As spring ripens into summer and you take a relaxing drive through Wisconsin’s Central Sands—from Coloma to Plover, barely 50 miles—you will see a remarkable diversity of crops taking shape on the landscape. Not many realize it, but you are travelling through the heart of one of the nation’s most important vegetable production areas, and also one of its most diverse. To be sure, the Midwest standards of corn and soybean are grown here, but they are overwhelmed by a fascinating mixture of vegetables and specialty crops: potatoes of all kinds abound—russets for baking and fries, reds and yellows for salads, round whites for chips, even sweet potatoes rarely found outside the Deep South. Sweet corn, green beans, peas, carrots, peppers, cucumbers and beets also dot the landscape. Most are bound for processing plants across Wisconsin and then ultimately for distribution across the US and countries around the world, but others are freshly available to you at local farmer markets and grocery stores. Think of it, from crunchy pickles to spicy relish, from sweet cranberry sauce to fresh mashed potatoes for holiday feasts, all of this grown right here in Central Wisconsin. By the way, did you know that Wisconsin is also the nation’s largest supplier of cranberries?
Together, this diverse collection of crops combine to make the Central Sands one of the top vegetable and specialty crop production areas in the US and a key component in the nation’s food security. You might ask why farmers would complicate their lives with such a bewildering diversity of crops when each has specific needs and presents unique challenges. Isn’t easier just to grow one type of crop? The answer is that through years of careful observation and research, farmers have learned that the very differences that make growing such a diverse mixture of crops challenging, can also be an advantage. Each crop has its own set of pests and unique nutrient needs, and if crops are grown continuously, pests quickly build to catastrophic levels and nutrients diminish. Farmers have been clever and learned to use crop differences to pit pest against pest by moving crops around in the landscape through time. This makes survival harder for the pests and also benefits the crops by building up soil nutrients—some plants use a lot of nutrients, while others add them to the soil. This clever plan of moving crops around in different locations and growing different crops on each year is called crop rotation. There are countless examples where crop rotations can prevent pest buildup, and each crop can provide positive benefits to the crops which follow it:
- Alfalfa provides nitrogen to potatoes.
- Dairy manure and crop residues build soil health.
- Corn reduces nightshade weeds for potatoes.
- Potatoes reduce root rots in peas and green beans
- Cover crops reduce nematodes for potatoes.
Individually, each advantage gained from rotation may not be vital, but together they combine to establish a sustainable, naturally-based foundation that keeps pests at manageable levels, maintains soil structures and nutrient availability, and ensures a reliable supply of high quality produce at affordable prices. So if you get a chance, take a short drive through this diverse landscape and know that at the same time it’s not only beautiful, but also essential to the security of our nation’s food supply.