Crop rotation has been a cornerstone of sustainable farming for thousands of years, but the practice has become more complex. There are many factors that today’s farmers need to consider when developing their rotational plans. Seth Naeve, Ph.D., University of Minnesota associate professor and extension soybean agronomist, provides a list of the most important below.
Know the Market
“It’s important to assess the market for all crops in a potential rotation,” Naeve says. “Farmers need to look beyond pricing to who will take it off their hands. You need an elevator or some type of market to be willing to purchase your crop. Sometimes that’s an easy thing, and sometimes it can be cumbersome. No matter what, you need to be aware of the economics of your crop rotation and have a plan to go to market for all your crops.”
Setting the Sequence
Timing is key when evaluating crop-rotation options. Naeve suggests looking at varieties with maturities that will allow adequate time for planting, harvesting and field preparation between crops. Picking the right maturity for each crop is critical. There are a number of problems that can occur if the sequencing doesn’t allow enough time between crops. For example, farmers planning to plant winter wheat may need to select an earlier maturing soybean variety to ensure they have adequate time to sow their wheat. If the crop sequence isn’t properly planned, one delay can lead to another and push back timing of input applications and harvests of subsequent crops.
Managing Fertility and Moisture
“It may sound basic, but farmers should keep in mind any crop that’s planted will always remove something from the soil,” Naeve says. “This may create a need for additional fertilizer or irrigation, and farmers need to take that into account on their balance sheet. Naeve points out this isn’t always a bad thing. “If there’s excess water in a field, an extra crop can help take care of that for you.”
Coordinating Weed Control
Crop rotation creates opportunities to use different herbicide chemistries with new modes of action, but it also requires detailed management.
“Making use of herbicides with differing modes of action can lead to better overall weed control and is critical in minimizing the risk of resistant weeds,” Naeve says. “However, farmers need to pay close attention to the residual properties of the herbicides they use to be sure they don’t run into unwanted restrictions. This goes back to proper sequencing and variety selection to allow enough time for pre-plant intervals with herbicides.”
Building Residue Levels
Naeve says crops that produce high amounts of residue enhance erosion protection, improve soil organic matter and offer greater soil moisture conservation. Farmers looking to increase the amount of high-residue-producing crops in their rotation should add corn for grain, wheat, grain sorghum, barley or oats to their rotation.