and Why the Date Matters
When it comes to soybean planting, the positive far outweighs the negative when planting earlier in the season. The earlier soybeans are planted, the greater yield you can expect. This is true because of many different variables. First, it’s important for soybeans to get as much sunlight as possible, earlier planting means more days of sunlight. Soybean planting later in the season means a lot of sunlight, but for fewer days resulting in a less than stellar yield. Plus, as the weather gets warmer there is a higher chance of soil evaporation. Soybean planting earlier in the season means cooler temperatures and less evaporation of soil water.
The soybean’s stem nodes are what is really important, the more the better. Soybean germination is dependent on temperature, however. Earlier season soybean planting and cold soil temperatures could mean it takes longer for emergence. But, longer germination and emergence times are not a bad thing. Even though it will take longer for the soybeans to reach full maturity, they will still be way ahead of soybeans planted later in the season. Also, early season soybean planting means the growth of more stem nodes, which can affect final yield. As a matter of fact, multiple studies have shown greater yields from soybeans planted earlier.
Soybean Planting Date Considerations
Even though most people prefer to plant early, there are reasons to consider planting later in the season. For instance, in late April you may still have to deal with freezing temperatures and severe weather. That could lead to a huge reduction of stems and possibly even the need to replant. Think about the date of expected emergence instead of the planting date. Only plants that have emerged will be damaged by temperatures below 32 degrees. Do some research in your area to determine when the average temperature is good for soybean emergence.
Additionally, some percentage of seeds could be lost to germination failure. Soggy soil is a huge contributor, not because of the excess water but the ideal environment for fungal growth. Sometimes, a fungicide is necessary and thought to be a worthwhile expense.
Another risk of early season soybean planting is bean leaf beetles. These nasty little insects love to munch on soybean roots. Most of the time, the damage isn’t bad enough to warrant the use of pesticides. The scary thing is the possibility of bean pod mottle virus, which can wreak havoc on crops. An insecticide treatment should be used if the beetles and bean pod mottle virus are common in your area.
Overall, there are a lot of things to consider when deciding on a date for soybean planting. Do your research about temperature and the potential for frost, and whether or not bean leaf beetles are a concern.