Agronomist Notes

Another six or eight inches of snow fell last week and the forecasted temperatures remain cool, hovering around zero or slightly above until next weekend. We’ll have to move our drill and tractor to high ground where we can work on it because by the time the ground around the shop firms up, we had better be seeding.

This week’s newsletter has a CTF flare to it. We’ll be look at how we modified our hitch, twice, to inter-row seed in our controlled traffic system. Next, we’ll look at optimizing seeding rates to boost maturity in wheat. I’ll answer a frequently asked question about unsown tram lines and a check list to help you begin the conversion to controlled traffic farming.

Agronomy

Setting up your hitch to inter-row seed in a controlled traffic system

Inter-row seeding inside a controlled traffic system is a natural fit. Traveling down the same tram lines each year with sub-inch accuracy allows you the opportunity to seed between the rows. Instead of nudging your GPS side to side each year like you would in a random traffic set up, you need to build an offset hitch to move your drill side to side. Most CTF farmers build an offset hitch half the width of their row spacing. For example, if you have 15 inch row spacing, then you would build a 7.5 inch offset hitch like the one you see pictured here.

The most difficult part of engineering an offset hitch is making sure you don’t move your drill too far one way that you end up moving a seed row out of the reach of the header. If you do, this will leave you with an unharvested check strip on every pass on every field. This nearly happened to us after we built our offset hitch in 2010. In order to reduce the amount of crop planted inside the tram line we decided to shift the drill 3 inches off centre one year then move the hitch another 6 inches in the same direction the following year. We would then remove a shank and opener from one side and bolt it on the opposite side.  Had we done this, we would have ended up with an unharvested check strip on the side we bolted the shank and opener to and here’s why:

• The knife on our 30-ft header is 29 ft 8 in wide. The 30-ft drill is actually 29 feet wide centre shank to centre shank.
• With the combine parked dead centre on the tram lines there should be 4 inches of room at each end of the knife. After moving 3 inches to the left with our ‘first generation’ hitch, it left us with an inch of room on one side and 3 inches on the other side. The math doesn’t work but it must be the way the drill sits, or pulls, or the shank spacing on each side falls and caused the oddity.
• Knowing that, if we were to move 6 inches in the same direction Year Two as planned and remove the shank and opener from the left side and bolt it to the right side, we would be outside the knife by 3 inches. That is, a 3 inch space plus a 6 inch move to the left would equal 9 inches. Bolt another shank 12 inches on the right side and we would have one row fall 3 inches outside of the knife. Problem!
• With a 3 inch offset hitch on 12 inch spacing, we had a 9 inch and 15 inch space between each pass in 2010.

To correct the problem this year, we’ll build a new hitch that falls 3 inches off centre to the left one year and 3 inches off centre to the right the following year to give 6 inches of movement from side to side. This eliminates the need to move a shank and opener to the opposite side in our system, where many other CTF systems require it. It also keeps all of our rows inside the width of the knife on the header to avoid check strips at harvest. See the hitch as it is today pictured below.

To begin building your offset hitch in a CTF system, measure the width of the knife on your header. From there, measure your drill width from shank to shank. The measurement will tell you how much wiggle room you have on each side of the header so you don’t fall victim to the unharvested check strip. Good luck! SL

Optimize maturity with custom seeding rates

Whether or not your seeding has been delayed this spring, it's vitally important to optimize your plant stand densities to avoid maturity delays. As we know, a thin plant stand can lead to excessive tillering and delayed maturity. A plant will develop a leaf or tiller every three to five days after emergence depending on temperature and moisture. If you provide a plant with enough room to grow by reducing the competition within each row, it will continue to produce tillers. For example, a wheat plant may produce an additional two tillers in a non-competitive environment. If that plant takes three to five days to produce each tiller, the maturity of that plant will be reduced by six to ten days when compared to a plant that has adequate inter-row competition through optimum seeding rates. Remember, 50% of your yield comes from the main stem and 50% comes from the next two tillers. Any more than two tillers on a wheat crop is a waste of energy and a detriment to maturity.

To give you an example why the two bushel an acre seeding rate rule can leave you with excessive tillering, have a look at the table below. I have nine samples and three varieties of wheat ranging from 46 grams to 35 grams per 1,000 kernels. For my clients, I've targeted a plant stand density of 30 plants ft2 with seeding rates ranging from 151 lbs/ac to 113 lbs/ac. If you look at the table you can see that if I recommended a two bushels an acre seeding rate, we'd be 20% under the mark with CDC Go and 6% over with Unity. There wouldn't be enough plant competition with CDC Go and there would be too many plants seeding Unity at two bushels an acre.

Successful farming is about optimizing a hundred little things. A simple boost in plant stand density can help produce higher yields and improve maturity. For those of you who will be pushing the limit on maturity this year, stop guessing and start measuring. SL

Seeding Rate Calculator
Seeding rate (lb/ac) = desired plant population/ft² x 1,000 K wt. (g) ÷ seedling survival rate (in decimal form such as 0.90) ÷ 10.4

• FAQs: yield loss in unsown tram lines
• Many people ask me how much yield is lost in the area given up to permanent tram lines. The area given up to tram lines is 13% in our system or 20.8 acres per 160 acres. That sounds like a lot and it would be if we were actually giving something up. Let me argue the point. We choose not to seed our tram lines but instead double up the seed tubes on the rows adjacent to the tram line to increase the plant stand density. We do this to boost maturity because the rows adjacent to the tram lines have greater access to sunlight, moisture and nutrients and greater yield potential. If we were to seed a single row beside the tram line it would cost us maturity, the last thing we want in our 100-day growing season. We didn’t see much use in growing a crop on top of a hard packed tram line. 
• The closest figures to date suggest there is no reduction in yield from the area given up inside the tram line. Research on wheat and lentils in Australia showed no decrease in yield from unsown tram lines due to the “edge” effect. The rows adjacent to the tram lines can see up to a 180% increase in yield due to less competition for moisture, nutrients and sunlight. Overall, any potential yield loss given up from unplanted tram lines is more than compensated by the increase in yield from the edge effect and the increased yield on the rest of the field. SL

12-month planning process to help farmers move to CTF

Tim Neale from Precision Agriculture in Queensland, Australia has been helping farmers convert to CTF for over ten years and I was fortunate to have him help me set up some of my machinery. I’ve included a list of the planning process he recommends producers go through before converting their farming system to controlled traffic.

• Calculate the approximate coverage of wheel tracks in current random system to the planned CTF system.
  • Zero till about 40-60% of field
  • Conventional/minimum till > 85% of field
  • Zero-till CTF <16% of field
• Develop a five to ten year plan
  • Think ahead to what you want to do in the future
  • What area do you want to be farming in 5 years
  • What are the time critical activities (how much needs to be achieved in a set timeframe)
• Tractor – are the axles strong enough to go to 3 M or 120 inches? Both front end and back end need careful consideration. For example, the rear axles on FWA tractors should be a minimum of 100mm in diameter. This is only a “rule of thumb” as some 90mm axles have worked, some have failed. Best to be safe than sorry.
• Decide on imperial/metric early and put everything on the same system – e.g. row spacing, spray nozzles, wheel track width, etc.
  • 3 M is 118.1 inches, not 120 inches, so stick to imperial for Canada.
  • You may have to make the row spacing fit the tramlines – just depends on the seeder configuration and manufacturing method (welded supports, etc., in the way).
• Decide on row spacing’s and tramline width. I would suggest not planting the tramline, but in some areas they do.
• Is the combine at 3M/120 inch track width or can it be adjusted? Some combines cannot come in to 120 inches (as well as some spray rigs).
• Decide on combine header width (combine needs to be matched into the system from the start)
  • Match other implement widths to combine header width or multiples of it. For example, if the header is 30 feet wide you could go with a 30 or 60 foot seeder.
• Modify air cart, spray rig, and other equipment
  • Match to header (multiplies of it)
  • Multiples of 3:1 is ideal for spray rig to seeder
• Choose tire sizes
  • 500 mm track favored – 19.68 inches (20 inches recommended wheel track width – this should reduce the amount of track erosion)
  • Ensure very large spray rigs are purchased with wider tires (20 inches preferable)
  • Combine tires
    • Duals just spread the compaction damage
    • Higher tire pressures cause surface damage
    • Deep compaction is done by axle load – tire width makes little difference
• Examine ways to improve efficiencies on the farm
  • Field/ farm layout
  • Topographic maps
  • Location of roads on ridges/removal of grain
  • Roads to improve truck “flow” through the farm, which minimizes trucks turning in the field
  • Length of runs based on header width, box capacity, avg yield, etc
  • Water, drainage, erosion to minimize concentration and water logging
  • Agronomic improvements to match new soil conditions

Moving to a CTF system doesn’t have to happen overnight. It’s important to do your homework before you make the leap and the process Tim’s outlined is a great platform to start from. SL

Controlled traffic farming according to John Deere, Australia

On our last trip to Australia back in December with the CTFA group we had a great chance to catch up with the head of strategic marketing at John Deere in Brisbane. He gave us a run down and presentation on the position of John Deere with controlled traffic farming. I’ve included the presentation below. It has lots of nuggets of information on CTF adoption rates, benefits and equipment.