February 19, 2014

Agronomist Notes

Hello Reader

I’ve wrapped up my whirlwind tour of Australia and I’m writing this issue on my 14 hour flight back to Calgary from Sydney. I’ve logged 40,000 km, seen a lot of country, and met with plenty of farmers, industry reps and researchers. Once again I’m inspired by the people who grow the same crops but attack the problems from a different angle.

I’ll begin this week’s newsletter with a few thoughts and facts I gathered on my trip. We’ll look at the Harrington Seed Destructor, a mechanical weed resistance tool designed in Western Australia and then we’ll review a trial that compared disks to tyne openers and narrow versus wide row spacing in wheat. We’ll finish with technical grain market news. It’s great to be home!

I did few interviews on my trip. You can listen to the GRDC podcast talking about root heat index, handling abiotic stress, controlled traffic farming and our offset hitch . <here>

Pictured above: The sun sets after a 46 Degrees Celcius day, near Temora, Western Australia.

Thoughts from my Aussie trip

I made some interesting observations during farm visits and presentations. Here are a few random points on my mind:

Our job is to harvest sunlight, water and carbon dioxide and turn it into grain. Why don’t we focus on systems that optimize how we capture each of those inputs such as row direction, soil bulk density, row spacing, zero-till, soil moisture storage, nutrient timing, and more.
Trying to solve a herbicide resistance problem with another herbicide is the definition of insanity. Trying to solve a disease resistance issue with another fungicide is also insane. We’re like a bunch of junkies waiting for the next herbicide hit to get us from one resistance problem to the next. Time for rehab.
The future will include farming systems that reduce pest problems in conjunction with pesticides; systems including crop rotation, tall stubble, row direction, variety, nitrogen timing, plant densities, stubble retention or others.
Weeds, insects, diseases and viruses make up a small portion of our lost yield potential in crop production. Abiotic stresses make upwards of 70% of the lost yield potential. Stresses include drought, heat, gas exchange, nutrients, flooding, sunlight, soil type, applied chemicals, frost, cold, wind and others.
Scarcity drives innovation. If you want to find innovative farmers, you’ll find them where subsidies are minimal, climates are variable and resources are scarce.
There is a lot to learn from producers outside of your own country and even outside agriculture. We all tackle the same problems but from different angles and perspectives. For example, think of access to capital, labour, expansion, growth, inputs costs, production issues, and succession planning.
The Aussie’s really know their evaporation rates, soil moisture holding capacity and what they should produce with the rainfall they receive. We could learn a great deal from their crop modeling to predict yield and the need for additional nutrients during the growing season.
The French-Schultz model suggests we should be producing 20 kg/ha/mm of water in wheat or 7.5 bu/ac/inch.
Subsoil moisture down to 3 feet is 3 times more efficient at producing grain from flowering until maturity than surface moisture.
Deep ripping and adding manure down the 30cm can increase yields on sodic soils by 60% on average with some years above 100% depending on subsoil and rainfall.

Sneak peak at the Harrington Seed Destructor

Mechanical weed control without cultivation

Ray Harrington understood long ago that herbicides were clearly not the single answer to solving weed control issues. With the inception of zero-till, cultivation was not the answer either. So, 18 years ago, he designed the first mechanical weed control machine that fit on the back of the combine (header) to control weeds before the seeds hit the soil surface. This began the Harrington Seed Destructor (HSD). I spent some time with Ray on his farm in Western Australia to see the most recent design of the HSD.

The picture above shows the original pull type design, where a conveyer belt captured weeds/chaff off the sieves and sent them to the hammer mill. The pulverized weeds and chaff were spread by spinners at the back of the machine. The original design required 250 hp to run and had its own diesel engine. The last pull type units were purchased for about $250,000. That was until Ray and a few researchers figured out a much better design.

I wasn’t able to take any photos of the new design due to patents pending but here is what I can tell you about the new HSD design:

First, they figured out the hammer mill only needed to knock the weed seed a few times to kill the germ and its viability instead of pulverizing the seeds into dust thus greatly reducing the horsepower requirements from 250hp to 74hp.
The current design is about half the size of a chopper and fits in between the sieves and the straw spreaders. It includes two oscillating flywheels rotating at high speeds to knock the seeds in half and damage the germ.
The original and current designs destroy 98% of weed seeds. To reduce weed populations you need to destroy at least 80% of weed seeds each year. Destroying 79% or less of weeds seeds will not reduce populations over time according to research.
The best fit for the HSD is on a Class 9 combine, which has an additional 100 hp over a Class 8.
The current design is hydraulically driven and requires 200 litres of oil per minute, which is a struggle for most combines to deliver.
Future designs will include a mechanical drive system run off the engine block or transmission.
The approximate cost for the new HSD will be around $100,000- $130,000 per unit.

The HSD technology has a fit for those who have serious herbicide resistance issues where herbicides do very little to control weeds. In the latest survey, Australia is No. 2 in herbicide resistant weeds, the US is No.1 and Canada is No. 3. It is clear that addressing herbicide resistance with additional herbicides is not the answer. With 98% weed control, the HSD could certainly have a major impact on herbicide costs, yield loss and include the mechanical weed control we’re missing in today’s no-till cropping systems. Herbicides are not a silver bullet and the HSD technology has huge potential with this new design. Let’s hope it makes it to the market soon. SL

Photo: The original Harrington Seed Destructor at Ray Harrington's farm near Temora, Western Australia. Photo source: S. Larocque

The debate on tyne versus disk openers and row spacing

Last week I had a conversation with Richard Konzag, a farmer from Mallala, South Australia and we discussed the effects of disk and tyne openers and row spacing. There is always a fierce debate about which system performs better. The tyne openers disturb more soil than disks, help aerate and warm up the soil but are limited by row spacing in a zero-till system because of poor residue flow. Disk openers on the other hand provide better seed depth accuracy, disturb less soil and allow for narrower row spacing because of improved residue flow. So which is better?

Richard provided me with some interesting observations from a recent trial he had comparing his John Deere ConservaPak on 12-inch spacing to a John Deere 1890 disk seeder on 7.5-inch row spacing. The photo you see here shows the plant stand difference between a disk opener on 7.5-inch row spacing (right) and the ConservaPak on 12-inch spacing (left).

Here are the results:

Planting date: Late April
Variety: Mace HRS wheat
Seeding rate: 90 kg/ha or 100 lbs/ac
Target: 200 plants/m2
JD ConservaPak, 12-inch = 306 heads/m2
JD Disk, 7.5-inch = 432 heads/m2
Heads/m2 increased by 41% in disk system on 7.5-inch spacing
Yield Increase: 0%

I'd say this is a classic example of utilizing soil, moisture and sunlight more efficiently with narrow row spacing. The increase in head numbers is likely from better seed depth, less in-furrow competition from improved seed spacing, and faster canopy closure from narrow rows improving early moisture retention. Yet, even with those benefits, there was an inability to capture the added yield potential from producing more 41% more heads per m2. Either moistrue or nutrition were limiting factors to the added yield potential.

I wonder how many ideas have been thrown out because they don’t add up to a yield advantage in the end? The reality is that adding yield potential requires additional nutrition to match the yield potential you’ve built. We often expect a yield increase by choosing a new variety yet we don’t fertilize to match the potential. We then conclude that it is no better than our current variety. The same situation exists when experimenting with row spacing. Perhaps we should take a second look at the way we compare new practices like narrow or wide row spacing and tyne or disk? Perhaps we’re missing the big picture?

In the case of wide versus narrow row spacing, disks versus tyne openers the jury is still out. My gut tells me we’re missing out on yield potential with wide rows in wetter climates. The trick is to build a narrow row system that can handle heavy residue. There could be 41% more heads per m2 in it for you. I know it has my gears still turning. SL

Photo: Richard Konzag