The following is an excerpt from a recent article published by Harvest Public Media, which discusses the implications of high nitrate levels in waterways in the midwest and some of the options farmers have to mitigate nitrate runoff.
This spring and summer, U.S. Geological Survey scientists waded into 100 Midwest streams to test for hundreds of chemicals used in farming … preliminary findings indicate that from May through early July, 21 percent of the region’s streams contained very high levels of nitrogen in the form of nitrates.
Lately, high nitrate levels have caused major problems for water treatment plants in parts of the Midwest that draw source water from lakes, reservoirs and rivers … how can farmers limit the amount of fertilizer they use – and therefore the amount of nitrates that wash into waterways – while still producing a bumper crop?
Some farmers believe they have an answer to that question in the form of a crop reflectance censor. These devices, when connected to a farmer’s sprayer, tell the applicator to put less nitrogen on healthy corn plants and more nitrogen on weaker ones… With price tags of up to $10,000 each, these crop sensors aren’t cheap. Yet a recent national survey found that this year, 7 percent of farmers are now using them, up from 4 percent in 2011.
Other strategies for reducing nitrate runoff include planting cover crops and nitrogen-efficient crop varieties. But it’s at the farmers’ discretion. Because currently, few states have laws, and there is no federal law, limiting the amount of nitrogen that farmers can put on their fields.
View the entire article here.