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The Cropwalker - Volume 4 Issue 13

Always read and follow label directions.

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Crop Conditions

Crop conditions - Weather this past week has generally stopped most field operations. Wheat is greening up. Slower than last year but last year we were 10-14 days ahead of average on this date. Still a bit early to check alfalfa for winter survival but nothing to suggest we lost much alfalfa last winter. Time to get these alfalfa fields fertilized. Apply sulphur in this first pass. We count on getting S from soils but it will be a while before soil is warm enough to release S. Corn and soybean planting at least one field of each planted in the Forest area. For the rest a number of growers are considering starting this week. Burndowns still too cold to apply. But not too cold to figure out what to apply. Winter wheat a bit early for second application. But if you are only applying one application now is the time to do it on silt loam and heavier soils. Very little winter kill. Some later planted on heavier wet soils will be ripped up. Probably less than 1% of acres. Essex County based Emma Epp, CCA-ON has commented she is finding wheat at first node (Zadok’s 31). Usually, later areas within the province will be at the same stage 7 to 10 days (if planted on the same date).


Things to do this week

1.     Figure out all spray mixes. Amount of water and amount of each product in a tank mix. Write this down and have ready for anyone to check.

2.    Check forage fields for winter survival and any big stones that need picking.

3.    Gather up last years seed and decide where to plant it. Old seed may lose some vigour so do not plant it first, but make sure it gets planted.

4.    Check all fire extinguishers.

5.    Check SMV signs so that they are secure and visible.

6.    Get planter ready to go

7.     Make arrangements for N on wheat.

Most asked questions this week

1.    How much nitrogen should I apply to my soft red wheat? Answer 135-150 lbs N//ac. Rate depends on fall applied N, manure history, yield expectations.

2.   How much boron should I try in a starter fertilizer for corn. Ans. One half pound actual Boron (not real fond of this idea, would prefer to see it applied broadcast or with your biggest N application up front). If broadcasting suggest you try 1 lb actual boron.

3.    When to start planting spring grain. Answer NOW. Air is cold but fields with sun shining are warming up. One grower took soil temps in winter wheat with a lot of residue and soil temp was 45 F. Time to get going as soon as ground is fit.

Q What is impact of drought out west?

Ans Really too early to tell. But typically, when this happens forages are short in Ontario. We have reduced acres as it is and if there is a drought out west, we will ship forages west. Make sure you have lots of forages for yourself and figure out how to grow some for sale.

Q How should I handle my cereal rye from last year?

1.     Ans If it is a cover crop burn it off as soon as you can. Too often rye gets big quickly and interferes with seeding. Unless you feel comfortable crimping it and seeding that way.

2.    If for forages get 40-46 actual N and 10 lbs S on ASAP.

3.    The yield drag, when you plant corn after cereal rye is still unsolved. It appears that if cereal rye is harvested as forage there is less of a corn yield drag. There does not appear to be a yield drag when soybeans are planted after cereal rye. (Could be a combination of allelopathy/C:N ratio issues.)

Q What forage should I seed if I want to sell it?

Ans. You have to establish your buyer first. Figure out what they want and you can sell rather than growing something and hoping you can sell it.

Nitrogen Volatilization

At this time of year this type of nitrogen loss is greatly overrated. I can find no research that shows any volatilization until soils reach a temperature of 45 F. At temperatures of 45-50 F the loss is very low, if no rain. Various researchers suggest that you need 0.1 to 0.4 inches of rain to move N into the soil to prevent loss. For wheat, the soil is usually not warm enough to cause volatilization. For corn ground, you can apply N, and if you do not get rain in 5-6 days, then work the N in. If you have that many consecutive days without rain, you should have time to work N in, and this working will also kill the small weeds.

Figure 1 - Nitrogen Volatilization by Soil Temperature and Time

Why Earlier Planted Soybeans Yield More

Plants reach V1 earlier resulting in earlier flowering (R1) and a longer growing season. Earlier R1 increases the length of the seed fill period. When plants reach V1 earlier, they accrue more nodes resulting in more potential pods and seeds per unit area. After V1, University of Nebraska research shows that nodes accrue at about 0.27 nodes per day, or, saying it another way, it takes 3.7 days to produce a new node. Internode elongation is dependent on temperature; in contrast, node accrual is time dependent. Earlier planting captures light earlier. Light "harvested" results in an opportunity to achieve greater yield. Early canopy closure reduces weed competition and evaporation from the soil surface and ensures more water availability for crop transpiration.

Fertilizing Forage Fields Without a Soil Test

For fields with mostly grasses consider using 75 lbs/ac urea, plus 100 lbs/ac MAP/DAP/MESZ, 50 lbs/ac Sul-Po-Mag (for sulphur and magnesium) plus 75 lbs./ac 0-0-60. If pushing forages, repeat after first cut. If 50-75% alfalfa MAP/DAP/MESZ 100 lbs/ac, Sul-Po-Mag at 75 lbs./ac and 0-0-60 at 125 lbs./ac. Repeat after first cut if you are pushing the field. I generally add 1 pound of boron after first cut. (It is better if you have a soil test.) If you farm in an area with high magnesium levels, replace the K-Mag or Sul-Po-Mag with Ammonium Sulphate.

Figure 2 - Hay Fertilizer Blends on Fields without Soil Tests

Have an article you want to read again?

We are starting to index all our articles. Haven’t figured out best way for you to access them. In the meantime, if you want an index e-mail me and I will forward it. patricklynch872@gmail.com

Partial index looks like this

Figure 3 - Partial Index of Cropwalker Newsletters

A reminder on Soil Tests…

Elston Solberg of Earth, Dirt, Soil said in a recent meeting that you need to remember that Phosphorus and Potassium soil tests results (and their respective extractants) are used to show how responsive a soil is to applied fertilizer, not what is available…They are an index, not an absolute value (like nitrate nitrogen).

Dan Quinn - Evaluation of Corn Management Practices following Rye Cover Crop

If you are planning on doing this, the summary of Dan’s thesis is… terminate the cover crop early (14 to 21 days prior to planting), use split N application, increase corn seeding rates; by doing this limits the potential for N stress, plant stand reductions and yield losses following a rye cover crop. Dan did not see a yield increase from in-furrow fertilizer, fungicide applications, or above optimal N rates. - Dan Quinn – Ph.D. Thesis – University of Kentucky

Dan Quinn - Ph.D Thesis

Corn following Rye Cover Crop

Ontario Canola Grower’s Yield Challenge

Fertility programs for the top 4 canola growers that won the 2020 Canola Yield Challenge. Bottom line if you have a massively good-looking winter canola crop… DO NOT SHORT the N!!! If you haven't already applied some N, you should be.

You can see the full presentation at; https://www.youtube.com/watch?v=9l5quIVdJZE&t=0s

Figure 4 - Ontario Canola Grower Challenge Winners and Fertility Programs

Growing Degree Days Required by Wheat Plant Stage

Figure 5- GDD by Wheat Plant Growth Stage

Source: https://cals.arizona.edu/crop/presentations/2012/ShawnaLoper.pdf

Wheat Stage Compared to Other Years? – estimated date for 1st node?

Since we need about 280-300 GDD to get to stem elongation, how many days would that take if we are already well into tillering? If the average temperature is 10 C per day? less than 28 days. If the average is 15 C, then less than 20 days. 20 C? less than 15 days. As far as I can see the forecast should have about 10 C per day for the foreseeable future, on very early planted wheat I think it would be realistic to be at 1st node well before the end of April, especially in warmer parts of the province. (already the case on some fields in Essex)

Figure 6 - Base Zero GDD for Walkerton, ON for next 13 days

Use the rate factor function!

When designing variable rate seed rate scripts for corn (and to a lesser extend soybeans), use the rate factor function if you decided to put a different hybrid than what was slated for that field. Not all hybrids perform optimally 32,000 or 36,000 or 40,000 plants. Think it does not matter? When you are pushing the envelope on population to the point the plants just starting to reach its breaking point, there is a difference between 32 and 36,000 plants/ac.

I want to no-till alfalfa – maximum seed safe rate of phosphorus?

Likely 20-40 lbs/ac of MAP, depending on soil type and soil moisture at time of planting and your tolerance for stand loss. Assuming 7.5” rows.

Figure 7 - Seed safe rates for seed placed MAP with Alfalfa

What does Hollow Stem mean?

Last week we had mentioned hollow stem in wheat. Hollow stem is a term used in the US Great Plains used to describe stem elongation.

Where to spend your first fertilizer dollar – Established Alfalfa

Yes, I am going to get heck writing this without having a soil test and making notes, so be it. First $10 I would spend would be on Sulphur. The next $20 would be on fall applied potash. The next $10 would be on spring applied boron. Why no dollars spend on phosphorus? Even on a low testing soil there is not as big a response to those other nutrients, but after taking care of some of those other nutrients, then I might consider applying phosphorus on established alfalfa.

Where to spend your first fertilizer dollar – New Seeding Alfalfa

Different answers here… First $30 I would spend would be on phosphorus. You can’t turn back time if you do not have phosphorus close to the roots for early growth. Once that door is closed, it’s too late. Almost all other nutrients can be surface applied after planting and make up somewhat for it. Less so with phosphorus. The next $10 would be on spring applied sulphur. The next $30 would be on fall applied potash. The last $10 would be on spring applied boron. If you have a low phosphorus and potassium testing soil, spend the money first on phosphorus at planting when it comes to new seeding. You can correct the potassium issue later in the season if needed.

Where to spend your first fertilizer dollar – Grass Hay

Last one… assuming no manure applied. First $30 I would spend would be on Nitrogen. Before the grass gets up much on every cut. The next $7-10 would be on sulphur with the nitrogen. The next $30-50 would be on fall applied potash. The last $20 would be on phosphorus. Grass will respond to phosphorus, but the other nutrients are more critical in my opinion in an established forage stand (only case would be extremely low phosphorus levels.

"Time keeps on ticking, ticking, ticking into the future."

- Steve Miller Band