March 12, 2013

Agronomist Notes

Hello Reader

I arrived home safe and sound last Tuesday to a happy family and a boatload of jet lag. I’ll get over the jet lag just in time to speak at the Nuffield Contemporary Scholars Conference in Niagara Falls this Saturday. After that, it’s spring client meetings and equipment fine-tuning before seeding in six weeks. Gulp!

This week I’ll walk you through the agronomy that produced a bin-busting 207 bu/ac barley yield achieved by Chris Dennison in New Zealand. Last, I’ll discuss the economics of variable rate lime to show you the direction I’m headed with some of my clients. We’ll finish with technical grain market news.

210 bu/ac soft white winter wheat crop of Mike Solari’s. Current Guinness World Record holder for wheat yield.

Big barley yields in New Zealand

207 bu/ac (11.2 T/ha) spring barley agronomy

The second last day of my visit to New Zealand I jumped in the combine with Chris Dennison from Oamaru while he was harvesting barley. From the ground it looked like a nice crop but then I climbed into the cab and saw the yield monitor averaging 195 bu/ac! Chris is no stranger to big yields and barley is no exception on this farm. I took the time to learn what he did differently to produce a bin-busting 207 bu/ac barley yield.

Agronomy

Crop: Barley (2-row), feed
Variety: Tavern
Seeding rate: 123 lbs/ac
Seed weight: 49 g/tkw
Seed treatment: Raxil MD
Seeding date: September 9th, 2012
Field prep: Disked once and rolled with one light tyne cultivation prior to seeding
Previous crop: Kale
Pre-plant fert: 0- 7.7 - 7.5 - 9.3 – 9.3 @ 180 lbs/ac + 41% Flexi N urea coated with 5.2% magnesium @ 90 lbs/ac
Herbicide: Hussar (idosulfuron- methyl-sodium) @ 150 g/ha
Tillering (GS 25): Applied 100 lbs N/ac as urea (4 weeks after planting)
Stem elongation (GS 30): Applied 160 ml/ac Proline (prothioconazole) fungicide
Awns emerging (GS 50): Applied 160 ml/ac Proline + 140 ml/ac Seguris Flexi (SDHI) fungicide + 400 ml/ac Terpel (mepiquat chloride+chlorethephon) plant growth regulator
Rainfall: 17 inches (4 inches soil + 10 inches rainfall + 3 inches irrigation)
Kernels: 22 kernels per head
Harvest date: March 4, 2013

Notes: This field grew kale in 2011, which is a forage brassica used to graze dry dairy cows. The field was grazed for several months.

To see a video of the Claas 750 making light work of the 200 bu/ac barley crop go here

What struck me most about Chris’s agronomy program was the amount and timing of nitrogen, fungicide used and kernels per head.

I find it interesting that Chris is applying 40 lbs/N/ac prior to seeding and then 100 lbs/N/ac at tillering for a total of 140 lbs/N/ac. If you want to stimulate tiller production, 100 lbs/N/ac at tillering should do the trick. This strategy also reduces the ratio of biomass produced relative to grain yield thereby increasing nitrogen use efficiency. What’s interesting is that tillering occurs four weeks after seeding which is very close to what we experience in Western Canada. Perhaps we can look at a strategy that applies a high does of nitrogen at tillering on top of a decent starter nitrogen application.

Did you notice the use of Proline (prothioconazole) in barley? Proline is marketed in Western Canada as a canola fungicide but in fact it is an incredible fungicide in barley. The active in Proline provides curative and protective control of spot and net blotch, scald and septoria. In my high yield barley trials, I’ve used Prosaro (tebuconazole + prothioconazole) at early heading and I have had green leaves up until harvest. Proline, in my opinion, is a killer barley fungicide. If only it was reasonably priced.

I didn’t get a chance to count the number of heads per square metre in the crop but I did count the kernels, which equaled 22/head. That’s a lot less than most would think possible to achieve a 207 bu/ac yield. In 2011, we had a trial do 141 bu/ac with the variety Champion and thought we may have stunted yield with the PGR + fungicide combo because it only had 22 kernels/head. But, after walking through Chris’s field and thinking on his agronomy, perhaps we just shorted the crop of nitrogen at 150 lbs/N/ac applied at seeding. Bottom line, a bin-busting barley yield does not need 28 kernels/head. It needs a lot of heads with 22 kernels.

The take home on this agronomy package is the value of split applying nitrogen with a high does of nitrogen at tillering rather than up front. With adequate moisture, you can build and maintain a serious number of tillers with 100 lbs/N/ac. Next, when targeting high yields, a product like Prosaro or Proline that contains prothioconazole is a must because it provides long lasting protection against leaf diseases and helps make use of the high nitrogen rates by keeping plants alive longer. Of course, we can’t forget the use of a PGR like Terpel, which is necessary to keep a barley crop standing after 140 lbs/N/ac. Last, targeting 25 plants ft2 with a target of 22 kernels per head and a typical 43 g kernel weight means you need four tillers per plant. At this number it is possible to achieve 200 bu/ac.

I understand that in Western Canada, laying out the inputs to reach a 200 bu/ac goal may be daunting and high risk. Consider though, high yield agronomy doesn’t have to be all or nothing. Pick your fields carefully and lay out the financial risk on the number of acres you are comfortable with. I do believe 200 bu/ac yields are possible with decent soil moisture and 15 inches of rain in-season. In my area, that kind of rainfall occurred in 2007, 2010 and 2011 so it does occur in some parts of the prairies. In my opinion, we just haven’t matched agronomy with yield potential. SL

What a rush! Harvesting a 207 bu/ac barley crop at Chris Dennison's near Oamaru, NZ. Photo S. Larocque

It’s time to start thinking about lime

Correcting soil acidity to boost yields

My recent visit to South Australia included several conversations about the use of variable rate liming programs to improve soil pH. There are numerous areas throughout Australia with acidic soils that require liming to correct pH and it’s a regular part of the program. In Alberta, we have barely begun to address low pH soils due to the high cost of lime and application. Having grid sampled close to 10,000 acres, I can tell you there are numerous areas inside fields with strongly acid soils all across my territory, which represents many soil types and climates. We know that liming is required but need a strategy to keep it economical and on target. Like the Aussie’s have realized, variable rate liming is the answer.

Acid soils account for roughly 20% of arable land in central and northern Alberta with up to 30% in the Peace Country. The combination of increased organic matter in zero-till and the use of ammonium based fertilizer have also contributed to soil acidity over time. Acid soils reduce the availability of phosphorus, nitrate, magnesium, molybdenum, sulphur and copper. They also reduce soil porosity and soil structure and leave land prone to soil crusting and water logging. Acid soils reduce the survival of nitrogen-fixing bacteria that supply pulse crops with nitrogen like peas and alfalfa. What’s interesting is that the majority of fields I’ve sampled contain areas of strongly acid soils rather than entire fields. This makes variable rate liming a viable and cost effective option.

The crops that respond the most to liming are barley, alfalfa, peas, wheat then canola and oats. In fact, research from Alberta Ag in one trial showed a 100% yield increase in barley and alfalfa after liming increased soil pH from 5.1 to 6.5. Now, I understand that's not the norm but interesting to see such a big yield response from liming. Oddly enough, the reason we chose certain fields to grid sample was because they weren’t performing as well as the rest, especially when growing barley in the rotation.

I chose to use a 5 acre grid sampling approach to measure pH using a Kriging method, which helps to predict the soil pH between grid sample points. From there we determine the soil texture to measure buffering capacity, soil pH and how much lime we need to apply to bring the pH to 6.0-6.5.

To make sense of the process let’s do a little Steve’s quick math to show you the value of VR liming on a 425-acre field we grid sampled recently.

Steve’s quick math
Soil sampling 5 ac grids: $5.30 ac (includes sampling + analysis)
Areas with pH below 5.8: 170 acres
Cost of lime: $30.00/MT (lime + VR application)
Average lime app: 1.5 T/ac
Cost of lime: 1.5 T/ac × $30.00/T × 170 acres ÷ 425 ac = $18.00/ac
Total cost of VR lime: $5.30/ac + $18.00/ac = $23.30/ac
Liming entire field: 1.5 T/ac × $30.00/T = $45.00/ac

As you can see, the total cost of VR lime would be $23.30/acre while liming the entire field would have cost almost double at $45.00/ac. The key is to narrow down which areas of the field are acidic and address those areas site specifically. Research from Alberta Ag has shown that correcting soil acidity through liming increased barley yields up to 19 years after application. That may not be the norm but the results are impressive and have me investigating VR liming programs for my clients. SL

Correcting soil pH in Alberta:
Correcting soil pH with wood ash:

SSG 5ac grid soil map showing pH levels.