Environmental Progress - Spring 2003

Barley Straw Works Wonders on Suspended Algae Solids

Bundle it, float it, and watch it rot

Q: If you are not a major brewery, what do you do with barley?

A: The days of filling a feedbag of a horse-drawn milk wagon being long gone, the sensible use is float it, the straw portion at least, on your pond, ditch, impoundment or reservoir. Why? Well, as some people in Illinois and England have found, your water will be clearer, cleaner and lower in suspended solids due to algae.

Volunteers distrbute barley straw atop storm fencing as they prepare a simple device to clear algae-laden ponds. The empty plastic jugs will act as flotation devices, since the straw "snake" works best if it doesn't sink.

Studied in the UK, the decomposition of barley straw and the observed effects on algae has been recorded since the late 1980s by multiple researchers including Dr. Jonathon Newman, University of Bristol, Department of Agricultural Sciences, Reading, U.K. Over 10 year’s worth of observations has distinguished “rotting barley straw” as an effective inhibitor of the color and suspended solids attributed to various types of algae. The research was done in “impoundments,” slow moving “canals,” and many other bodies of water and has been confirmed by laboratory studies.

What causes barley to be so effective is not truly identified. Researchers have analyzed many chemical constituents produced by rotting barley straw. No one chemical is predominant and the combined effect appears to be the controlling factor. Not the presence of the straw, but decomposition products appear to provide the effect. Other straws and plant material have been tested and dismissed in preference to barley. For example, green plant material like alfalfa and hay impart an organic load on the system while wheat straw, corn and lavender stalks, common Illinois plant materials, seem to have poorer effects and longevity. Despite uncertainty of the exact mechanism or product that produces the benefit, a benefit it is. One easily measured and observed, at that.

Changes tied to overall improvements

Transferring the technology, if one can refer to rotting barley straw as technology, to wastewater systems at best would seem a stretch. Newman’s own studies indicate that algae growth continues with sufficient nutrient concentrations. Further, algae and fungi appear to be affected while all other aquatic animal and plant life are not. Nor is dissolved oxygen. Therefore, no detrimental conditions would be expected.

The application to water bodies of all types is fundamentally simple; bundle it, float it and watch it rot! No need to search for the “right” type of barley straw or the vintage year, if there is one. Contact the nearest, cheapest and most readily available source and have at it. A slight oversimplification perhaps, but years of observation have demonstrated these few basics.

The finished product is hauled to its watery destination.

What few basic tenets have been displayed in use in Illinois include these: First, the straw must be floating throughout the application period. When allowed to sink, it seems to become a detrimental organic load. Second, since the original uses were in surface water ponds and impoundments and not wastewater systems, repeated applications are necessary from spring thru warm weather. Warm weather and wind action on the surface are two necessary ingredients. Keeping the straw loosely packed inside a long open-web material such as common snow fence is ideal and preferred to the more openweave“ Christmas” wrap where straws can escape.

Barley straw has been used in all corners of our state. Measurable and observable benefits without any detrimental environmental effects abound. First used in Gardner at the wastewater pond system, it reduced the use of copper sulfate while improving the effluent suspended solids for weeks in the hottest part of the summer of 2000. The operator at Sorrento experienced similar benefits during the summer of 2002 at the water plant where lower turbidity was demonstrated and fewer applications of copper sulfate were needed.

Other wastewater applications include the ash pond treatment at the Amerens Hudsonville Generating station. Barley straw here reduced the algae count in the effluent along with the suspended solids while positively affecting the pH of the discharge to the Wabash River. Using the straw at Ohio, Illinois, was done late in the summer in 2001. Not expecting a huge margin of success as a result of sludge pockets in all pond cells, the floating barley straw booms were effective in keeping the effluent suspended solids from exceeding the permitted limits for weeks.

No conflict with the EPA Federal Insecticide Fungicide and Rodenticide Act (FIFRA) would be expected when used in the privacy of one’s own non-public water-body or pond, as the above were. In fact, barley straw has been promoted without apparent conflict in the landscape pond industry for decades.