A regenerative design is based on lots of choices: what should the system look like? Which plants, crops and trees are combined into a planted ecosystem? And how does the business model looks like?
But this above-ground design must then also be translated to the subsoil: the soil life must be completely in line with the above-ground planting. Because the associated soil life is quite different for different grasses, row crops, shrubs or trees. That's what this blogpost is about.
The Soilfoodweb
More and more we are discovering that the subsoil is not an inert medium, but that a healthy soil is full with an abundance of life. And life adapts to the circumstances and is therefore not always the same. Yet if you look at healthy soils, there are clearly groups of organisms living together in the soil in a well functioning ecosystem. Some are receiving exudates from plants, other are eating dead plant material, or are eating the soil organisms.
Elaine Ingham has developed the concept of the soil food web, showing how all that soil life relates to each other. The soil food web has been discussed extensively in this blog post (in my Dutch blog). The image below shows the soil food web concept. The fungi and the bacteria are the primary digesters of plant material (2nd order trophic level); they are eaten by protozoa, nematodes and small arthropods (3rd order trophic level), which in turn are eaten by larger nematodes and larger arthropods (4th order trophic level), etc.
The fungi/bacteria ratio
Understanding the ecosystem in the subsoil is the first step; the next step is that the composition of the soil food web appears to differ in different types of ecosystems. The different succession stages from bare ground, to grassy plains and arable land, to shrubs, to trees and finally to pine trees all appear to have a different bacterial and fungal ratio and therefore have a different soil ecosystem. In bare soil, certain bacterial species are dominant. The more wood there is in the system, the more dominant fungi become (with the number of bacteria - but different species - still increasing).
This shows that fungi should also be present in healthy agricultural soil, because almost all plants want to live in symbiosis with the (endo)mycorrhizal fungi (see, for example, this presentation given by Gabe Brown). Ploughing the soil, however, destroys all fungal networks and thus further eradicates the fungal population. The result is that the plants cannot get enough nutrients, while the fungal networks could supply this. Conversion of cropland to a more forest-like system (food forests) may therefore require inoculation of the soil with the right soil life. This can be done by making good compost or compost extracts (for a good education on this, see the SoilFoodWeb courses).
However, as the image below shows, only a very small proportion of the plants lives in symbiosis with the ectomycorrhiza: mainly trees. This underground woord-wide-web is therefore only found in forests. These large widespread networks will not be found on agricultural lands with annuals, but mainly the (just as important!) small networks of the endomycorrhiza.
These 2 main groups of mycorrhizal fungi are found in the plant succession in relation to the soil food web. Only in the last stage of the succession - the old well-grown forests and jungles - do the ectomycorrhiza occur in large numbers, in the stages before that it is mainly the endomycorrhiza that occur.
Conclusion
An ecosystem is not only an above-ground system, but also has an underground system. And in a good regenerative system design, the right plants and trees are combined into a healthy ecosystem. For this system to function properly, it is very important that the ecosystem in the subsoil (the soil food web) is also fully present. Especially when converting arable land (where due to ploughing, and usage of fertilizer and pesticides little or no fungi and other soil food web predators are present any-more), it is highly recommended to inoculate the soil with the right soil life, so that the planted vegetation can establish itself better and faster. Because these plants want to live in symbiosis with the soil life! This will mean that if the soil is inoculated, the plants will take root much faster!
The composition of the soil life, and in particular the fungal/bacterial ratio that must be present in the soil, strongly depends on the vegetation above the ground. In general, the more woody the vegetation, the more fungi dominant the soil population needs to be. Proper alignment of the soil life with the vegetation above the ground is therefore crucial for healthy above-ground vegetation.
Sources
- http://www.nuleaflawncare.com/wp-content/uploads/2012/02/00_sfw_dgrm2.gif
- http://www.sciencedirect.com/science?_ob=MiamiCaptionURL&_method=retrieve&_eid=1-s2.0-S0176161714002314&_image=1-s2.0-S0176161714002314-gr2.jpg&_cid=273190&_explode=defaultEXP_LIST&_idxType=defaultREF_WORK_INDEX_TYPE&_alpha=defaultALPHA&_ba=&_rdoc=1&_fmt=FULL&_issn=01761617&_pii=S0176161714002314&md5=ec20ef7e8640258ed5b0a117215b3599
- https://www.soilfoodweb.com/
- https://vimeo.com/250723320
- https://en.wikipedia.org/wiki/Hartig_net
- https://www.youtube.com/watch?v=uUmIdq0D6-A
But this above-ground design must then also be translated to the subsoil: the soil life must be completely in line with the above-ground planting. Because the associated soil life is quite different for different grasses, row crops, shrubs or trees. That's what this blogpost is about.
The Soilfoodweb
More and more we are discovering that the subsoil is not an inert medium, but that a healthy soil is full with an abundance of life. And life adapts to the circumstances and is therefore not always the same. Yet if you look at healthy soils, there are clearly groups of organisms living together in the soil in a well functioning ecosystem. Some are receiving exudates from plants, other are eating dead plant material, or are eating the soil organisms.Elaine Ingham has developed the concept of the soil food web, showing how all that soil life relates to each other. The soil food web has been discussed extensively in this blog post (in my Dutch blog). The image below shows the soil food web concept. The fungi and the bacteria are the primary digesters of plant material (2nd order trophic level); they are eaten by protozoa, nematodes and small arthropods (3rd order trophic level), which in turn are eaten by larger nematodes and larger arthropods (4th order trophic level), etc.
|
| Source: http://www.nuleaflawncare.com/wp-content/uploads/2012/02/00_sfw_dgrm2.gif |
The fungi/bacteria ratio
Understanding the ecosystem in the subsoil is the first step; the next step is that the composition of the soil food web appears to differ in different types of ecosystems. The different succession stages from bare ground, to grassy plains and arable land, to shrubs, to trees and finally to pine trees all appear to have a different bacterial and fungal ratio and therefore have a different soil ecosystem. In bare soil, certain bacterial species are dominant. The more wood there is in the system, the more dominant fungi become (with the number of bacteria - but different species - still increasing).
|
| Source: Elaine Ingham; https://vimeo.com/250723320 |
This shows that fungi should also be present in healthy agricultural soil, because almost all plants want to live in symbiosis with the (endo)mycorrhizal fungi (see, for example, this presentation given by Gabe Brown). Ploughing the soil, however, destroys all fungal networks and thus further eradicates the fungal population. The result is that the plants cannot get enough nutrients, while the fungal networks could supply this. Conversion of cropland to a more forest-like system (food forests) may therefore require inoculation of the soil with the right soil life. This can be done by making good compost or compost extracts (for a good education on this, see the SoilFoodWeb courses).
The two main groups of mycorrhizal fungi
While there are 7 types of mycorrhizal fungi, two types are the most important to know about: the ecto- and the endomycorrhiza (also called VAM (Vesicular Arbuscular Mycorrhiza)). The endomycorrhiza make small networks around the root hairs, while the ectomycorrhiza make a mat around the root (the hartig net) and create the so called wood-wide-web (see this blogpost in Dutch about it), the kilometer long network through which minerals, water, signal substances and other things that can be transported.However, as the image below shows, only a very small proportion of the plants lives in symbiosis with the ectomycorrhiza: mainly trees. This underground woord-wide-web is therefore only found in forests. These large widespread networks will not be found on agricultural lands with annuals, but mainly the (just as important!) small networks of the endomycorrhiza.
|
| Source: http://www.sciencedirect.com/science?_ob=MiamiCaptionURL&_method=retrieve&_eid=1-s2.0-S0176161714002314&_image=1-s2.0-S0176161714002314-gr2.jpg&_cid=273190&_explode=defaultEXP_LIST&_idxType=defaultREF_WORK_INDEX_TYPE&_alpha=defaultALPHA&_ba=&_rdoc=1&_fmt=FULL&_issn=01761617&_pii=S0176161714002314&md5=ec20ef7e8640258ed5b0a117215b3599 |
These 2 main groups of mycorrhizal fungi are found in the plant succession in relation to the soil food web. Only in the last stage of the succession - the old well-grown forests and jungles - do the ectomycorrhiza occur in large numbers, in the stages before that it is mainly the endomycorrhiza that occur.
|
| Bron: Elaine Ingham, Soil Food Web School |
Conclusion
An ecosystem is not only an above-ground system, but also has an underground system. And in a good regenerative system design, the right plants and trees are combined into a healthy ecosystem. For this system to function properly, it is very important that the ecosystem in the subsoil (the soil food web) is also fully present. Especially when converting arable land (where due to ploughing, and usage of fertilizer and pesticides little or no fungi and other soil food web predators are present any-more), it is highly recommended to inoculate the soil with the right soil life, so that the planted vegetation can establish itself better and faster. Because these plants want to live in symbiosis with the soil life! This will mean that if the soil is inoculated, the plants will take root much faster!The composition of the soil life, and in particular the fungal/bacterial ratio that must be present in the soil, strongly depends on the vegetation above the ground. In general, the more woody the vegetation, the more fungi dominant the soil population needs to be. Proper alignment of the soil life with the vegetation above the ground is therefore crucial for healthy above-ground vegetation.
Sources
- http://www.nuleaflawncare.com/wp-content/uploads/2012/02/00_sfw_dgrm2.gif - http://www.sciencedirect.com/science?_ob=MiamiCaptionURL&_method=retrieve&_eid=1-s2.0-S0176161714002314&_image=1-s2.0-S0176161714002314-gr2.jpg&_cid=273190&_explode=defaultEXP_LIST&_idxType=defaultREF_WORK_INDEX_TYPE&_alpha=defaultALPHA&_ba=&_rdoc=1&_fmt=FULL&_issn=01761617&_pii=S0176161714002314&md5=ec20ef7e8640258ed5b0a117215b3599
- https://www.soilfoodweb.com/
- https://vimeo.com/250723320
- https://en.wikipedia.org/wiki/Hartig_net
- https://www.youtube.com/watch?v=uUmIdq0D6-A
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