Corn has seen some moderate acreage gains recently as a crop for farmers in Manitoba, and for good reason. The yield per acre seeded has grown exponentially over the past 20 years.
But that growth in acres hasn’t been exponential as well. It’s been more in the realm of the slow and steady. For example, in 2018 StatsCan reported a record of 428,000 acres were planted, up 4.4 per cent from the previous year.
That’s nothing to sneeze at, but it’s a pittance compared to the acreage taken by other crops that year. Canola, for example, covered 3.4 million acres. Spring wheat was seeded to about 2.8 million acres. And another relative newcomer, soybeans, was planted on just shy of 1.9 million acres.
Why it matters: Corn is one of Manitoba’s most profitable crops but it still lags other options in terms of planted acres.
Speaking to an audience at the CropConnect conference in Winnipeg, Yvonne Lawley, an assistant professor in the plant science department at University of Manitoba said that, while there has been some great work by plant scientists in adapting corn to Manitoba, farmers need more information if corn is really going to take hold in the province.
“Yield alone may not be enough to realize corn’s great potential,” she said. “Sometimes we need the whole package.”
That “whole package” is now beginning to take form. The numbers are in from a study of corn agronomics in Manitoba and the news is encouraging for farmers who cycle corn into their rotation.
The Corn Agronomy Project had the goal of developing agronomic best management practices for successful corn production in Manitoba. Lawley was the lead researcher for the project. She was joined at CropConnect by Derek Brewin, an associate professor at the department of agribusiness and agricultural economics at the U of M.
The study covered a broad range including crop rotation, residue management, phosphorus fertilization and evaluating corn heat units. However, the scope of the discussion at the CropConnect conference was limited to crop rotation and economics.
The project began in 2014, with the seeding of test fields with some common Manitoba crops: corn, canola, wheat and soybeans. They rotated those crops year by year through to 2017, so that they had three years of comparative data.
Conveniently, each year saw very different field conditions. 2015 was just about perfect, 2016 was very wet and 2017 started out good, but ended up being very dry. The plants were analyzed at an early stage and at the silking stage. They looked at biomass, phosphorus uptake, arbuscular mycorrhizal fungi (AMF) root colonization and yield.
The researchers discovered that the preceding crop affected early corn growth but didn’t greatly affect overall yield. It found that canola grown before corn is a special case, with lower biomass and phosphorus uptake in early stages; shorter plant height in later stages; and a delay in cob silking.
When pencilling out any crop rotation profitability is a prime concern.
Agricultural economist Derek Brewin explored the economic impacts of plant rotations. When compared to other major grain crops, corn on average provides net returns greater than all others.
Spring wheat comes in at $150 per acre; oats is $136 per acre; canola at $179 per acre; soybeans at $170 per acre; and corn at an impressive $241 per acre. But of course, yield decreases year by year without crop rotation, so farmers need to know what works best.
In the study, rotating corn with soybeans gets farmers the best bang for their buck. When averaged over five years, that rotation netted $227 per acre. For comparison, a wheat/canola rotation (the most common in the province) nets only $177.
But the research went much further than that. They did simulations of just about every permutation and combination of rotations and ranked them. As expected, the most profitable rotation for a 13-year price series was soybeans and corn and these two crops were part of all the top 10 rotations. Canola and wheat both entered four of the top 10 rotations. Canola was part of the highest-earning rotation in three of the last 13 years.
Brewin noted how crucial Manitoba crop insurance data was in teasing out the economic impacts but said that more information is needed.
“I think we do need plot level, field-after-field studies in the long run to confirm some of this,” he said.