Jeff Coulter and Seth Naeve, University of Minnesota Extension agronomists, offer these tips for successfully finishing up corn and soybeans:
Don't mud them it. Although it is important to finish corn and soybean planting as soon as possible, it is also important to avoid the temptation of planting when soils are too wet. Sidewall smearing can occur on heavy soils when double-disc openers on the planter cut through wet soil, resulting in compacted soil around the seed that is difficult for seedling roots to penetrate. Seed furrows can also open up after heavy soil dries following wet conditions at planting, resulting in poor seed-to-soil contact and poor stand establishment. In addition, soil crusting can greatly hinder soybean emergence in fields planted under marginal conditions. In some fields, growers may need two planting dates: one for the majority of the field when it is dry enough, followed by a second planting date to fill in the remaining low areas after they have dried sufficiently.
Reduce rate of overseeding only slightly. Research conducted at Lamberton, Morris, and Waseca, MN from 2008 to 2010 that was funded by the Minnesota Corn Growers Association clearly shows that the optimum final stand does not change when planting is delayed. However, with warmer soils, growers may be able to slightly reduce the rate of over-seeding for a desired final plant population. In general, a 5% over-seeding rate is reasonable for normal to late planting dates.
Don't plant corn shallow. A corn planting depth of 1.75 to 2 inches is optimum for most fields and planting dates. In corn, poor stand establishment is often the result of insufficient moisture in the seed zone after planting. Thus, it is important to avoid the temptation to plant shallow. Emergence will occur quickly when planting is late and soils are warm. Shallow planting depths increase the risk for poor establishment of the nodal roots that develop between the seed and the soil surface. While soybean does not require deep planting for proper root development, producers should continue to closely monitor soybean planting depth so that seeds are placed on top of the moisture and will have ample access to moisture
Source: U of M E-Crop News