Wheat row spacing requires narrow focus: grower

New way of working | Agronomist Phil Needham says Western Canadian farmers should rethink wide row spacing

Western Canadian farmers and the folks who build their seeding equipment seem to have a love affair with wide row spacing, but is it a healthy relationship?

Phil Needham says not.

Needham feels the love-in is based more on emotion than rational thought.

He said it might not be healthy at all, especially for the third member of the triangle: the crops.

“In Western Europe, where they grow those mammoth wheat crops, the row spacing on their seeding equipment is four inches, 4.5 inch or five inches,” said Needham.

Research in Western Canada hasn’t always shared his opinion.

He said there are two main reasons for going narrower:

  • Wheat plants have better access to all the available sunlight, moisture and nutrients if there are no bare gaps on the surface.
  • Wider row spacing concentrates more seeds and more fertilizer into a tighter area, resulting in seedling damage, while narrow spacing spreads things out within the row so that farmers can put down more seed-placed fertilizer and the plants aren’t crowded.

Needham said wheat growers can take a page from corn research that has proven growers get better corn yields if the plants have more shoulder room within the row.

As an example, he said a grower can put down the same seed-applied fertilizer rate and the same plant population in two fields. One field has six-inch spacing. The other has 12-inch spacing.

Plants in the field with 12-inch row spacings are crowded and suffer from the impact of nearby fertilizer.

Plants in the field with six-inch spacing have more room and better access to sun, moisture and nutrients, because plants in the rows are more spread out into the spacings. Fertilizer is less concentrated, so it does not cause seedling injury.

“Almost all the row spacing research I’ve conducted concluded that 7.5 inch (spacings) out-yield wider (spacings),” he said.

“There have been a few trials in high-stress environments that resulted in the same yield, but never a yield advantage for wide rows.”

He said that wide row drills and seeders are slightly cheaper to buy and operate, but added the higher yield created by the narrow spaces between crop rows should pay the difference between the two designs.

Needham said wheat seed singulation trials have been conducted in North America with the Horsch Anderson Maestro corn planter. Preliminary results are positive.

  • Paul Overby

    Way back in the mid- 1990′s Dr. Jim Helm from NDSU was discussing a study at the University of Manitoba that showed wheat plants prefer a 4 inch diameter zone for optimal performance. Planter spacing is being driven by sales — “keep costs down while going to a wider seeder to cover more acres” — rather than wheat performance. I have been disappointed in shopping for a new airseeder because they are all coming in 10 and 12 in widths. I am sticking with my 7.5″ spacing for now.