Greenhouse gases, largely carbon dioxide, worry some people who believe in global warming. Hypoxia, or a shortage of oxygen in Gulf waters due to excess nitrates going downstream, bother more people. Increases in phosphorus levels in Lake Erie bother those who don't want to see the lakes polluted. Silting-in of rivers, including the Mississippi River, threatens navigation and leads to costly dredging activities just so barges can get down the river to the Gulf.
No-till with cover crops in a well-managed system won't solve all of these problems overnight, but Barry Fisher believes it definitely could be part of the answer. Fisher is a soil health specialist and state agronomist with the Natural Resources Conservation Service. He tells farmers whenever he gets the chance how important such a change in farming practices could be. Those farmers who are doing it are catching the attention of political leaders, too, who are starting to ask questions and envision solutions to farm bill questions that involve these types of farming systems.
"You leave residue on the soil and then cover up the field with a growing cover crop in the fall and winter," Fisher says. "What you're doing then is pulling carbon dioxide out of the air, not just in the summer, but almost all year long. Growing plants are using carbon dioxide and releasing oxygen into the atmosphere."
More carbon in the soil isn't the only benefit of these systems, Fisher says. It also helps recycle nutrients. In years like 2013, a growing cover in the fall captured much of the nitrogen left behind not used by drought-stressed crops. It will gradually be returned to the soil after the cover crop is killed this spring. In fields where no cover was grown, it is likely that much of the nitrogen either evaporated or left the soil in tile lines and will wind up in rivers and streams.
Plant Cover Crops In A Drought Year? You Bet
Cover crops can help conserve moisture, keep soil covered and provide residue going into the cropping season. Download our free report Cover Crops: Best Management Practices