It’s that time of year again!
As we emerge from what seems like the longest, coldest, wettest winter in history, spring planting season is upon us. We can all agree that the groundhog lied, but spring is finally here.
Across the country’s main crop-producing states, the spring planting window stretches from April through May. Winter brought more moisture than recent years to the Midwest and Corn Belt, and rolling into April with rain in the forecast, it could be a challenging season.
The planting window
Optimal planting time for spring crops in the U.S. varies widely from south to north, beginning as early as March 1 in southern states like Texas, and ending as late as July in parts of California. Across most of the Corn Belt, the region accounting for more than 80 percent of the U.S. corn crop, planting begins in early April and wraps up in mid-May. (The same data show that the majority of soybean planting also begins in April and wraps up in May.)
An article by The Weather Channel noted that 2018 was the wettest year on record for much of the eastern third and midwestern regions of the country. As wind chills dipped far below zero, winter hit the planting region with snowstorm after snowstorm, dumping inches and inches of snow week after week. Many places are only now climbing out of the mud, while others still have difficult conditions to deal with.
“The planting window might be shorter this year than the previous one,” says Ignacio Ciampitti, associate professor and cropping systems specialist with Kansas State University. “The cold temperature is not the main concern yet, but the moisture content is quite high and this could be a real problem to start early planting crops.”
Don’t jump the gun
With just a few weeks to get hundreds or even thousands of acres in the ground, farmers may want to jump in the tractor and go mudding when the calendar flips to April. Ciampitti says resist the urge.
With many of the region’s fields a swampy mess, herbicide and fertilizer application are proving particularly difficult this year. That means it’ll be pedal to the metal when the dust flies. The planting window for corn is wide and Ciampitti emphasizes the need to hold off from entering the field until soil moisture conditions are adequate.
“Too-wet conditions can promote issues related to side-wall compaction and lack of uniformity (poor emergence), consequently affecting the final number of plants and yield potential,” he says.
An article by Michigan State University Extension supports Ciampitti’s theory. The article points out that soil type should be considered, as lighter soils will drain faster and heavier soils will need more time to dry. Evaluate fields and start planting in those lighter soils, then fill in fields with heavier soil types as they’re able to dry out.
Sidewall compaction of young corn and soybean plants is a concern anytime planting takes place in wet conditions, Ciampitti says. Surface compaction and crusting both inhibit the exploration of root systems and plant emergence, restricting proper root development, diminishing nutrient accessibility and limiting early plant growth. If soils remain saturated after the plant has emerged, root growth and leaf-area expansion will both take a hit.
If plants don’t develop a good root system, they’ll be susceptible to nutrient losses, he points out. “It all depends on what happens in the next six to eight weeks,” he says.
Wet conditions at planting followed by dry weather can cause “rootless corn syndrome” or floppy corn. In these conditions, the secondary roots of the corn plant may be inhibited, causing the plant to flop over in wind or to wilt.
A potential concern for this year’s corn crop is nitrogen loss. In saturated soils, nitrogen fertilizer can be lost by processes of denitrification, the loss of nitrogen to the atmosphere, mainly as nitrous oxide; or by leaching, the movement of nitrogen beyond the rooting zone. Under wet spring planting conditions, Ciampitti suggests splitting nitrogen applications. Corn may respond to in-season nitrogen applications if a large portion of early-applied nitrogen is lost to these processes.
Soil saturation can cause significant damage and loss to soybean stands. Data collected by K-State Research and Extension indicates that during germination, saturated conditions lasting 48 hours can decrease soybean plant germination by 30 percent to 70 percent depending on the timing of the saturation with nearly twice the yield decrease resulting from durations of 24 hours or less. For plants that have emerged, waterlogged conditions lasting less than two days often cause little to no noticeable yield reduction. As saturated soil conditions persist, the greater are reductions in plant population, plant height, pods per plant, yield, and leaf tissue nitrogen.
How wet is too wet?
Most farmers know what optimum planting conditions are, but if the planter isn’t closing the row, it’s too wet. If mud is sticking to implement tires, large clods are forming and surface soil is visibly compacting, it’s probably safer to try again later.
Of course, every planting season goes more smoothly when all machinery is optimally serviced. Take the mud delay and spend it in the shop getting the planter tuned up. No excuses this year — you’ve got plenty of time.
Shelby Mettlen is a writer, photographer, and daughter of a fifth-generation farmer from central Kansas.