Current & Completed Research Projects
Organic Production Systems
Organic Dairy Herd Health. (In-Progress)
This trial is in progress, starting with a literature review comparing organic and conventional herd health in Canada, the US, and Europe, to be followed with surveys of producer practices and experience in concert with Organic Meadow, the largest organic producer co-operative in Canada.
Species Composition and Weediness in Grazed Pasture. (In-Progress)
A 1-year study was conducted in 2005 at Alfred College to assess the effect of windbreaks on grazing and manuring intensity, and hence, on species and nutrient redistribution.
Cover Crops in Organic Farming. (Complete)
A 3-year study was conducted between 2003 and 2005 at the Ignatius Jesuit Center (IJC) to test the efficacy and reliability of cover crop species in controlling weeds, conserving N, and adding OM within the late summer/fall interval, and to assess carryover effects on winter grain crops. Seven species were compared over 2 years, with subsequent cereal yield monitored in the third year. The best and most consistent crop was sorghum-sudan, whether for weed control, biomass accumulation, or N immobilization. However, fall rye grain yield in 2005 was lower following sorghum-sudan than other crops, possibly due to N immobilization from the large volume of wide C:N residues incorporated prior to rye planting. Capitalizing on sorghum-sudan for system services without reducing subsequent yield may require following with a spring rather than fall cereal or changes such as earlier incorporation to narrow the C:N ratio and reduce immobilization.
Grain Yield and Weed Control in Organically Managed Spring Oats (Complete)
A 3-year study in oats was conducted at the IJC on certified organic land, between 2002 and 2004. Grain yield and weed control were compared over oat cultivars, seeding rates, seeding methods, and times of seeding. Ida was consistently highest yielding, producing an average of 741 kg ha-1 or 29% more than OAC Paisley. Yield increased up to 450 plants m-2 in all years, although the statistical benefit was generally exhausted by 250 plants m-2. Drilling improved yield by 10 to 13%. Delaying seeding from 6 to 28 May reduced grain yield by a third or 1.3 t ha-1. However, cultivars differed in response to delayed seeding, with Ida less affected than OAC Paisley or AC Stewart. In the aggregate, weed biomass was lower in Ida than in either OAC Paisley or AC Stewart, and declined incrementally with increasing seeding rate. Drilling reduced weed biomass by about a third, while delayed seeding increased weed biomass by about a third. Ida - the preferred oat cultivar on surveyed organic farms (next title) - proved to be superior in both yield and weed control. Higher seeding rates, drilling, and timely seeding were also shown to reduce weed yield. Oat yield under organic management averaged 2942 kg DM/ha (3.4 t/ha at 14% moisture), which compared favorably with the Wellington County average of 2.5 t/ha in 2004.
On-Farm Surveys of Organic Farm Practice in Ontario (Complete)
From 10 to 13 farms were surveyed annually between 2001 and 2003 to establish a database of agronomic and soil management practices, and to enable planned contrasts between hort and field crop farms, and between degrees of livestock impact. Assessments were based on broccoli, carrot, and potato crops on hort farms, and spring grain, winter cereal, and soybean fields on field crop farms. Soils under permanent pasture were significantly higher in SOM, K, and Mg than hort and field crop soils, with similar (ns) trends in P and Ca. Soils did not differ between hort and field crop farms in any measured parameter, with SOM of 4.1 (n=30) and 3.8% (n=39), respectively. Most hort as well as field crop farms employed either perennial forages in the rotation or composted livestock manure (imported) or both. Crop rotations averaged 7+ courses on both hort and field crop farms, with living winter soil cover on 32 and 67% of the hort and field crop farms, respectively. Pest species identified by farmers were highly site-specific. The site-specificity of both the management practices and pest problems will necessitate novel research methods to serve the organic farming community.
Nutrient and Energy Flows on Organic and Transitional Farms in Ontario (Complete)
Seventeen farm-crop combinations from six Ontario organic farms were monitored in 2003. The goal was to quantify nutrient and energy flow and soil, crop, and livestock management on farms differing in livestock and forage dependence. Yields were roughly 50, 70, 100, and 120% of provincial yields for soy, spelt (v. winter wheat), mixed grains, and hay, resp. Total labor for seedbed preparation, planting, weed control and harvesting averaged 2.8 hr/ha on mechanized vs. 7 to 40 hr/ha on horse-drawn farms. Number of field passes for seedbed preparation and weed control ranged from 1 to 5 (mean 3.5) per field. Most nutrients were supplied by composted manure, which was applied almost solely to soy and spelt for sale. Compost provided up to 148, 55, and 184 kg N, P, and K/ha respectively. Small grains grown primarily for on-farm feed tended to be unfertilized or were preceded by a forage plowdown or hay crop. Implied nutrient export averaged 41, 57, and 78 kg N/ha for spring grains, spelt, and soy, respectively. Comparable figures for P were 9, 14, and 9 kg/ha and for K were 13, 19, and 24 kg/ha, respectively. Perennial forages were prominent on most farms, with N-fixing crops accounting for 60%, and living winter covers for 64% of reported 6-year rotations. Results will contribute to efforts underway at the Organic Agriculture Centre of Canada to model nutrient and energy flow on organic farms.
Pasture and Grazing Management
Does it Pay to Reseed? (6-year trial, 2000-2005; complete)
Pasture supports animal-friendly, environmentally sound production of livestock, with additional benefits to both animal welfare and human nutrition. In this replicated, multi-year trial, rotational grazing and fertilization to soil test allowed a 16 to 21 year old predominantly grass pasture to support the same rate of individual calf gain (1.3 kg d-1 or 205 kg/calf over a mean 160 day grazing season) as was attained on resown swards. However, resowing to alfalfa-based mixtures increased per hectare calf gain by 29%, from 506 kg ha-1 in the old sward to 654 kg ha-1 in resown swards, an effect which was sustained throughout the 6 year trial. Gain was sustained even as alfalfa content declined, apparently due to the presence of other species, including tall fescue, which were similarly adapted to dry midseason conditions.