One thing Scott Ebelhar and Dennis Brown were high on at Beck's Field Day last week was splitting the nitrogen application for corn. Beck's includes a nitrogen demonstration plot as part of their practical farm research demonstrations so that Bob Nielsen, the Purdue University Extension corn specialist, can add it to the data he' collecting on nitrogen application rates and yields across Indiana. Nielsen and Jim Camberato, also a Purdue Extension specialist, began three years ago a project to update nitrogen recommendations in Indiana based on actual work in the field.
One of the combinations included in the trial at Beck's this year was N applied at planting in a 2 inch by 2 inch placement, followed by the rest of the nitrogen sidedressed later after the corn was up. While some sources are reporting N shortages even where farmers sidedressed this year, the Beck' plot appears to be holding well. The combine will tell the tale of the tape when the plots are harvested this fall.
"We're basing our preference to put some N down at planting and then follow with sidedressing the rest of the N later on work that's been done showing how hybrids use nitrogen during the season," Ebelhar says. He and Brown displayed a graphic that clearly indicated most of the uptake occurs as corn reaches the grand growth phase, usually after the growing point emerges from underground.
"It only stands to reason that having enough N there when the growth spurt kicks in will benefit the plant," Ebelhar says. "With fall applications, even with N-serve, enough loss tends to have occurred most years that there may or may not be enough N left to power the growth phase and carry the crop through ear development.
Many planters no longer have fertilizer boxes for dry fertilizer or liquid tanks for starter on them. Particularly in no-till, agronomists such as Barry Fisher, state agronomist with the Natural Resources Conservation Service, believes starter, particularly nitrogen is needed at planting time. Otherwise, if wet weather delays sidedressing, plants may approach the grand growth phase where N use suddenly shoots up and not have enough N reserves to draw upon in the soil. It's particularly important in no-till because the seedlings often get off to a slower start, since soils are somewhat cooler and wetter, particularly in flat, naturally wet fields. Adding nitrogen and making it available to plant roots helps offset those problems.
Becks will harvest their plot later this fall, and add the data to Nielsen's summary he is collecting. Several farmer trials will also be included in that set of data.