Agronomist Notes
Expose yourself and you’ll hear all about. My FarmTech presentation and Western Producer article (which was news to me) has raised some eyebrows and I’ve been fielding phone calls and emails all week. It’s been rewarding to say the least and I’m eager as ever to get things into place before spring. I’ve been busy pricing RTK systems, openers, tires and pondering what all it will take for Mitch and I to get set up for controlled traffic in 2010.
In this issue of Beyond Agronomy News, we’ll look at how to reduce the impact of herbicides on crop maturity, plant health, and yield while improving weed control. I’ve got an awesome example of this from Robert Ruwoldt of Horsham, Victoria. Next, we’ll revisit last week’s article on economies of scale and controlled traffic farming after I received a few comments from Aussie readers with controlled traffic experience. We’ll finish up with fundamental and technical grain market news. Have a great week. SL
A new concept in weed control systems
An overlooked area in our production system today is the way we apply our herbicides and its effect on crop growth, disease, maturity and yield. We ignore the stresses we create by applying herbicides because we see the benefits from proper weed control. How many people apply Odyssey (imazamox + imazethapyr) on peas knowing that phytotoxicity or yellowing, stunted maturity and yield loss may follow? How many have people have seen Achieve Liquid (tralkoxydim) shrink a wheat crop when night time temperatures drop below five degrees after application? How about the growth regulating abilities of Everest (flucarbazone sodium) when applied on high pH soil or in dry conditions? Ever spray Puma Super on barley past the five leaf two tiller stage? Yikes! These might be extreme cases but I believe herbicides are quietly affecting maturity, compromising plant immune systems and reducing our yield potential.
Here lies the problem. We typically apply herbicides during the three to five leaf stage in cereals. Unfortunately, this causes unnecessary stress at one of the most inopportune times in the plants lifecycle, the reproductive phase. The size and number of heads in each plant is being determined at the same the plant is forced to metabolize herbicide. To worsen the problem, we apply herbicides under stressful conditions like temperature extremes, cold weather, frosts, low fertility, drought, saturated soils, disease or insect pressure and the list goes on. This is where plant immune systems are compromised, maturity is delayed and yield is reduced. Thankfully, we can do something about it. The solution is inter-row seeding, RTK guided autosteer, wider rows, tighter nozzle spacing using 80 degree nozzles. Let me explain.
The secret to minimizing stress during herbicide application is simply to reduce the amount of herbicide you apply on any given crop. I learned that this is possible from Robert Ruwoldt from Victoria, Australia. He has designed a spray system that allows him to spray herbicide between the rows using a number of tweaks in the system. Have a look at the picture to the right. The nozzles are spaced 15 inches apart and directly between the stubble rows. This allows him to apply herbicide between the rows to target weeds and apply less herbicide to the crop. He combines this with 80 degree nozzles which have less than 50% overlap and allow him to spray closer to the ground, reducing drift and targeting more spray between the rows. Another bonus during fungicide applications is to shift over and target the crop to maximize the coverage of fungicide on the foliage and avoid applying wastefully between the rows.
Let’s compare our system to Robert’s:
- 110 degree nozzles vs. 80 degree nozzles
- 30 inch nozzle centre vs. 15 inch nozzle centre
- Random seeding pattern vs. inter row seeding pattern
- WAAS or Omni-star GPS auto-steer vs. RTK GPS auto-steer
- 9 to 12 inch row spacing vs. 15 inch row spacing
- 30 inch boom height vs. 18 to 20 inch boom height
You can see that Robert has made a number of tweaks to his spray system. It’s this kind of outside of the box thinking that has led him to record moisture use efficiencies on his farm. Reducing the amount of stress at herbicide timing can reduce days to maturity, improve disease tolerance by keeping plants healthy, increase yield and ultimately do a better job of weed control. I believe we can achieve this in our current herbicide system with some thought and common sense. SL
Matching economies of scale to controlled traffic farming – continued from last week
I received a few comments from our readers in Australia who work with or use controlled traffic on their farms. Two comments recommended an equipment width I never included in my study. I had originally stated that 30 ft widths are the most efficient. My friends in Oz tell me 36 ft and 40 ft widths are better and more efficient and many who began on 30 ft equipment widths are now going wider. First, let’s look at the reader comments set the stage.
Reader Comments
Andrew Newall, NewAg Consulting, Horsham, Victoria
"I’ve been thinking about your time frame and urgency to get crop in the ground and then off to a quick start. To develop a suitable controlled traffic system, I think you need to concentrate around the 35-40 ft widths, as residue spreading is still OK at these widths and there some additions that can be added to spread the distance easily enough like a Reddekopp chopper. A 30 foot set up is easy but there are some real issues with efficiency and the amount of wheel tracks in the field. A lot of guys that started at 30 ft are now looking at or have moved to 35 or 40 feet equipment widths.
As for using grain carts, it can be a little more challenging on 35 or 40 feet but can easily be done. There are a number of catches that can be added to the grain carts to take grain on the go. With the limited time you have to sow and harvest these wider widths would be more suited to your system.”
Dave Fulwood, Cunderdin, Western Australia
“Have you thought about a 12 metre or 40 foot controlled traffic system? We have a 12m (40 ft) DBS seeding bar, 12m (40 ft) MacDon header and a 36m (120ft) sprayer. We spread lime at 12m (40 ft) and also urea and potassium at 24 M (80 ft). I think the best systems have a 3:1 seeder to sprayer ratio. We pull off the tram line with the grain cart at harvest and back on the run line when moving up and back with the grain cart.
We tried a 30ft system with 30ft header, 60ft bar and 120ft sprayer but it was very confusing trying to keep everything lined up – you have to overlap the sprayer on the second run to line up with the seeding tractor and leaves a 15ft strip along the edge when harvesting. There is talk of a 60 ft header coming soon!”
Crunching the numbers: 36 ft CTF system
The 36 ft seeding system is still on the small side for a seeding tool width at first glance and at 5 mph would allow for a 3,500 acre farm to seed comfortably in the 20 day window, provided there are no rain or snow delays. You could average 22 acres per hour, which is on the low end but doable. A switch away from a tyne drill to a disk drill would require more horsepower but you could get you up to 40 acres per hour by doubling seeding speed while maintaining seeding depth accuracy. Add in some inter-row seeding to help with residue clearance and eliminate hair pinning, you might be on to something.
Next, the sprayer width is more than adequate at 108 ft wide so no issue there. Last, the 36 ft header width on the combine would give you the harvest efficiency most are looking for and with the right chopper, you could spread out to 36 ft on most days. As Andrew Newall pointed out, there are a number of catches that can be added to the grain cart to take grain on the go to maintain harvest efficiency without having to drive off the tram lines. The 36 ft system or 3:1 seeder to sprayer system looks promising. The amount of area given up to tram lines has dropped in half to just 14% of the field. Not bad!
The downside of a 36 ft CTF system looks to be the narrow seeding toolbar width but with a switch to a disk drill combined with inter-row seeding, you could gain back the efficiency by travelling faster. Maintaining 30 to 40 acres per hour seeding is more than adequate for most. On the harvest side, most 36 ft headers are offset mounted on the combine which doesn’t work in a CTF system- they must be centre mounted. I’ve been told that MacDon makes a 36 and 40 ft centre mounted header. I think these two issues could be addressed to create a good CTF system.
Crunching the numbers: 40 ft CTF system
The 40 ft system provides another step in spraying and harvest efficiency. The footprint of the 40 ft CTF system is really insignificant by reducing your compacted area to just 13% of the field. Travelling with a 120 ft sprayer may not be for everyone but at 4 acres per minute or 40 minutes per 160 acres, who can argue the efficiency? You’ve only gained another 2 acres per hour in seeding speed moving from 36 to 40 ft so once again, depending on how many acres you need to seed, a disk drill combined with inter-row seeding may help you attain the 40 to 50 acres per hour you need to cover the ground in 20 days.
Last, I question the increase in harvest efficiency with a 40 ft header. Depending on the size of crop and if you can do 4 mph on a 40 foot cut, it’s roughly 19 acres per hour. That would be the top end from anything I see in my area given average yields. Compare that to 5 mph using a 30 ft cut which we can do comfortably in a 60 bu/ac crop with our vintage Gleaner, that’s only an increase of 1 acre per hour comparing the 40 ft to our 30 ft header and only dropping speed by 1 mph.
In the end, the 36 ft and 40 ft CTF systems have proven to work well Downunder and may prove the same here in Western Canada. Adjustments can be made to maintain harvest efficiency with grain catches mounted to the grain carts provided a proper chopper can spread residue across the width of the cut 90% of the time. The only true bottle neck seems to be seeding with the narrow seeding toolbar widths. We can improve seeding efficiency by moving to a disk drill which most have avoided because of hair pinning issues. However, if you combine inter-row seeding with CTF, you can cut stubble higher putting less residue on the ground, allowing you to seed into soft soil between the rows, travelling at greater speeds while maintaining seeding depth accuracy. Perhaps 36 to 40 ft controlled traffic systems aren’t out of the question. SL
