Winning with Winter Wheat

Thursday, August 24, 2023

Start with Soybean Harvest, Then Timely Wheat Planting with a Starter Fertilizer

By Paul Hermans

Everywhere you look there is a lot of data that talks about the benefits of crop rotation. Adding winter wheat to the mix is a no-brainer.

Winter wheat helps spread workload, improves soil health, and provides cover crop benefits over the winter. Economically, it increases the yield potential of corn and soybeans in the rotation.

If you want to win with wheat, what are some of the tips to gain higher yields? There are three answers: 1) Planting Date, 2) Fertility and 3) Variety Selection.

To achieve success in all three, one must have the end in mind and start with a strong two-year cropping plan. Having a clearly defined plan will lead to bigger gains in wheat.

Planting Date

Most growers will plant soybeans and then rotate into winter wheat.

Soybean variety selection is key to ensure planting dates for winter wheat are as early as possible.

Selecting a soybean variety that has a relative maturity four to five days earlier than your standard variety will gain harvest days to improve your winter wheat planting date without sacrificing soybean yields. I say this because soybean breeding has improved yield gains in the earlier maturity zones.

For my trading area we grow a 0.9 to 1.2 maturity soybean. Going down to a 0.6 relative maturity soybean is recommended for fields that will be cropped in winter wheat. Planning soybean fields and variety selection for 2024 starts this winter.

Added to that, an early soybean planting date will ensure timely harvest. Beyond the middle of May, for every three days you are delayed in soybean planting, expect a one-day delay at soybean harvest time.

Other avenues are being researched into improving soybean harvest times. Research conducted in the United States has shown that utilizing a soybean pre-harvest desiccation improves harvestability timing and yields. In one study soybeans were desiccated at the R6.5 stage.

Ten days after application there was a notable difference in soybean foliage stay-green and in weed load.

Harvest was earlier for the desiccated soybeans, had higher yield (2.4 bushels) and less dockage.

This could be an option for growers who want to improve winter wheat planting dates and have cleaner weed-free fields at planting time.

Higher soybean yields may be gained by planting "normal" soybean maturities for a given zone rather than decreasing maturities by three to four days of relative maturity.

Big gains occur with earlier planting dates. Ontario data would suggest a 1.1 bushel per acre per day decrease in yield for each day in delay planting beyond the optimum planting date for your region.

For optimum planting dates for your area check out OMAFRA's publication Optimum Planting Dates for Winter Wheat in Ontario – Field Crop News.

Let us not forget about planting conditions! Having a uniform soil-to-seed contact in the seed bed and consistent planting depth will lead to better wheat stands and higher yields.

Repeatedly poor wheat stands are a result of improper soybean residue-spreading at harvest time.

Setting up the combine for proper chaff-spreading is critical. Explore options from manufacturers to improve chaff-spreading across the entire header width.

Winter wheat should be planted at a uniform depth of one inch (2.5 cm). Just like corn the yield penalty for planting too shallow is far greater than too deep. So, err on the deeper side.

This will also ensure proper crown root development and avoid potential frost-heaving throughout the winter before spring green up occurs.

Fertility

Starting the wheat crop off right each fall starts with a sound starter fertilizer program.

OMAFRA data would suggest on average a five to seven-bushel yield response to winter wheat that had starter applied. This was strikingly evident this year when I was scouting a variety plot that we planted last fall.

The grower had a custom planter drill in his wheat. For the field there was starter applied with the seed at planting. However, to ensure consistent seeding rates for the wheat variety plot, starter fertilizer was not applied.

I went early this spring to look at varietal differences and was astounded by the growth differences in the part of the field with applied starter versus the part of the field that did not (Figure 1).

The wheat with starter fertilizer was applied with 100 lbs. to the acre of 11-52-0.

Drone and subsequent NDVI scores showed a substantial difference in plant health across the field (Figure 2).

Notable differences in plant height from the fall-applied MAP to the none-applied were observed as well. These simple measurements further proved that starter fertilizer is key to a sound winter wheat start.

Stay tuned for more fall yield data on this location. Our plan is to weigh the strips to see the yield differences.

Variety Selection

The starting point to great wheat yields is variety selection. Taking advantage of higher yielding new wheat varieties is necessary for higher gains. Since the mid-1980s, yields have almost doubled in Ontario as a result of new varieties.

Emphasis on variety selection should focus on key trait scores that have above-average scores for winter hardiness, lodging, stripe rust, Fusarium head blight and powdery mildew.

Other agronomic scores may be more important for your given area but, in general, these capture the heavy hitters when looking at variety traits.

To summarize, winning with wheat starts with soybean planting and harvest, followed by timely wheat planting with a starter fertilizer.

Variety selection with new varieties will lead to big wheat yields.

Here's hoping your bean harvest is bountiful and timely so your wheat planting process leads to a bumper wheat crop in 2024! BF