Soil Food Web

OK, let’s start with a food ‘chain’; a food chain shows how plants and animals obtain their energy. It starts with a ‘producer’ such as plants which are then eaten by an animal, the ‘consumer’. An animal that eats the consumer is a ‘predator’. This is a food chain. A food ‘web’ describes a community of organisms where chains cross-link. The soil food web is the community of organisms living all or part of their lives in the soil. The main characters are microscopic and include bacteria, archaea, protozoa, diatoms, nematodes, fungi, and microarthropods. Macroscopic players include worms and larger arthropods but also creatures such as moles. Plant shoots and roots are also part of the soil food web.

‘Trophic’ refers to feeding habits. In a food chain or web there are organisms that share the same function; the position those organisms occupy are called trophic levels. It’s a bit like the levels of organisation in a business with various departments providing specific functions. In the soil food web there are the producers, decomposers, shredders, grazers, predators, and higher-level predators. Trophic levels are often described in terms of trophic ‘cascades’ because the loss of one level has a knock-on effect on all the others.

The bacterial and fungal trophic players work to produce the sugary glues and strands that pull soil particles together giving healthy soil its finely granular but very strong structure. This provides plenty of pore space in-between soil particles for organisms and roots to breath freely. A good structure is also essential in preventing compaction and waterlogging.

This is very important! As well as great structure, the trophic players, working as nature intended, are key to providing nutrients in bio-available form for plants. This is the main way plants want and need to be nourished.

Essential nutrients like phosphorous are often found in forms that are insoluble in water. The act of making these forms soluble (or bio-available) so that plants can absorb them through their roots is carried out by microbes in various ways such as by changing the pH of the soil.

Great question! Mycorrhizal fungi are fungi whose hyphal threads form an intimate connection to plant roots thereby hugely extending the nutrient-gathering ‘reach’ of the plant. ‘Myco’ means fungi and ‘rhizo’ means roots, so ‘fungi-root’! Mycorrhizal fungi (also called mycorrhizae) come in two main forms; the endo-mycorrhizal hyphae actually penetrate the cells inside the plant root where they can obtain sugar from the plants in return for minerals provided by the fungi; the ecto-mycorrhizal hyphae form a sheath around the root tips and only penetrate the space between cells; exchange of nutrients takes place across the cell membrane. There are several types of endo- and ecto-mycorrhizal fungi. Trees are mainly supplied via ecto- types. The endo- types seek out and sequester nutrients for more than 85% of all other land plant species clearly indicating their vital role in plant nutrition.

Well, as bacteria metabolise, they excrete nitrate. When grazers such as protozoans and nematodes eat bacteria, they excrete ammonium. Depending on the plant and where they fit into ‘succession’ they grow best with specific amounts of both nitrate and ammonium. Weeds prefer nitrate; old growth forests prefer ammonium.

Succession describes the evolution of ever more complex plant groups and microbial trophic levels on a piece of land over time. On bare ground dominated by bacteria the nitrate-rich ‘dirt’ encourages weeds. Left alone to nature more woodier plants move in such as brambles (we all know how that feels with a neglected neighbouring allotment!). Soon enough shrubs and small trees get a root-hold as ammonium overtakes nitrate as the main microbial poop fertilizer. Fungi also help to keep nitrifying bacteria in check with their secretions of organic acids. The end-game for nature (well, at least in most climatic zones) is an old growth forest where fungi rule the soil!

This is a microorganism, usually bacteria or fungi, that lives inside a plant for at least part of its life cycle without causes disease; in fact scientists are beginning to unravel just how much these microbes are contributing to the health of the plant!


Unfortunately, payments cannot be split without incurring additional processing charges.

Weather would have to be extremely foul for RhizoPhyllia to cancel; this is because with numbers limited to a maximum of 6 there will be plenty of room to continue much of the workshop undercover of the summerhouse, and indoors in the Fossil Room. Of course such a workshop benefits tremendously from access to the allotment and gazebos will be in place to enable this. The Compost Station is undercover and dry; it is your host more likely to get wet in such circumstances! Unfortunately, I cannot be held responsible if the weather is so bad that it makes travel to the venue impossible but I will be more than willing to rearrange bookings in those circumstances.

Unfortunately, discounts are not available for multiple bookings.

Lunch will be provided, either in the ‘Fossil Room’ indoors if weather is iffy, or on the patio in suitably warm and not too windy weather. Lunch will be whole food plant based. Special requirements can be entered when booking.

RhizoPhyllia is dog-friendly but we would ask you to be sure your own dog is ‘dog-friendly’. If you wish to bring your dog please be certain to notify us in advance; it will only be polite for us to let other attendees know. We have an 18 month old ‘dog-friendly’ Ridgeback who loves to play. We are fortunate to have a secure back garden suitable for a good run around. I would ask if you intend to bring your dog that you arrive half an hour early so your pooch can run some energy off and acclimatise. At all times your dog and its behaviour to other customers will remain the owners responsibility.

Please contact us directly so that we may better understand your mobility and needs and we will gladly try to accommodate. Access to the garden and summerhouse around the side of the house is wheelchair friendly with only one small step to negotiate where a removal ramp will be in position; likewise in through the back door which immediately faces the downstairs washroom. The actual door to the washroom is 62cm/24’’ wide. There are a few steps in the garden but they are wide and ramps will be in place. The allotment has a 70cm wide flat concrete path running the length through the middle with a gate at the end onto the lawn so you will have as much access as anyone to the heart of the veggies.