Combined effects of cool weather during the last week of March and first weeks of April, with the much-needed rain in the last few days, keep delaying corn planting this year. In 2017, close to 50% of the corn had been planted by the first week in May. The latest numbers from the USDA National Agricultural Statistics Service show just 27% planted as the week ending on April 30th (Figure 1). The majority of progress has been in the Southeastern Division, followed by the East Central and Northeastern Divisions.
Rainy conditions could present challenges for planting corn into ideal soil moisture. It is best to allow time for the soil to dry adequately before tillage or planting operations if at all possible. Wet conditions will make the soil more susceptible to compaction. Compaction can occur in the seed furrow itself, restricting proper root development, diminishing nutrient accessibility and early plant growth.
If wet weather conditions persist for more than a week, corn emergence will be delayed and seedlings will be more vulnerable to the presence of insects and diseases. Uneven corn stands likely will be greater when planting in cold and wet soils. This situation will directly affect plant-to-plant uniformity, impacting potential yield.
Weather outlook for Kansas
For the next 7-days, ending on May 11 (Figure 2), the outlook for precipitation shows a probability of receiving from an inch (southeast Kansas) to less than a tenth of an inch of rain (western Kansas), adding to the limited precipitation already received this past month (Figure 3). Given the dry conditions in the western and southwest parts of Kansas, this is unlikely to limit field work, but may provide a more favorable moisture environment. Warmer-than-normal temperatures will help warm soil temperatures to more favorable ranges. You can monitor changes in soil temperatures at the Kansas Mesonet: http://mesonet.k-state.edu/agriculture/soiltemp
The precipitation outlook for the medium-term (6-10 and 8-14 days) is calling for near normal conditions across all but the western parts of the state, followed by drier-than-normal conditions to end the period (Figure 4).
Optimal soil conditions have a large impact on corn uniformity and early growth. Lack of uniformity in emergence can greatly impact corn potential yields.
There is still time to plant corn and get good yield potential. If possible, wait and plant under uniform soil temperature and moisture conditions to guarantee a more uniform early-season stand of plants.
More information about corn planting progress and late-planted corn will be discussed in upcoming issues of the Agronomy eUpdate. Stay tuned!
Ignacio Ciampitti, Crop Production and Cropping Systems Specialist
Mary Knapp, Weather Data Library