Premium Manitoba Spaghnum Peat Moss

Quality Control

The Product
Canadian Sphagnum Peat Moss is regarded by both professional growers and experienced retail consumers as an optimal soil conditioner. Sphagnum Peat Moss is a partially decomposed Sphagnum species, whose unique cellular structure consists of large cavities that absorb air and water like a sponge (Peat Moss can hold many times its weight in water). Because the right balance of air and water is essential for root development and plant growth, organic sphagnum peat moss is considered the highest quality growing medium available. Manitoba Sphagnum Peat Moss is regarded by a majority of Western Region Growers as simply the best growing media available due to its fibrous nature, light color, high porosity and water holding capacity, low pH and bulk density.
Professional Growers, Mushroom and Forestry/Seedling grades are produced.

Quality Control Starts

Selection of the Peat Bog
Sunterra bogs are vast acreages located in Manitoba Peat lands and represent many years of peat reserves. Sunterra has selected these bogs for development and harvest based on a careful review of engineering reports and numerous core samples. Core samples were analyzed to identify premium sphagnum peat moss suitable for the professional Horticulture grower. A copy of the detailed botanical analysis for one of the core samples is included in the appendix (see page 7).

Quality Control Continues

Bog Development Activities
· Brush, pile and burn or push-off the overburden.
· Dig necessary perimeter ditches, settling ponds and drainage take-off runs.
· Root/Stump removal.
· Install field ditches on 100' spacing.
· Rotovate (Merri-crush) surface.
· Profile fields and re-ditch.
· Road building.
· Weed Control.
Once the water table is drawn down, the peat surface is prepared for harvest by removing roots, stumps and embedded logs from the uppermost layer of peat. Then the remaining peat area between the drainage ditches is harrowed up, leaving a crown or ridge of loose peat to dry in the sun, before being harvested.

Harvesting and Packaging Process
When the surface loose peat has dried to the desired moisture content, it is collected by large vacuum harvesters and either stockpiled in the field, or hauled directly to the processing plant or to an adjacent dry storage area.

Areas where loose peat have been vacuumed are immediately turned over by a spoon harrow, to a depth or 2 to 3 centimeters, and the process of creating new ridges of loose peat to dry is repeated. Typically, over the course of the summer harvest, a layer from 6 to 10 cm, will be extracted from the bogs. Also, typically there are between 45 - 55 days per season suitable for harvest operations.

The harvested peat is transported to the processing plant where it passes through a series of adjustable screens (depending on the coarseness of finished product desired), and passed through a compression baler, where the loose peat is compressed 2:1, baled and packaged into sealed "Megapak" 64 cubic foot bags yielding 128 cubic feet when uncompressed or 4.74 cubic yards.

The bales are then palletized, stacked and stored in a warehouse area. In preparation for shipping, pallets are loaded, 24 per load on covered shipping trailers and delivered by rail and or roadways.

Customer Input to Quality Control
The most important aspect of Quality Control is communication with customers to ensure that the quality process is continually improving.

Communication focuses activities on the factors critical to customers, resulting in improved customer satisfaction and improved growing results. Growing trials in particular provide a means of measuring success. Trials to date have been very positive with some customers comments:

We plan to continue to survey customers and issue newsletters in the future.

The Environment is an Important Element
Every precaution is taken to ensure minimal impact on the environment. Research carried out on bog harvesting operations indicate that the water quality from the bogs meet strict standards imposed by several licensing bodies including the Environment, Water Resources, Mines and Natural Resources.

Care is taken to hold bog drainage water in settling ponds. This water is routinely tested and must meet standards before being released into water courses.

Water quality, siltation and flow rates are some of the factors taken into account. Site reclamation plans have been made with a goal to return bogs to functioning peat land capable of supporting sphagnum and lichen growth.

Quality Control Never Ends
Sunterra and our distribution network are committed to quality and service.

Quality Control is Measured
As the primary distributor of Sunterra Peat Moss, and a large consumer of quality peat moss as a component of soil mixes, West Creek Farms performs extensive quality testing in their lab in Fort Langley, British Columbia. The lab is led by their soil scientist, Laura Principe MSc., and supported by Gail Schultze BSc. and is capable of analyzing pH, electrical conductivity, particle size distribution, stick content, airspace at container capacity and readily available water content. West Creek Farms also runs annual weed germination trials at a local grower's greenhouse. Samples for pathogen screening and full chemical analysis are sent out to independent labs. West Creek is collaborating with an MSc student on a proposed NSERC research project on peat moss quality for the 2005-2006 season.

Some Important Growing Media Terms
Cation exchange capacity is a measure of the ability of a soil or growing medium to hold nutrients. Most plant nutrients are positively charged ions or 'cations' (exceptions are nitrate, phosphate and sulphate). These cations are attracted to and held on negatively charged sites of soil particles and will later be released into the soil solution and become available to plants. CEC is a measure of the total amount of positive ions a media can hold. In a mineral based (i.e. sand silt and clay) system, the only way to increase CEC is to increase the clay or organic matter fraction of the soil. Being organic matter, peat has a high CEC. See page 8 for a copy of CEC analysis. It is important to remember that CEC is the ability of a medium to hold plant nutrients, not the nutrient status of the medium itself.

Electrical conductivity (EC) is the ability of a solution to conduct an electrical current. The current is conducted predominantly by the ions dissolved in the water or soil solution. Since plants can only take up nutrients that are dissolved in water (ionic), EC is an estimation of the nutrient status of a soil. However, EC doesn't distinguish between ions essential or nonessential to plant growth, rather, it is the sum of all ions in solution.

A suitable growing media component will have a low EC, and a high CEC so that the resulting mix can be charged with plant nutrients in the form of specific and balanced fertilizers.

Nutrient availability is dependant on the pH (acidity) of the growing medium. Although pH is relatively easy to adjust with liming amendments, a bulk ingredient must have a consistent pH so that the end target pH of the final mix is realized. See page 9 for a summary and comparison of EC and pH of Sunterra peat moss.

Air space at container capacity is an important physical quality of growing media. Physically, a growing medium consists of solids and pores. Plant roots need a balance of air and water - both are found in soil pores. Whether a pore contains air or water at any particular moment depends on its size. Container Capacity is the point after a thorough irrigation when water stops dripping from the soil. Since this is the point at which the air content of a soil will be the lowest, this is the reference point for quoting air content of media. At container capacity, the large pores (macropores >0.08mm) contain air, while the smaller pores still contain water. As the soil continues to dry beyond container capacity, the volume of pores holding air increases while the volume of pores holding water decreases. Once water is used or lost from the smaller meso- and micropores, plants begin to wilt. At this point, the only water remaining in the soil is contained in pores so small (<0.005mm), the plant cannot extract it. The amount of water lost between container capacity and wilting point is the amount of water that is readily available to the plant. Readily available water content is measured in the lab by simulating the dry down process on samples in a pressurized tank. Water retention curves are generated over 2 to 50 cbar. Air content at container capacity may range from 10%-50% - with the ideal range being 15%-25%. Readily available water content of a final mix should be at least 20% and ideally greater than 30% without compromising air space at container capacity.

Pore size and volume is dependant upon the degree of compaction of the media during pot filling and the distribution of particle sizes. Particle size distribution (PSD) is simply a way of describing the proportion of a sample in specific particle size ranges. To do this, we take a stack of sieves that decrease in mesh size and have a pan on the bottom. The oven-dried sample is placed on the top sieve, the lid is put in place and the stack is shaken for a set period of time. There are key sieve sizes for each media component and use, for example, for a grower grade peat, the largest particle size tolerated is around 2.5cm and anything that falls through a 0.6mm sieve is considered dust.

One of the challenges in processing peat moss is the balance between removing the twigs, roots, and other plant parts from the natural bog vegetation without creating a very fine product. These twigs and root are referred to as 'sticks' in the end product. Sticks can clog flat fillers; jam machinery chains and bridge pots hindering the pot filling process. During the PSD analysis a stick count is done. For Grower's grade peat moss, a stick is defined as anything larger than 0.6x2.6mm or anything longer than 7cm.

A pathogen is a disease-causing organism. It is important that growing media be free of plant pathogens including, fungi and bacteria, nematodes and insect pests. See page 12 for a copy of an independent analysis for common root pathogens.

Since growing media and greenhouse/nursery conditions are designed to optimize plant growth and weed management is costly, it is important the growing media components be reasonably free of weed seeds and vegetative plant parts. West Creek Farms is currently running its third annual weed germination trials on bulk growing media components.