GROWING CORN
In the New Millennium
By Greg Stewart, OMAFRA Specialist

My vision into the future extends to supper time most days, although the clarity of that vision depends somewhat on how much I had for lunch. That said, this article will take a look at some aspects of growing corn in the years ahead.

We close out the last decade with two relatively good years for growing corn in Ontario, with record or near-record yields recorded in many parts of the province (provided you received somewhere near normal rainfall). A new world record for on-farm corn grain yield was established in 1999 in Manchester County, Iowa with a yield of 394 bu/ac (at that yield, a combine with an eight-row head and a 200-bushel grain tank can go 1,100 feet before needing to dump!). Average corn yields are a long way from this type of record but have been increasing at a rate of approximately 1.5 per cent per year. What is the future for corn yield potential?

Dr. Thys Tollenaar of the University of Guelph’s Department of Plant Agriculture would emphatically say not to worry about yield potential; it’s already plenty high at some 500 bu/ac. Tollenaar says what we really need to understand is how to capitalize more efficiently on the corn plant’s already massive potential. Tollenaar believes much of the yield gain we have experienced in the past 40 years comes not as result of increasing the corn plant’s yield potential, but in increasing its ability to withstand environmental stresses. That allows it to deliver an ever-increasing percentage of its yield potential to the combine bin.

Seed companies have been the driving force in selecting for these high yielding, stress-resistant hybrids. They’ve tested countless thousands of lines over the years and choose only those lines with high yield and yield stability over numerous locations, years and stresses. With biotechnology firmly in place, will this brute-force approach to plant breeding give way to genetic engineering? Will actual yield gains stagnate because seed companies invest so many of their research dollars into developing corn hybrids with unique traits? The reality is that biotechnology will most likely provide us with new traits and uses for corn, and help unlock its yield potential as well. At the current rate of genetic gain we should have average yields in Ontario of 140 bu/ac in 2010; however we will be selecting from a list of hybrids where yield will only be one component of the crop’s potential value.

Corn producers can view their production practices from a stress perspective as well. Cropping techniques should minimize stress on the crop for it to achieve greater yields. It appears that the big challenge is going to be the same as it was in the last millennium: spend as little money as possible to eliminate the maximum amount of stress. Corn-yield trend researchers have implied that when long-term experiments have not shown steadily increasing yields, it may be a result of deteriorating soil quality. Certainly the new millennium should bring increasing pressures on corn producers to optimize soil productivity and environmental stewardship.

On the soil front, I have been convinced for some time that there must be one or more compounds that can be placed on the corn seed to guarantee better seed-to-soil contact, improved water uptake and more uniform emergence in a wide variety of soil conditions. For instance, there are starch compounds that have amazing capacities to absorb water. The future will deliver a planting additive that holds enough moisture close to the corn seed to guarantee uniform emergence in shallow plantings, imperfect seedbeds or rainless springs. Dr. Tony Vyn and I received funding from OCPA and CanAdapt to look at this approach and some progress has been made. I am convinced that in the future we will see more non-agricultural innovations brought to farming.

Another soil issue will arise from the concern over the earth’s atmosphere. Greenhouse gas concerns will continue growing and agricultural soils may be given credit for their ability to sequester carbon from the air, if managed under a no-till regime. The research data from Eastern Canada seems to give a rather limited endorsement for no-till and the total amount of carbon we might expect to sequester from the atmosphere as a result of eliminating tillage. It appears that good crop rotations may be equally effective as no-till in sequestering carbon in the soil. The new millennium will bring new opportunities for cropping systems and research efforts which promote reducing tillage, enhancing crop rotations, utilizing cover crops and managing soil resources. Seed coatings and seed treatments will offer new cropping system opportunities such as a polymer coating on red clover (similar to the one used on fall-seeded spring canola), so that you plant it in the fall with winter wheat. The coating prevents the clover from germinating until spring when it comes up much more uniformly even with significantly reduced seeding rates.

Just as we may have increased interest in what we can add to our soils we will be under increasing scrutiny over what leaves our soils. More efficient use of nutrients will be required both as a result of economic realities and public policy. The progress towards more efficient nitrogen management systems and adoption of new techniques by producers has been slow here and in the U.S. Significant improvement will lie ahead as the industry uses a range of tools, from soil testing to site-specific management to remote sensing, in order to maximize nutrient-use efficiency. Adaptability to both new regulations and new technologies will be essential for success. Producers who build a comprehensive network of information sources, advisors and collaborators will be best positioned to move forward in the coming years.

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