Agronomist Notes
Hello Reader
Man alive it’s cold outside but the memory of Canada scoring two gold medals in Olympic hockey is keeping me warm! Those games were magnificent.On the farming front there is some wheat being hauled but things are slowing down as we enter March. For now, crop plans are in place, inputs are bought and most of the machinery has been gone over.
Fertilizer prices continued to climb from logistical supply issues with some companies not even offering fertilizer pricing. Today’s prices vary quite a bit depending on supplier but urea is in the $700’s a tonne range, MAP around $760 and AMS around $490. The system will correct itself eventually, but those who haven’t pre-bought fertilizer may be in a tough spot.
This week we’ll look at some technology that helps plant seed beside the row, a technique we’ve found very beneficial. Next, we’ll look at our wheat yield potential based on the French-Schultz method and how we should look at benchmarking moisture use efficiency. Last, I’ve included a few apps that will be worthwhile using next spring to measure green area index for top dress nitrogen management. We’ll finish with technical grain market news.
Pictured above: Yours truly, speaking at the GRDC grower update in Temora, NSW, Australia. Notice the article heading below my photo. Out of left field is about right!
iTill technolgy from Australia
Seeding beside the row works on both sides of the planet
Two years ago we designed a 3-inch offset hitch to seed between the rows inside our CTF system. With 12-inch spacing we didn’t see the need to plant directly between last year’s stubble with a 6-inch offset, so the 3-inch offset hitch was born. Little did we know that planting beside last year’s stubble row would result in such an improvement in germination and emergence. We’ve noticed a 10-15% improvement in cereal emergence and 20% in canola. It turns out the Aussie’s have found the same results in Western Australia.The photo above shows our 3-inch offset hitch. Year 1, pull from centre, Year 2, pull 3 inches to the right and Year 3, pull 3 inches to the left of centre. The photo below shows the canola emerging beside the stubble row.
Paul Hicks from Pingrup, WA has a 61-foot John Deere 1820 drill with a technology he’s developed called the iTill. The iTill includes a specially designed, 2-inch sideband opener plus active guidance drawbar steering to steer opener's beside last years stubble row. Instead of an offset hitch like ours, Paul has designed a drawbar steering system that results in the same effect. I see this technology as a simple, yet valuable advancement in managing residue through inter-row seeding coupled with ideal placement beside the row. See information and photos of the iTill technology here.
If you think about it, your best chance to find soil moisture is in the root zone of last year’s crop. The driest and hardest area of the field is dead centre of last year’s rows where evaporation is highest. Planting in the middle of last years stubble rows can leave seeds in dry soil and create uneven seeding depth. However, planting into the mellow, moist soil beside the row improves seeding depth from better soil flow and emergence from consistent soil moisture.
If we want to talk seriously about precision agriculture, it is technology like the iTill, which places seed beside the row that will generate higher returns. The returns will come from a reduction in seed costs with the added bonus of higher yields from better emergence in dry, tough seeding conditions. I don’t know the cost of the iTill but active guidance systems run in the range of $8,000. At that price, it wouldn’t take much to generate a quick return on the investment. SL
Photo credit: S. Larocque
Taking moisture use efficiency to yield
A look at the French-Schultz method
When it comes to moisture use efficiency in Western Canada, there has been very little work done to calculate optimum yield potential based on the rainfall patterns and evaporation rates in each area. In Australia, researchers French and Schultz developed a model to calculate the maximum wheat yield potential for a given rainfall and evaporation rate back in the 1980’s, which is still widely used today.The French-Schultz yield calculation is a simple and measures the attainable yield per unit of water use. For example, research determined that it was possible to produce 20 kg of wheat per hectare for each millimeter of moisture based on rainfall and soil evaporation rates. The main criticism of this model is that it doesn’t take soil type, rainfall patterns or drainage into account. Though not perfect, it was a great starting point. A lot has changed since the 1980’s with the adoption of minimum tillage or direct seeding systems. Some have altered the evaporation rates to reflect todays zero till systems. Here are examples of the old and new equations:
French-Schultz, Old equation
(Growing Season Rainfall – Evaporation) x 20 kg/ha for Wheat
(350 mm – 110mm) x 20kg/ha / 1,000 kg/ha
4.8 tonne/ha or 71.2 bu/ac
New equation
(Growing Season Rainfall – Evaporation) x 20 kg/ha for Wheat
(350 mm – 90mm) x 20 kg/ha / 1,000 kg/ha
(350 mm - 90) x 20kg/ha / 1,000 kg/ha
5.2 tonne/ha or 77.1 bu/ac
To put this method into practice there is a website available here that allows you to enter post-harvest rainfall, in-season rainfall and your seeding date to calculate a yield estimate based on a wet finish or a dry finish.
Oddly enough, I ran our wheat yields through a calculation that didn’t include soil evaporation and generated 21 kg/mm/ha. Now, 2013 was an exceptional year but at the same time, we’ve achieved similar moisture use efficiencies in previous years.
94 bu/ac / 12 in = 7.8 bu/inch
6,300 kg/ha / 300 mm = 21 kg/mm/ha
If there is one thing I’ve learned from the Aussies, it’s their attention to soils and climate and their impact on yield. We have a lot to learn about benchmarking yield potential in Western Canada. If we don’t know what our yield potential should be, how are we going to find out whether our systems (rotation, agronomy) are over or under performing? Every successful business set targets so they know what they want to achieve. Production agriculture should be no different. Perhaps we could encourage our researchers to find out. SL
Research on French-Schultz here and here.
Photo source: Chris Dennison, NZ
Canopy Assessment Tool Apps
I thought I would provide an update on a few interesting apps that measure green area index for wheat, canola and corn. These tols can be used to determine top dress nitrogen rates in-season.GAI Tool for winter wheat: Free
The Canopy Assessment Tool provides an accurate and consistent assessment of crop nitrogen from its green area index (GAI) and crop lodging risk from a digital photograph. Only available through Apple here
GAI Tool for oilseed rape: Free
The Green Area Assessment Tool provides and assessment of crop nitrogen requirements to by measuring the green area index from a photo. From there you can calculate how much nitrogen to apply to achieve the optimum GAI which translates into optimum yield. To find out more on the use of GAI in canola go to this archived BA News issue http://beyondagronomy.com/newsletter-archive/june-12-2012
Only available through Apple here
FieldScout GreenIndex + Nitrogen App: $99.00
The FieldScout GreenIndex App measures the chlorophyll content of corn leaves and computes nitrogen application recommendations to maximize yield. The App comes with background pink, yellow and green reference boards to calibrate chlorophyll/nitrogen levels. It is only useful for corn at this time but I would hope cereals and oilseeds in time.
Only available through Apple here
Market News
Canola Nov 14: The long and short term trends are down.
HRS Wheat: Dec 14: The short term trend is up and the long term trend is down.
Corn Dec 13: The short term trend is up and the long term trend is down.
Soybeans: Nov 14: The short term trend is up and the long term trend is down.
Canadian $: Mar 14: The short and long term trends are down.
USD: Mar 14: The short and long term trends are down.