Soil Diversity 101 - Why do we need it?
Diversity is the most effective, easiest, cheapest and most sustainable way to help agriculture adapt to change - Cary Fowler
The answer lies in diversity
When our soil becomes lazy
- When we look at how food is industrially grown right now, the widespread use of chemical fertilisers by farmers stop natural protein & sugar production by favourable microbes (fungi being a subset) that help create topsoil over time. In commercial farming, the soil is unable to rebuild key nutrients on its own because nutrients are being supplied externally.
- The once robust economy in soil where traders and brokers used to make a living by supplying plants with nutrients at a fraction of what it costs the plants to get themselves are now rendered useless.
- It is no wonder that many cash crops such as banana and coffee are under siege right now - the soil has been so well fed by nutrients from chemical fertilizers that it has lost its ability to attract or grow organically the microbes that produce or unlock the same nutrients in soil, while simultaneously turning into an attractive breeding ground for fatal fungi strains like Fusarium, Phytophthora and Verticillium etc.
Panama Disease (Fusarium Fungus) on Bananas
Take care of your soil, and it will take care of you
Biologically Barren - Aside from fertilizers, commercial use of weedkillers, pesticides, nematicides have significantly contributed to the decline of soil diversity and health.
Over time, conditions around beneficial microbes change for the worse and they no longer have a reliable support system to thrive upon. Without these key players and their useful mechanisms, the barriers to entry are lowered considerably and the opportunistic pathogens find it a lot easier to enter the “market”, to multiply and establish their populations comfortably without worrying about being outcompeted or killed. These fungi are almost impossible to isolate once established as their spores travel easily and freely through air, water and soil. Farmers then widen the circle of entropy by intensifying chemical treatment in hopes of solving the issue. It's a cruel nightmare that perpetuates itself.
Supporting Symbiosis - we need to support our soils with a bustling and health microbial ecosystem that has the ability to not kill, but outcompete pathogenic fungi. A fungus that was once a foe can now be managed by numerous beneficial strains that compete for the same energy/carbon source, hence preventing its evolution of a more fatal version and given enough time, would phase out naturally.
How can I boost diversity in soil?
The Green Revolution has encouraged many practices focusing on short-term KPIs that have been rather detrimental to our soils - to be fair, the world population was booming and the urgency to feed humanity was legitimate.
However, it is not too late to restore a healthy microbiome for long-term sustainability.
Here are some natural methods that could be applied in isolation or combination to augment and accelerate the effects in soil:
1. Weeds can be useful
- Fermentation, not annihilation: Granted the dust of the recent Monsanto RoundUp saga has not yet settled for good, but the industry urgently needs to find practical and safe alternatives for commercial weed & crop residue management. Weeds are in fact a rich source of nutrients if they are recycled in the right form. Microbial fermentation transforms plant biomass into soil organic matter that is a food source for the microbes you want to grow and stay.
- Safer than weedkillers: Glyphosate-based products have been proven to suppress and reduce spore availability and colonization of beneficial fungi (e.g.: Arbuscular mycorrhizal fungi (AMF) and Entomopathogenic fungi) that support plant defences and biological pest control. Weedkillers work by preventing certain enzymes that produce proteins in plants from working, and this affects the populations that are beneficial for crop growth.
- Upcycling the carbon: This zero-waste, value-added process keeps a bulk of plant-based carbon where you need it most and attracts the microbes you want, especially when incorporated in the top 10-15 cm “A” horizon of your soil profile.
2. Building topsoil
- Hungry for humus - Natural soil enhancers that contain humates, humic and fulvic acids contribute to superior plant growth and quality. Humic substances are complex organic compounds that were once in abundance and have been eroded over time. Humid acids promote fungal growth and creates stable organic carbon compounds called “glomalins” that retain their residence in soil for lengthy periods of time.
- NPK ain’t OK - it is a little known fact that industrial NPK fertilizers become less effective for plant growth over time. Judging the efficacy by total amounts of nutrients, instead of their bioavailability to plants, is misleading and quite a costly error if not corrected early enough. Without the soil traders participating in the acquisition, conversion and transportation of fed nutrients to plants, there is not much benefit to be gained from adding these nutrients. They are either lost through atmospheric release, locked up or leached out of soils.
- Crazy for compost - this material is rich in organic matter, which has available nutrients for plant uptake and encourages the sustained growth of beneficial microbes that strengthen the quantum ecosystem and rebuild organic soil carbon (humus) slowly in the soil profile.
- Rest the soil: Microbial fermentation, followed by a fallow period allows the gradual revival of nature and incubates the processes that builds carbon consistently in soil
3. Diversity breeds diversity
- If you are thinking of adding probiotic-based inputs are to be added to promote bacterial or fungal growth, keep in mind that adding products with a limited number of strains may not have the effect you are hoping for as they usually lack the ability and support system (of other microbes) to adapt to the environment it is applied in.
- Select those with a diverse consortium of microorganisms that have a respectably long shelf life, preferably in liquid and not powder forms.
The list is definitely not exhaustive....feel free to share your own experiences or tips in the comments below!