WINNIPEG — Some farmers now have equipment that could allow them to place ammonium sulphate in the seed row.
Don’t do it.
That was a message from soil scientist Don Flaten to growers at Manitoba Ag Days.
“It can be really deadly,” said Flaten in an interview after his presentation.
“The 21-0-0-24 we use to supply sulphur in canola can be extremely toxic to canola seed, especially in high pH soils.”
Ammonium sulphate is a great way to deliver both nitrogen and sulphur to a crop, either with mid-row placement or broadcasting, but the worry is farmers could also be tempted to deliver it where they would normally just place phosphate in the seed row.
However, the sulphate soil chemistry can have terrible effects on seed, especially in soils with pH levels higher than 7.5.
As summed up by Agvise Laboratories, “the high pH soils contain calcium carbonate, which reacts with ammonium sulphate to create calcium sulphate and ammonium carbonate. The higher reaction pH of ammonium carbonate produces free ammonia. Free ammonia in soil is toxic to living organisms and kills germinating seeds.”
Flaten said he is astounded by the cost of some of today’s canola seed, with $1,000 per bag no longer the stuff of fantasy, which means farmers can’t afford to see a big portion of that pricey product killed by ammonium sulphate.
“We’ve got enough challenges with seed row fertilizer in canola without putting ammonium sulphate in there to really screw things up,” said Flaten.
“I don’t want that canola in contact with ammonium sulphate.”
