CALGARY Ñ Addressing soil phosphorus deficiencies has become one of the top priorities for the organic research community.
“It seems to be a very high concern for soil scientists and for producers at this point,” says Brenda Frick, prairie co-ordinator of the Organic Agriculture Centre of Canada.
“We get a lot of calls on that.”
Farm surveys and long-term rotation studies in Saskatchewan and Manitoba have found phosphorus levels to be depleted or severely depleted on organic farms where fertilizer isn’t allowed.
The results may be exaggerated by a shortcoming of traditional soil tests that only measure readily available levels of phosphorus, overlooking what might be bound up in the microbial inhabitants of the soil. However, the results are disturbing enough to send a collective shiver through the organic industry.
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Phosphorus is important for proper root development, plant growth and metabolism and rapid crop emergence.
“Without being able to pick up phosphorus, they’re not going to be strong, vigorous plants, they’re not going to be good competitors, they are going to have issues,” Frick told growers at the recent Going Organic conference in Calgary.
That’s why a number of prairie research facilities have initiated projects to determine how to recharge organic soil with the critical element.
One idea is to use phosphorus-scavenging crops like pulses as green manure. The hypothesis is that their phosphorus-rich residue can be absorbed by the following crop.
Another project will explore the phosphorus-attracting ability of plants with acidifying roots, such as mustard, canola and buckwheat.
Yet another will study how certain plants such as pulses encourage microbial activity in the soil. Certain microbes break organic matter down, releasing phosphates.
The Western Grains Research Foundation has also agreed to entertain proposals from breeders on developing low-phosphorus wheat lines, although no project has been approved yet.
Another research thrust is to conduct variety trials under circumstances more suited to organic production systems. To that end, Agriculture Canada breeders are testing how new lines of cereal crops perform in low-input situations.
Frick said potentially useful organic crops are deemed losers under high-input research trials.
“A lot of things don’t make the cut. Some of those may have been good for organic farmers or they may not, we don’t really know. But this is a way of testing that.”
For instance, crops that have wider leaves are thought to be inefficient in many traditional breeding programs but could work well under organic constraints.
“Really competitive crops have not been a real target under high-input systems because you don’t really need to compete with weeds if you blast them all away,” Frick said.
One shortcoming raised by producers at the conference was the lack of research on organic livestock production, such as determining which annual forages work best.
Frick said she is trying to put together funding for a study on organic parasite control, but that’s about it for livestock production.
“They’re right. There isn’t a whole lot being done yet and we’re definitely wanting to move in that direction.”
