Farmers aim to reduce nutrient runoff in U.S. waterways

With increased runoff of agricultural fertilizers into waterways, U.S. farmers are adopting more environmentally sound crop production methods.

Nov. 11, 2013 -- In light of increased runoff of agricultural fertilizers into streams, rivers and watersheds, farmers across the United States are adopting more environmentally sound crop production methods and technologies that address this problem.

One major concern is the agricultural use of phosphorus fertilizers which is receiving growing attention from farmers who are striving to minimize runoff of this vital plant nutrient. "Farmers take the hit for the phosphorus that runs off into watershed areas, but agriculture is not the only culprit," says Dale Bartholomew, a certified crop adviser with a key agricultural retailer in Caledonia, N.Y.

The state of New York is second only to California in the development and enforcement of stringent regulations designed to keep phosphorus and other nutrients from flowing into major water bodies such as the Chesapeake Bay and the Great Lakes. According to Bartholomew, farmers in the region are being increasingly proactive in their efforts to not only meet those regulations but also to exceed them in the interest of being good environmental stewards.

"Increasingly, our farmers are using fertilizer enhancers and stabilizers that ensure more uptake of phosphorus and other nutrients by crops, versus leaving those nutrients in the soil," he says. "Other proactive steps include use of precision application techniques and less reliance on plows and tillage to minimize soil erosion."

Indeed, soil erosion is a significant part of the challenge, as nutrients attach themselves to soil particles and are then vulnerable to runoff into waterways. Dr. Gary Tuxhorn, an agronomist for United Suppliers, a major provider of inputs for agricultural retailers headquartered in Ames, Iowa, notes that phosphorus tends to become absorbed in the soil and remain unavailable for plant uptake. It can remain fixed for long periods of time following application if a product such as AVAIL® Phosphorus Fertilizer Enhancer is not used.

"In the Midwest, AVAIL is often used with phosphorus fertilizers in no-till production systems that reduce or eliminate plowing," Tuxhorn says. "This tandem approach helps reduce the amount of phosphorus that gets tied up in the soil, makes more of the nutrient available for plant uptake and minimizes the off-site movement of soil through erosion."

Dr. Barney Gordon, professor emeritus at Kansas State University and an expert in soil fertility and fertilizer efficiency, notes that many farmers favor fall applications of phosphorus following harvest. "Applying phosphorus with AVAIL in the fall allows the nutrient to be worked into the soil by natural moisture over the winter," Gordon says. "As a rule, fall weather is conducive to fertilizer applications due to good conditions and the fact that farmers have the time to make the applications, versus applying fertilizer in the spring when they should be focused primarily on getting their crops planted. The weather in the spring tends to be more unpredictable and can prevent the farmer from making timely phosphorus applications."

A good case in point is the heavy spring rains across much of the Midwest and Northeast in 2013 that delayed planting and wreaked havoc with spring fertilizer applications. "Improved plant uptake of phosphorus is key to healthy crops and better yields, and it also translates into less phosphorus left in the soil, which can be lost through erosion," Gordon emphasizes.


More in Environmental