Editor’s Comments: News From the Fields

Over the last few months, some surprising results and trends have emerged from the agricultural sector regarding the care and feeding of our soil. Overall, I think they bode well, even if on a small scale, and I want to take a closer look here at two recent items.

One piece of news, announced at a January meeting of the Ohio Farmers Union, seems at first glance like a setback for agricultural conservation efforts. Mark Williams, a soil drainage researcher with the US Department of Agriculture (USDA), explained that USDA has been testing runoff from agricultural fields and has found, in many cases, an increase in dissolved phosphorus. This of course is exactly the opposite of what the agency hoped for; excess nutrients in runoff, such as nitrogen and phosphorus, are responsible for algae blooms in receiving waters, and because much of the testing Williams described is taking place in the western Lake Erie basin—the same Lake Erie that has experienced multiple toxic algae blooms in recent years, one of them in 2013 severe enough to temporarily cut off Toledo’s drinking water supply—the results are especially concerning. Doubly disappointing is the fact that the farmers who own many of the fields tested have been practicing USDA-recommended no-till farming, which is supposed to decrease erosion and nutrient loss.

The upside, though, is that researchers think they know why this is happening and how to fix it. On the no-till fields, the loss of sediment and surface phosphorus is indeed reduced; the increased phosphorus levels are found only in tile drainage. Williams explains that although phosphorus concentrations are actually higher on the surface, the larger volumes of water flowing through the tile drains leach out more phosphorus. And while no-till farming has the benefit of allowing nutrients to infiltrate slowly, it also means they aren’t well incorporated into the soil, instead following natural cracks, pores, and fissures and therefore washing out quite easily. Tilling the soil, on the other hand, would incorporate the nutrients into the soil better and result in less nutrient loss.

The solution, says Williams, is not to abandon no-till practices, but rather to investigate other ways of incorporating the nutrients into the soil—which USDA is now doing—such as subsurface injection or other means. A combination of best practices could provide even greater benefit than no-till farming on its own.

And a promising ag trend is the increasing use of cover crops, at least by some farmers. Although this ancient practice has largely fallen away with the advent of modern applied synthetic fertilizers, cover crops—that is, non-cash crops like hairy vetch, cereal rye, Oregon ryegrass, and others that are planted in the off-season—have advantages that fertilizers alone can’t provide. They add carbon and help maintain the organic elements of the soil like bacteria, fungus, and microbes, leading to increased crop yields. Some farmers have also reported fewer pests and less water and fertilizer needs once the cover crops have improved soil health. The process requires some investment and patience, though—the soils might take a few years to show results, and there is a cost for the cover crop seed in the meantime. The federal government has endorsed use of cover crops and offers small subsidies to farmers who adopt the practice, and research into the benefits is ongoing. Although the last Census of Agriculture report in 2012 showed that less than 3% of the nation’s farmland was being planted with cover crops, more recent surveys have shown the practice is growing; the next census takes place in 2017 and will provide a more accurate picture.