The tile drainage systems in upper Mississippi farmlands — from southwest Minnesota to across Iowa, Illinois, Indiana and Ohio — are the biggest contributors of nitrogen runoff into the Gulf of Mexico, reports a Cornell/University of Illinois-Urbana study.
Nitrogen runoff has been identified as a major contributor to dead zones in the Gulf, where nitrogen fertilizes algae and causes it to bloom, which in turn, depletes oxygen from the water and suffocates other life forms over thousands of square miles each summer.
Tile drainage has greatly increased yields in fertile soils since the 1800s where there once were wetlands. The systems consist of burying perforated pipes under the soil and draining them into canals. When such fields are fertilized, more nitrogen runs off into the Mississippi River watershed, according to the study…
To reduce such runoff, solutions include installing wetlands in areas where tiles drain to biofilter the water and fertilizing fields in the spring instead of the fall. Also, “we know that we are losing nitrogen in the period between cash crops when nothing is growing in the field,” said Laurie Drinkwater. “If we plant winter cover crops and diversify crop rotations, nitrogen losses could be reduced quite a lot.” A 2006 study by Drinkwater’s research group found that, on average, cover crops reduced nitrogen leaching by 70 percent.
Drinkwater added that policymakers need to increase incentives that reward environmentally beneficial farming practices. Currently, direct payments to farmers focus on production outcomes and do not sufficiently emphasize environmental stewardship, she added.
Ain’t she polite?
I’d be hard-pressed to think of any avenue of money between the government and productive enterprise – agricultural, industrial or otherwise – that cared for little else other than profit.