Let’s take a look at how the SoilFixer trial beds are coming along.
Quick Recap
I’m participating in a trial for Soilfixer.co.uk, testing two of their compost / soil enhancement products against regular compost and plain soil. In mid-April I’ve set up four small raised beds, and planted broad beans and sowed two varieties each of turnip and beetroot in each. The simple aim of the trial is to assess whether the product-enhanced beds result in better crops.
Planting and Sowing
Each bed was planted with two broad bean ‘The Sutton’ plants (stated off in modules in the greenhouse, in identical, shop-bought compost). I also direct-sowed a row each of beetroot ‘Detroit 2’ and ‘Boldor F1’, and turnip ‘Purple Top Milan’ and ‘Petrowski’.
Good, Strong Growth
The beetroot and turnip seeds germinated well – I made a note that the germination in the SF60 bed seemed to be slightly stronger than the others, although not by much – and, along with the broad beans, have grown strongly in all four beds. Here’s a quick comparison of just one bed (the plain soil control bed) to give you an idea of how much growth they’ve put on:
May 25th – Just over a month after planting / sowing, and following an earlier thinning of every row, and everything is starting to grow away nicely:

May 31st – A few days later and the increase in leaf-mass on the turnips in particular is quite considerable:

June 11th – Another 12 days’ worth of growth and the plants were beginning to choke each other:

At this point all four beds were thinned to 10 or 11 beetroot and six turnips per row.
Comparison
As for the comparative growth rates between the four beds, I have to say that there’s not much in it at this stage. Here are the four beds on the 25th May, which probably gives the clearest indication of how the individual plants were growing, before the mass of foliage makes differentiation difficult:
(Click on the images for a larger version, if you’re interested in more detail, and your screen-size allows)




As you can see, much of a muchness. But the end result that matters is the quality of the crops, so there’s still a way to go before I can draw any firm conclusions.
Next Steps
I’ve planted out a pair of ‘Redbor’ kale in each bed, to start filling up the as yet un-planted half. I’ll be adding two or three cabbages before too long as well.
Pest Problems
Unfortunately, the broad beans in the trial beds have been hit pretty hard by an aphid infestation of assorted blackfly and greenfly. Or at least, three of them have, so far. Here’s a pic from June 11th of the beans in bed #4, the plain soil control bed:

The same problem was spotted on the broad beans in beds #1 and #2. However, bed #3, the SF60 bed, was pretty much pest-free:

A couple of days later I checked again, and there were now a few blackfly on the bed #3 beans. It could be that the pest just hadn’t found these beans when I took the pics on the 11th, or it could be that something in the SF60 imparts a quality to the beans that makes them less attractive to the fly. It would need a much larger trial to reach a firm conclusion, of course.
And I’m happy to say that a small tribe of ladybirds has since moved onto the beans and is hopefully making short work of the blackfly problem:

Additional Observations
As I mentioned, it did seem as though the SF60 bed produced slightly stronger seedlings, but as all the others have performed as well in the long run, it may just have been a quirk in the seeds.
Also, all four beds have been quite weedy – as you’d expect on an allotment site such as ours; very windy and so open to incomers from all directions – but the two compost beds were the weediest. That’s more likely to do with the quality of the home-made compost that was used. Sterile, shop-bought compost might have resulted in fewer weeds, but the point of that part of the trial was to see if the C.H.A. produced better home-made compost, so the weed seeds were probably inevitable.
I’ll continue to observe and record, and the next update will hopefully include a cropping comparison.