Searching for the Source

The old idiom of "too much of a good thing" rings especially true for salt. From kitchen tables to water tables, it is present nearly everywhere you look. Human bodies need it to survive, and french fries wouldn't be the same without it. But, just as doctors have told us for years, it can be harmful in high concentrations.

Jane Holzer, Director of the Montana Salinity Control Association, recently returned from an annual meeting which addresses soil salinity in Eastern Montana. "I was letting them know, or remind them, what our program is," Holzer said. "We work with individual producers and on a watershed basis. We will do an initial review and look at a site. We do that for free. Then, we can give the individual some idea of what they would need to do to improve their saline problems. Sometimes it's very obvious, but sometimes we do what is called a shallow groundwater investigation."

The special investigation can be a combination of historical research and scientific inquiry. Sometimes, old photos can indicate if the saline area has been there for decades, or if it is a relatively new issue. "For the most part, there are a few natural saline areas in Montana," Holzer said, "but most are recently developed since the 1940s."

Holzer explains soil salinity can occur slowly and over long periods of time. The tell-tale white crust will eventually appear, but it is simply a visual indication of a deeper problem. "If the geology or substrate is that there is salt in the profile, then what happens in the fallow period is some water leeches below the rooting zone, below the cash crop," Holzer said. "Once it goes deeper than that, you don't have any way to use the water. It's lost to you. It eventually builds up on the bedrock. Over time that water table builds up, it's elevated, then at some point the water table reaches the surface. Then, that's where the salt is. The water evaporates and the salt is left behind."

Each investigation can be unique, but the prescription for recovery generally includes changing from a cash annual crop to a perennial crop like alfalfa. Holzer states alfalfa uses the annual precipitation and has a deep rooting system. This may take from five to ten years, but it can lower the water table in the discharge and recharge areas and allow reclamation of the land.

Although salinity most clearly affects farmers, ranchers have cause for concern as well. "In the farm land, it takes land out of production," Holzer said. "If it's groundwater, it can contaminate the surface water."

To begin reclaiming the salt laden areas, the Montana Salinity Control Association (MSCA) helps landowners by giving them a clear outline of what will work for their situation. "We try to get the history of the cropping system and from that we do a reclamation plan," Holzer said. "We give them a report on the saline and water quality, then give them a recommendation on what to do."

This initial evaluation is free to anyone in need of assistance, but there is a fee for a full groundwater investigation if the causes are unclear. Holzer notes there is funding available to help shoulder much of that extra cost if it becomes necessary.

For more information on how to begin the process of reducing soil salinity, visit http://www.montanasalinity.com, call the MSCA directly at 406-278-3071, or email [email protected].