Finding the Right Row Spacing for Your Fields
Row spacing is a planting factor that can help you optimize yields and profitability. For decades, researchers have claimed narrow rows as the next big thing in higher yields, so we wondered what farmers in FBN are actually choosing for row spacing in their fields.
As equipment and practices have evolved over time, agronomists have studied the benefits of adjusting row spacing. Some have found that narrower row spacing offers plants even more access to light, water and nutrients and leads to faster canopy closure, meaning less lost solar energy and reduced moisture evaporation. Eventually, 30 inches became the row width of choice for many farmers and a standard width for headers and planters alike.
As you can see in this data, from 2014-2018 farmers in Illinois have pretty consistently stuck with 30-inch rows - at a rate of 95 percent. South Dakota shows a similar trend, with only 14 percent of acres planted to narrower rows.
Studies have shown yield advantages in moving from 40- to 30-inch rows, but the move from 30- to 20-inch seems to be less conclusive. For much of the country, results vary year over year and don’t tell a consistent story. This could be caused by the multiple factors that play into how changes in row spacing impact each individual farm.
The data tells a different story in the northern Corn Belt, particularly in North Dakota, where 22-inch rows have been steadily gaining in popularity. This could be because the narrower row spacing allows for some growers who plant corn, soybeans and sugarbeets to keep the same planter set up across three crops, reducing the costs associated with equipment change over. It could also be because the shorter growing season farther north leads to the selection of earlier maturing hybrids, which have less leaf area to intercept sunlight, according to research from the University of Minnesota2.
Whatever the reason may be for each individual operation, farmers in Minnesota and North Dakota have been more willing to move to narrower corn row spacings, with 40 percent of acres making the leap in Minnesota and 44 percent in North Dakota.
Which way should you go on row spacing?
The overall profitability for your operation should be the main consideration when deciding whether or not to change your row spacing plan. While there is data indicating that narrower corn rows can achieve higher yields in certain circumstances, it’s unclear if this yield advantage outweighs the other costs of changing row spacing, such as equipment and labor.
Analyzing yield data from different row spacings, along with other planting factors, such as soil temperature, seeding rate and planting date can provide a more complete look at what planting practices have been successful for farmers in your area.
The planting data above is based on real-world farming data. Information on seed hybrids has been aggregated across millions of acres of data from 2018. Maturity range includes 108-114 days in Illinois; 93-106 days in Minnesota; 83-98 days in North Dakota; and 93-105 in South Dakota.
1. https://crops.extension.iastate.edu/corn/production/management/planting/row.html 2. https://extension.umn.edu/corn-planting/narrow-row-corn-production-minnesota 3. http://www.dakotafarmer.com/story-case-narrow-row-corn-north-9-121047