| | Developing cost-effective beneficial management practices (BMPs) is essential to make progress toward healthier watersheds. A $5.65-million national study, led by Agriculture and Agri-Food Canada, is examining the effectiveness of various agricultural BMPs on a watershed basis at seven sites across Canada, including one in southern Alberta.
Called the Watershed Evaluation of BMPs Study (WEBS), it will quantify the environmental and economic effects of selected BMPs on water quality at a microwatershed scale (about 300 hectares in size).
The watershed approach is key to the study. BMPs are often evaluated on test plots or small fields, and then the net effects at the watershed level are predicted using scientific models. But complex interactions between diverse factors can alter how farm-level changes affect overall water quality in a watershed, so the predictions need to be checked with reality to ensure that the BMPs are truly effective.
The microwatershed in Alberta is a small portion of the Little Bow River watershed and lies northeast of Lethbridge. Dr. Jim Miller of Agriculture and Agri-Food Canada is leading this project. He says, “We picked the Lower Little Bow River because it had been intensively studied in the Oldman River Basin Water Quality Initiative, so it had a good historical database.”
The project runs from 2004 to 2008. So far, the Alberta research team has set up monitoring equipment and started implementing the following five types of BMPs in the microwatershed:
- Off-stream watering with fencing – to compare water quality upstream and downstream of a 6 riparian pasture that has been fenced off since about 2001 to keep cattle out of the river
- Off-stream watering with no fencing – to compare water quality before and after off-stream watering systems are installed in a winter pasture and a summer pasture.
- Conversion to forages – to compare the water quality of the runoff from two fields before and after they are converted from irrigated barley to forages.
- Buffer strips – to assess the ability of various types of buffer strips to filter sediments from field runoff, comparing tame grass strips, tame grass/shrub strips, and native grass strips, each at widths of 5, 15 and 30 m.
- Beef manure application rates – to compare the runoff water quality from plots with no manure to plots with application rates based on the crop’s annual nitrogen requirement, its annual phosphorus requirement, and its three-year phosphorus requirements.
The project is a cooperative effort, explains Miller. “We have a large committee with people from different agencies, and everyone brings a different perspective. It’s good to get different viewpoints on different problems from the economists to the fisheries person, extension agents, researchers, and all the other people.” The committee includes representatives from: Agriculture and Agri-Food Canada’s Research Branch and PFRA; Alberta Agriculture, Food and Rural Development; the County of Lethbridge; Fisheries and Oceans Canada; Ducks Unlimited Canada; and the University of Alberta.
WEBS is funded mainly through Greencover Canada, a five-year, $110-million federal initiative to help producers improve grassland management, protect water quality, reduce greenhouse gas emissions and enhance habitat. Ducks Unlimited Canada is a national partner in the study, contributing $1.25 million of the total cash funding. For more information on WEBS, visit http://www.agr.gc.ca/env/greencover-verdir/.
Correction on methane emissions: the true truth!
The Summer 2004 issue of Green Matters included the “true story” of methane (a greenhouse gas) emissions from cattle. It turns out the truth we printed wasn’t quite true! The article stated that, “Some bacteria in the rumen produce methane as a by-product. That methane is absorbed into the bloodstream, goes through the bloodstream into the lungs, and then is exhaled. That’s where the bulk of the methane comes from. So we can put to bed the myth that cows are incredibly rude burping, farting creatures!”
In fact, only some of the methane is absorbed by the bloodstream and exhaled by the animal. Most of the methane comes out via “eructation” – the cow’s deliberate expulsion of rumen gas through its mouth and nose. Eructation is done quite silently though, beef scientists assure us! A small amount of gas is emitted through the rectum as well. So we can still say that our cattle are no more rude than the rest of us! |
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