What to do,
what not to do.

This is the final chapter of the series.

We have covered the reasons (economic, physical, biological) to transition to microbial farming, and the implementation at each scale (full-time, part-time, self-sufficient).

Last, this chapter pulls together the concrete principles for how to operate it on the ground.

What is offered here, however, is not a "manual." A manualized method cannot absorb the differences between lands, climates, and crops. You need to understand the principles and then adapt them to your own site.

The 8 principles below are the core that natural farming (Masanobu Fukuoka), American regenerative agriculture (Gabe Brown and others), and soil science (Christine Jones and others) all share.

8.1 No-till — Don't Till the Soil

Principle: do not till the soil.

Tilling has been treated as the basic motion of modern agriculture. In microbial farming, however, it becomes the first thing to avoid.

Why?

• Tilling physically severs the fungal hyphal networks in the soil
• Severed mycorrhizal fungi die. Or lose function.
• Tilling mixes topsoil with subsoil and breaks the layered structure of the ecosystem
• Exposed organic matter decomposes rapidly and escapes to the atmosphere as CO2
• Aggregate structure breaks down and the channels for water and air disappear

Soil is not "just dirt." It is a three-dimensional ecosystem in which millions of species live in layers. Tilling is like sending a bulldozer over that city to flatten it every year.

In conventional farming, tillage handles weed control, soil aeration, and incorporating last season's residue. In microbial farming, each can be handled differently.

• Weed control → cover the ground with diverse crops and cover crops; remove only locally where needed
• Aeration → pores formed naturally by earthworms, roots, and hyphae
• Residue → leave it on the surface; microbes will break it down

Tilling is breaking the microbes' house every year. Not tilling is keeping the house intact.

8.2 No Bare Ground — Cover the Surface

Principle: never leave the soil surface bare. Always have something covering it.

When the soil is bare — direct sunlight on it, rain hitting it directly — the following happens.

• Soil temperatures swing wildly (over 50°C in summer)
• Microbes die from the heat
• Rain washes the soil away
• Evaporation drains moisture
• Weed seeds germinate more readily (paradoxically)

To avoid bare ground:

• Cover the ground with the crop itself (dense planting, polycultures)
• Use cover crops (rye, hairy vetch, Chinese milk vetch, etc.)
• Leave residue on the surface
• Mulch with fallen leaves, cut-and-laid grass, straw, etc.

But there is an important distinction here. "Covering the soil" and "covering with living plants" are not the same thing. Section 8.4 looks at this in detail.

8.3 Diversity — Don't Plant a Single Crop

Principle: combine diverse crops and plants.

Conventional farming has treated large-scale monocropping as peak efficiency. The same crop, on the same field, every year. This was deemed efficient for mechanization and pest management.

In microbial farming, however, this is counterproductive.

• Single crops let specific pests and diseases explode
• A single crop's root exudates have a single composition, which uniformizes the soil microbiome
• Specific nutrients in the soil get drawn down preferentially
• Continuous-cropping problems emerge

Why diversity matters:

• Different crops put out different root exudates → they feed different microbes
• A diverse microbiome is harder for any one disease to dominate
• Different crops send roots to different depths → the whole soil is used
• Roles such as "legumes fix nitrogen, deep-rooting plants pump up minerals" come into being

In practice:

• Intercropping (multiple crops grown together in the same field)
• Crop rotation (changing crops year by year)
• Cover crops (multi-species mixes between main crops)
• Conservation of surrounding vegetation (keep the ecosystem intact, including weeds, trees, and hedgerows around the field)

A single-crop field is, ecologically, close to a desert. A diverse field is close to a forest or grassland. The latter needs neither fertilizers nor pesticides.

8.4 No-weeding — Keep Living Roots in the Soil at All Times

Principle: as far as possible, do not cut weeds. Keep living roots in the soil at all times.

This is the principle this series most wants to explain carefully. And it is the point where Masanobu Fukuoka's natural farming and the latest soil science meet.

Why not cut weeds

In conventional farming, weeds are "the enemy." They compete with the crop for nutrients, lower yields, look bad. So you weed. Herbicides, mechanical cutting, hand-pulling.

From the perspective of microbial farming, however, weeds are an important partner.

Why?

• Weed roots also supply liquid carbon to mycorrhizal fungi (Chapter 6)
• Weed roots build the soil's aggregate structure
• Diverse weeds feed diverse microbes
• Weed roots draw nutrients from deeper layers
• Weeds keep feeding microbes even when the main crop is dormant

What mycorrhizal fungi need is "living roots." If the roots are alive, the species doesn't matter. A weed's roots are a perfectly fine "payroll source" for the fungi.

Masanobu Fukuoka grasped this fact through observation and intuition long before soil science had figured it out. The core of his natural farming was the four:

• No-weeding (do not cut weeds)
• No-tillage (do not till the soil)
• No-fertilizer (no chemical or organic fertilizer)
• No-pesticide (no agrochemicals)

Seen through modern soil science, these all line up as principles for getting the most out of the microbial network.

How this differs from "cut-grass mulch"

Now, to clearly mark the difference from cut-grass mulch (cutting plants and laying them on the soil), which is often discussed in overseas regenerative agriculture.

Cut-grass mulch does:

• Cover and protect the soil
• Feed microbes
• Suppress weed germination

These are real benefits.

But cut-grass mulch has an important weakness.

A cut plant no longer photosynthesizes. No more liquid carbon comes out. No more "wages" paid to mycorrhizal fungi.

A cut plant is just "dead organic matter." Lay it on the soil and it does function as a cover. It does feed microbes.

But the liquid carbon mycorrhizal fungi directly need is supplied only by living roots. Just placing dead grass on the ground does not maintain the symbiosis.

Fukuoka's no-weeding and Jones's liquid carbon are saying the same thing

Masanobu Fukuoka: weeds are not the enemy, do not cut them, do not break the roots. Christine Jones: plants put out liquid carbon from living roots, and this feeds microbes.

The two are saying the same thing in different languages.

Keep living roots in the soil at all times. This is the core principle of microbial farming.

That is why no-weeding (leaving the living plants standing) matters more than mere "cut-grass mulch" (laying down dead grass).

Obligate biotrophy — the iron rule

The decisive difference between "no-weeding" and "cut-grass mulch" comes from a biological property of arbuscular mycorrhizal fungi (AMF). This is not metaphor or preference; it is a fact at the molecular biology level.

Through evolution, AMF have completely lost the ability to live independently by decomposing dead plant tissue (organic matter) — that is, the saprotrophic ability. To grow, reproduce, and complete the life history that maintains their hyphal network, AMF must depend completely on "the living root cells of a host plant."

This property is called obligate biotrophy.

AMF live on up to 20% of the carbohydrates (sugars) and lipids the host plant produces by photosynthesis. In exchange for this enormous carbon supply (energy investment) from the plant, AMF deliver phosphate and water gathered from the soil to the plant in equivalent amounts (Mycorrhizal-Host Nutrient Exchange).

The decisive difference between "dead grass" and "living roots"

Once you understand this mechanism, the limit of "cut-grass mulch" becomes clear.

If you cut weeds or a cover crop at the base and kill them, at that moment carbon production via photosynthesis stops, and the energy supply line to the AMF is fully cut.

What can decompose dead, rotting roots and the dried grass spread on the surface is only saprotrophic bacteria and some filamentous fungi (the mushroom group, etc.) that can break down cellulose and lignin. AMF can extract no nutrition from dried grass; the hyphal network, having lost its host, rapidly stops functioning in the soil and begins to collapse.

Therefore, to maintain a vast phosphate supply network in the soil and to keep aggregate structure held together by glomalin, "living roots" must not be allowed to disappear from the soil, even temporarily.

Conventional vs. superficial regenerative vs. traditional natural farming

Comparing how each system treats plant residue and roots, and the impact on the microbial network, you can see that Fukuoka-style natural farming and the latest soil science are in complete agreement.

To make microbes (especially AMF) "carry" the agricultural balance sheet, beyond "do not till" and "do not use chemical fertilizer," "do not cut off living roots (do not sever the energy supply line to the obligate biotroph)" is an absolute physical requirement.

In the latest Western regenerative agriculture as well, the principle has moved one step beyond superficial cut-grass mulch to "Keep living roots in the soil year-round" as the most highly emphasized one. The "no-weeding (keep grass alive)" philosophy that Masanobu Fukuoka arrived at in the 1970s by experience and observation is, with surprising precision, fully consistent with the principle of "obligate biotrophy" revealed by 2020s genome analysis and transcriptomics.

8.5 When You Have to Cut — Jones's 50% Rule

Even so, there are situations where complete no-weeding is not possible.

• Weeds completely overrun the crop
• Airflow is poor and disease appears
• Walkways disappear
• Boundary management with neighbors forces it

In such cases, cutting weeds is fine. But how you cut matters.

Christine Jones's papers suggest a principle that could be called the 50% rule [unverified: exact citation].

Cut no more than 50% of the plant's aboveground portion at one time. Cut more, and root growth halts and liquid carbon supply also stops.

The reason is the balance between a plant's aboveground portion and its roots.

Plants set the volume of roots and the amount of liquid carbon supplied based on the leaf area aboveground. When leaves are cut to less than half, the plant goes into survival mode: it stops extending roots and squeezes down the release of liquid carbon.

The same principle is used in livestock grazing management. Take half, leave half — this is the rule that prevents overgrazing and maintains the pasture.

Practical guidelines:

• If you cut, keep it to half the standing height or less
• Cut in rows or spots rather than across the whole field
• Lay cut grass on the soil (it functions secondarily as cut-grass mulch)
• Cut only around the main crop; do not cut the whole field

This is not about "absolutizing no-weeding," but about a workable arrangement that keeps the supply of living roots from being broken, within the realistic operation of a farm.

8.6 No Chemical Fertilizers or Pesticides

Principle: no chemical fertilizers and no chemical pesticides.

The reasons were already covered in Chapter 5.

• Chemical fertilizer breaks the symbiosis between plant and mycorrhizal fungi
• Chemical pesticides kill useful microbes too
• Both are rising in price and are not economically sustainable

That said, there is no need to insist on full organic. For example, compost, rice bran, rice husks, plant-and-wood ash — locally available organic materials are fine to use in a supporting role.

What matters here:

Do not have humans, via fertilizer, do "the work the microbes do."

That is the point. Without leaning on chemical fertilizer, and without leaning excessively on organic fertilizer, the original goal is to build a state in which soil microbes can cycle nutrients on their own.

8.7 Saved Seeds — Save Your Own Seed

Principle: as far as possible, save your own seed.

Seed is another bottleneck of modern agriculture.

• F1 hybrid seed has to be bought from seed companies every year
• Many staple crop seeds are dominated by global corporations
• Seed prices, like fertilizer, are climbing
• Dependence on overseas sources is high

Seed saving is the only way around this. Grow open-pollinated varieties, save seed from your own field every year, plant it the next year. Do that repeatedly, and:

• Seed cost goes to zero
• "Land seed" adapted to your soil and climate develops
• You can keep going even if seed supply is interrupted
• Diversity stays in the region

You don't need to save seed for every crop. But for staple crops — rice, wheat, beans — that matter both in quantity and quality, move toward saving seed yourself as much as possible.

This works strongly when combined not only at the individual level but with regional seed banks and seed exchanges.

8.8 Storage and Distribution — Share, Not Just Sell

Principle: don't depend on commercial distribution alone; have channels for storage and barter.

Industrial farming has assumed large-scale distribution (JA, the markets, supermarkets, trading companies). A system has been built that moves things efficiently from field to consumption point.

Microbial farming, however, is small in scale and harvests are dispersed, so it is hard to put on large-scale distribution. Instead:

• Sell through direct sales, farmers' markets, CSA (community-supported agriculture)
• Process into preserved food (pickles, dried goods, fermented foods, miso, soy sauce)
• Consume via barter, distribution to family and neighbors
• Use online direct sales (your own site, social media, subscription delivery) to reach the whole country

These channels are the way forward for small-scale production that doesn't ride on commercial distribution.

And these have the effect of strengthening relationships with neighbors, family, and the local community. Economically and socially, they distribute risk.

The Series' Conclusion — Economics Chose the Farming Method

We have covered eight chapters.

Let's return to the proposition put up at the start. Economics decides the farming method.

When chemical fertilizer was cheap, industrial farming worked. Cheap fertilizer was what made that method possible.

In an era when chemical fertilizer becomes expensive, industrial farming does not work. Expensive fertilizer forces a move to a different method.

And that "different method" is:

• No-till, no bare ground, diversity, no-weeding
• No chemical fertilizers, no pesticides
• Let soil microbes handle the nutrient cycle
• Save seed, lower distribution risk via storage and sharing

— and converges on the farming method that Masanobu Fukuoka's natural farming, Christine Jones's soil science, and Gabe Brown's regenerative agriculture have each been describing in their own languages.

This is:

• Not a path chosen by ideology
• Not a path chosen by ethics
• Not a path the government made you take
• A path the market, physics, and biology left behind by elimination

We are not going to natural farming because we should. We are going because we will not be able to buy chemical fertilizer. Natural farming is the only viable farming method for the era to come.

That is the conclusion of this series.

Implementing the Chapter 3 Decision Through the Operating Principles

In Chapter 3, this series presented an explicit decision:

In 2027, phosphate fertilizer will become hard to obtain in Japan (short-term, imminent). The phosphorus resource depletion is also serious in the long run (peak phosphorus around 2033, structural, irreversible). Therefore, decide to transition to regenerative agriculture, now.

The 8 operating principles laid out in this chapter (no-till, no bare ground, diversity, no-weeding, the 50% rule, no chemical fertilizers/pesticides, saved seeds, storage and sharing) are the concrete answer to how to implement that decision in the day-to-day on the ground.

The decision is in Chapter 3. The implementation is in this chapter (Chapter 8). The intervening Chapters 4 to 7 are the bridge between decision and implementation.

Closing — Where to Start

Last, here are some actions readers can take after this article.

Household level

• Start small with herbs on a balcony
• Start composting (kitchen scraps, fallen leaves)
• Shop with awareness of grocery spending and dependence on imports
• Rent a few rows in a community garden or rental field
• Learn Fukuoka-style natural farming, permaculture, etc. (books, courses, visits)
• Try growing without tilling

Small-scale / side-job level

• Stand up natural / regenerative farming on a one-tan scale on a 5-year plan
• From an existing conventional operation, reduce chemical-fertilizer dependence in stages
• Join a local natural-farming group or organic-farmer network

Full-time / serious level

• Stand up regenerative farming as your main business on a several-to-tens-of-hectares scale (or convert from an existing operation)
• Design a business model that bypasses the middlemen through direct sales, CSA (community-supported agriculture), restaurant partnerships, and value-added processing — using price and relationships to make up for yields below conventional
• Build the technical stack of polyculture, cover crops, no-till, and seed saving — operating all of them at once, assembled over years
• Take on abandoned farmland and regenerate it (MAFF's 98,000 ha of recoverable degraded farmland can serve as the receiving capacity for full-time farmers)
• Take in trainees and successors to pass on technique and experience — the know-how for the conventional-to-regenerative transition does not transfer through books alone
• Keep updating technique through primary sources and on-site visits to Gabe Brown, Allan Savory, Christine Jones, and others
• Run a side practice of transition consulting for conventional farmers, or operate a regional seed bank, seedling supply hub, or production base for microbial inputs (AMF, PSB)

Social / policy level

• Build, or back, the small local infrastructure that supports microbial farming (seed banks, distribution networks, training institutions)
• Bring the microbial-farming view into food and agricultural policy debates
• Build farming experience into children's education, corporate training, and welfare programs

All of this can start now. And unless it starts now, it will not be in time.

Economics chose the farming method. The new method for the new era has already begun.

To everyone who read this series. From the prologue through Chapter 8 — thank you for following along.

aiseed.dev will keep covering both AI-native ways of working and farming in collaboration with nature.

References

Natural farming and traditional practice

• Masanobu Fukuoka, The One-Straw Revolution (Shunjusha, 1975) — the four principles of no-till, no-weeding, no-fertilizer, no-pesticide
• Masanobu Fukuoka, Returning to Nature (Shunjusha, 1983)
• Yoshikazu Kawaguchi, Practical Guide to Natural Farming — natural farming practice in Japan

Obligate biotrophy

• Molecular biology literature on AMF having completely lost saprotrophic ability
• Western regenerative-agriculture literature on the "Keep living roots in the soil year-round" principle
• Research on Mycorrhizal-Host Nutrient Exchange, in which AMF consume up to 20% of the photosynthate from the host plant
• Soil microbiology literature explaining the decisive difference between "dead grass" and "living roots"

Regenerative agriculture

• Gabe Brown, Dirt to Soil: One Family's Journey into Regenerative Agriculture (2018)
• Allan Savory, Holistic Management: A New Framework for Decision Making (1st ed. 1988, revised 2016) — Holistic Planned Grazing
• Tony Rinaudo, The Forest Underground: Hope for a Planet in Crisis — the FMNR story
• Subhash Palekar, Zero Budget Natural Farming — the ZBNF movement in India

Soil science

• Christine Jones, Light Farming: Restoring Carbon, Organic Nitrogen and Biodiversity to Agricultural Soils (2018) — the liquid carbon pathway, soil-fixation rates of 8.3% (aboveground-derived) vs. 46% (root exudates), the 50% rule
• Sara Wright et al. (USDA-ARS) — glomalin and soil aggregate structure
• "Phosphorus dynamics and sustainable agriculture: The role of microbial solubilization" — PMC11647644

Mycorrhizal fungi and plant science

• Standard soil microbiology literature on arbuscular mycorrhizal fungi (AM fungi)
• Botanical literature on the non-mycorrhizal Brassicaceae and Amaranthaceae

Empirical evidence for the operating principles

• Rodale Institute, Farming Systems Trial (40-year long-term study) — organic wheat yields reaching parity with conventional

Foundational data shared across the series

• Ministry of Agriculture, Forestry and Fisheries (Japan), "Situation Surrounding Fertilizer" (annual editions)
• World Bank, Commodity Markets Outlook
• USGS, Mineral Commodity Summaries (annual editions on phosphate rock)
• IPCC AR6 (climate change and agriculture)

The end of each chapter also lists chapter-specific references.