Soil Succession

Written By Kevin Wallace

From Weedy, Degraded Soil to a Self-Sufficient Food Forest in Central New York

Soil succession—also called pedogenic or ecological succession in soils—is the natural, gradual process by which bare, compacted, nutrient-poor, or “soilless” (highly degraded) ground transforms into deep, biologically rich, fertile soil. It is a cornerstone of broader ecological succession, where pioneer organisms modify the environment, making it suitable for more complex plant and microbial communities. In central New York (USDA zones 5a–6a, with glacial till-derived loams that are often slightly acidic), this is typically secondary succession on previously disturbed land (old fields, construction sites, or abandoned farmland). If left undisturbed or minimally managed, a weedy patch can evolve into a resilient, self-sustaining food forest—a multi-layered edible ecosystem mimicking young deciduous woodland (oaks, maples, birches, hickories, with berries, herbs, and ground covers).

This process relies on teamwork between pioneer plants and soil microorganisms. Each stage builds organic matter, improves soil structure, and shifts microbial communities from fast-growing bacteria to efficient fungi. The result is a closed-loop system with high carbon sequestration, nutrient retention, and natural pest/disease suppression—no synthetic inputs required.

Why No-Till Is Essential (and Why Plowing or Tillage Destroys Progress)

Tillage physically shreds fragile fungal hyphae—the “underground internet” that connects plant roots—and exposes organic matter to rapid oxidation, resetting succession. No-till preserves:

  • Intact mycorrhizal networks (arbuscular and ectomycorrhizal fungi).

  • Soil aggregates that improve aeration, water infiltration, and carbon storage.

  • Higher fungal-to-bacterial ratios and symbiotic microbes.

Research confirms that no-till combined with cover crops dramatically increases arbuscular mycorrhizal fungi (AMF) abundance, fungal diversity, and stress-tolerant (K-strategist) microbes—exactly what later successional stages and food forests need. In central New York’s freeze-thaw climate, undisturbed soil also resists compaction and erosion far better.

Kickstarting Succession with Diverse Cover Crop Seeds

To accelerate microbial establishment without tillage, broadcast (or no-till drill) a diverse, multi-species cover crop mix tailored to central NY. These plants act as “microbe hotels,” providing varied root exudates (sugars, amino acids, phenolics) that selectively feed different microbes while adding biomass and fixing nitrogen.

Recommended starter mix (fall or early spring seeding; ~40% legumes, 30% grasses, 20% brassicas, 10% herbs):

  • Legumes: Hairy vetch, crimson/red clover, alfalfa (host rhizobia for N-fixation).

  • Grasses/cereals: Winter rye, oats, annual ryegrass (massive root carbon for fungi).

  • Brassicas: Daikon/forage radish (bio-drill compaction; glucosinolates suppress pathogens).

  • Dynamic accumulators/herbs: Yarrow, comfrey, plantain (mine deep minerals).

Chop-and-drop the biomass as mulch each season. Cornell and NRCS-NY resources confirm that such mixes boost soil microbial diversity more than monocultures and are reliable in upstate NY conditions.

Microbial Succession: Specific Microbes, Functions, and Stage-by-Stage Transitions

Microbes are the invisible drivers. Succession follows a predictable shift from bacterial-dominated (r-strategists: fast-growing, nutrient-loving) to fungal-dominated (K-strategists: efficient, competitive) communities. Plants and microbes create positive feedback: root exudates and litter select for certain microbes; microbes improve nutrient availability and structure for the next plant stage.

  1. Early Stage (Pioneer/Weedy Phase – Years 0–5+; Bacterial-Dominated) Hardy annual weeds and legumes (crabgrass, horseweed, clovers from your seed mix) colonize bare, low-nutrient soil.

    • Key microbes: Nitrogen-fixing bacteria (Rhizobium, Bradyrhizobium in legume nodules; free-living Azotobacter). Function: Convert atmospheric N₂ into plant-available ammonia.

    • Fast-growing copiotrophic bacteria (Proteobacteria, Actinobacteria). Function: Rapidly decompose simple sugars/exudates, releasing nutrients quickly.

    • Early arbuscular mycorrhizal fungi (AMF) – Glomus, Rhizophagus, Funneliformis spp. Function: Extend roots for phosphorus/water; produce glomalin (a sticky protein) that begins forming soil aggregates.

    • Transition created: These add organic matter and nitrogen, improve water-holding capacity, and stabilize soil. Dead roots and exudates feed the next wave, allowing perennials and shrubs to outcompete annual weeds. Pioneer plants reshape microbial communities and enhance soil multifunctionality even on degraded sites.

  2. Mid Stage (Perennials, Shrubs, Early Woody Plants – Years 5–20+; Rising Fungal Presence) Organic matter accumulates; C:N ratios rise. Perennials and nitrogen-fixing shrubs dominate.

    • Key microbes: Saprotrophic fungi (early Ascomycota like Mortierella, Penicillium; then more complex decomposers). Function: Break down lignin-rich tissues that bacteria struggle with.

    • Increased AMF diversity (Claroideoglomus, Septoglomus). Function: Denser networks share nutrients/water between plants and buffer central NY’s winter stress.

    • Protozoa and beneficial nematodes. Function: Graze bacteria, releasing bound nutrients (“microbial loop”).

    • Transition created: Fungi-to-bacteria ratio climbs as complex organic matter favors slower, efficient fungi. Soil aggregates improve; nutrient cycling slows and becomes retentive. Shrubs act as “nurse plants,” conditioning soil for woody trees.

  3. Late Stage / Climax (Mature Food Forest – 20–50+ Years; Fungal-Dominated) Multi-layered system: canopy trees (apples, cherries, oaks, birches, hickories—many ectomycorrhizal hosts), shrubs (berries, hazelnuts), understory herbs, and ground covers. This mirrors central NY’s young deciduous woodland.

    • Key microbes: Ectomycorrhizal fungi (ECM) – Russula, Lactarius, Boletus, Suillus, Cortinarius. Function: Mine organic N/P directly from litter/wood; form vast networks connecting trees for resource sharing (carbon, nutrients, water, stress signals).

    • Diverse saprotrophic Basidiomycetes. Function: Full breakdown of woody debris into stable humus.

    • High-diversity bacteria (including Acidobacteria, Verrucomicrobia) plus rare taxa. Function: Fine-tune cycling and pathogen suppression.

    • Full soil food web (earthworms, mites, etc.). Function: Creates self-regulating fertility.

    • Self-sufficiency achieved: High fungi: bacteria ratio retains nutrients efficiently and buffers freeze-thaw cycles. “Tree islands” of scattered birches/oaks act as ECM reservoirs, helping new seedlings establish. The system becomes a closed loop: litter → microbes → nutrients back to plants.

In central New York secondary forests, EM “tree islands” serve as natural inoculum sources—another reason to plant diverse woody species once the microbial foundation is set.

The Payoff: A Self-Sufficient Food Forest

Undisturbed (or no-till guided) succession turns a weedy patch into deep, dark, crumbly, biologically alive soil that grows abundant, nutrient-dense food with minimal work. Secondary succession can restore key functions in 15–50 years; intentional techniques (diverse covers, chop-and-drop, minimal disturbance) speed it up while respecting natural microbial shifts. The resulting food forest is resilient to central NY’s variable weather, sequesters carbon, suppresses weeds/pests naturally, and requires no external fertilizers or pesticides.

This is nature’s proven blueprint—backed by decades of chronosequence studies worldwide and local northeastern research. Start small: seed a diverse cover mix this season, plant perennials and trees gradually, and let the microbes do the heavy lifting. Your soil (and future harvests) will thank you.

Key Scientific References (many open-access):

Kevin Wallace
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