Agronomist Notes

Last week was quiet for me while I sorted out farm, personal and business books for the accountant. The best feel good news I had was how Mitch and I decided to buy out of our Series A feed wheat contract for a whopping $25. Now with a new deal in hand we’ll get all of our feed wheat sold and moved for $5 a bushel at the bin. Not bad at all with the slow movement of board grains.

This week we’ll be going through an exercise to see what it would take to produce 220 bu wheat in Alberta. Next, I’ll go through the potential for manganese deficiencies in wheat in certain areas of Alberta. Last, we’ll run through an efficiency exercise to see which 400 bushel air tank provides the most seeded acres per fill. We’ll finish with fundamental and technical grain market news.

Agronomy

What would it take to produce 220 bu wheat in Alberta?

The Guinness World Record wheat crop in New Zealand is 15 T/ha or 220 bu/ac. As an exercise for the mind I decided to dig a little further into what it would take to produce a 220 bu/ac wheat crop in Alberta. It might sound ludicrous but I think it’s important to understand the details behind the production of a crop that size. Is it even possible in Alberta? The highest spring wheat yield I’ve hit with a client is 120 bu/ac with CDC Go and that was near Three Hills in 2010. Hey, we’re only 110 bu/ac away from reaching the New Zealand record! Let’s have some fun and run the numbers on plant populations, kernel numbers, TKW, required grain fill and the moisture necessary to produce a 220 bu/ac wheat yield.

When it comes to grain yield, it really comes down producing X amount of heads with X amount of kernels at X kernel weight per unit area. The calculation is: plants/m2 × heads/plant × kernels/head × TKW ÷ 1,000 grams ÷ 100,000 = T/ha. Based on this, I have come up with a theoretical plant stand density of 400 plants m2 (39 ft2) with an average of 32 kernels per head with a 40 gram TKW. This measurement would give us a theoretical yield potential of 15.36 T/ha or 227 bu/ac in Alberta. On the flip side of the globe I’ve given you a comparison of what the numbers look like for a 15 T/ha world record wheat crop in New Zealand. 

Steve’s quick math

Alberta  

• 400 plants per m2
• Average 3 heads per plant (1 main stem + 2 tillers)
• Average 32 kernels per head
• TKW 40 grams (thousand kernel weight)
• 400 × 3 × 32 × 40 ÷ 100,000 = 15.36 T/ha (227 bu/ac)

New Zealand, Guinness World Record

 

• 125 plants per m2
• Average 4 heads per plant (1 main stem + 3 tillers)
• Average 60 kernels per head
• TKW 50 grams (thousand kernel weight)
• 125 × 4 × 60 × 50 ÷ 100,000 = 15.0 T/ha (222 bu/ac)

The next component to look at is the grain filling period, which begins at flowering and ends at physiological maturity. To set up a crop for a world record yield you need ample sunlight, low daily temperatures, a long grain fill period and adequate soil moisture. When we think of New Zealand, most of us know they are usually blessed with all four. So where do we stack up? You’ll find the mean daily temperature, solar radiation (sunlight energy) and grain fill period comparing our 5-year average at Three Hills to the record setting 15T year in 2002-03 in New Zealand below:

Three Hills, AB 5-year avg 06-10

• Solar radiation: 17.3 MJ/M2/day
• Grain filling period: 45 days
• Moisture: 237 mm
• Avg. daily temp during grain fill: 14.5C

New Zealand 2002-03

• Solar radiation:  26 MJ/M2/day
• Grain filling period: 51 days
• Moisture: 500 mm
• Avg. daily temp during grain fill: 16.5C

You can easily pick out the differences not in just moisture, but in solar radiation. New Zealand receives 50% more sunlight during the grain filling period than we do at that growth period. They say rain makes grain but in reality solar radiation is just as important when it comes to building yield. It’s sunlight that turns rain into grain. Also, there’s a common misconception that New Zealand enjoys a longer grain filling period, when in fact it’s very close to ours at roughly 50 days. That being said, the grain filling period is highly variable from year to year and can be 30 days one year and 50 days the next in both countries.

New Zealand’s 10-month growing season does allow the 500 mm of rain to be spread over a longer time frame. If you compare moisture use efficiencies we’ve got a long way to go to keep up. We can produce roughly 16 kg/mm/ha of wheat compared to New Zealand at 30 kg/mm/ha. If you work that back to standard units, that’s 6 bu/ac/inch compared to 11.2 bu/ac/inch. With an average of 6 bu/ac/inch we would need 36 inches of rain to produce a 220 bu/ac crop, which is outrageous. In reality we should be introducing wheat genetics that provide us with 10 bu/ac/inch. Unfortunately, at this time there are numerous high yielding varieties that won’t see registration in Canada because they don’t meet the quality criteria set out by the CFIA. For now that is.

Now on to the similarities and we do share a number with New Zealand that we can capitalize on. We have varieties that consistently produce 40 to 50 gram TKW’s whether it’s AC Superb and CDC Go or any varieties in the CPS, Durum and Extra Strong wheat class. Our average daily temperatures during grain fill are similar and we can get up to 20 inches of plant available water in the growing season, especially under irrigation. The biggest discrepancy between the two climates is solar energy which tells me that’s where we need to focus. If sunlight turns rain into grain then maximizing the number of grain filling days is a big key in unlocking a theoretical 220 bushel wheat yield.

In summary, this was an exercise to see what it would take to produce a world record crop. I think the take home message is the importance of the grain filling phase. We need to find new ways to maximize the number of grain filling days without risking frost at the end. Everything from starter and in-season nutrition, planting date, seeding rate, variety, seeding tools, fungicides, and the list goes on. I recommend focusing attention on getting the plants to flower as soon as possible while keeping them green and healthy all the way to the end of the growing season. If mid-July is the average start date of flowering, start finding ways of getting the crop there a few days sooner each year. Is it possible? I see two-week delays in maturity from poor residue management alone every year. In the end, every day you can extend the grain fill period is one step closer to higher yields. SL

Guinness World Record Crop Summary: http://www.cropscience.org.au/icsc2004/poster/2/7/3/662_armourt.htm

Manganese deficiencies may be robbing yield in some areas of Alberta

On a trip to the UK in late 2009 I had a great visit with a farmer who grew wheat and canola in rotation near Oxfordshire. He was showing me around while discussing his fertility practices and mentioned the use of a foliar manganese program on his wheat in some soils. He said without the three applications of manganese each year on his winter wheat, his yield would be cut in half. This gentleman farms high pH, high organic matter soils >15% and grows 180 bushel winter wheat in a direct seeding system.

We don’t farm in the UK but if you look at the organic matter map for Alberta

[http://www2.agric.gov.ab.ca/icons/acis/maps/agricultural_land_resource_atlas_of_alberta/soil/soil_quality/organic_matter_content_cultivated_soils_big_map.png], there is a large area with OM levels greater than 8% between Red Deer and Edmonton. I know there are a huge number of acres that have peat moss or muskeg running through them in Northern Alberta with OM levels above 15%.

To break it down, manganese promotes germination, accelerates maturity and increases the availability of phosphorous and calcium. It also plays a significant role in enzyme activation but in simple terms, a deficiency can cause a reduction in photosynthesis, root growth, nitrate assimilation and ultimately yield. 

In our system and climate, manganese deficiencies may show up for a short time early in the growing season. Manganese can be tied up by microbial activity during the break down of crop residue as the bacteria that break down organic matter require manganese to function. Couple that with cold soils, high pH >7 and low soil manganese levels and it’s very likely that a deficiency could show up each spring in some soils.

The conditions that lead to Mn deficiencies are:

• high soil pH
• high organic matter content >8%
• poor root development
• poor root‐soil contact, in unconsolidated (fluffy) seedbeds
• low soil temperatures
• below average rainfall
• Above average rainfall (Under short-term waterlogged conditions, plant available Mn++ can be reduced to Mn+, which is unavailable to plants.)
• Mn:Fe Balance (Soils high in available Iron can reduce Mn uptake.)
• Soils with less than 33 ppm of Mn

The symptoms of Mn deficiency are generally seen around early tillering. They occur as yellow-green patches with irregular, but defined edges. These become paler and the plants wilt and droop in warm weather. You may also find light gray flecking and striping that appear at the base of the youngest fully opened leaf. Under severe manganese deficiency, the new growth may emerge with this flecking and striping over the entire leaf. In barley, Mn deficiency shows up as dark brow spots formed along the veins of the leaf. The photo on the left shows the speckling in wheat and the photo on the right shows the brown spots forming along the leaf veins.

The product of choice for correcting a manganese deficiency is manganese sulphate, applied to provide 2 lb/ac of actual Mn using a 25% manganese sulphate product. Ideally, you would apply it during or before tillering during high humidity with high water rates of 40 gal/ac and higher. You need the high water volume with sulphate products to avoid leaf burn as it can enter the plant quite rapidly and scorch the leaves. You can also use chelated manganese products which are much easier to use and more compatible with herbicides but a lot more expensive per pound of actual nutrient. Soil applied manganese is generally not effective because the mineral gets tied up in unavailable forms so sticking to a foliar program is best.

Most foliar manganese products range from $3.50 to $6.00 acre with 0.5 to 1L/ac application rates. I suspect like with most micronutrients there will be areas of the field that are deficient and certain weather patterns that induce the deficiencies. Be mindful of those low areas with high organic matter or peaty areas with high pH. In these cases, a variable rate may be very cost effective if you can drill down those areas with high OM and high pH soils. SL

Products:
Stoller MP Manganese 5%: http://www.stollercanada.com/products/pdfs/product_info/Manganese.pdf
NutriAg ManMax 5.5%: http://nutriag.com/products/manmax.html : 
Wolf Trax Manganese 33%: http://issuu.com/omex/docs/foliar_product_guide
Omex Manganese 17.5%: http://issuu.com/omex/docs/foliar_product_guide

Source: http://www.spectrumanalytic.com/support/library/ff/Mn_Basics.htm
Barley photo source: http://www.barclay.ie/media/16159/bvr%20manganese500%20lr.pdf
Growth stage & nutrient chart source: Stoller USA 

Not all 400 bushel grain tanks are the same

I think we assume that air carts generally have the same capacity. I mean a 430 bushel John Deere or New Holland tank hold the same amount of volume right, so they should provide the same number of acres per fill with a given blend and seeding rate, right? When you breakdown the volume each compartment holds in each grain tank, you’ll notice there are slight differences. Out of curiosity I took a look at the seeded acre capacity of the top seven air tanks in the 400 bushel class.

Let’s run the numbers. I’ll take a standard 230 lb/ac fertilizer blend with a 120 lb/ac seeding rate of wheat. We’ll place seed in the front and fertilizer in the back compartment.

As you can see from the chart the clear winner is the Bourgault 6450 air tank with a minimum capacity of 72 acres per fill. It is the biggest air tank in the 400 bushel class with roughly 20 bushels more capacity than the rest.

The second runner up is the JD 1910 430 bushel tank with a minimum of 69 acres per fill. Giving up some size in the middle tank to make a larger 150 bushel tank makes sense.

The Case/NH and Morris tanks come in a close third and fourth. The Morris tank is 3 bushels bigger than the Case/NH but has an oddball tank split that forces you to have mega capacity in two tanks and only 62 acres per fill in one. I calculated the Morris tank two ways and 62 acres was the most I could get out of one fill. I think Morris should take a lesson from John Deere and give up some tank space in the middle to help increase the acres per fill.

The last two on the list are the two compartment SeedMaster and SeedHawk air tanks. The SeedMaster has 20 bushels more capacity than the SeedHawk but still comes in 4 acres less per fill. The two tank system really can’t compete in this class and until these two manufacturers upgrade to three compartment tanks, I think more people will be hitching onto Case/NH and Morris tanks.

So the difference in efficiency from highest to lowest in the 400 bushel class is the Bourgault 6450 which can do 36% more seeded acres per fill than the last place SeedMaster SXG 425. The next time you decide to upgrade tanks, have a look at your fertilizer and seeding rate program, then run the numbers on which tanks are most efficient with your program. It just might save you time, money and have you finish seeding a little bit earlier next year. SL