This year’s spring wheat and corn acres are behind schedule, according to the most recent statistics from the USDA-NASS.
The agency reports only 13 percent of spring wheat and 3 percent of corn planted in North Dakota so far. More usually spring wheat would be at 37 percent at this time of year, and corn 23 percent.
The optimal window for planting spring wheat is the last week of April for those south of Highway 2 to I-94 and the first week of May north of Highway 2 to the Canadian border. For corn, it’s the first two weeks of May.
Yield charts do show a 1 percent reduction in potential for each day planting is delayed beyond the optimal range, but a variety of factors play into final yield statistics, according to NDSU researchers, and it is not beneficial to rush planting in soil that is too wet or, for corn, too wet and too cold.
Among the most critical factor for good yields is establishing a uniform stand, Extension Agronomist Professor Dr. Joel Ransom said. Tilling while the soil is wet results in a poor seed bed and a poor stand, while planting in wet soil leads to sidewall compaction, which affects establishment as well as later growth and development.
Ransom said last year’s wheat and corn were also planted late. Spring wheat didn’t reach 50 percent until after May 14 and corn until after May 21.
Despite that, corn had its second highest yielding year ever and spring wheat was also among the highest on record, at 49 bushels per acre.
“It’s not like we are falling off a cliff as far as yield is concerned,” Franzen said. “Even though we are kind of beyond the optimum planting dates for wheat.”
Late-planted wheat means kernels will be maturing and filling when the temperatures are warmer, which depresses yields.
“Even though we are losing some yield by waiting we still want to establish a crop that’s going to have high potential for yield,” Ransom said. “So we don’t want to get in such a rush that we end up with half a stand or variability in emergence.”
Farmers who are planting late can increase the seeding rate to help keep yields high. The recommended rate during the optimal planting time is about 1.4 million seeds. That can be increased by 1 percent for each day of delay beyond the optimal window, up to 1.6 million seeds.
Extension service gives the recommendation in number of seeds, rather than weight, because seed lots can vary substantially in kernel weights.
For corn, Ransom said next week looks better than this one for planting corn.
“Corn doesn’t really start to germinate until soils warm to 50 degrees,” he said. “And there is a risk of planting into cold soils, then getting a cold rain shortly thereafter, which can result in chilling injuries.”
As producers get closer to May 20, they should consider planting an earlier maturing hybrid.
The other potential issue facing producers is a potential fertilizer crunch.
With cool season and warm season crops likely to go in the ground in the same two-week window, that shortens the time frame for fertilizer application.
Spot shortages of nitrogen fertilizer and lack of equipment make it difficult, if not impossible, to get everything fertilized in a two-week window.
Nitrogen can be applied after planting as a side dressing for corn and other row crops, NDSU Extension soil specialist Dr. David Franzen says. It can be top-dressed for wheat and solid-seeded crops.
In that case, an NBTP inhibitor should be applied as well.
“That stops the enzyme that splits the urea to ammonia and carbon dioxide for a week and a half,” Franzen said. “So having that on is really important if you are going over the top.”
The situation with phosphorous is a little bit different. Certain crops experience a substantial yield loss without it.
Wheat and other small grains are among those, as well as canola.
“It’s very important that they use a phosphate starter with the seed for those crops,” Franzen said. “I don’t think (phosphorous) is going to be short. They use that at a lower rate than nitrogen, so I think that’s going to be OK.”
In the case of phosphate, even if the producer has to delay planting a day or two for the application, it’s worthwhile, Franzen believes.
“It could make a 20 percent difference in wheat yields,” he said. “Nitrogen is more forgiving.”