There is a lot of buzz in beef and forage production systems around the concepts of sustainability and soil health, and the numerous different production practices that can support those ideas. Intercropping is one strategy that can improve efficiency and soil health.
Manitoba producer Alan MacKenzie considers intercropping to be two crops that are grown at the same time to be harvested together. The cow-calf producer has been an organic farmer for 20 years and used intercropping on and off as a tool on his mixed farm for the past decade.
“I would say the main benefit is just trying to get some diversity and any time we can get some legume in the mix for the nitrogen, that’s good,” said MacKenzie, who farms near Nesbitt, south of Brandon.
He has tried cash crop combinations such as pea and mustard, a pea/oat mix, and wheat with flax, but he said there are numerous combinations that could work depending on the individual farm.
“I seed everything at the same time, same depth,” he said.
MacKenzie also typically underseeds his cash crop mix to a forage ‘relay crop,’ and usually seeds everything in one pass in the spring.
“Relay cropping opens extra things, I’ll throw in vetch or Italian ryegrass or sweet clover at the same time,” he said.
For example, he’ll harvest an intercrop of peas and oats, spread or bunch the straw, and then his cattle will graze the green forage crop that’s growing underneath in the fall. Some years it’s very dry and you don’t see the response, or sometimes some crops outshine the others, but this cattle herd always has access to good feed, he said.
Terms like intercrops, cover crops, and relay crops are often used interchangeably, however, all are strategies for intensifying how to utilize land to capture sunlight, said University of Manitoba professor and researcher, Yvonne Lawley.
“The important thing is to think about what your goals are and what strategies are going to help you meet your goal,” said Lawley.
“If one of your goals is soil health, understand what aspect is important to you. Is it infiltration? Nutrient cycling? Then find a measurement that is successful for you that you can follow over time to see if that investment is impactful to you.”
Lawley has worked with University of Manitoba colleague Emma McGeough to evaluate corn intercropping systems for cattle grazing.
“Corn is a great winter feed crop because it has so much biomass and energy in a small amount of space, but the inherent problem with corn is that is has lower protein,” she said.
McGeough will study how cattle perform on intercrops compared to corn alone and there are collaborative test sites set up in Alberta, Saskatchewan, and Manitoba.
The advantages of diversity
On his farm, diversity is about managing risk and not putting “all their eggs in one basket,” said MacKenzie.
He seeds a plow-down crop, such as sweet clover and vetch, every three years, terminating the crop by working it into the soil to incorporate organic matter and clean up weeds. It’s a versatile mix and the plow-down crop is sometime used for feed.
“We will benefit from that, utilizing that cropland as cattle feed that doesn’t cost a lot of money,” he said.
Seeding intercrops or cover crops can create multiple opportunities, said Lawley.
“From a livestock perspective you can grow forage for different windows and provide more options for grazing throughout the entire growing season,” she said. “Are the crops for feed? For soil? In reality, it’s for both.”
MacKenzie identified a few challenges, including separating crops after harvest.
“Make sure you have buyer acceptance,” he said, explaining some buyers with stringent guidelines may, for example, reject a nice sample of oats if it has a minimal amount of pea chips present.
Cleaning seed is a fair amount of work and sometimes there may not be enough of a reward in the marketplace to offset the hassle, he said.
MacKenzie experienced other learning curves, such as the time he used lentils in an intercrop mix.
“Timing the species right is so important,” he said. “By the time the other crop was ready for harvest, the lentils had shelled out.”
Accessing versatile equipment can be another frustration, Lawley said.
“Having equipment that allows you to easily intercrop either by adjusting rate on alternate rows or allowing you to have bins that you can set different rates on for different seed sizes,” she said. “Those become important if you’re doing this on a large scale or want to operationalize over large acres.”
Connecting with others using intercropping is helpful for sharing ideas and learning from others’ experiences.
“They learn from the failures and thinking through what went wrong, regrouping, pivoting, and moving forward,” she said. “The surprises are where a lot of learning is going to happen.”
This article has been edited and abridged. The full article can be found at the BCRC blog at beefresearch.ca.