Every year a low-oxygen, or hypoxic, area forms in the northern Gulf of Mexico, just below the mouth of the Mississippi River. Fish and other wildlife often avoid hypoxic zones, which can be deadly to marine organisms. Known contributors to the Gulf’s hypoxic zone include runoff from urban areas, land development and agriculture.
USDA’s Natural Resources Conservation Service (NRCS) works with farmers and ranchers to help reduce agricultural runoff that may contribute to the hypoxic zone, in part through the Mississippi River Basin Healthy Watersheds Initiative (MRBI).
The Mississippi River Basin drains a huge portion of the United States, including parts or all of 31 states. As water drains off land and enters the river, it can transport nutrients from soil, fertilizer, animal wastes and sewage. The river carries water down the continent to the Gulf of Mexico, where any excess nutrients the water contains can stimulate the growth of algae, which consume large amounts of oxygen in the water—creating a hypoxic zone. The zone in the Gulf varies in size, but is often 7,000 or more square miles. Scientists have been studying the area since the 1970s and mapping it since the mid-1980s.
Shivers Farms, located outside of Indianola, Miss., is one of the farms participating in MRBI to reduce nutrients transported to the Mississippi River and, ultimately, the Gulf of Mexico, with the goal of increasing water quality in both bodies of water. The farm sits on 300 acres along Porter Bayou, and runoff from its lands enters the Sunflower River, eventually flowing into the Gulf.
But now about half of the water used on the farm stays on site when it drains off the fields, because the farmer has installed a series of underground pipes, ditches and a storage reservoir, funded in part by NRCS. This system allows time for nutrients and sediments to settle in the reservoir, which provides irrigation water for the crops.
Reusing water improves water quality by reducing the amount of runoff entering the river and helping filter out nutrients and sediments. It provides benefits for farmers, too: the nutrients in the water fertilize the plants, which prefer the warmer reservoir water to cold aquifer water, since the latter takes more energy for them to process. And the reuse of water means that less water is drawn from the aquifer.
The farm’s manager is happy with the benefits, and says that he hopes other Delta farmers take advantage of MRBI. In the future, he plans to look into other NRCS conservation programs.
MRBI was launched in 2009, and Mississippi is one of 13 states participating. The effort stretches across the 2,350-mile basin from Lake Itasca, Minn. to the Gulf.
Find out more about the Mississippi River Basin Healthy Watersheds Initiative.
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