Narrow Row Corn: Prescription for Profit?

Corn • 

When planting corn in narrow rows, farmers may ask what yield increase they can expect at harvest. However, they should ask: How will narrow row corn add to my bottom line?

Some agronomists say that to reach the next level of yield potential, plant populations will need to increase. Increasing plant populations above 38,000 plants per acre in a 30” row places plants so close together in the row that they compete for nutrients and sunlight. This competition actually reduces the potential for grain yield. By planting in narrower rows, the distance between plants in the row increases, which provides more equal amounts of nutrients and sunlight to each plant.

Results vary by climate zone, soil type, growing conditions, and plant population. However, studies by Dr. Bob Nelson, Purdue, suggest yield may not increase drastically, just 2.7% on average in central U.S. corn belt states. Some 15” growers have claimed as much as a 12% increase.

The question remains, “What is right for my operation?” The answer quite often is tied to what equipment is currently owned and what would have to be purchased to make a transition to narrow rows. Of course, the first consideration is the planter. Is it limited to 30” rows or could it be modified? If not, what is the cost of a planter configured for narrower rows? Have a “splitter” planter? If so, you can simply add corn seed meters to every other row unit and plant corn on 15” rows.

Then, the question turns to managing nitrogen and weed control applications. Conventional systems may need to be reconsidered depending on row spacing selected and tire sizes. Alternative options would be total preemerge programs, tram lines, and aerial applications. Some 15” growers have reported that by driving sprayers at an angle to the rows, very little damage occurs.

Next to consider is harvest equipment. In the past, very few options existed as far as headers to harvest narrow rows. Today, Geringhoff offers corn heads to harvest 15”, 20” and 22” narrow configurations.




So, it’s not all about yield results and how far apart to plant corn.

It could depend on climate and tough growing conditions, too.

In the northern corn belt, in states such as Minnesota, a shorter growing season could mean narrow rows show a benefit at harvest time. Yields have been tested at a seven-to-eight percent increase by Extension educators there. That’s substantial, of course, although it’s not always consistent.

The University of Minnesota Extension educators agree that planting in narrow rows results in more equidistant spacing of plants. Which in theory helps minimize competition among plants for water, nutrients, and light. It may not demonstrate a difference in good conditions, studies show. However, in tough growing conditions, narrow-row yield is expected to be better.

So, yield has to be thought about not so much as more, but also in the context of what risk may result in wider rows when conditions are tough.

Lucas Richard of L.F.R. Farms & Greenhouse in Newton, N.C., says for him, his move to 20” narrow rows was based on soil – he farms in a clay sandy loam there. Narrow rows mean his plants are spread about the field, better helping them canopy quicker, controlling weeds, and retaining soil moisture.




“The clay doesn’t drain like sand. It will hold its moisture well but only if the crop provides a plant canopy to shield it from the sun,” he says. “If you can canopy it quicker from the sun, you can keep the moisture in the clay instead of baking it out of the soil.”

In sum, ask about more than yield. Consider the overall bottom line. Narrow rows are about accommodating your situation based on growing conditions overall, long-term crop production efficiency, and using the right equipment to do the job.

Ultimately, profitability is the driving force. Invest in doing some on-farm research of your own this year to determine what works best for your situation. Your future depends on it!

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