Biobeds offer a safe way to dispose of pesticide rinsate on a farm. It can be easy to overlook the potential effects of disposing of pesticide rinsate but this is where the great benefits of a biobed come into practice.
A biobed is a lined, waterproof below-ground pit or above-ground box designed to remove pesticides from sprayer rinsate. Filled with a substrate of straw or wood chips, compost and/or peat plus soil, the biobed filters rinsate and provides an ideal habitat for naturally-occurring soil microbes and bacteria to break it down.
Farming Smarter will host a biobed research project led by Lethbridge-based Agriculture and Agri-Food Canada research scientist Dr. Claudia Sheedy. Visitors to Farming Smarter's events will be able to see it while on site.
Up to 70 per cent of pesticides in surface waters could come from pesticide handling areas, spills and equipment washings. The design of on-farm pesticide rinsate biobeds help remove pesticides and resolves issue of pesticides reaching surface water sources. The most effective biobeds are two-cell systems where effluent percolates to the bottom of an initial biobed then gets pumped to the top of a second biobed.
A biobed can effectively manage 10 litres of rinsate per square metre per day. Translated to a 100-day growing season, a single square metre of biobed can process 1,000 litres of rinsate per year. According to Sheedy's research, the liquid at the bottom of the second bed contains between 90 and 98 per cent less pesticide than the original rinsate applied to the top of the first biobed. To visually show the effectiveness of the system, each biobed is seeded with grasses. The first biobed shows no growth on it, while the second has a lot of growth.
The cost of a biobed system can range from $6000 to $23,000 depending on the size and materials used to construct the collection pads and on the size of the system required to treat the annual volume of rinsate. In Europe, producers typically replace the biomix every five to seven years. In Canada, with colder temperatures, the biomix may last longer. The current recommendation is to replace the biomix every five years pending further Canadian research such as Sheedy's research at Farming Smarter. The project's primary objective is to test a trough system adapted to sprayers with large booms. The biobed would allow management of 100 per cent of the pesticide rinsate produced at the farm.
Sheedy is confident on-farm implementation is ready today, however more research on biobeds continues in order to gain more information on a positive new resolution to common pesticide use among farmers.