When you have to change corn planters and/or combine headers, consider changing to narrower rows, advises Rich Larson, an agronomist at Peterson Farms Seeds, Harwood, N.D.
In one of his latest blogs, Peterson writes:
Even at $3.00 corn, a 1,000 acre corn farm could see a $20,000-$40,000 income bump. As you will see, changing from 30" rows to 20" or 22" rows has a positive effect on higher yields in North Dakota and Minnesota.
Corn row width has been the subject of extensive research in Iowa and Illinois for more than two decades. In those area, row widths of less than 30 inches haven't shown consistent advantages. For a while, we assumed the same was true "up north", but we were mistaken.
Long-term research from the northern Corn Belt shows that corn prefers narrower rows by consistently producing higher yields at the same population. Most of the corn in our region is still planted in 30 inch rows, but is trending toward 20 inches or 22 inches rows among growers who want to push the envelope on yield. Our longer days of sunlight are the generally accepted reason given for the positive yield response.
A University of Minnesota study shows that growers in northwestern Minnesota increased yield by an average of 16% when corn was planted in 19- to 25-inch rows versus 26- to 32-inch rows. This was reported in the FINBIN Farm Financial Database over an average of 33 and 19 fields, respectively.
A bit farther south, growers in west-central Minnesota showed an average yield increase of 5% when planting corn in 19- to 25-inch rows versus 26- to 32-inch rows. (Source: FINBIN Farm Financial Database on an average of 46 and 180 fields, respectively.)
Data collected in southern MN did not show yield advantages with narrow rows, but the advantages climb consistently as you travel north.
NDSU hasn't studied row width extensively enough to evaluate, but data for Minnesota and Wisconsin is consistent with data and feedback from North Dakota growers who have made the move to narrow rows.
Other advantages come into play with narrow rows, some of which attribute to increased yield. If you use the same planter for both corn and soybeans, the narrower row width for soybeans may not boost yields, but the quicker canopy of both crops reduces weed competition. In corn, increased light interception by individual plants and less crowding of plants are key advantages. This is why you can push population a little more in narrow rows, pushing yields even higher with added fertility.
Consider this plan for your best ground: Narrow rows; 35,000-36,000 plants per acre and added fertility for the higher population. Be sure to include more than just nitrogen and phosphorus. High populations can cause decreased stalk diameter, so potash should be part of the fertility program, too.