This branch of the project sets out to model, research and develop an adaptation of an approach to horticulture that prioritises the proliferation of Arbuscular Mychorhizal Fungi (AMF), a type of soil fungi that form mutualistic symbiosis with up to 75% of plants.
We are basing the design of our methods on other existing innovative practices in horticultural as well as recent discoveries of the effects of the AMF on plant metabolism, growth and development.
One horticultural practice that has gained notoriety in recent years is that of Shumei Natural Agriculture. This approach differs from conventional methods in that it assumes that excessive tillage, crop rotation and the addition of animal manures is detrimental to the long term health of the soil and concomitant metabolic potential of the plants. Instead, the Shumei Method looks to create permanent succession schemes using polycultures of complimentary plants, minimal disturbance to the soil, the absence of manure fertilization, and the conscientious saving of seed.
Furthermore, there is a growing interest in the “no-dig” approach to horticulture with leading figures such as Charles Dowding and Richard Perkins arguing for a more holistic understanding of soil health as an expression of the totality of the interrelated organisms in that particular ecosystem. From this perspective soil can be viewed as a living organism in itself or a complex digestive system in a similar way that the health of our own metabolic processes are dependant on a microbiome comprised of many different organisms. The no dig approach involves little or no disturbance of the soil horizons, the use of mulching and biofertilisers such as liquid or folio feeds and complimentary cropping plans to preserve and enhance the soil food web. Interestingly, practitioners that apply this approach to horticulture report that they find crop rotation of less importance.4
Species of Arbuscular Mycorrhizal Fungi (AMF) belong to the phylum Glomeromycota, to date 230 species have been identified. Also known as Endomycorrhizae these types of soil fungi penetrate the roots cells of partner plants and exchange nutrients for carbohydrates. A plant that has formed a symbiosis with AMF has access to a far larger surface area within the soil through the mycelial network compared to relatively cumbersome root hairs. The fungal partner is much more chemically adept in accessing nutrients looked up in the soil. AMF can provide their pant partners with up to 80% nitrogen and 100% phosporus as well as other important nutrients such as zinc and copper. This increased surface area also mean better access to water conferring much greater drought tolerance for the plant partner. Plants allocate as much as 30% of carbon to the fungi.
The plants fungal partner can make a significant difference on its growth and development. Once study showed that the different species of AMF affected the flavour in strawberries, other aspects were affected such as attraction to pollinators, yield, and appearance. Studies carried out on other crops have shown similar changes in growth, development and behaviour in plants depending on the species of AMF. *
We theorise that the Shumei approach as well as “no-dig/till” methods, have incidentally maximized the conditions for the co-adaptation of AMF with particular plant families. With a minimal disturbance of soil and permanent succession schemes particular species of AMF gradually adapt and predominate to create beneficial conditions in the soil microbiome most suitable for the anticipated plant species. We intend to enhance these conditions with the use of succession specific AMF inoculum (following the Roledale Institute technique), extensive seed saving and the application of aerobic and anaerobic bio-fertilizers.
In doing so we hope to demonstarte economic benefit in the reduction off site inputs, increased carbon sequestration, enhanced nutrient density, and improved resilience of plants in the face of changes in climatic conditions.
To prove that this approach is effective and scalable we are creating a market garden on a 2 acre site at the NationalBotanic Gardens of Wales. The market garden will test the method with a control area on 1/5 of the growing site where a crop rotation plan will be applied over 5/6 years. Another 1/5 of the garden will applying a similar cropping plan but will strickly apply the Shumei methods used at the UK centre in Yatesbury. We will carry out annual tests for levels of soil carbon, diversity of microbial activity, the quantity of glomalin and levels of water retention.
We plan to erect a twin span polytunnel for our covered crops and to harvest rainwater for irrigation. Two small mushroom grow rooms built through converting used refridgerated truck boxes will be place adjacent to one of the tunnels. The exhaust fans of these mushroom grow rooms will be directed into the polytunnel creating elevated levels of CO2 that should increase levels of photosynthesis. We will test for differences in growth rate and yield by comparision of the two tunnels.
The Market Garden site will also serve as a demonstration of various mushroom cropping schemes that compliment and can easily be adapted to horticultural enterprise. The grow rooms will be used to exemplify methods of intensive “indoor” cropping cycles that can avoid the use of single use plastic. We will be using reusable cropping containers to grow Oyster (Pleurotus ostreatus) and Golden Reishi (Ganoderma curtsii). We will cultivate Wood Blewitts (Clitocybe nuda) in the marginal areas used for biomass crops such as comfrey and sida hermaphrodite. Wine Cap (Stropharia rugussoanulata) mushroom beds will serve as a mulch under sweetcorn, fruit bushes as well as inoculating woodchip paths. We will also test two other mushroom mulches, the Elm Oyster (Hypsizygus Ulmarius) as a companion mushroom for brassicas and the Almond Portabello (Agaricus subfrunescens) as a compost mulch with tomatoes in the polytunnels.
We are working towards ensuring that the project can sustain itself into the second through revenue from crop sales. We hope to be able to sell directly to the Botanic Gardens Café, develop a small CSA share scheme and explore the possibility of supporting a local “REKO” style direct sales market.
The horticultural activies at Coed Talylan will work in symbiosis with the project adopt the same practices in the cropping schemes to increase the capacity for seed saving. There are three separated growing areas situated within the 70 acre woodland at Coed Talylan. This provides good conditions for seed saving with increased possibibilties of isolation. The AMF inoculum will be prepared at Coed Talylan and early propagation, where necessary, will be carried out using a “dug in” greenhouse. This technique, sometime refered to as a “walipini”, utilises the thermal mass of the earth embankments to create a stable temperature. Maximizing solar gain and the addition of low input thermo-genesis or compost heating systems will allow for low energy input early propagation.
We will also be making and using “Biochar” produced as a by product of making charcoal with the use of an Exeter Kiln at the National Botanic Gardens of Wales. The Biochar will be applyed as a substitute for vermiculite in the soil mix used for culturing AMF inoculum with a ratio of 4:1 biochar to compost produced from woodchip, spent mushroom substrate and other sustainable sources of biomass. Using a starter soil of indigenous AMF taken from associated palnts, rye grass will be grown in 120l garden sacks over a year. This inoculum is then used in seed and potting mixtures. We will be mostly using using cell trays for propagation but for some crops such as squash, coucmbers and tomtatoes we will be experimenting with soil blocker.
We will be regularly sharing updates with our progress at the garden so if you would like to follow us you can find the Farming with Fungi project on social media:
*For AMF and crop interatcions see: Orell (2019) strawberries; plant pollinator interactions Davis et al (2019); basil Copetta et al(2006); Tomoates Copetta et al (2011), Rouphael et al (2015); mint Gupta et al (2002); lettuce Baslam et al (2011) Artichokes Ceccarelli et al (2010); St John’s wort and echinacea Rouphael et al (2015); bread Torri et al (2013)