What this means is that wind erosion can both reduce the overall microbial diversity in farm fields, as well as deplete topsoil of specific groups of essential bacteria, say the researchers. At the same time, certain important groups, such as Actinobacteria that promote soil aggregation, remained in the parent soil despite the erosive conditions generated in the wind tunnel. And while fine dust can travel extremely long distances, coarse particles rarely move more than 20 feet, suggesting that theyand their associated microbesshould be fairly easy to retain with cover cropping and other soil conservation measures, Acosta-Martnez notes.
Helping farmers and land managers adopt practices that better conserve soil is one of the main goals of the USDA-ARS team's work, which also includes Ted Zobeck, Scott Van Pelt, Matt Baddock, and Francisco Caldern. In the Southern High Plains region, for example, intense cultivation of soil combined with a semi-arid climate can result in serious wind erosion problems. In fact, last summer's drought brought Dust Bowl-like conditions to the area, says Acosta-Martnez.
But "wind erosion is a national problem," she adds, with significant erosion occurring even in places where the growing season is humid and wet. Organic histosol soils in Michigan and many other parts of the country, for instance, are very susceptible to wind erosion when dry, especially since they're usually intensively farmed and often left bare in winter. Cover cropping or crop rotations not only help keep these soils in place, but can also build soil organic matter, which in turn promotes soil aggregation, water penetration, and general soil health.
It can take years, however, for farmers who've adopted new management practices to detect noticeable changes in levels of soil organic matter and other traditional soil quality measures. This is why Acosta-Martinez and Gardner have been analyzing soils wit
|Contact: Teri Barr|
American Society of Agronomy