The right soil conditions are worth the wait to plant
Assessing each field for the right planting conditions improves uniformity of corn emergence, enhancing productivity.
April 28, 2011 - Author: Marilyn L. Thelen, Michigan State University Extension
Planters are ready, tractors are serviced, the seed is in the barn and farmers are just waiting for some sign that spring has come to Michigan. We are certainly dealing with a different spring than last year! According to AgWeb, Corn planting was reported as 1% in Michigan as of April 24, 2011. Last year Michigan was 28% planted and the current 5-year average is 11% planted on this same date.
Conditions have not even been tempting! However, as the temperature begins to rise and fields begin to dry farmers will need to determine – is it ready? Don’t be tempted to compromise standards to get the corn planted. According to MSU agronomist Kurt Thelen, the optimum time to pull the trigger on the switch to a short season hybrid will vary from year to year depending on the weather conditions, but it is generally around the third to fourth week of May for much of Michigan. So, there is still time.
Planting in conditions that provide for uniform emergence is important. R.L. Nielsen, agronomist at Purdue University, says that uneven soil moisture throughout the seed zone is the primary cause of uneven emergence. This can cause yield losses of 8 to 10 percent. Uneven moisture can be the result of localized dry areas, but can also be the result of scattered wet spots. Planting depth can be adjusted in an attempt to place seed into uniform moisture. Patience often pays when fields are wet. Variability may also be addressed by adjusting planting depth. Seed should not be planted less than 1.5 inches, but could be planted as deep as 2.5 to 3 inches.
Cool soils can also lead to uneven emergence. Corn should be planted into soils that have temperatures of greater than 50 degrees. Soils in the mid-50 degree range can lead to emergence in 7 days or less. An inexpensive soil thermometer or tracking soil temperatures on MSU’s Enviro-weather are valuable tools in tracking temperature. However, once we reach the last week of April or later, disregard soil temperature as a planting time indicator and rely solely on field moisture conditions for determining when to plant. Creating an environment that allows for more uniform temperature at seed depth can be accomplished by removing residue with row-cleaners, as well as maintaining uniform planting depth.
Seed soil contact is best accomplished when soil conditions are optimum. Having the patience to wait for soils to dry avoids the risk of sidewall compaction, soil clods and hair-pinning from wet residue. These conditions can decrease germination, reduce stands and limit root growth.
Finally, avoid conditions that may lead to surface compaction. This situation can result from over tillage, breaking soil into a powder-like consistency. Planting in these conditions when a rain is likely prior to emergence will crust soil and decrease emergence. Surface compaction can also result from working wet soils.
When spring finally arrives in Michigan, exercise patience. Waiting just one more day may provide pay off!