AROWRN Keoma Demonstration Site Field Tour 2016

In October, 2016, members of AROWRN and interested individuals met to tour the City of Calgary biosolid demonstration site. The site, the largest willow plantation of its kind in North America, is located approximately 30 kilometres northwest of downtown Calgary, on land operated by the Mountain View Hutterite Colony near the hamlet of Keoma. Visitors were able to see the site, comprised of stands planted with 20 different willow hybrids, and observe willow harvesting technology demonstrations.

Over the past three years, 150,000 bulk tonnes (bt) of City of Calgary biosolids have been applied to 28 quarter-sections (approximately 1,813 hectares) on a rotating basis of 7 quarter-sections each year. Application rates have ranged from 85 bt/ha to 140 bt/ha. Since the first planting, 498 ha have been seeded (166 ha/yr) with approximately 2.5 willow cuttings. Biosolid application-harvest cycles are on a short three-year coppice rotation, with an expected project life of up to 30 years. The October, 2016 harvest demonstration followed the first harvest trial in the spring of 2016. Sylvis have been the project managers and scientific leaders, with the field management, planting, and harvesting undertaken by Mountain View Colony.

Visitors to the site in October, 2016 represented a large number of stakeholders: academic, applied science, representatives of three levels of government, along with producers, woodlot managers, and other interested individuals. Many of the participants travelled in two buses that departed from Edmonton and Calgary. Because of the distance to the site, Edmonton-origin participants had time to enjoy informational presentations before arriving at Keoma. Mark Teshima of SYLVIS, Richard Krygier of the Canadian Wood Fibre Centre, and Andrew Dunlop of Grande Prairie Regional College, respectively described the Keoma project, the work undertaken by the CWFC over the past ten years, and the role of AROWRN. The Calgary group heard similar information from Shawn Northwood of SYLVIS, Martin Blank of the CWFC, and Kelly Manuel of GPRC.

Hearing the project details

Once at the Keoma site, the two bus groups convened with members of the Mountain View Colony and other individuals who had travelled to Keoma on their own. Participants heard additional information presented by representatives from the City of Calgary and Alberta Innovates on the importance of the project for Calgary’s long term biowaste disposal, and the end uses for the woody biomass. Following Shawn Northwood’s background primer on the Keoma site, participants were invited to inspect the initial trial stands, noting the different growth rates, sizes, and densities of the various hybrids. They also learned about the trial hybrid selection and propagation, as well as soil morphological and chemical changes within the stands.

After inspecting the experimental stand, and following a much-appreciated warm-up coffee break on the buses, the group reassembled for the highlight of the day: the harvesting demonstration. The weather at the Keoma site was ideal for the machine demonstrations, with the temperature hovering around 0°C, with a light fog, and no wind. The demonstration organizers noted that harvesting was normally done when the willow stems had frozen, but for the spectators’ comfort, an earlier demonstration date had been chosen.

The Anderson Biobaler

Using one two-year old stand planted with one hybrid species, colony operators demonstrated the capabilities (and limits) of three different pieces of harvesting equipment. The first machine to cut a swath was the Anderson WB-55 Biobaler. Field speed was reasonably quick, with little clogging, but the machine tended to tear the trees, leaving stems badly fractured, and much of the root matter disturbed.

Next into the stand was the Claas Jaguar 870 forage harvester fitted with a wood harvesting header. Although the header was able to cut two rows simultaneously, consistent field speed was difficult to maintain as the header was prone to clogging, particularly around the saw blade guides. Mountain View Colony machine operators have been experimenting with this header, trying to determine the optimal field speed and cutting height. Much of the clogging issue appears to be related to age-related wear on the header, and the Mountain View crew still feel the Claas setup has the greatest potential.

The third test was undertaken using a JF192 Z10 silage harvester adapted for single-row wood harvesting. Although commonly used in many countries, this harvester was disappointing in a number of ways. Because of the narrow intake design and the three-point mounting arrangement, many stems were left uncut or torn. Due to the trailing, side mounted position of the collector, passes could only be made in one direction, greatly reducing harvest efficiency.

During the demonstrations, all three pieces of equipment suffered issues with clogging and/or rough cutting. Harvesting rates were disappointingly slow. Some observers speculated that much of these issues were due to the stems not yet being frozen, which would make the wood more brittle. The relatively large stem diameter and hardness of the initial demonstration hybrid was also suspected to be causing poor results. A decision was made to try again, this time on a stand planted with a different hybrid. In this demonstration, the Claas was re-tried, with much better results. Cuts were generally clean at a reasonable field speed, with less uprooting and tearing.

In the end, the demonstrations proved that much equipment trialling is still required. Optimal variables of hybrid selection, stem temperature, field speed, and cutting height still have to be determined. Of the three technologies demonstrated, the Claas forage harvester holds the most promise, with a general agreement amongst the Mountain View operators and spectators alike that an improved header design, which is already commercially available, would likely result in much better performance.

With the demonstrations complete, the Calgary and Edmonton spectators boarded the buses and the field day concluded with conversations enroute about next steps for AROWRN.