Unless you are practicing an unconventional system of cultivation like hydroponics (see this great blog if you are interested in doing so) then soil is the foundation of everything you grow.

Gardeners tend to value their soil – they see what they are taking out in terms of crops and try to put something back – often by adding compost, soil improvers or fertilizers. My favourite addition to the soil is compost because it doesn’t cost me anything – I am converting what others would regard as waste (from the kitchen, garden or chickens) into a useful resource. I don’t tend to use commercial fertilizers or feeds, relying on compost, woody material from the willow hedge and other prunings, and worm wee. That’s not to say that I won’t use commercial fertilizers, I’m just too mean to buy them! I received a free gift of some organic liquid tomato feed earlier in the year and so I have recently been using this on potted crops – although it does make the greenhouse smell like someone has been storing fish in there for a week!

Unlike gardeners, many large-scale agricultural enterprises don’t use their ‘waste’ outputs as a resource, choosing instead to treat organic matter as rubbish and buy in fertility in the form of fertilisers derived from the petrochemical industry. In a recent post, Yambean highlighted the shocking waste when Spanish farmers dumped cucumbers in protest at being paid so little for them by the supermarkets. I asked her about this and commented that they would, surely, have been better composting them and returning them to the soil, but she tells me that composting is unheard of in that part of southern Spain and the soil is, as a result, completely impoverished. It’s shocking to me.

Soil is a complex system consisting of a mineral component, organic matter in various states of decomposition (from freshly fallen leaves and recently deceased animals to humus and root exudates) and living organisms (bacteria, fungi, worms, insects, other invertebrates, plant roots etc). It is common sense that we need to nurture such systems if we wish to make use of them. Unless we replenish the soil, it will not continue to be productive. This was the basis of the organic movement in the UK, you know? Ever wondered why the Soil Association (one of the regulators of organic produce here) is called the Soil Association? Well, it was founded in 1946, partly because of concerns about “the loss of soil through erosion and depletion”. In 1967, the association stated that “The use of, or abstinence from, any particular practice should be judged by its effect on the well-being of the micro-organic life of the soil, on which the health of the consumer ultimately depends.” So, you can see that their name really does reflect an acknowledgement of the key importance of the soil.

In large-scale systems, particularly where it is common to have periods when the soil has no vegetation cover, erosion is common. As the Soil Association noted in 1946, soil is not simply lost as a result of nutrients being extracted because we grow crops in it, erosion is also a problem. If you live beside the sea (as I do) you cannot help but notice the brown water around river mouths after heavy rain… this is the soil that was previously supporting plants. It does get replenished naturally – rocks weather and add to the mineral component, organisms die, excrete and shed parts of their bodies and add to the organic matter – but bare land is subject to high levels of erosion that can take a significant time to be replaced. Thus we lose substrate, nutrients and water-holding capacity because we chose to leave soil bare – a simple ‘green manure’ such as clover could reduce the erosion and enhance fertility (clover fixes nitrogen).

If we do not care for our soil is it any wonder that there is an increasing need to add to it from external sources and rely on non-renewable resources? Many people, when thinking of organic growing, focus on the absence of pesticides, herbicides and artificial fertiliser, but I’d like to suggest that one of the most important reasons to support organic production is because its practitioners care for the soil and are, thus, ensuring that it is available for future generations to use too. In my garden, I would like to think that I will leave the soil in a better condition than when I found it… not just preservation, but enhancement.