When I was creating my survey I thought (and it was also suggested by colleagues) that I look at the type fertilizers and soils available on the island and the available sizes these inputs came in. However, after doing an initial compilation of what was advertized online, and seeing the variability I decided it wasn’t really the best option (as I couldn’t really make generalize what “a bag” size was or what the N:P:K of pellet fertilizer would be). In addition, I thought I was going to be doing the gardening survey online and the limesurvey question types were not going to be conducive to including pictures of lots of different bags and fertilizer options.
However, after doing a few surveys I found myself wanting to know about the range of inputs easily available to gardeners so that I could ask them the right “probing” questions and also be able to complete information about inputs if they only knew some of the information. For example, if they know it was a 30 l bag of soil of a certain company, I can look-up what the weight and maybe even some N:P:K ratios.
I bit the bullet and spent a weekend going to a Canadian Tire, Home Depot, Rona, and a Walmart (the big ones with lots of selection) and taking pictures of every type of garden (so excluding lawn or flower) soil, fertilizer, manure, compost, and mulch (and other amendments). I then made an excel spreadsheet with all the available info about each input, including brand, volume, weight, blend components, and N:P:K ratio. I then validated them online and looked for other products and sizes available for the brands sold. I also looked at the websites for the smaller gardening stores on the island to include their products in my “master” list.
Unfortunately the Canadian government does not require companies to test for the nutrient concentration of the soils they sell. Thus, even though I contacted the largest companies that sell top-soil, potting-soil, and soil-compost mixes they were not able to tell me the origin, density, or the nutrient content of the soils. When soil was enriched with other amendments sometimes the N:P:K ratio was on the bag, but never for non-enriched soils. I contacted smaller garden centers on the island that sell their own soil mixes or do bulk orders in the hope that they might give me more information I can use to convert the mass of inputs I get from my survey questions into P flow values.