“Fertigation”: Alternative Lawn Fertilization Studies
Researchers in New Mexico are studying possible methods to reduce waste while fertilizing grass. Dr. Bernd Leinauer of New Mexico State University is proposing a fascinating method of conserving water and simultaneously providing high quality fertilization for turf at golf courses and homes.
When you or I decide to fertilize our lawns, we often do so by putting an extra sprinkler on in the evening, or by applying lawn fertilizer from the store. Beyond those options, we are pretty limited in our options. But, when we hook up our sprinklers, we draw from a clean, potable water supply from our private wells or the city water supply. Then, if we apply pellet or liquid fertilizer, we essentially add minerals (primarily nitrates) and other nutrients because they have been removed from our drinking water supply. The problem is that these two actions work against each other; filtered water in our sprinklers doesn’t contain the nutrients that we must replace with chemical fertilization.
The system that Dr. Leinauer and others have developed combines a solution for both problems. To counteract limited water supplies in arid regions, “fertigation” reuses city waste water. While this is not a new approach, the next step certainly is. Dr. Leinauer and his team have proposed a method of waste water treatment that does not remove all of the nitrates from the water. Because most water treatment facilities remove all of the nitrates to produce potable water, current methods are very expensive, energy-consuming, and complex. However, if “fertigation” waste water could retain some nitrates (about 15 parts per million), it could be used as an effective fertilizer for lawns. Because this recycled, fertilizing water is still harmful to people, it would be applied to the turf through underground drip systems.
Although this new system is still in development, the ideas behind it are powerful and intriguing. Could we begin to replace chemical fertilizers with in-ground systems using recycled waste water? Is this system possible on a large-scale? Who would operate a new system of waste-water fertilizing? Could this system be used for producing sustainable crop production? To see how their experiments are going, check out the picture below.
Here is the caption from Science Daily: “ReNUWIt turfgrass test plots at New Mexico State University. Cool-season tall fescue (top row) and warm-season grasses bottom half. Grasses irrigated with tailored water on right side, plots on the left side are irrigated with potable water and fertilized with calcium nitrate.”
Source: American Society of Agronomy. “‘Tailored’ Water: the Latest in Lawn Care.” ScienceDaily. ScienceDaily.com, 11 July 2014. <www.sciencedaily.com/releases/2014/07/140711092144.htm>