Pulse School: Peas potentially get mycorrhizal boost when grown on last year’s wheat field

(Kara Oosterhuis/RealAgriculture)

There’s a possible yield benefit for peas following wheat in a crop rotation rather than canola, according to research done through the University of Manitoba.

This Pulse School episode features Brodie Erb, MSc student and field technician at the U of M, who has spent the past three years looking at how preceding crop, residue management/tillage, and starter phosphorus impact pea yields. The results were presented at the Manitoba Agronomists Conference in Winnipeg this week (see poster below).

Of those three factors, Erb found preceding crop had the most significant effect on pea yields, with peas grown on wheat stubble significantly out-yielding peas on canola in two of the three years in plots at Carman, MB.

That’s likely due to mycorrhizae populations in the soil helping with early phosphorus uptake, he says. Wheat and peas are both mycorrhizal crops, while canola is not a host for mycorrhizae.

“The thought process is that theoretically peas grown on wheat stubble should out-yield peas grown on canola stubble because of that association, and because of that greater networking opportunity following wheat stubble,” he explains.

In corn, also a mycorrhizal crop, a starter phosphorus application can help counter that early phosphorus deficit following canola, but Erb’s research with peas did not show any significant yield boost from a 15 lb P2O5 starter-P application — both seed-placed or banded 2” away from the seed row. These results require further investigation, including looking at the three-way interaction between the different management factors, he says.

Check out the video below for more with Brodie Erb on his research looking at the interaction between preceding crop, residue management, and starter P in peas.

(click to enlarge)


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