It\u2019s time for a science lesson. Promise it won\u2019t take long. But it\u2019s essential to understand why water has become a hot topic for discussion in the Midwest. The problem: nitrates.<\/p>\n

Nitrates are odorless, colorless, tasteless compounds found naturally in the soil and groundwater. They\u2019re one of several soil microorganisms. When microbes like bacteria, fungi, and protozoa break down organic material \u2014 stuff like dead plants, animals, and manure \u2014 they produce nitrate. Nitrates help make up protein and chlorophyll, the latter being necessary for photosynthesis, the process by which plants make their food. Without nitrates, the plant dies.<\/p>\n

Everyone from industrial farmers to backyard gardeners uses nitrate-rich chemicals to fertilize their crops. These fertilizers supercharge the soil. Crops absorb these excess nitrates and turn them into chlorophyll \u2014 allowing them to convert more of the sun\u2019s energy into food, which allows them to grow bigger, so they can suck up more nitrates \u2026 and the cycle is never-ending. The result? Larger, healthier plants with higher yields. Farmers who want to guarantee profits will definitely have nitrate-rich fertilizer as a part of their arsenal.<\/p>\n

The problem is that typical summer crops like soybeans or corn can\u2019t consume all the nitrates added to the soil during their four- to five-month lifecycle. This leads to runoff. \u201cNitrate is lost because the soil contains huge amounts of nitrogen, and if there is no growing plant to use that nitrogen, [the nitrate] is susceptible to loss to our water ways,\u201d says Michael Castellano, assistant professor of agronomy at Iowa State University.<\/p>\n

After corn and soybeans are harvested, soil lies fallow for months, which makes it subject to erosion. That’s particularly true if a farmer doesn’t practice methods to minimize such erosion. Nitrates in that exposed soil get washed away by the rain and snowmelt and flow into local streams, rivers, and lakes. They can also get left behind in the soil, where they eventually seep into groundwater. Either way, the problem isn\u2019t that farmers are using too many nitrates in their fertilizer. If the soil was held in place by plants all year, there would be no runoff, and the plants would absorb most of the nitrogen that seeps into the ground and into our waterways \u2014 alleviating much of the problem.<\/p>\n

For years, farmers have been blamed for dumping too much fertilizer into the soil, causing water pollution and other environmental problems.<\/p>\n

What people forget is that farmers are no longer growing crops to feed their families \u2014 or towns \u2014 like they did half a century ago. An individual farmer reaches 155 people globally with his yields. \u201cWe have gone beyond feeding people in the United States and gone on to feeding people throughout the world,\u201d Carol Miller says. Simply put: Farming is business. And just like every business, farmers want to feel their pockets jingling with money.<\/p>\n

Fertilizers are not at the core of the Midwest’s water pollution problem. Exposed soil and soil erosion is. \u201cThe natural, organic soil in the nitrogen is about 10,000 pounds per acre, and that is quite a bit more than what we apply to our fields,\u201d Miller says.<\/p>\n

Like many farmers, the Millers use several methods to minimize soil erosion and fertilizer runoff. When planting, they disturb the soil as little as possible, a technique known as “minimum till.” After harvesting their corn, they leave the crop residue in the ground instead of plowing it under. They leave their soybean fields untouched after harvest. Doing so helps hold the soil in place over the winter. The Millers’ farm also employs terraces, which prevent erosion by flattening sloping terrain.<\/p>\n