Planters are being repaired, upgraded, and modified, as well as torn apart and reassembled in machine sheds throughout the Corn Belt. New gizmos are being attached, electronics added, and soon planters will be pulled out into the sunlight with new paint, new grease, and scrubbed spic and span. They will be ready for work, burying seed corn at whatever rate per acre you want. And by the way, what rate will that be?
Purdue cornmeister Bob Nielsen says, “Of all the many agronomic management decisions a corn grower makes each year, one would think that choice of seeding rate would be among the simplest. Yet, this topic continues to garner a lot of attention in coffee shops, Internet chat rooms, the farm press, and in crop seminars. So, apparently this decision is not clear-cut.”
Hardly. About every farmer has a different seeding rate, but every farm is different. And for that matter every field is different, and in many fields there is a significant agronomic difference just from here to there.
Interviewing a young farmer for my morning television program earlier this week, he planned to make a number of changes in hybrids as he moved across a field. Another young farmer scheduled for the program later this week puts several different varieties in his planter at the same time. But seeding rates have been staying the same. Nielsen says, “Identifying the optimum seeding rate for corn is difficult because it involves a delicate balancing act among the various yield components that multiply together to determine grain yield:
Yield = [Plants per acre] x [Ears per plant] x [Kernels per ear] x [Weight per kernel].”
In a year like 2012, many farmers who had lower plant populations than their neighbors actually had higher yields because of the shortage of soil moisture. With prospects for wet soils in the eastern Corn Belt and dry soils in the western Cornbelt, the National Agricultural Statistics Services field surveyors will have a challenging time coming up with an average plant population for 2013. But your challenge is determining the plants per acre rate you want, because the 2013 planting season will hit when the baseball season starts, and the pitchers and catchers are already at training camp.
When reading the farm magazines that have been piling up, the winners of the National Corn Growers Yield Contest told you their populations were 40 thousand or more per acre or some very expensive number. 40 thousand would be $200 per acre, just for seed. Nielsen says, “Crop input suppliers sometimes recommend to their customers that seeding rates should be in the neighborhood of 35,000 or higher to maximize yield and furthermore show yield response data that appear to support those recommendations. Results of some university research also tend to favor these higher seeding rates.”