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Vol.102 Issue 11
NOVEMBER 2016

November 2016 1.pdf

Making a case for biosolids on interior ranches  [Tom Walker]


CLINTON – Stepping out of the truck, I think to myself that these south Cariboo grasslands don’t look very grassy. Parched, crumbly soil shows between small clumps of grass that are barely as high as my hiking boots. I’m not looking at the towering bunch grass I remember 40 years ago as I headed south from Kamloops through Knutsford on my first trip to Merritt.


It isn’t from lack of rainfall. Area ranchers I’m talking to tell me it’s been one of the wettest summers they can recall. Indeed, about 30 meters away, the grass is thick and green, not quite the “belly high to a horse” of legends, but perhaps knee high and high enough that it’s falling over in the late September sunshine. There is a thick thatch layer, native grasses crowd out the weeds, and the soil is dark and rich-looking.


Same land, same rainfall. What’s the difference? The lush green patch is a demonstration plot that has been treated with biosolids from the Lower Mainland.


Lawrence Joiner speaks in a soft tone as he describes the soil on his 5,000-hectare deeded rangelands.


“When the ministry range agrologist tested it, the results came back: no nitrogen, no organic matter,” says Joiner as he addresses a tour of his OK Ranch restoration project. “I came up from the coast so I was used to putting chicken manure on the grass to make it grow.”


He says he tried chicken manure and cow manure and chemical fertilizers but nothing helped.  


“Let it rest, said the agrologist, and I did,” says Joiner. “But it didn’t improve.”


Overdrawn

“You can think of the soil as a bank,” explains John Lavery, an agrologist and biologist who works with SYLVIS Environmental. “At some point, the bank became over drawn.”


There’s talk of over-grazing and the effects of the drought in the 1930’s. This area west of Clinton up against the Fraser River used to have enough families for two schools and now there is but one family.


Looks like compost

An hour later, I’m standing next to a 2,000-square-meter biosolids pile that looks like compost. In fact, it is very similar to compost. This material started as municipal sewage in the Lower Mainland but has been treated in an anaerobic digestion process much like composting and it meets the regulatory standards of “Class A” biosolids. The slang term is “municipal sludge” but that’s wrong. It’s not sludgy at all. It’s a stable pile, slightly moist and nearly odorless. That’s right. This poop smells like the bottom of a marsh if you were to stir it with a stick.


Lavery grabs a handful and it clumps together like damp dirt. He explains this pile has been here for perhaps two days. A manure spreader works the nearby grasslands in a manner that is practiced in hundreds of locations in countries around the world.


“Scandinavia, Europe, South America, the United States ...” Lavery rattles off a list.


The team at SYLVIS have contracts with several BC municipalities to manage roughly 25,000 wet tonnes per year at the OK Ranch. That will cover between 300 and 500 hectares of

Joiner’s land a year. The rest goes over to Alberta.


Joiner says the effect of the first test applications in the early 2000’s was “immediate.” The steers that grazed on test plots were up to 150 lbs heavier than their range-fed cousins. OK Ranch range grass has about 10% protein content. If you feed that grass biosolids, the protein jumps to 19-22% and slowly drops over four years back to 10%. Even after four years, average forage production on biosolids plots was 2,280 kg per hectare compared to 460 kg per hectare, untreated.


The treated land greens up earlier in the spring, fades later in the fall and the taller grass is easier for the cattle to graze through light snow. Joiner says his animals can stay at least a month longer on pasture and that means a month less of buying hay.


“This is such a valuable resource,” says Joiner.


Comparisons

The last stop on the tour is to view a test plot that had one application of biosolids in 2002 when the project first started. Half of the fenced-off area was treated and half has been resting. The non-treated, rested area is marginally better than the grazed land outside the fence. But the affects of one application of biosolids 14 years ago are marked. The gaps between the clumps of small bunch grass are filled in. It is clear there is organic matter in the soil that supports a healthy range eco-system. That “soil bank” that Lavery described earlier has had a major deposit and it is maintaining a healthy balance sheet.