One of the great things about being a member of your local Horticultural Society is that they organise talks on all sorts of topics. I went along to our village hall on Friday for a talk given by Ray Broughton from Sparsholt Agricultural College. He’s doing a series of 4 talks for us and whilst I missed the first one I really wanted to learn more about the soil in my veg beds and what I needed to do to improve it. I’d already taken and dried a sample as instructed and Ray then talked us through a series of tests to determine the soil texture, structure and pH. I have a clay loam textured soil, with a crumb structure and a pH of 7.7. The last two factors are not great for the veg garden but not disastrous (as I know from what I managed to grow this year!). But I do need to improve the structure of my soil. With a crumb structure I need to add a 50/50 mix of fine and coarse improver such as compost mixed with half-rotted organic matter. It’s important on a clay-type soil which is heavy, holding water, not to add a manure that is too well rotted as this will make the situation worse.
My soil’s pH is too alkaline at the moment. Most soil in the South Wiltshire / West Hampshire region is a chalky alkaline soil. You need to aim for a pH of between 6.5 and 7.0 as optimum. If you have 7.5 or above as I do start adding organic matter such as horse manure (use well rotted if you have a sandy soil or half-rotted if you have a clayey soil like mine). With an alkaline soil you need an acidic soil improver so avoid anything alkaline such as Growmore or Fish, Blood & Bone. Other good soil improvers for alkaline soils are seaweed, chicken manure such as Rooster, Miracle Gro, Maxi Crop, Vitax Q4. Half rotted leaves will also help on clay soil and woodash in moderation is a good additive.
Ray mentioned that the tests we completed in a couple of hours would cost over £200 if you sent your soil away for analysis so it’s well worth joining your local society and persuading them to get hold of someone who can run this through with a group – we all paid £6 which was a bargain!