sarahscottdavies wrote: Certainly hope you don't think i was being patronising by calling your experiment unscientific.
Hi Sarah
I don't think you did call me unscientific - I call myself that!
I wish you the very best of success with your experiments.
Alan
Cred air o bob deg a glywi, a thi a gei rywfaint bach o wir (hen ddihareb Gymraeg) Believe one tenth of what you hear, and you will get some little truth (old Welsh proverb)
Dear Sarah, if you do the testing, i wonder if you would think about putting your results on the forum for us all to read. I'm sure everyone on here would be very grateful.
I know for one, that Alans tests have been very interesting and also very helpful to give people an idea of what composts are all about.
I think the biggest problems you are going to face are, what exactly are in the different makes of composts, and in what quantities, and also that the contents of the compost seem to vary so much from batch to batch even though it is the same make. Please don't take that last comment as a negative to your testing, just as a little warning what you will be up against.....
I was one of the ones who helped last year, though I haven't the time to do so this year. For peat compost which I have found consistent over the years I would suggest either Levington or Westland Heath. The situation with non-peat seems, unfortunately, still in a state of flux in terms of content and consistency. And you may get different results depending on the type of seed you use - large seeds like peas or beans have more food and so can survive longer in composts which lack nutrients.
This actually quite a difficult type experiment to do really scientifically as there are so many variables to control - or out of your control. I would suggest keeping it as simple as possible both in terms of the numbers of composts and the types of seeds. Ensuring that all sets get the same attention is quite difficult enough.
Do you have the facilities to analyse any of the composts?
Hi all...Oldherbaceous, no i don't think they are negative comments, but very true. Hi Colin too. The more I look into this, the more i feel my tutor will advise me against this as a project, because the results will be too vague and not 'scientific enough', but I will see what he says nearer the time. Sadly being an Open Universtiy degree I don't have access to a lab. I'm sure I can measure water content, pH and possibly even organic content (if I can find a hot enough oven!). But I think i'd have to rely on the manufacturers guidance for more specifics. Basically we have to think of a hypothesis that can be tested in an area that interests us (relating to environmental science). And we can either perform the experiment ourselves or use research. My hypothesis would be that peat-free composts can perform as well as peat based composts, or something like that....but like Alan, even i don't use this for my degree, i may well do the experiment anyway out of personal interest.
What do you want to test? A seed raising compost has to give good germination and nothing more, the germinated seedling can be immediately pricked out. A good product would have a texture that gives good contact with the seed and no resistance to root formation with moisture retaining properties that create a stable environment not prone to water logging or drying out. It must also be free of pathogens that would inhibit germination or damage a seedling. A compost for growing on is a more difficult proposition. Often comparisons are based on how long they can keep the plant growing, you have mentioned 'enhanced with plant food'. I am not sure how relevant this is as if you are keeping the plant in compost you need to feed eventually anyway. Ultimately the best compost is again one with a texture that encourages growth and with that difficult to define characteristic of ideal water retention and probably ease of judging the correct water content. I wonder if you could almost eliminate the original fertiliser content as a variable by adding JI Base at say No.2 rate before you start - if there is no doubt there is plenty of food you are truly testing the other possibly more important characteristics of the compost. Presumably a multipurpose compost is supposed to let you germinate and grow on in the same formulation. So what do you want to test; germination, growing on with or without food, ability to handle simple sow and grow - it really is difficult which is why so much testing is inconclusive.
Hi Geoff, thank you for your post. It has given me plenty of food for thought, it is something I will have to think about...what I am actually testing, seedlings starting or length of time they can sustain growth? It leads me to question, when businesses and/or individuals say they could not manage without peat (in the wake of the announcment they will try to ban its use in a certain amount of years), what is it people say they have trouble growing without access to peat? Is it they feel their seedlings will not grow too well, and thus end up with poorer plants for the rest of the season? Or do people use their peat to keep their plants far healthier for the whole of the season in container growing. I'd love to hear peoples opinions.
Sarah, if you look at the links that Alan has given I think you will get the picture. The non-peat seem to suffer from a lack of consistency and, in some cases as with the Bulrush I used, a lack of nutrients.
Also search for other discussions on peat/non-peat on this web site for a very wide range of views.
