Though many farmers consider planting soybeans as the activity following corn planting, adjusting your soybean planting date might be worth exploring. The conventional thought on soybeans is that they scavenge leftover soil nutrients, compensate for stand losses and tolerate planting into June with little yield penalty. However, with better technology and management systems, early planting of soybeans is shown to be beneficial.
Using multi-year Golden Harvest Agronomy in Action research across Midwest growing regions, the graph on the right illustrates how early planting is helpful. Note the variability in yields prior to May 1 and after June 15 in the graph. When planted prior to May 1, soybeans are more
vulnerable to weather like cool, wet soils and frost, so take soil conditions into account when considering early planting. Though it may not always result in an advantage due to weather, early planting can provide significant yield advantages in favorable years.
Soybeans are a C3 photosynthetic crop which uses the Calvin cycle for fixing carbon dioxide. This means they are highly dependent on efficiently capturing sunlight for photosynthesis to produce energy that will later go into building yield. Early planting can help soybeans reach
canopy closure earlier in the season to more efficiently capture sunlight and help with weed management. Reducing row width can also help achieve more efficient light capture. Achieving canopy closure by the summer solstice, June 21, is extremely important for maximizing light capture.
Soybean yield can be influenced by several components: plants per acre, nodes per plant, pods per node, seeds per pod and seed weight. Several of these yield components interact with one another. For example, as plants per acre decrease, the number of pods per plant tend to increase. Planting early can help maximize early vegetative growth which can increase the number of nodes per plant. Pods per node can be influenced by length of photoperiod (day length). Having a longer reproductive timeframe as result of earlier vegetative growth can help maximize the number of flowers that become pods. However, seeds per pod and seed weight are less likely to change due to planting date.
Another benefit of early planting is that it allows farmers to plant fuller season maturities that typically provide higher yields. An earlier harvest may also help farmers with favorable weather windows, field maintenance or planting winter crops.
It’s important to note that seed treatments become much more important with early planting to help protect against fungal pathogens found in cool, wet soils as well as early season insects like bean leaf beetles.
Although there is more risk associated with early planted soybeans, the benefits often maximize yield which outweighs the risk. Benefits include:
- Earlier canopy for weed control
- More robust canopy for light capture
- Increased nodes per plant
- Extended length of reproductive stages
- Potential to plant longer RM with additional yield potential
- Earlier maturity for harvesting sooner
Contact your
Golden Harvest Seed Advisor with questions or for more insights on soybean planting timing and product placement.
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