Farm-Scape, Episode 1559

Research underway in Saskatchewan shows the addition of swine manure fertilizer to the soil to have a variable, but usually beneficial, effect on soil organic matter content.

Adding organic matter to the soil improves the soil's structure or tilth and increases its nutrient storage capacity while, at the same time, increasing carbon sequestration which reduces carbon dioxide in the air.

A graduate student study, underway as part of the University of Saskatchewan's long term research into the use of swine manure fertilizer, is examining the impact of repeated application on soil organic matter content.

Senior Researcher Dr. Jeff Schoenau says the study has shown a somewhat variable effect.

"Generally we see some increases in organic matter content, especially in soils where the organic matter content was low to begin with and that have a fairly high clay content which helps the soil absorb the organic matter and protect it from decomposition.

We did have some instances as well where the application of swine manure resulted in some decreases in organic matter.

Those instances were where the manure was applied at one of our sites and, because of a lack of sulfur, we got very little crop response to the nutrients, the nitrogen that we applied in the manure.

Because of that lack of stimulation of plant growth and perhaps because the nutrients in the manure itself stimulated microbial activity, we saw no influence and perhaps even a slight negative impact of the manure addition on soil organic matter content.

However, at sites where we had low organic matter to begin with and where we saw lots of yield stimulation we do see an increase of the soil organic matter content."

Dr. Schoenau says scientists are now focusing on the impact of repeated swine manure application on microbial populations and enzyme activity in the soil.

He expects that work to be completed by the fall.

For Farmscape.Ca, I'm Bruce Cochrane.