Standard Planting Guidelines Might Not Apply in 2013
The main objective at planting time is to provide seed with an environment that promotes rapid germination and vigorous early growth. Corn needs water, aeration and temperature – all in the right portions – as well as seed-to-soil contact to germinate and emerge. Obviously, soil temperature and soil moisture are key to germination. If the soil is too dry or too cold, the seed will just lay in the ground without germinating.
When soil moisture is at field capacity, the optimum planting depth is 2” deep for corn and 1.5” deep for soybeans. Current field conditions in some areas across the U.S. aren’t “optimal.” Due to late-season snowfall and early spring rains, some fields are extremely wet now. In other areas, however, field conditions remain extremely dry.
In dry conditions, seeding depth can differ. If we receive the rain that’s forecast in the next 10 days, however, soil moisture could be more than adequate at planting time. Three factors affect corn’s response to seeding depth: (1) soil texture; (2) tillage system; and (3) residue cover.
Knowing the soil texture will help dictate how deep seeds need to be placed for adequate available moisture for successful germination. No-till fields should retain adequate soil moisture at a reasonable planting depth in most years. Minimum-till also helps conserve moisture.
Planting too deep just may have the opposite effect of what you’d like. There are two major problems that can result from planting too deep: (1) delayed emergence and (2) uneven stands. Stands may become uneven due to crusting, too. If a hard, pounding rain falls shortly after planting, seedlings can have a very hard time breaking through crusted soils.
Also keep in mind that planting too shallow can also provide negative results. Corn seed planted too shallow most often results in poor root development and may affect the crop all the way to harvest. Seeds that are planted too shallow have a tendency to develop “rootless corn syndrome,” causing plants to fall over because they lack nodal root development.
There are “best management practices” farmers can implement this spring. Keep the conservation of moisture in mind, and make the most of the good field conditions. Fewer passes across the field with disks or field cultivators will help conserve moisture. Also bear in mind how the amount of residue may affect planting conditions. Take notice of debris in the field. Too many stalks or root balls can inhibit seed emergence.