises designed and patented a fertilizer injector. The proportioning injectors make fertilizing not only easy, but economical and efficient as well.

Tom Strong shows off a variety of PVC fertigation tanks. The smaller units on the left are suitable for residential use; larger properties and grounds use tanks similar to the tank on the right. Even bigger tanks are used in agricultural settings.

They fit into any drip, sub-surface or conventional sprinkler irrigation system, and are totally proportioning. In other words, the concentration of fertilizer being delivered is at a constant rate from start to finish, unlike other injectors.

They accept any water-soluble fertilizer on the market today like Scotts Miracle Gro and Peters Professional, when premixed with water. In addition, a wetting agent can be dispensed to break-up compacted soils, as can micro-nutrients or Vitamin Institute?EUR??,,????'???s SUPERthrive, with its vitamins and hormones for healthier plants, and vitamin B-1 when transplanting trees and shrubs.

They can also be installed before a manifold of valves under full line constant pressure up to 125 PSI, or can be installed after a single control valve. A fertilizer injector is an essential part of any drip irrigation system, as are a filter and pressure regulator.

The concept of fertilizing directly through the irrigation system, commonly known as fertigation, has been used by the agricultural community for quite some time. When commercial growers began to utilize drip irrigation and to abandon flood or conventional overhead sprinklers, they immediately realized that they must also provide a method to fertilize their crops. Thus sprang the concept of fertigation.

The fertilizer tank for this fertigation system is the white cylinder at center. Water passes from left through the backflow-prevention device past the pressure gauge (at top), which limits system pressure to 125 psi to protect the system.

Lawns, trees, shrubs, and potted plants absorb fertilizer more efficiently when it’s in liquid form. Why? Because liquid fertilizers not only work faster than dry pellets or granules, they move through the soil and are more readily available for absorption by your lawn or garden plants. Therefore less fertilizer is used, making it more environmentally friendly.

Over many years, tests have concluded that applying liquid fertilizer on a regular basis is much more beneficial to a plant than being fed infrequently with a dry, granular form of fertilizer. Liquid fertilizer is absorbed far more easily by a plant?EUR??,,????'???s root system, and there are no leftover residues or minerals that can, over a period of prolonged use, damage a plant or lawn.

Many landscape contractors and landscape architects have already learned the benefits of fertigation. In particular, no longer do you have to laboriously spread fertilizer by hand, using spreaders and/or hose-end applicators, thus saving significantly on labor and on the cost of fertilizer.