Changing farming habits may offer solution to Blue-Green Algae blooms

Blue Green algae needs a few key things to survive, and thrive, in the water: Calm waters, plenty of rain, sunlight and nutrients.

" It doesn't take much of any nutrient to produce a lot of algae." says Zach Simon, with K-State Research and Extension. "I believe it's 5 pounds of nitrogen, 7 pound of phosphorous can produce 500 pounds of algae."

Plenty of algae, from a very small amount of nutrients that make their way to the lake from well-fertilized fields.

"The primary cause is nutrients, or phosphorous" says Ron Graber, a watershed specialist with K-State Extension. "Phosphorous is the one that, most often when we see erosion from fields, into the river streams and ultimately into the lake."

This is an issue he says he's very familiar with.

"The objective is to try to stop that now, and prevent any more or at least slow that down as much as possible so we're not adding more nutrients."

Cheney Reservoir is another area that has battled the blooms in the past, and changing some of the farming practices in the area have helped curb the problem.

"Some of those practices are things like converting from a conventionally tilled situation to no-till, so we can keep more residue on the fields." Graber says.

Farmers in that area have also used cover crops, and grass buffers to help keep the sediment from making it's way into the lake.

"Even just a 20 foot strip of native grass can reduce about 85 percent of the sediment that would go through that."

Those are solutions some near Marion Reservoir are exploring as well.

"There's a group up there that's above Marion that's been meeting for quite a while." Graber says. "They're promoting and implementing some of those same practices to try to slow erosion and the movement of sediment and phosphorous into the lakes."

But even with those practices in place, Graber says it will likely take years before we see an end to the blooms.

"We've had a lot of years of those nutrients going into the lake, so there's a pretty big bank - if you will - of phosphorous in the bottom of the lake." he said. "There's still a bank there, the algae is still there, and when conditions are right we'll still see excessive growth and algae blooms."