Tough phosphorus problem has no easy solutions

By Matt Reese

At the Conservation Tillage and Technology Conference in Ada this week, attendees were bombarded with photos charts and graphs illustrating the water quality problems in Ohio. A glass full of green ooze scooped out of Lake Erie, an algae

filled spray behind a jet ski, countless charts showing a steady drop then a sharp rise in phosphorus levels in Ohio’s waterways – there is no shortage of evidence that there is a problem. There is, however, a shortage of viable an across-the-board solutions to the problem.

“We know what the issue is, but we don’t know how to solve it. We need research on this. Environmental groups are just saying, ‘Well, stop using phosphorus.’ We know we can’t do that,” said Glen Arnold, with Ohio State University Extension. “We had the worst algal bloom in 40 years in Lake Erie that provides 5 million people with drinking water it and contributes $10 billion to the economy.”

The numbers though, have many scratching their heads.

“We’re using less phosphorus than we ever have before, but the amount of dissolved phosphorus is going up,” Arnold said. “Even though we are using less, more is getting away from us. And it is not a lot of phosphorus that we’re losing in terms of the total amount applied, but we have got to get it under control. Just a quarter of a pound of loss per acre can make a big difference.”

The current problem is the dissolved form of phosphorus that can move with the water through surface drainage or through tile lines.

“A pretty good chunk of that phosphorus is going out of the tile,” Arnold said. “Rainfall, tile, incorporation, surface roughness, vegetative buffers, concentrated flow areas, waterways, crop reside, tillage, and the location nutrients applied all affects the movement of nutrients off fields. We really want water to absorb into the ground if at all possible. Frozen ground and heavy rain are perfect conditions for big losses of nutrients. Don’t apply on frozen ground. Currently there are no proposed regulatory changes for the state, but it is critical for farmers to use common sense, follow good manure testing, follow soil testing agronomic recommendations, and keep good records.”

The 4R recommendations for putting the right source, at the right rate, in the right place at the right time are also crucial to remember.

“I know that the 4Rs are commonsense and elementary, but these are the types of things we are looking at and we have to get this under control,” Arnold said.

Phosphorus needs to be close to plant roots and in soils with good structure that can facilitate vigorous and productive plants. These types of soils can be developed through long-term no-till with cover crops and good drainage (from tile).

“There is a lot of difference in soil structure out there. Poor soil conditions allow for a lot of quick

run-off,” said Joe Nester, with Nester Ag Management in northwest Ohio. “There have been some darts thrown at no-till and I don’t necessarily buy that. There is also talk of a moratorium on tile and that would be the wrong way to go. Tile creates a much better environment to produce a crop that removes the nutrients that are there. Once water moves through it brings air into the soil and we have to make sure that tile doesn’t get evaluated poorly here. It is a matter of risk verses benefit. This is extremely complex. You can’t just take a chart and say, ‘Do this.’ The soil is a living thing and if you manage it that way you will be better off.”

The problem is such that changes will be coming to the farms are managed in Ohio.

“Rate, and timing of application will be regulated and blanket applications will not be allowed in the future,” Nester said. “You can say, ‘This can’t happen,’ but it is happening and this is an opportunity for agriculture to do something.”