Thoughts for Food #4

Keeping the soil where it belongs!

When the warm winds blow from the south in late March, it is a sure sign of spring! While it might be
welcome to many, it can be a big problem for the vegetable growers in Central Wisconsin. The winds can Newly_Planted_Windbreakeasily pick up small grains of sand from bare soil and blow them from the carefully tended fields—this may be of little consequence in a place like the Sahara desert but it cannot be tolerated in the Central Sands where the farmers spend lifetimes building the soil to the structure and health needed to grow quality vegetables. So what can they do?

The first step is to protect the soil from wind erosion. Each fall and winter following harvest, growers ensure that their fields have a protective cover by planting a type of grass or deep rooted crop so that the field is not left bare and vulnerable to wind. This protective cover is called a cover crop. In general, the Central Sands landscape is very vulnerable to soil erosion, because the land is flat.  Each year, a landowner can lose a tiny fraction of topsoil due to the wind; those small losses could amount to tons of soil loss if fields are left unprotected.  Cover crops serve to hold precious topsoil in place and limit soil loss, but they also do so much more! They enhance beneficial organisms in the topsoil by providing stable micro-habitats; they limit nutrient and water losses on fields by capturing unused nitrogen from previous crops, thereby reducing leaching potential; and they build soil health by adding beneficial organic residue and sequestering carbon. Cover crops are not grown to generate a profit but to protect the precious soil resources on the farm.

The second approach that farmers use is to break-up the flat land surface, which can disrupt the impact of wind.  This is accomplished by planting a windbreak system along field edges to block winds coming into and leaving fields.  The most effective windbreaks incorporate several species of shrubs and trees to provide habitat diversity (they significantly enhance pollinator and songbird populations for example) and to effectively block winds at differing heights. Windbreaks are a large investment for the grower, but since they are very effective in limiting soil loss, they are well worth the price! According to Shannon Rhode, manager of the Central Wisconsin Windshed Partnership group (a collaborative effort between the industry, local counties, the State and the University of Wisconsin): “ properly planted and maintained windbreaks can limit soil losses and over time and can be very effective in maintaining the production viability of the region.”  Rhode notes, “In the last 20 years, hundreds of miles of new windbreaks have been planted by the Windshed Partnership, which has a goal to plant and install 15.5 new miles of windbreaks per year. These plantings have resulted in thousands of acres of cropland being protected”.

In all, a simple thing like the wind may seem like a nuisance (or sure sign of spring) to most of us, but to growers in Central Wisconsin, it is far from simple. Being the stewards of the land, they work hard and invest heavily to keep the soil where it belongs, ensure conservation on and around farms, and build the soil quality for generations to come.

Comments are closed.