July 10, 2014

Agronomist Notes

Hello Reader

Fungicide timing is over. Phew! Leaf diseases have remained low in the canopy but the humid weather has kept canopies wet into late morning. Insect pressure has been low although few areas are experiencing high counts of cabbage seedpod weevil in canola. Crops are handling the 30C weather so far but a few weeks of this heat will take the edge off of yields.

We’re gearing up for our field day next Tuesday at 1pm. We have long-time controlled traffic farmer and good friend Robert Ruwoldt as our guest, so if you have questions about CTF, this is your chance to have them answered!

In this week’s newsletter, we’ll briefly discuss the top two yield limiting factors in Prairie crop production. Next, we’ll look at some recent water infiltration tests comparing random traffic to controlled traffic farming on our farm. Long-time no-tiller and cover crop guru Blake Vince gave me a great reminder on the impacts of fungicides on residue breakdown and what that means in our system. Last, wheat crops starting to head out I’ve provided some info on scouting and control of wheat midge. We’ll finish with technical grain market news.

Have a great week.

Pictured above: Our bolting canola 5 days ago, ready to rise above the 16-inch tall wheat stubble, near Morrin, AB.

Crop Staging

(Calgary to Drumheller to Three Hills)
Seeded May 1-7 May 8-15 May 15-22
Wheat flowering boot stage flag leaf
Canola 50% bloom 30% bloom 5% bloom
Barley Heading boot stage flag leaf
Peas 10% bloom 1% bloom 14th node

Steve's tips and tricks of the week

Follow me on Twitter for in-season updates @BeyondAgronomy

Watch for uneven head emergence. Now is a great time to locate uneven shanks on drills and other emergence issues.
Stripe rust has shown up within 100 km of our area. Scout flag leaves in wheat for signs of stripe rust.
Continue sweeping canola for cabbage seedpod weevils up until 30% bloom. After that the damage has been done and you've missed the optimal window.
Watch the Delta T range from last weeks newsletter. Humidity plays a large role in how hot you can apply fungicides.
Time to start scouting for wheat midge as GDD's reach levels where emergence begins.

Agronomy

CTF tour Tuesday, July 15th, 1:00 pm

We're hosting a field day with CTF Alberta Tuesday, July 15th from 1pm - 4pm at our farm NW of Morrin, AB. Please join us!

When: 1:00 PM to 4:00 PM
Where: One mile west of Morrin, AB on HWY 27 and 1.5 miles north on RR 20-4 (N 51 40.234 and W 112 47.543)

Google map and directions

The Plan

1:00pm – Sign in
1:30pm – Crop walk and lessons learned after 5 years in CTF – Steve Larocque
2:30pm – CTF systems Q&A with long time CTF farmer Robert Ruwoldt, Vic, Aus
3:30pm – Improving soil quality – Peter Gamache & Roger Andreiuk
4:15pm – Nitrogen side dressing in wheat and canola on narrow rows
5:00pm – Chinwag and refreshments

There is no charge for the event. Refreshments will be provided. Qualifies for three Soil & Water CEUs.

Top 2 limiting factors in Prairie Agriculture

Wheel traffic and poor residue management

As crops begin to head out and canola begins to flower, there is no better time to evaluate drill performance and residue management than right now. I’ve been sent a flurry of photos by email and twitter on the impact of wheel traffic and poor residue management this year. If we don’t address these issues soon, we can look forward to uneven crops, saturated soils and heavy dependence on timely rains for crops to finish well.

Top Photo: Aerial photo showing multiple years of wheel tracks from large scale heavy machinery. PS: Looks great from the road, not from above.

Middle photo: 40-ft John Deere 1830 hoe drill pulled by a John Deere 9430 wheel tracked with 800mm duals.

Bottom photo: Multiple years of tractor, air cart and liquid wagon running on the same AB line for 3 years. The lentils are 5” shorter than outside the tracks.

If you calculate the impact of wheel traffic from tractors, castor wheels, air carts, combines, sprayers, grain carts and truck traffic, you’re looking at close to 50% of your land base covered by wheel tracks every single year. Now, kick it up a notch with poor residue management by spreading a 36-foot cut across just 10 feet and you can tack on another 20-30% of your land base with poor emergence, slow crop growth and uneven maturity.

The compounding effects from wheel traffic and poor residue management make it nearly impossible to stage herbicides, fungicides, insecticides, swathing and harvest timing properly. The whole system falls apart when crops are uneven. Those who are dealing with these issues right now know exactly what I’m talking about.

Steve’s (conservative) quick math
4,000 acres x 50% of land base x 10% yield loss x $400/ac revenue = $80,000.00

If you look at the wheel track damage in most fields from just the tractor and drill again this year, the yield loss is much greater than 10% because it is so visible, like in the photos above. A 4,000 ac farm may see up to a $250,000 loss in yield potential from wheel track damage and poor residue management. I suspect many will continue to go on business as usual and try to solve the problem through tillage. That may solve the residue issue but in-season wheel traffic cannot be solved with tillage. We have to start looking at tires, ground pressure and innovative systems like CTF to manage wheel traffic. You can only count on timely rains to keep crops alive for so long. When the timely rains stop, it’s going to hurt. SL

CTF resources: <here>

Photo source top: Brandon Gibb

Photo source middle: Steve Larocque

Photo source bottom: Stuart Lawrence

Random vs. controlled traffic

Water infiltration rates

If you look around the countryside, you can easily see the impact of saturated soil on crop health. If there was one thing that could have increased yield by a large margin over the last few years it would have been proper water infiltration and the ability to prevent saturated soils conditions. In 2014, we introduced three lanes of random traffic inside a CTF field that is now in its 5th year to see how CTF improves water infiltration and storage.

To simulate random traffic I simply ran the tractor and drill off the tramlines by driving down and back on the same swath after seeding with the openers out of the ground. This created 25% more wheel traffic compared to the CTF side. One inch of water equivalent was poured into 7-inch rings and timed for infiltration speed. Here are the results:

CTF
1) 0.17 sec, 2) 0.13 sec, 3) 0.05 sec, 4) 0.05 sec, 5) 0.05 sec, 6) 0.07 sec, 7) 0.03 sec, 8) 0.04 sec, 9) 0.03 sec, 10) 0.08 sec

Random
1) 0.06 sec, 2) 0.10 sec, 3) 0.08 sec, 4) 0.10 sec, 5) 0.05 sec, 6) 10.00 min, 7) 10.00 min, 8) 0.13 sec, 9) 2.46 min 10) 0.05 sec

As you can see, the CTF infiltration rates were extremely quick with one inch of water draining in 17 seconds or less, most under 5 seconds. A second trial was done to see what another inch would do and the infiltration rate increased to just 52 seconds after two inches of rain equivalent.

The random traffic side where 25% wheel traffic was imposed almost stopped infiltration rates completely on 25% of the area, which happened to be where the wheels travelled. That’s just from one pass with a tractor and drill after seeding almost 60 days ago and after 5 inches of rain!

If you want to measure the financial impact of proper drainage and the value of CTF let’s run the numbers: Let’s use a 2-inch rainfall inside 30 minutes where CTF is able to absorb 90% of the water compared to random traffic that may be able to absorb 30%.

Steve’s quick math
CTF: 2-inches of rain x 90% x 5 bu/ac canola/inch x $10.00 bu = $90.00 ac
Random: 2” of rain x 30% x 5 bu/ac canola/inch x $10.00 bu = $30.00 ac

In this crude example, you can see that CTF could generate another $60.00 per acre in revenue by simply allowing 60% more rain to infiltrate quickly and limit runoff or evaporation. That’s not taking into account the loss of nitrogen and unnecessary crop stress caused by poor drainage and saturated soils.

The key to unlocking the yield potential we’ve achieved through no-till is to undo the damage we’ve done with random wheel traffic over the last few decades. You don’t have to look far to see the impact of poor drainage and if we think we’ve seen yield loss from saturated soils, just wait until rainfall is limited. I don’t know what it will take to open the eyes of no-tillers everywhere to the tremendous impact wheel traffic has on the bottom line. Until then, Mitch and I will keep on pushing forward, down a different road but on the same tracks. SL

Top photo: Random traffic imposed after 4 full years of CTF.

Bottom photo: Controlled traffic lane in its 5th year of CTF.

The impact of fungicide on residue breakdown

Chasing yield outside of disease

As we enter the end of fungicide season I was reminded of a presentation given by Blake Vince, a passionate no-tiller and cover crop guru from southern Ontario. He is the self-proclaimed soil fun-guy of the south. He made a very interesting point about the over-use of fungicides to chase yield at all cost, even outside of disease pressure and it’s impact on crop residues.

Photo: Mushroom attached to corn residue. Fungi play a key role in residue breakdown.

Here are his comments:
“Today the use of fungicide to chase physical yield is rampant here in Southwestern Ontario. (Also in Western Canada) This is also true in the Corn Belt of the U.S.A. When I speak I like to remind growers that beneficial fungi help to break down cellulose from crop residue to be utilized for current crop production. The additional use of fungicides kills off the beneficial fungi, and residue is slow to decompose. This perpetuates the need for additional tillage to assist in the sizing of residue to aid in decomposition. I like to encourage people to walk through a forest and observe the trees that have fallen on the forest floor. This heavy cellulose is generally covered with mushrooms aiding in the decomposition of the fallen tree, which benefits the living plants in the forest.”

So here we are in Western Canada coming off four years of heavy fungicide use and now looking at tillage options to help break down the rapidly accumulating residue. Coincidence? We’ve never seen so many fields impacted by poor residue as we have in the last four years. Sounds exactly like what they’re experience in Southern Ontario and the US corn-belt.

It was a good reminder from Blake that fungicides are not benign to the environment and they do have an impact on our farming system. Chasing yield with fungicides to the point of overuse can seriously impact residue breakdown. Is it a coincidence that one of the biggest challenges in Western agriculture is managing residue loads? Maybe it’s time to re-evaluate how we use fungicides and consider their long-term impact on our farming systems. Thanks again to Blake for the great reminder. SL

Follow Blake’s blog <here>

Photo credit: Blake Vince

Wheat Midge

Identification, Damage & Control

With wheat beginning to head out, now is the time to prepare for Wheat Midge scouting. We’re nearing the threshold growing degree day number where they begin to emerge. These small bugs are about half the size of a mosquito and bright orange. They lay eggs in the wheat head and the larvae will then feed on the wheat kernels.

Damage Potential

One midge per 4-5 wheat heads can decrease yield by roughy 15%. They can also reduce the grade of your wheat. If there is more than one midge per 8-10 wheat heads there is a risk of a reduced grade. The Canadian Grain Commission limits midge damage in No. 1 CWRS wheat to 2% and 8% in No.2. In durum the tolerances are similar.

Scouting
Adults appear in late June and early July. Wheat fields should be scouted regularly between heading and flowering. Scout in the evenings, from about 8-10 pm, when the temperature is around 15 degrees Celsius and there is no or very light winds. Also, scout four or five places in the field for a more accurate count.

Threshold
One adult midge per four or five wheat heads is usually enough to warrant control measures.

Control
Cygon™, Lagon™, Lorsban 4E™, Nufos™ and Pyrinex™ are all registered for use on wheat midge in wheat. Check the label for any other restrictions regarding the chemicals. For example Cygon™ and Lagon™ do not control the eggs, just the adults. Also, application in the evenings are most effective. Check the label for application timing.
Cost: Lorsban: $8.40 acre + $7.50 ac/aerial application = $15.90/acre

Considerations for Control
Late evening or early morning are the best times to control the adults, as the females are most active in cool night time temperatures (but above 15 degrees Celsius or 59 degrees Fahrenheit) and when the wind is less than 10 km/hr (6 mph). Also, good coverage is critical for control if your chemical controls eggs as well; make sure the water volume is adequate. Optimal control happens when 70% of the crop is in the heading to flower stage. If 30-60% of the crop is flowering then it needs to be sprayed immediately to have good control on the wheat midge. If 80% of the crop is flowering then control is not recommended as the window has passed and the midge damage has already started. Spraying therefore should be done early to protect the main stem and first tiller, as this is where most of the yield potential of the crop is.

Wheat Midge Forecast Maps
Midge emergence can be modeled using accumulated temperature calculations called Growing Degree Day (GDD). Data provided by Agriculture & AgriFood Canada (AAFC), Saskatoon suggest using a base temperature of 5°C for predicting midge emergence patterns using accumulated GDDs. Thresholds for combined emergence of male and female midge are:
10% emergence     693 (±39) GDD
50% emergence     784 (±38) GDD
90% emergence     874 (±41) GDD

As of July 9th in the Calgary corridor we are at 601 GDD.
Wheat Midge Information
Alberta Midge Forecast map
Prairie Midge Emergence maps

Market News

The charts I use take a short and long term look at whether the market is oversold, neutral or overbought. I use charts as a way to pull the trigger, not to determine the best price.

Canola Nov 14: The long and short term trends are down.