October 1, 2013

Agronomist Notes

Hello Reader

Welcome back! I enjoyed that two-week harvest break.

This bin busting harvest is nearly complete with producers in the eastern part of my territory 99% done and to the west roughly 75%. Wheat yields are better than the records we set in 2011 with many reports of 85 to 100 bu/ac spring wheat yields. Proteins are low according to my local Cargill and Viterra elevators and movement is slow or non-existent on low protein wheat. Canola yields are average to above average and the same for malt and feed barley. Even with falling prices, net margins will be excellent for most in the 2013-14 crop year.

In this week’s issue I’ll discuss the exciting results from our side dress nitrogen toolbar experiment in wheat. Next, I have a good reminder to pass along on the value of crop rotations and then I’ll end with a quick guide for estimating nitrogen removal for fall fertilizer purchases. As always we’ll finish with technical grain market news.

Photo: Sun setting while filling a grain bag full of wheat. SL

Triumph with side dress nitrogen toolbar

A successful first attempt at boosting yield and protein with split N

We know that spit applications of nitrogen are a great way to boost yields, protein and harvestability by matching nitrogen demands throughout the growing season. I’ve heard wild tales of 30% yield increases in wheat with top dressing liquid nitrogen and each time rain chased the sprayer out of the field. I wanted to know how to capture a positive response without sacrificing nitrogen use efficiency by laying it on the surface and counting on rain that may never come.

So, this summer, we took the concept of side dressing nitrogen in corn and applied it to our 12-inch wide narrow row wheat. See video of our 60-foot, FAST 8100 side dress toolbar in action on flag leaf wheat here. The toolbar is set up with 20-inch coulters on 24-inch spacing which fertilizes two rows every two feet like a mid-row banding concept. With CTF, the accuracy of the system allows us to run coulters between the rows very consistently with minimal crop damage. The liquid UAN 28-0-0 is placed 3 inches below the surface, right into moisture where roots have immediate access.

We set up three 40-acre side dress nitrogen trials in two wheat fields; two on a 160-acre field of hailed out pea stubble with 5-6% organic matter and one on a 230-acre field of canola stubble with 3.5 to 4% organic matter, both have 50 to 60% clay soil and pH between 6 and 7. The UAN was side dressed at flag leaf on one field and heads emerged on the other. Here are the details:

Pea Stubble Check
Variety: PR 5700 CPS wheat
Spring Fert: 90-27-0-0 (15 P as 11-52-0-0 and 12 P as 6-22-4)
Yield: 96 bu/ac
Protein: 12.1
Moisture: 14.8%

Trial 1
Spring Fert: 90-27-0-0 (15 P as 11-52-0-0 and 12 P as 6-22-4)
Side dress: 60 lbs/N using liquid 28-0-0 at flag leaf
Yield: 120 bu/ac
Protein: 12.2%,
Moisture: 15.0%,

Trial 2
Spring Fert: 15-17-0-0 (5 P as 11-52-0-0 and 12 P as 6-22-4)
Side dress: 60 lbs/N using liquid 28-0-0 at flag leaf
Yield: 86 bu/ac
Protein: 12.0%
Moisture: 15.0%

Canola Stubble Check
Variety: PR 5700 CPS wheat
Spring Fert: 100-27-0-0 (15 P as 11-52-0-0 and 12 P as 6-22-4)
Yield: 78 bu/ac
Protein: 10.5
Moisture: 12.5%

Trial 3
Spring Fert: 100-27-0-0 (15 P as 11-52-0-0 and 12 P as 6-22-4)
Side dress: 60 lbs/N using liquid 28-0-0 at heads emerged
Yield: 80 bu/ac
Protein: 12.2%,
Moisture: 10.5%,

Based on our results, we were amazed to see a 25% yield increase on the pea stubble while maintaining 12.2% protein. There was no delay in maturity with the added nitrogen as indicated by no change grain moisture content. The straw on the side dress trial did stay green longer than the check but that was rectified with pre-harvest glyphosate. The N removed in the grain worked out to 34 lbs/N/ac yet we applied 60 lbs/N/ac as a side dress. I would have expected a higher nitrogen use efficiency than 50% but we were roughly 10 days late in applying the nitrogen. I would prefer to have applied N at the ideal timing of GS 30-32 which is the beginning of stem elongation and not at flag leaf (GS39). Perhaps we drove yields higher in the tillers from the late N application but missed the main stems which contribute 50% towards final yield.

The 15N at seeding with 60N side dressed at flag leaf still yielded well at 86 bu/ac, which is a 10% decrease in yield over the check. This wasn’t a true side by side because I had to sacrifice some phosphorus by cutting back the 90-15-0-0 blend to get my 15 lbs/N starter. Oddly enough, there wasn’t any visual difference in plant height up until flag leaf but you could see disease like septoria and stripe rust come in early. What’s interesting and encouraging is that we applied just 15 lbs/N at seeding and followed up with 60 N as a side dress late at flag leaf and still ended up with an 86 bu/ac wheat yield. That was an eye opener! The only data I have handy for split apps of N in spring wheat is from North Dakota back in 2002. They found a 23% yield increase with a 50/50 split N app using UAN at the 2nd node stage under irrigation (source). The dryland sites using 50/50 split N at seeding and at 2nd node stage saw a 5% yield decrease which tells you the importance of placing nitrogen in the ground and not relying on rainfall to wash the nitrogen into the root zone.

The last trial we had on canola stubble showed little difference in yield between the check and side dressed nitrogen. Granted, the wheat was at GS52 so heads were emerged but flowering had not begun when we applied the nitrogen. The difference showed up in the protein with a 1.7% increase in the side dress N side with a small drop in grain moisture content. The protein I understand increasing with late nitrogen but a drop in moisture content was interesting. We actually sped up maturity by laying on another 60 lbs/N for a total of 160 N/ac. We didn’t delay maturity like most would think at such a high nitrogen rate.

This year’s trials were very promising. The fact we saw a 25% yield increase on pea stubble with late nitrogen timing is amazing for a first trial run. What’s encouraging is that we achieved yield responses with our side dress system that are comparable to results found under irrigation like that found in North Dakota on spring wheat (source). My vision from the start was to create a system where timely rainfall was not required. If we’re going to spend $30 to $40 an acre on nitrogen in-season we better make it count. With CTF, side dressing nitrogen between the rows is simple and proves we can apply at any growth stage in wheat up to flowering. There is potential to make radical improvements in nitrogen use efficiency by supplying nitrogen in stages. The side dress concept needs more trial work but in this first season, we’ve gained yield, protein and did it without delaying maturity. Win-win-win. SL

Photo: Our FAST 8100 side dress toolbar in flag leaf wheat.

What is a good crop rotation really worth?

Pulses pay back

We all know that proper crop rotation is important and can lead to less disease, insects, nutrient cycling, soil quality and ultimately higher yields. That said, it’s often difficult to put a dollar value on a good crop rotation. I thought I’d share some great information from a side by side trial comparing wheat on wheat versus wheat on pea stubble.

In 2012, Shawn Berreth from JHB Farms near Beiseker ran short of pea seed on his last field and decided to plant wheta on the remaining 40 acres inside a 140-acre field. In 2013 the entire field was planted to wheat and Shawn took the time this fall to measure yield and protein on both sides. This is what it looked like:

Wheat on wheat: 2012: 65 bu/ac wheat, 2013: 70 bu/ac wheat 14.4% protein
Wheat on peas: 2012: 50 bu/ac peas, 2013 85 bu/ac wheat 13.5% protein

The wheat on pea stubble yielded 24% more than the wheat on wheat stubble. The foliar disease was kept in check with fungicides which means there is alot more going on to hurt yield below the ground than above. Some of the yield on pea stubble would come from greater stored soil moisture but not 15 bu/ac worth I suspect.

The gross margin on pea stubble was close to $100.00 acre more than wheat stubble which is eye opening. Even better, net margins have been close or better growing peas compared to wheat the last few years. As you plan your next year's crop rotation I highly suggest you look at adding a pulse to the rotation. I know they've always been a "good" idea to include but the profitability wasn't there. With proper management, good varieties and strong prices pulses are now a seriously viable option.

Back of the envelope nitrogen estimates for pre-buying fertilizer

It’s that time of year where producers are starting to pre-buy fertilizer if they haven’t already. I know the recent sell off in commodities has everyone on the sidelines waiting on prices to fall. That said, you’d be interested to know that fertilizer prices have dropped only twice from fall until spring in the last 32 years. Pretty small odds when you think about it. So with that, here are some rough estimates of how to calculate nitrogen removal in wheat, barley and canola to help estimate nitrogen requirements for 2014.

To calculate the nitrogen content removed in the wheat, you must divide the protein content by a factor of 5.7. For example, a 75 bushel wheat crop with 12.5% protein divided by a factor of 5.7 will indicate the nitrogen content of the grain.

Wheat: 65 bu/ac × 64 lbs/bu × (11.5% ÷ 5.7 ÷ 100) = 84 lbs/ac.
*The factor of 5.7 is unique to wheat.

Barley: 105 bu/ac × 54 lbs/bu × (14% ÷ 6.25 ÷ 100) = 113 lbs/ac.
*The factor of 6.25 is used for all other grains and nitrogen removal can be determined using the same formula.

Canola: 55 bu/ac × 1.88 lbs/bu = 103 lbs/ac.

I encourage you to look through your yields, proteins and bushel weights in wheat and barley as well as canola. After 2013 yields we know N removal rates will be enormous. These calculations should help get you close to what you need for 2014 prior to soil sampling. SL

Market News

Canola Nov 13: The long and short term trends are down.