By Steve Whittington
Spring is an exciting and busy time of year on Michigan farms, with field prep and planting in full swing. One common practice observed during this season, especially among livestock and dairy operations, is corn-on-corn rotations, also called continuous corn. Planting corn in the same field each year helps producers meet high feed demands, typically in the form of corn silage. However, managing continuous corn has its challenges, such as nutrient management, residue management and disease pressure. In order to add diversity into the rotation and protect soil with living roots through winter, some farmers plant a cereal rye cover crop following corn harvest in continuous corn systems. The rye will establish in the fall, survive winter dormancy, and will be terminated before planting corn again in the spring.
While continuous corn with cereal rye offers benefits to a livestock producer in terms of feed supplementation, it does not fully replace the advantages of a longer, diversified crop rotation. Additionally, with high input costs and the potential for a yield reduction, the long-term profitability of the operation could be affected.
The importance of a crop rotation
Crop rotations are a fundamental strategy for sustaining productive and profitable farming systems. By alternating different types of crops over time, farmers can manage soil nutrients more effectively. Crop rotations disrupt pest and disease cycles, suppresses weeds, maintain soil structure, and uses soil fertility more efficiently. Corn-on-corn systems, by contrast, are limited in these benefits due to the short nature of the rotation itself. Growing the same crop year after year can lead to nutrient depletion, in particular nitrogen, which is critical for successful corn production. These systems can also allow a buildup of persistent insect and pathogen populations. Over time, this puts added stress on soil and demands more inputs to maintain yields.
Managing continuous corn
Yields in continuous corn are often lower than corn yields in corn-soybean or corn-soybean-wheat rotation. The yield reductions in continuous corn are largely driven by the cumulative effects of nutrient stress, less-than-ideal soil conditions at planting from residue, and disease pressure.
Nutrient management
A cropping system like corn-on-corn will require careful nutrient management, especially nitrogen. Corn is a heavy feeder of nitrogen, and adequate levels of nitrogen must be available at the right time for optimal uptake and performance of the crop. In corn-on-corn systems, this means using starter fertilizer, considering the use of nitrogen stabilizers, and applying a side-dress application during key growth stages of the crop.
Relying on manure from livestock operations helps, but manure alone often doesn’t meet the full nutrient demands of continuous corn. Its nutrient release is slower and less predictable compared to commercial fertilizers, which means timing and availability can be challenging.
Source : msu.edu