Fact Sheet Barley Straw And Algae

<Algae Control with Barley Straw    Filamentous algae is the most common aquatic weed problem in ponds. Its "sudden" appearance as it floats off the bottom causes consternation to pond owners as it degrades the aesthetic and recreational value of their ponds. Additionally, large amounts of filamentous algae can lead to a fish kill if specific climatic conditions occur A number of mechanical, biological, and chemical control measures are available, each with their own advantages and disadvantages.    Barley straw has received considerable attention as an algaecide based on research done in England. Results showed that barley straw prohibits the growth of many types of algae, but not all. However, recent research in the United States has not yielded conclusively positive results. While research results are inconclusive, the use of barley straw to control pond algae has grown. The purpose of this fact sheet is to provide pond owners with application guidelines should they decide to try barley straw as an algae control technique. How Barley Straw May Work    The decomposition of barley straw in water produces and releases many compounds, one of which may control algae populations. The chemical compound does not eliminate existing algae cells but interferes with and prevents the growth of new algae cells. As "old" algae cells naturally die off, few new algae cells are produced and the algae population is controlled as long as the compound is being produced. There are a number of other types of straws available, including wheat, linseed, and oil seed. However, research in England has shown that barley straw is the most effective straw and provides control for a longer period of time. Note: pond owners should use dried straw, not barley hay or fresh barley. The addition of those materials actually releases nitrogen and phosphorus into the water which promotes algae growth. These fresher materials also decompose very quickly and can cause low oxygen problems in ponds. How Much to Apply    The amount of straw to apply is based on pond surface area rather than volume It is generally recommended that about 0.025 pounds of straw be used for every square yard of pond surface area. In a small ornamental pond of four square yards (about 100 square feet), only 0.01 pounds is needed. In a one-acre pond, the amount required would be about 107 pounds of straw or 2-3 standard bales. In a pond with a history of algae problems, a higher initial amount of 225 pounds per surface acre may be warranted. How and Where to Apply    The production of the critical compound during straw decomposition must occur in the presence of oxygenated water. In small ornamental ponds, simply place the small amount required loosely in a mesh bag and place in the water. A weight of some sort should be added so the bag is on the pond bottom. In larger ponds, more effort is needed. Each bale should be broken up as much as possible so that nearly all decomposition will occur in the presence of oxygen. About 1/3 of a bale should be placed in a large, weighted permeable bag of some sort. If an intact bale is placed in the pond, only the decomposition occurring along the outside of the bale will occur in the presence of oxygen. Decomposition inside the "tight" bales will occur in the absence of oxygen and will not produce the chemical. In a one-acre pond, this will result in 6-9 loosely filled separate bags. These bags containing loose straw should be placed around the perimeter of the pond in water no deeper than 6 feet. Most algae production occurs in shallow water so the bulk of the control compound needs to be located there. Attaching a rope to each bag is advisable in order to retrieve the bags and replace the decomposed straw with fresh straw as needed. Barley straw is not a "cure-for-all" to controlling filamentous algae in ponds. Sometimes chemical treatment is needed. Consult your local agriculture agent for more advice. Call For Price 440-320-7854