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Issue: March 13

Fertigation, applying fertilizer with drip irrigation, can work for you.

Q. I have been reading a lot about the benefits of fertigation for the home garden. I would like to be able to deliver liquid fertilizer (fish and seaweed based) to my vegetable garden in Albuquerque using my existing drip irrigation system. Please let me know your thoughts.

Michael D.

A. Fertigation, the application of fertilizer in the irrigation water is an efficient way of providing nutrients to plants. For plants to use the nutrients, they must be dissolved in water. Fertization provides nutrients already dissolved and ready for uptake by plant roots. Applying these nutrients through the drip irrigation system helps minimize water use, yet directs the nutrients to the location where roots will be most able to use the nutrients.

There are some factors to consider when applying nutrients through the drip system. Drip irrigation systems are subject to clogging of the emitters. This can happen with traditional chemical fertilizers if they do not dissolve completely, or if the dissolved nutrients react with each other to produce precipitates (undissolved compounds) while traveling through the irrigation lines. Upon reaching the emitters, small solid particles may clog the emitters.

You are suggesting using soluble nutrients from organic sources. It is important that there are no solid particles from your nutrient sources entering the irrigation lines and that no chemical reactions occur within the lines. In the case of the fish emulsion and seaweed based fertilizers, there is less chance of reaction in the lines, but it is still possible. Do not try to use too high a concentration of nutrients in the system. Particles that exist in the original solution can be filtered from the system before entering the irrigation lines if your filtration system is adequate for the fertilizer source material and is maintained properly.

The system you choose for injecting the nutrients into the irrigation line must be one adapted to the material you are using and one that does not allow the growth of microbes in the holding tank before the fertilizer enters the irrigation lines. If bacterial growth, algae, or other microbes develop, they may pass through the drip irrigation filtration system and continue to grow in the lines. If they form large enough colonies or develop mucilaginous materials, they may clog the irrigation system.

A properly designed system (injectors and distribution lines), properly maintained should allow you to fertigate your garden efficiently and effectively. Careful selection of the fertilizer source materials is also important.

For more gardening information, visit the NMSU Extension publications World Wide Web site at http://www.cahe.nmsu.edu/pubs/_h.

Send your gardening questions to:

Yard and Garden, ATTN: Dr. Curtis Smith
NMSU Cooperative Extension Service
9301 Indian School Road, NE, Suite 112
Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.