Farm Horizons, August 2008
Are early-planted crops always best?
I have always been a proponent of early-planted wheat, corn, and soybeans. In my opinion, the earliest-planted fields are nearly always the best yielding.
I say nearly always, because this year may be the exception, when later-planted fields stand out.
Minnesota is on the northern edge of the corn belt, so we need to get the crop planted early and take advantage of as many growing degree units as possible.
Growers are also able to plant more full-season varieties with early planting dates, so these early-planted fields normally have a yield advantage.
I have walked many corn and soybean fields the past month, and have observed soil compaction in a number of growers’ earliest-planted corn and soybean fields.
Early this spring, sidewall compaction in the seed furrow was quite evident. This type of compaction is worse in soils with higher clay contents.
Growers can expect less lateral root development, causing nutrient deficiencies and the potential for stalk lodging. In July, soil compaction was evident in fields exhibiting stunted plants, uneven stands, and yellowing. I doubt if these areas will recover to produce satisfactory yields.
As soybean product manager, I prefer soybeans be planted in relatively warm, dry soil. The damping off type seedling diseases are much less problematic if fields are planted in mid to late May.
According to research, sometime around May 10 to 15 in Minnesota we begin to see soybean yield loss with delayed planting dates.
The yield loss, though, is so slight at this stage of the growing season that growers should not feel forced into planting fields that are unfit.
The advantages of no soil compaction and plants that are off to a fast start far outweigh the value of early planting in less than ideal conditions.
A grower told me this summer, “Plant in the dust and bins will bust.”
I have also been told, “When you think fields are ready to plant, wait an additional two days, and then plant.”
This year made me a believer that we need to pay more attention to field conditions and less attention to the calendar.