The latest findings in Fred Below's 25-year research quest to achieve a consistent 300-bu. corn crop focus on a combo of precision fertility and racehorse hybrids."We also have developed a way to identify these so-called racehorse hybrids that respond to high-yield management," says the University of Illinois plant physiologist. How to move your corn yields towards 300 bu., according to Below.


Leave no plants behind

RTK guidance brings more precise fertility needed to position specific nutrients in cornrows. Below bands the whole supply of P, sulfur (S), zinc (Zn) and some N 4-6 in. deep. He then plants corn directly over top the banded nutrients.

"Banded fertility gives corn plants nutrients they need for high yields right from the start. Roots do not have to travel to find phosphorus and micronutrients, which are immobile in the soil," he says. "I believe you must feed the plant, not the soil. You have to focus on nutrients that are highly allocated to the grain – including N, P, S and Zn – since grain makes corn yield."

Below's trials in 2011 showed a 14-17 bu./acre increase in yield (versus standard practice – see table) with placed fertility, even in soils with medium to high levels of P. Soil tests have worked well to determine plant nutrient needs for the last 50 years, but he speculates whether soil tests are calibrated high enough to feed the higher plant density and grain requirements for 300-bu. corn. Below believes you have to supplement soil tests with application and fertilizer technologies that supply those nutrients in the right amount at the right time to reach 300 bu.

"We have confirmed that with higher plant densities, placed fertility is more effective, sustainable and cost-efficient," he says. "We believe in the concept of 'no plant left behind,' and we see fewer early stragglers with better placed fertility, since yield potential begins as soon as the seed is planted. All plants must grow rapidly right from the start to achieve high yields."