Evaluating the Agronomic Building Blocks of the 2012 Corn Crop

How many of you as you have sat in the combine driver’s seat controlling the speed and flow of the corn you are harvesting have thought about the specific segments that held yield at bay for you this year? Yes for sure we had a nasty, hot and intensely dry summer all across the Corn Belt from Indiana to the Front Range of the Rockies. Just saying that, climate conditions limited nearly everyone’s yield potentials to tweak that 250 bu/acre+. The heat was overwhelming, the lack of rain just about cooked many, many corn fields and enduring dry about broke our backs.
We, the Orthman Farms farm manager and I were weighing the weed control efforts and fertilization program when having a break as we loaded a semi-trailer couple of days ago and were asking what would have been the step in our management plan that could have helped out our corn yields. We are still very pleased with 196 – 230 bu/acre irrigated corn yields don’t get me wrong – but as we looked at the ears of corn rolling into the combine they are filled out to the very end, 16 to 18 rows and 33-37 kernels in length at a final stand of 29900 – 30950 plants per acre. Our corn is weighing in at 59 and 60lbs per bushel. We are scratching our heads with that as the dominance of the ears, but we see plants that are in the mix at 14 – 16 rows and 25 -28 kernels in length. Same hybrid and variety and the stand came up even with our strip-till methods of seedbed preparation and fertilization, and this variation just sort of boggles our minds. Our irrigation was taking care of the needs even at 108°F., so what gave us such wide variation was our question.
As some of you know at the Orthman Research Farm this year we carried out a late foliar application of slow release N and a dose of micronutrients and humic acid to see what the effects would be. Last year we did much the same when the anthers just started turning brown after pollination and the 18 varieties we carried this out on, showed a boost in yield from 2 to 11 bu/acre compared to where we did not apply. This year we believe it is much the same but waiting on the actual numbers? We also applied FBSciences Carbon Boost-S® product and saw a stimulated response of about 16 bu/acre over the control in our 8.0-8.2 pH soils. We did not apply the Carbon Boost over all our acres which could well be a big part in tapping the 220+ yield rung on the ladder. You can see there has to be a set of keys that when linked together we should peak yields and feel confident in maintaining those yields for years to come. But I know that above 100°F. conditions of stress in rain-fed and irrigated corn were incredible. We had a thick layer of remaining corn residue between the rows to help insulate from the heat that hammered us in June and decrease evaporation losses. We were judicious to spray with solid choices for weed control, weeds were well controlled even those late season nuisances like Black Nightshade and grasses.
Similar to the same head scratching you have been going through? We planted hybrids we felt were going to withstand heat of July and August, but from June 3rd to September 1st – yikes!! We even dug root pits and determined our corn rooted down to depths of 6.5 to 7 feet and filled the upper 36 inches of the soil profile. The “Heat Units” were 350 days above numerous years prior and should have had some marvelous yields. We did not scrimp much on N-P-K-Zn and S that’s for sure. Before the head scratching goes too deep and draws blood, the climatic conditions of low humidity levels, nights that rarely cooled down into the 60’s, hot winds and steady temperatures above 95°F. all had to have caused more internal stress on corn from tapping 250+ than we have considered in the last 6 years. Conditions were perplexing to say the least. As an agronomist I do believe we can place numerous management practices in play to help alleviate the stresses of heat and drought, but for 60+ days – wow we need help from the skies.
We invite any of you to wade into this discussion and interact as to what steps you thought was helpful to you maintaining a sustained high yield in corn or soybeans this year.

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