After sowing large green lentils on 180 acres of oriental mustard stubble this spring, Kevin Hursh was surprised by the amount of volunteer mustard that emerged. He’d expected a few volunteers from last year’s crop, but not the number of plants that established.
“That field looked awfully yellow by July,” says Hursh, who farms at Cabri, northwest of Swift Current, Sask. “I didn’t think the volunteers from the mustard would be a large issue, and by the time I saw how much tame mustard was coming, weed control options were really limited because the crop was getting past the proper stage to take any control actions.”
So instead of sweating it, Hursh decided to make the best of his unintentional intercropping experiment. He went out and purchased a used rotary grain cleaner with the intent of separating the mustard and lentils after harvest to see what he ended up with.
Interestingly, the field matured early.
“It wasn’t seeded first but it did mature first, although I am not entirely sure that was because of the mustard in it.”
Colin Rosengren, who farms near Midale, Sask., and has years of experience with intercropping of canola (a close relative of mustard) and lentils, relates that in his experience the volunteer mustard did contribute to the early maturity.
Hursh was able to use Reglone as a desiccant because it’s registered on both lentils and oriental mustard, and harvested the field before the late-season wet weather set in. The harvest rain delay gave him the opportunity to clean the two crops, which took longer than he expected.
“We could run through about 300 bushels an hour,” says Hursh. “And it wasn’t perfect; we lost a few of the lentils into the yellow mustard.”
Still, he feels the result was worth it. Hursh ended up with around 900 bushels of oriental mustard and also had a good-yielding lentil crop this year of 30 bushels per acre plus, which Rosengren suggests could partly be due to less disease pressure.
“I had some leftover mustard that had to be shipped anyway and so the 900 bushels went as well,” says Hursh. “The end result was that the mustard that was cleaned out of the lentils was worth just over $9,000, and that was almost exactly what the rotary grain cleaner cost.”
Although Hursh’s intercropping was entirely unintentional, he doesn’t see it as an ideal way of dealing with volunteers, especially if previous rotations include canola (which would be impossible to separate) or where there have been infestations of wild mustard (which could seriously lower the value of any tame mustard crop).
Having said that, he believes the two crops growing together had a few advantages. It was much easier to harvest because the mustard held up the lentils, and he suspects that having a denser crop helped suck up some of the excess moisture this year.
“It’s definitely is a more efficient use of moisture,” says Rosengren. “In wet years especially, it will help maturity because the mustard will use more moisture than the lentils, which don’t need a lot of moisture anyway.”
Usually, farmers take measures to control brassica weeds in their lentil crops. That wouldn’t be possible with mustard intercropping. There are also different fertilizer requirements. Hursh had only applied the 30 pounds of phosphate per acre that he usually uses on his lentils. The mustard didn’t seem to lack for nitrogen, but no comparative analysis was done.
Although it’s the first time Rosengren has heard of a mustard/ lentil intercropping mix, he feels it’s potentially a good combination, and could help solve the problem of swaths blowing away, a reason he has often limited the acres of canola/lentils he has grown.
“The actual agronomics of growing them together is quite good,” he says. “In the case of mustard and lentils, that’s probably a good fit because you could straight cut them.”
For Hursh, although his intercropping has been an interesting experiment, he doesn’t think that he’ll be repeating it again next year — or at least not deliberately.