A wet spring can put farmers behind their planting schedule and leave them feeling rushed. Timely planting is critical for maximizing yield and delays due to rainfall can lead to farmers planting into wet soils to make up the difference. Before rushing to plant, farmers should weigh the risks of compaction-related yield loss against that of delayed planting.
While planting within the optimum window can impact corn yield anywhere from 2-5%, three other factors are also important to optimizing yield at planting:
Uniform emergence (5-9%)
Correct population (1-2%)
Uniform plant spacing (1-2%)
The ability to get corn planted within the optimum planting window is largely driven by weather conditions. This window that can vary greatly from year to year and lead to planting into wet soils, potentially creating compaction issues.
Compacted soils can limit the ability of plant roots to grow into new soil to extract water and nutrients. This can reduce the amount of the soil profile that is available to contribute to supplying water and nutrients for crop growth. According to Iowa State University in favorable years, moisture availability, well-timed rain and fertilizer use can mask the effects of soil compaction. In unfavorable years, however, yields can be reduced by as much as 20%, potentially outweighing the drawbacks of late planting.