Scientist Vernon Rodd explains how the sleigh-foot method of spreading liquid manure works. Early results indicate the method, being tested in Nappan, will be better for the environment and agriculture production. (TOM McCOAG / Amherst Bureau)

By TOM McCOAG Amherst Bureau

NAPPAN — Ahhh, it’s springtime that wonderful time of the year in rural Nova Scotia when liquid manure spreaders are out in full force and the smell of agriculture’s perfume hangs heavy in the air.

To some the smell is heavenly, a sign of good, clean country living. To others the odour — like that of a dead skunk on the side of the road — causes them to hold their noses and gag.

The latter may be in for a break if a new liquid manure delivery system being tested at the Nappan Experimental Farm proves its worth — and early indications from scientists there indicate it is living up to its billing.

"Reducing the smell is but one benefit of this sleigh-foot delivery system we are testing," research scientist Vernon Rodd said in a recent interview. "It also has the potential to reduce harmful effects on the environment and improve crop yield."

Spreading of manure on fields is a big issue in Nova Scotia, where nearly 80 per cent of agricultural land is devoted to the growing of forage crops and grasses, like Timothy, that farmers turn into hay for their animals.

The preferred fertilizer for these crops is liquid animal manure, and 80 per cent of the manure spread in Nova Scotia is used for that purpose, Mr. Rodd said.

The current practice involves a tractor pulling a tank full of liquid manure over a field. The manure is ejected from the tank under pressure. It hits a splash pan located high up on the back of the tank, which turns the stream of manure into a fine mist. It then mixes with the air and settles gently onto the ground.

"The smell is caused by the mixture of the manure with the air. If it’s even a bit windy, the smell is carried into the air and to places where it can offend people," Mr. Rodd said. "We also lose about half of the nitrogen, the main ingredient that benefits the plants."

The floating nitrogen can also land in ponds and rivers, encouraging the growth of algae. That decreases the amount of oxygen in the water, which in turn harms wildlife.

The new sleigh-foot delivery system, developed in Europe, has shown some success there, "but we didn’t know, because of our different climate, if it would be as effective here," Mr. Rodd said.

After viewing the system out west, Agriculture and Agri-Food Canada researchers at the experimental farm teamed up with scientists from the Nova Scotia Agriculture College and AgraPoint to see if the system would work in eastern Canada.

The research began two years ago.

The sleigh-foot method uses the same holding tank as the splash pan method. But instead of spraying out and hitting the splash pan, the manure is pushed through a distributor — much like the distributor cap of a car — and down plastic piping to the sleigh shoe. The shoe slides across the ground, depositing the manure directly onto the soil and under the crop canopy.

"We have shown that we can reduce the amount of nitrogen that is being blown away by the wind by 50 to 70 per cent," Mr. Rodd said. "That means the smell is decreased and the chances of runoff into waterways is greatly diminished.

"It also means more of the nitrogen is getting to the crop, and as a result we are seeing the yields from the fields increasing by 15 per cent."

Because the manure is spread directly to the ground under the canopy, farmers can wait two or three weeks later in the spring before applying manure, when the soil is drier and less compacted, which in turn is also better for the crop, Mr. Vernon said.

Another benefit is that most of the components for the system, aside from the distributor, can be manufactured with material most farmers already have on hand, he added.

Buoyed by the results, Mr. Rodd said researchers are now looking at whether the distribution system would work with cereal crops like wheat and barley. They are also looking at the possibility the system could be used to safely distribute human waste as a fertilizer.

"Before we know if either of those is viable, we will have to conduct many more experiments," Mr. Rodd said.