You bet your bottom dollar. The 6 inch rain moved many many many tons of soil. I would predict a fair amount of phosphorous moved also.
I work on a farm. The filter strips are a joke when more than moderate rain falls. Farmers are installing larger tile everywhere there footsies get damp. With less ponding, less marsh area, and less hay/ pasture to absorb or slow the runoff huge torrents of water hit rivers and lakes more quickly. Even the almighty U of M refuses to do indepth studies on massive tiling. Why?
Unfiltered tile inlets are sewer drains for all ag pollutants.
How often does someone check on farmers to see if they are compliant? And we pay these slackers "subsidies"(blackmail payments) so they won't be really bad boys and ruin their land and our water. "Stewards of the land"...horse manure. If no-till and other consevation practices weren't heavily subsidized, and a tactic for more profit, most would end the practice. Almost every method used in row crop large ag-land practices is degenerative. Their soil is compacting, becoming less productive. So they spread more amonia and other poisons on to keep their mono-culture growing.
Anyone who says phosporous is not leaving farm land is....well, others have commented on that. Farmers should spend less time in Las Vegas and more time learning real land management. Their backs don't hurt cuz they are working to save the land. Maybe they should stop patting themselves so endlessly on the back. These huge confinements are some of the worst. Imagine the manure(phosphorous) runoff from pen areas. A neighbor lets his sludge run into a ditch, then a drainage ditch, then into a swamp area near a lake where it is well diguised. Clever.
Along with the farmers(and all those turf fanatic yuppies of past and present) the ag corporations should be held libel for destroying lakes, rivers, land, and well water.
