NMSU researchers look at surfactants for water conservation and their impact on soil health

New Mexico State University’s Extension Turfgrass Specialist Bernd Leinauer and his team which consists of Research Assistant Professors Matteo Serena and Elena Sevostianova, Extension Agronomy Specialist John Idowu and graduate assistant Will Bosland are studying the impact chemical surfactants have on water use, irrigation requirements and overall soil health.

The surfactants being used are chemically very similar to dishwashing soap and are listed in the same chemical group. But dishwashing soap is known to be toxic to plants, therefore chemical surfactants have been modified to be used frequently without the detrimental impact on grass.

“The chemical surfactants help to break the surface tension of the water which then allows the water to penetrate more easily into the soil,” Leinauer said. “The water distributes more evenly and allows for the roots to access more of it which then reduces the need of irrigation water. We’ve conducted and published two studies already which documented a lower irrigation requirement of about 15 to 30 percent when you use these surfactants.”

Measurements of the soil are then taken and with Idowu’s expertise, are examined to understand if biological and microbial activities are impacted in the soil. While most of the chemical surfactants being used are commercially available products, Leinauer is adding a slight twist to his research.

“We have our plots where we use some of these soil surfactants on bermudagrass and Kentucky bluegrass,” Leinauer said. “However, our study is unique because we not only look at commonly used products but are also including organic products. The two organic surfactants are one produced by bacteria and the other one comes from yucca plants. These are very similar to biodegradable soaps.”

Leinauer explained that usually when studies are conducted it takes a little while for any changes to be documented, but glimpses of some changes can already be seen.

“On the water conservation side at least one of the products we have is showing results. Whether or not they are having any impact, negative or positive, on the microbiological activity, is too early to say. We can only indirectly assume that when you have adequate soil moisture, the microbes also benefit,” Leinauer said. “Microbes need water just as the plants and if the soil is dry the microbes can’t be active or survive. So, indirectly we would assume that having more water available benefits the microbes, but we don’t have the data to document that just yet.”

Leinauer and his team have received funding for four years but would like to continue their research for as long term as possible to collect the necessary data. Right now, their biggest supporters are the United States Golf Association and the Colorado Golf Course Superintendent Association.

“The longer we can keep this project going, the more data we can collect on the long-term effects of these chemicals on soil health and irrigation water conservation. Ultimately, we would like to look at this for five years or longer,” Leinauer said. “On a larger scale, products like these could benefit and enhance arid soils which would allow other crops not just turf to be grown more sustainably with less water.”