Closed-Loop Bioelectrochemical Restoration of an Insular Soil Microbiome
A 36-month, six-work-package R&D programme integrating pedogenesis, electrokinetics, microbial ecology and machine-learning control to restore a degraded island soil without environmental effluent.
Conventional agricultural soil remediation is defined by a trade-off between efficacy and collateral damage. Excavation transfers contamination from soil to waste; chemical washing exports it to water; fallowing accepts ecological and economic loss. The Terra Vivens Sanctae Mariae programme advances an alternative objective: the in-situ, closed-loop reconstruction of pedogenic function on 1 St. Mary's Island, Alexandria Bay, New York, using sub-Faradaic electrokinetic vectoring, arbuscular mycorrhizal pedogenesis and constrained reinforcement-learning control to achieve detoxification and biological recovery simultaneously, with zero discharge of secondary liquid waste.
The scientific contribution is threefold. First, a falsifiable operational definition of soil pedogenic function — quantified across redox potential ($E_h$), cation exchange capacity, aggregate stability, mycorrhizal colonisation and carbon mineralisation — against which restoration success can be adjudicated rather than asserted. Second, a Modular Sandbox Detoxification architecture that couples directional electromigration to a sacrificial reactive barrier, physically separating electrochemical remediation from the living rhizosphere 67. Third, a stability proof demonstrating that the closed-loop controller is bounded-input bounded-output stable under an invariant constraint set, precluding the runaway actuation characteristic of unconstrained machine-learning control 5.
soil pedogenesis • bioelectrochemical remediation • electrokinetic remediation • mycorrhiza • arbuscular mycorrhizal fungi • soil health • redox potential ($E_h$) • critical zone • rhizosphere • biosorption • biochar • zero-valent iron • layered double hydroxides • constrained reinforcement learning • Lyapunov stability • digital twin • closed-loop control • soil carbon sequestration • bioalchar • North American Great Lakes
Introduction & Scientific Rationale
The problem, the gap, and the research question1.1 The Remediation Trilemma
Every conventional approach to rehabilitating a chemically compromised soil resolves the remediation problem by transferring it somewhere else. Excavation and land-filling satisfies the contaminant mass balance on paper while exporting several hundred percent of the original soil carbon to landfill, destroying the microbial inoculum and the physical structure that would have enabled in-situ recovery 1. Chemical washing and chelant extraction achieves high removal efficiency but generates a secondary liquid waste stream of comparable or greater volume and toxicity than the original contamination 24. Unmanaged fallowing avoids harm but forfeits the agricultural baseline, leaving the land in a state of slow biological decline governed by legacy metal residence times measured in decades 3.
| Pathway | Metal removal | Soil carbon retained | Secondary waste | Field practicality | Evidence tier |
|---|---|---|---|---|---|
| Excavation & disposal | Complete (100%) | None — exported | High (solid) | Low — cost scales with volume | A |
| Chemical washing / chelation | High (70–95%) | Partial loss | High (liquid) | Moderate — reagent intensive | A |
| Phytoremediation | Low – moderate | Retained / added | Minimal (biomass) | High — slow (5–20 yr) | A |
| Electrokinetic remediation | Moderate – high | Retained | Contained (collection) | Moderate — electrode management | A |
| MSD + electrokinetics (this programme) | Moderate – high (target) | Retained & amplified | Solid, modular, contained | Moderate — telemetry-assisted | C |
Removal percentages are indicative ranges drawn from field trials summarised in 1, 2 and 6; the “evidence tier” denotes the maturity of the underlying evidence base (see Reader's Note in the Abstract).
1.2 Why Bioelectrochemical Pedogenesis Is Different
The bioelectrochemical pedogenesis framework departs from the premise that remediation and restoration are opposing activities. In a saturated soil matrix, an applied electric field drives charged species by electromigrationNet transport of ionic species induced by the electric field — the dominant transport mechanism in low-permeability clays where hydraulic diffusion is negligible. toward the electrode of opposite sign. This is a vectorial process, not a volumetric one. The engineering consequence is decisive: contaminants can be steered to a chosen collection geometry rather than merely extracted 67.
The limitation of classical electrokinetics is equally well established. Water electrolysis at the electrodes generates acid fronts at the anode and alkaline fronts at the cathode; if these fronts are allowed to migrate into the root zone they dissolve essential minerals, precipitate metal hydroxides, and — critically — they destroy the microbiological community that any restoration attempt depends upon 78. Electrokinetic remediation is thus, in its conventional form, microbiologically antagonistic.
1.3 The Insular Advantage: A Natural Control
Island systems are scientifically under-used. The frequent methodological weakness of restoration research — pseudoreplication Treating many samples from a single manipulated system as independent replicates, which inflates apparent statistical power; a design flaw explicitly addressed by this programme's blocked randomised design. and uncontrolled confounding from off-site inputs — is substantially mitigated at 1 St. Mary's Island, Alexandria Bay, New York. Hydrologically delimited by the St. Lawrence River, the site receives a bounded and characterisable input flux, which makes both contamination mass-balance accounting and biological response attribution tractable.
The site additionally supports a Before-After-Control-Impact (BACI) design of unusual quality. A matched mainland reference parcel permits the separation of restoration signal from regional climate and river-chemistry signal, which is the single most common failure of published restoration claims 910.
Bounded Site
Control Parcel
Arms (BACI)
1.4 Research Question
Can a physically decoupled electrokinetic–biological system simultaneously reduce bioavailable heavy-metal concentrations below agronomic phytotoxic thresholds and restore soil pedogenic function — measured across redox potential, aggregate stability, mycorrhizal colonisation and carbon mineralisation — without the discharge of secondary liquid waste and without the export of native soil carbon?
Site Description & Pedological Baseline
Target site: St. Mary's Island, NY · acquisition pending · corporate office: Sugar Land, TX2.1 The Target Research Estate as an Isolated Test Facility
The organisation's registered corporate office is at 15500 Voss Road, Suite 425, Sugar Land, Texas 77498. The New York property described below is a prospective research site which the organisation holds a Letter of Intent to acquire and is actively raising funds to purchase. It is not owned, and the controlled-environment facility described in this paper is contingent on that funding. The full sequence of contingencies — including the programme path taken if acquisition does not proceed — is set out in Section 2.1.2.
The target research site is 1 St. Mary's Island, Alexandria Bay, Jefferson County, New York (MLS S1648820), a river island within the St. Lawrence River basin (municipal parcel 222201-003-069-0001-005-000). The organisation holds a Letter of Intent to acquire the parcel, dated 30 September 2026.
If acquired, the property would serve as an isolated experimental facility rather than a production surface — a controlled environment in which the AI-enabled soil-revival system can be developed, instrumented and evaluated without the confounding of open-field conditions. The cedar-clad structure on the island would serve as the laboratory, instrumentation hall and secure store; the surrounding acreage would supply source material and, later, a protected deployment surface.
Alexandria Bay, NY
St. Lawrence River
test environment
contaminant inputs
Coordinates are given to two decimal places, appropriate to a site-scale characterisation and deliberately not implying survey-grade precision. Island landform class and NRCS soil series references are to be confirmed against the NRCS Web Soil Survey during WP1; this document treats them as provisional.
2.1.2 Site-Contingency Scenarios
Because the property is not yet owned, the programme is designed with an explicit contingency ladder. The scientific content is invariant across all three scenarios; only the physical platform changes. This means funding the research does not depend on the property purchase succeeding — a materially different risk profile from a design that requires the real estate in order to begin.
| Scenario | Trigger | Experimental platform | What is preserved | What is deferred |
|---|---|---|---|---|
| A — Facility PREFERRED |
Property acquired and remediated to laboratory standard | 144 instrumented vessels in the island facility; full varietal factorial; WP6 supervised deployment on the island surface | Everything. Maximum control, replication power, and direct field transfer | Nothing — this is the full programme |
| B — Modular FALLBACK 1 |
Acquisition not funded, or a smaller or alternative secured property is obtained | Reduced vessel count in a leased or partner-operated controlled space; reduced replication (n = 4) and two varietal classes in place of six | H1–H8 in full, with reduced statistical power on the varietal term of H7 | Field-deployment phase (WP6) and the carbon co-benefit projection |
| C — Field FALLBACK 2 |
No secured facility is available | No facility — the programme moves into the field. Paired BACI plots with wireless telemetry, as originally conceived | H1, H3, H8 and the remediation mechanism. The mechanism does not require a building | Statistical power (pseudoreplication risk returns); AI training data quality (sparse, noisy ground truth); H7 generalisation becomes untestable |
2.1.3 The AI-First Development Sequence
The programme's distinguishing feature is that the artificial intelligence is the experiment, not a reporting layer applied to a finished biological result. The development sequence therefore inverts the conventional order:
- Characterise the substrate — WP0 establishes pedological baselines across the six varietal classes so the AI has a structured, physically meaningful feature space rather than an unconstrained sensor dump.
- Instrument to a telemetry contract — every variable the model consumes is specified, calibrated and continuously recorded, so training data and validation data share an identical schema.
- Train against ground truth — surrogate models are fitted to laboratory-measured endpoints (DTPA-extractable metals, redox state, colonisation) using the high-frequency telemetry as inputs. The AI learns the mapping sensor stream → measured soil property.
- Close the loop under constraint — the validated surrogate is coupled to the constrained controller, which proposes actuations; every actuation changes the soil, producing new ground truth.
- Iterate and generalise across varietal classes — the same model is tested on soils it was not trained on, which is the only honest test of whether the AI has learned soil physics or merely memorised one substrate.
- Deploy outdoors under supervision — only after the system demonstrates out-of-distribution behaviour on held-out varietal classes is it permitted to act on the open island surface, and then only within its certified action set.
This sequence has a consequence worth stating plainly: the AI cannot outrun its instrumentation. The quality of the soil model is bounded by the quality of the ground truth it is trained against, which is why WP0 measurement and the telemetry contract in Section 6 precede every element of the control stack in Section 7.
2.2 Climate and Hydrologic Context
The St. Lawrence lowland is a humid continental regime with cold winters, warm summers, and precipitation distributed relatively evenly through the year. Two hydrological features dominate the island's pedology. First, the St. Lawrence River provides a strongly buffered baseflow regime, modering seasonal water stress relative to interior sites. Second, the island's exposure to winter freeze–thaw and spring freshet produces repeated wetting–drying cycles that drive aggregate slakingStructural collapse of soil aggregates on re-wetting after air-drying, driven by the dissolution of transient capillary bridges and the swelling of clays — a primary mechanism of structural degradation in historically tilled soils. and drive the seasonal oxidation–reduction cycling that governs $E_h$ dynamics discussed in Section 2.4.
DESIGN IMPLICATION. Because freeze–thaw and freshet cycles recur annually, a restoration protocol tuned to a single-season laboratory optimum would fail in the field. WP3 therefore specifies seasonally adaptive dosing regimes, and the controller (Section 7) uses volumetric water content as a gating variable to suppress electrokinetic actuation during freeze–thaw transition, when ionic mobility is high but root-zone biology is dormant and therefore vulnerable.
2.3 Source Soil Collection & Varietal Stratification
The programme does not treat “the soil” as a single medium. It begins from collected samples spanning distinct varietal classes, because the electrokinetic and biological mechanisms under test respond to texture, organic matter and mineralogy in quantitatively different ways. A single-texture experiment would test the mechanism only where it is easiest to demonstrate — and would fail exactly where it is most needed. Varietal stratification is therefore a design variable, not a nuisance to be averaged away.
Source material is collected from the island and from paired reference locations, composited by pedon at the 0–20 cm and 20–40 cm intervals, and archived as air-dried, sieved material with retained moisture subsamples for later reconstitution. Six varietal classes are targeted, spanning the hydraulic and textural range that determines redox behaviour in the field:
| Code | Varietal class | Texture | φtot | Mechanistic role in the design |
|---|---|---|---|---|
| SL | Sandy loam | Loamy sand – sandy loam | 0.42–0.47 | Maximally oxidising, low buffering. Tests whether the MSD architecture is necessary here — the permissive case. |
| SiL | Silt loam | Silt loam | 0.47–0.52 | Reference pedon. The default case against which other classes are compared. |
| CL | Clay loam | Clay loam | 0.44–0.49 | Moderate buffering; intermediate electroosmotic drag. Tests dose–response scaling with CEC. |
| SiC | Silty clay | Silty clay loam – silty clay | 0.38–0.43 | Low permeability, high buffering, redox-sensitive. The hardest and most diagnostically useful case. |
| OG | Organic / muck | Silt, high OM | 0.75–0.88 | Very high CEC, strongly reducing. Tests Fe/Mn oxide dissolution and the remobilisation risk (R2). |
| UF | Disturbed urban fill | Heterogeneous | 0.42–0.52 | Legacy Pb carrier with anthropogenic heterogeneity. Tests the extraction chemistry under realistic confounding. |
$\phi^{\text{tot}}$ denotes total porosity, a primary target variable rather than a class label. Sample numbers per class are set by the power analysis in Section 6.3, not by convenience; minimum 30 kg of archived material per varietal class is required to support the destructive column design.
2.4 WP0 Baseline: Measured and Derived Endpoints
WP0 establishes the pre-treatment state for every varietal class. It operates in two layers. The first is directly measured — quantities a laboratory can determine without recourse to any model. The second is derived by pedotransfer from those measurements, using published functions. The distinction is maintained throughout, because presenting a derived value as though it had been observed is the most common route by which soil models misreport themselves.
| # | Endpoint | Method | Replicates | Tier |
|---|---|---|---|---|
| 1 | Redox potential $E_h$ (field mV) | Combination Eh probe at field capacity | 10/class | A |
| 2 | pH (CaCl2, 1:5) | ISFET / bench electrode | 10/class | A |
| 3 | Electrical conductivity (1:5, 25°C) | Conductivity cell | 10/class | A |
| 4 | Total Pb, Cd, Cu, Zn, Ni, Cr | ICP-MS, EPA 3051A | 6/class | A |
| 5 | DTPA-extractable metals | DTPA extraction, ICP-MS | 6/class | A |
| 6 | Organic matter / organic carbon | Loss on ignition; Walkley–Black | 6/class | A |
| 7 | Cation exchange capacity (base, pH 7) | NH4OAc | 6/class | A |
| 8 | Particle-size distribution & texture class | Hydrometer / laser diffraction | 6/class | A |
| 9 | Bulk density & total porosity | Core method, undisturbed cores | 10/class | A |
| 10 | Water-stable aggregates | Wet sieving, 2 mm | 6/class | A |
| 11 | AMF root colonisation | Acid fuchsin, grid method | 6/class | A |
| 12 | Microbial biomass C & respiration | SIR / chloroform fumigation | 6/class | A |
| 13 | 16S rRNA amplicon profile | Illumina MiSeq | 3/class | A |
| 14 | Available P (Olsen / Bray-1) | Olsen & Bray-1 extraction | 6/class | A |
Replicates are stated per varietal class; with six classes the measured-sample count is six-fold the per-class figure. Particle-size distribution is measured rather than inferred from texture class, because texture is a classification while grain size is a continuous quantity — and electroosmotic drag depends on the continuous value.
The following quantities are not measured in WP0. They are computed from the measured set using standard pedotransfer functions, and are reported so that controller thresholds, dosing schedules and the power analysis can be specified before any treatment is applied.
| Derived quantity | Functional basis | Why it matters here |
|---|---|---|
| Water retention ($\theta_{fc}$, $\theta_{wp}$) | Saxton & Rawls (2006) equations from sand/silt/clay fractions and organic carbon 33 | Sets the moisture at which the system is energised, and the hydraulic gate on actuation |
| Air-filled porosity $\epsilon_a = \phi - \theta$ | Derived from total porosity and water content | The dominant control on O2 diffusion and therefore on $E_h$ |
| Oxygen Supply Index → predicted $E_h$ | Nernst mapping of OSI, Section 2.5 | Defines the redox regime each varietal class starts in, and the treatment implied |
| Effective diffusion coefficient $D_e$ | Millington–Quirk tortuosity model 34 | Governs the rate of electrokinetic transport toward the cassette |
| Distribution coefficient $K_d$ for Pb | Log-linear in pH and organic carbon, per surface-complexation behaviour | Converts total Pb into the mobile fraction electrokinetics can actually move |
| Modelling target Pb | $C_{\text{mobile}} = C_{\text{total}}/(1 + K_d\,(V/\rho_b))$ at the DTPA ratio | The concentration the controller must drive to target, per varietal class |
| AMF colonisation potential | Inverse relation to available P; optimum near pH 6–7 | Establishes whether H3 is achievable per class, or whether P must be managed first |
Every controller threshold derived from these functions is re-estimated from WP0 measurements before Gate 1. The model sets the plan; the measurement sets the plan’s parameters. Where a function is used outside its calibration envelope, that use is declared in the pre-registration.
2.5 Redox Potential as the Master Diagnostic
Of the measured endpoints, oxidation–reduction potential ($E_h$) occupies a unique methodological position: it is the cheapest to monitor continuously, the most sensitive to biological state, and the most diagnostic of the conditions governing metal bioavailability 1112. Under oxic conditions ($E_h$ above roughly +350 mV) iron and manganese are oxidised and largely insoluble, and metal cations are held by exchange and by precipitation on oxide surfaces. Under reducing conditions ($E_h$ below roughly +100 mV) Fe(III) and Mn(IV) oxides dissolve, releasing sorbed metals back into solution and generating phytotoxicity 13. Restoration, in redox terms, is the recovery of a stable, aerobic, biologically productive $E_h$ regime.
Because $E_h$ governs both the contaminant chemistry and the microbial community, it is the state variable the controller must hold. The next subsection makes it predictable.
2.6 Redox from First Principles: The Oxygen Supply Index
Redox potential is not an independent variable of soil; it is the consequence of a supply–demand imbalance. Oxygen is produced at the surface faster than it can diffuse inward, so the profile is set by the ratio of O2 diffusion capacity to microbial O2 demand. Defining that ratio explicitly makes $E_h$ predictable from measurable soil properties rather than something that must be waited for and observed.
The construction runs in three steps.
STEP 1 — EFFECTIVE OXYGEN DIFFUSIVITY
Gas transport in a porous medium is reduced by tortuosity. The Millington–Quirk relation expresses the effective coefficient as a fractional power of the air-filled porosity:
$D_0$ = diffusion coefficient in free air; $\epsilon_a$ = air-filled porosity; $\theta$ = volumetric water content; $\rho_b$ = bulk density; $\rho_s$ = particle density ($\approx 2.65$ g cm−3 for mineral soils, $\approx 1.5$ for organic soils).
STEP 2 — OXYGEN SUPPLY INDEX
Demand is taken as proportional to the respireable organic carbon pool, scaled by temperature. The Oxygen Supply Index (OSI) is the dimensionless ratio of supply to demand. An OSI above unity indicates that oxygen arrives faster than it is consumed, and the soil is oxidising; an OSI near zero indicates diffusion limitation and reducing conditions:
STEP 3 — MAPPING THE SUPPLY RATIO TO $E_h$
A soil is not in equilibrium with atmospheric oxygen; it is a diffusion-limited reaction front. The controlling couple therefore shifts with the supply ratio. Fully oxidised soil is governed by the MnO2/Mn2+ boundary, $E_{\text{Mn}} = 1230 - 118.3\,\text{pH}$; an anoxic soil by the Fe(OH)3/Fe2+ boundary, $E_{\text{Fe}} = 771 - 59.16\,\text{pH}$. These are bridged by a logarithmic supply term:
$S$ = 190 mV per decade of OSI. Calibrated so that OSI = 1 yields ≈ +490 mV (well aerated) and OSI = 10−4 yields ≈ −210 mV (strongly anoxic), matching published field ranges for mineral soils. The functional form is a calibrated transfer function, not a thermodynamic identity: the exact value is re-fitted against WP0 measurements before Gate 1.
The curve shows predicted $E_h$ across the available water range for the selected class; the marker shows the current setting. Where the curve falls below +100 mV, Fe(III) and Mn(IV) oxide dissolution is expected and sorbed metals are at risk of remobilisation 13.
| Quantity | Value | Class |
|---|
Theoretical Framework
From soil as substrate to soil as organism3.1 Soil as a Living Medium
Conventional agronomy treats soil as a passive medium — a container in which nutrients dissolve and roots are inserted. The modern critical-zone perspective treats the soil surface layer as the principal regulatory interface of the terrestrial biosphere: the zone in which atmosphere, lithosphere, hydrosphere and biosphere intersect and exchange 1516. Within this framing, soil organic carbon is not merely a fertility amendment. It is the structural matrix that determines aggregate architecture, water retention, cation exchange and the habitat in which microbial and fungal communities persist 1718.
A degraded soil exhibits the simultaneous loss of all three: carbon, structure, and biological community. These losses are mutually reinforcing. Compaction reduces porosity, which reduces oxygen diffusion, which drives $E_h$ downward, which suppresses aerobic decomposition, which slows mineralisation, which further starves the microbial community of substrate. The restoration problem is therefore not the removal of any single negative factor but the re-establishment of a self-sustaining positive feedback loop.
3.2 Four Contested Claims, Graded Honestly
A proposal that conflates established science with speculation invites the loss of credibility that attaches to the whole programme when the speculative components fail. The four mechanistic pillars of this work are therefore stated with their evidential status attached.
Biochar's aromatic graphitic domains and surface functional groups adsorb metal cations through electrostatic attraction and surface complexation, while its dissolved organic carbon complexes metals into soluble species that are then leached or further sorbed 1920. In parallel, iron- and manganese-bearing biochar fractions buffer redox excursions, now reasonably well characterised 21.
Nanoscale zero-valent iron (nZVI) reduces Cr(VI) to the far less mobile Cr(III), degrades chlorinated organics by reductive dechlorination, and immobilises metals as mixed-valence iron oxides and magnetite 2223. Efficacy depends strongly on passivation and is sensitive to competing soil constituents including dissolved organic matter.
Arbuscular mycorrhizal fungi deliver phosphorus and nitrogen in exchange for plant carbon, and their extraradical mycelium and glomalin secretions bind metals extraradically, limiting translocation to shoots 1424. The protective effect is well documented in metal-contaminated soils.
The proposition that weak, low-frequency electric fields accelerate microbial metabolism and root development is contested. Plant electrotropism to imposed fields is real but occurs at field strengths orders of magnitude above the sub-Faradaic regime, and the literature contains both supporting and irreproducible findings 2526. This programme treats bioelectric stimulation strictly as a hypothesis under test (H6), gated behind a stop-rule, and never as a load-bearing design assumption.
3.3 Governing Transport Model
Solute transport in a saturated porous medium under an imposed potential follows the classical electrokinetic form of the advection–dispersion equation, with electromigration added as a dominant sink term 627:
$c$ = dissolved concentration; $\mathbf{u}$ = pore-water velocity; $D_{e}$ = effective dispersion coefficient; $z$ = ionic charge number; $F$ = Faraday constant; $R$ = gas constant; $T$ = absolute temperature; $\mathbf{E}$ = electric field; $\lambda$ = decay/sorption rate constant. The fourth term is the electromigration flux that makes directed steering possible; the last term represents sorptive loss to the reactive matrix.
Simplified Langmuir-type sorption response with saturable reactive capacity; the dashed line marks the 0.3 mg kg−1 phytotoxic threshold. This model is illustrative for design intuition only and is not predictive — validated kinetics replace it from WP2 onward.
Hypotheses & Research Objectives
Eight falsifiable propositions with explicit disconfirming conditionsEach hypothesis below is stated in a form that permits disproof. For each, the programme specifies (i) the null hypothesis, (ii) the effect size that would constitute a meaningful result, and (iii) the disconfirming observation — the measurement that, if made, would cause the programme to abandon or redesign that component. Hypotheses are grouped into restoration (H1–H3), control-system (H4–H6) and AI-generalisation (H7–H8) families.
Directional electromigration from a central root zone to a perimeter reactive cassette produces a ≥4-fold spatial gradient in bioavailable metal concentration, with sandbox concentrations significantly exceeding root-zone concentrations, while root-zone concentrations remain at or below the untreated control.
Spatial distribution of bioavailable metals is statistically indistinguishable between sandbox and root zone; the $\chi^{2}$ statistic for spatial heterogeneity is not significant at $\alpha = 0.05$.
If, after 30 days of energisation, root-zone bioavailable Pb exceeds the paired pre-treatment control by more than 15% at $p < 0.05$, the spatial-decoupling premise is falsified and the MSD architecture is abandoned in favour of full excavation and off-site treatment. This stop-rule is absolute: it is not subject to override by other positive results.
A composite of nZVI (10%), thiol-modified biochar (15%) and layered double hydroxide (5%) in washed silica sand achieves a combined working capacity of ≥120 mg Pb kg−1 at breakthrough, sufficient to treat the modelled site inventory with four cassette changes over 36 months.
If measured working capacity falls below 60 mg kg−1 in pilot columns, or if nZVI passivation exceeds 70% within 21 days, the cassette media formulation is replaced — with steel slag or supported bimetallic particles 22 — and the consumable-media budget is revised upward.
Inoculation with Rhizophagus irregularis at ≥100,000 viable propagules m−2 increases AMF root colonisation from baseline to ≥35% within 18 months and raises water-stable aggregate fraction by ≥8 percentage points relative to the matched un-inoculated control.
If AMF colonisation fails to exceed 25% by month 18, or if the aggregate response is <2 percentage points, the inoculation approach is abandoned. The programme does not claim mycorrhizal pedogenesis as site-specific; the literature establishes the mechanism generically 1424. H3 concerns only whether it transfers to this pedon.
A constrained reinforcement-learning controller (PPO with a convex action set enforcing $\dot{E} \le 0.1$ V cm−1 min−1 and $E \le 1.2$ V cm−1) reduces cumulative energy input by ≥35% relative to a fixed-schedule controller while achieving equivalent target reduction in bioavailable metal, and produces strictly lower variance of field excursions 28.
If the learned policy fails to beat the fixed schedule by 15% on energy, or if any single actuator excursion exceeds the hard cap, the learned policy is discarded and the programme reverts to a rule-based controller carrying the same constraint set. The safety envelope is non-negotiable; the learned component is replaceable by design.
Within the convex admissible action set $\mathcal{K}$, the closed-loop system is BIBO (bounded-input bounded-output) stable: all state trajectories remain within an invariant set of radius $R_{\text{bound}} = \|\mathbf{P}\mathbf{B}\|\,A_{\max}/\alpha$. This is a theorem, not an empirical observation — see the Lyapunov derivation in Section 7.4.
The stability claim is falsifiable in exactly one way: by producing a non-zero state trajectory that escapes the invariant set while remaining within $\mathcal{K}$. Hardware-in-the-loop testing (WP6) exists specifically to search for such trajectories using randomised and adversarial input sequences.
This is the programme's only genuinely speculative claim, and it is isolated deliberately. No other work package depends on H6. If H6 fails — a null result being the more likely outcome, given the irreproducibility documented in the plant-electrophysiology literature 2526 — the remainder of the programme proceeds unaffected. A positive field result is a bonus; it is never a foundation.
A 7.83 Hz pulsed field at ≤50 mV cm−1 increases soil respiration flux by ≥20% over sham-treated controls at constant moisture and temperature, with the effect persisting ≥7 days post-treatment.
A surrogate model trained on the telemetry of four varietal classes predicts DTPA-extractable Pb, $E_h$ and respiration flux in the two held-out classes with a coefficient of determination $R^{2} \ge 0.70$ and a normalised RMSE below 20% of the observed range — i.e. it has learned transferable soil physics rather than per-substrate curve fits. Cross-substrate transfer is a genuinely hard generalisation problem, and the expectation that it succeeds is optimistic 35.
Performance on held-out classes is no better than a per-class regression fitted on those classes alone. This is the default expectation for cross-domain models and must be actively tested, not assumed away.
If held-out performance falls below $R^{2} = 0.50$, the surrogate is declared class-specific and retrained per varietal class with explicit substrate features ($K_d$, CEC, $\phi^{tot}$) supplied as inputs. The programme then claims no cross-substrate transfer; it claims a per-class calibrated model, which is a weaker but honest result. The AI is a means, not the claim.
Across the full programme, 100% of commanded actuations satisfy the constraint set $\mathcal{K}$ of Section 7.2: field strength within $[0, 1.2]$ V cm−1, rate of change within $0.1$ V cm−1 min−1, and no actuation issued while a hard interlock is asserted.
A single logged command violating $\mathcal{K}$ — or a single actuation issued during an asserted interlock — is a compliance failure. The AI layer is disabled pending root-cause analysis, the rule-based fallback is restored, and the gate is failed until the cause is identified and demonstrated fixed. One violation fails the gate; a thousand compliant commands do not excuse it. Compliance is measured as a count of violations, not a rate.
System Architecture: Modular Sandbox Detoxification
Physical decoupling as the central engineering decisionThe MSD architecture is a permeable reactive barrierA barrier through which pore water and ions pass freely, but which immobilises dissolved contaminants; here realised as a replaceable cassette rather than a fixed excavation. configured as a modular, sacrificial cassette positioned between the treatment electrodes and the vegetative root zone. The design resolves a deceptively simple problem: how to confine the three things electrokinetic remediation generates — migrating contaminant ions, electrode-generated pH fronts, and the heat of electrolysis — away from the biological zone that restoration depends upon.
Titanium mesh anode in an isolated sump. The electrolysis-generated acid front (pH 2–4) is confined to this chamber and never migrates into the treatment matrix, preventing dissolution of native minerals in the root bed. Chamber liquor is neutralised and reclaimed for reuse; no discharge to the St. Lawrence River.
5.1 Cassette Formulation
| Fraction | Vol. % | Primary function | Mechanism | Saturation target |
|---|---|---|---|---|
| Washed coarse silica sand | 60–70 | Hydraulic backbone | Maintains permeability; prevents clogging under sustained flux | Non-sorbing |
| Thiol-modified biochar | 15–20 | Cation sorption | Carboxyl, hydroxyl, phenolic groups; graphitic $\pi$ domains 19 | 85% BET |
| Nanoscale zero-valent iron | 10 | Reductive immobilisation | Cr(VI)→Cr(III); magnetite precipitation 22 | 70% passivation |
| Layered double hydroxide / zeolite | 5–10 | Anion exchange | Interlayer anion capture: arsenate, chromate 28 | 80% CEC |
| Steel slag fines (contingency) | 0–10 | Alkaline buffer | Neutralises acid front; raises pH ceiling | Substituted if H2 fails |
Layered double hydroxides are specified specifically because standard silica sand and biochar fail to capture anionic species; a reactive barrier that targets only cations is ineffective against oxyanion contamination 28.
5.2 The Four-Stage Telemetry Mesh
Field nodes use ESP32-S3 / nRF52840 solar micro-nodes communicating over LoRaWAN (915 MHz) or RS-485 Modbus RTU, with an edge controller (Raspberry Pi 5 / Jetson Orin Nano) running containerised MQTT ingestion, a time-series store, and local inference 29.
Materials & Methods
Controlled-environment vessels · varietal blocking · continuous telemetry6.1 Source Material Characterisation
Characterisation of the six varietal classes follows the USDA-NRCS Soil Survey Manual. Material is sampled by depth increment to 40 cm using a soil auger, with undisturbed cores taken for bulk density, porosity and aggregate determination. Samples are composited within varietal class and never across classes, so the substrate assigned to a treatment arm is homogeneous and reproducible across replicate vessels.
Because the design runs in an isolated facility rather than open ground, three classes of variance that normally dominate field experiments are removed by construction: weather events, uncontrolled hydrological flux, and off-site deposition. What remains is the variance the programme actually cares about — substrate class, treatment, and their interaction — and each is separately blocked and estimable.
6.2 Controlled-Environment Experimental Design
The design is a randomised complete block factorial, replicated across vessels, run in controlled-environment growth space. The vessel is the experimental unit — the unit randomised, the unit treated, and the unit of inference. The varietal class is the blocking factor, which converts substrate heterogeneity from a confound into a tested effect.
Each vessel is a replicated column packed with a single varietal class at a specified bulk density, containing an instrumented MSD cassette and a planted root zone. Moisture content and temperature are actively held at the class-specific set points derived in Section 2.6, so that redox state is a controlled variable rather than a weather-dependent outcome.
| Factor | Level | Vessels / class | Role |
|---|---|---|---|
| Treatment (fixed, crossed) |
C0 — Untreated control | 6 | Baseline drift; AI surrogate validation |
| C1 — Biological only (AMF + compost) | 6 | Isolates biological effect (H3) | |
| C2 — Electrochemical only (MSD) | 6 | Isolates electrochemical effect | |
| C3 — Coupled bioelectrochemical (full MSD) | 6 | Tests the interaction term (H1) | |
| PEMF sub-factor (split within vessel) |
PEMF off (sham) | 12 | Sham control for H6 |
| PEMF 7.83 Hz on | 12 | Tests H6 | |
| Block = varietal class | SL — Sandy loam | 4 × 6 | Permissive case |
| SiL — Silt loam | 4 × 6 | Reference pedon | |
| CL — Clay loam | 4 × 6 | CEC dose–response | |
| SiC — Silty clay | 4 × 6 | Hardest case | |
| OG — Organic / muck | 4 × 6 | Reducing regime; risk R2 | |
| UF — Urban fill | 4 × 6 | Legacy Pb; extraction chemistry | |
| Total experimental vessels | 144 | 24 per varietal class | |
The PEMF sub-factor is applied by splitting the treatment vessel longitudinally, so both PEMF states sit within the same substrate, moisture history and microbial inoculum. This is a stronger control than separate vessels: it removes substrate heterogeneity entirely from the H6 comparison.
Reproducibility, replication power and causal attribution are all markedly better under controlled conditions. The corresponding cost is external validity: a vessel is not a field, and the programme will therefore make no claim about open-field performance until the system has been deployed on the island surface under supervision in the final phase. The controlled environment is where the mechanism is shown to work and the AI is shown to generalise — not where transfer outdoors is proven. That is a separate, later claim with its own evidence requirement.
6.3 Telemetry Mesh & Closed-Loop Instrumentation
The instrumentation layer is what makes restoration an engineering discipline rather than a horticultural one, and it is also what supplies the AI with its training data. The dashboard below renders a replay of the modelled 36-month trajectory for a single instrumented vessel (treatment arm C3, varietal class SiL), demonstrating how controller actuations and soil response co-evolve. Values are simulated from the model of Section 3.3 and exist to demonstrate the telemetry contract — the signals, units, thresholds and alarm semantics the real system will report. They are not observations.
—
6.4 Laboratory & Field Protocols
Soil physical, chemical and biological analyses follow the methods in Table 2.1. Total metals are determined by EPA 3051A digestion with ICP-MS quantification; bioavailable metals by DTPA extraction, which better predicts phytotoxic exposure than total content because it approximates the plant-available pool. Redox potential is measured in situ with combination electrodes at field capacity, logged at 15-minute intervals.
Disturbance discipline. Sampling uses a fixed georeferenced coring template across all sampling dates. Wireless nodes are installed to fixed depth in permanently marked sleeves so that repeated insertion does not progressively compact the measurement volume. This matters more than it appears: sensor insertion is itself a disturbance that would otherwise become a confounding trend in a 36-month series.
6.5 Amendment Protocol (Arms C1 and C3)
- Physical decompaction without inversion. Subsoil shank or broadfork at 35–45 cm. Ploughing and inversion are prohibited: tillage crushes existing fungal hyphae and oxidises residual organic matter, compounding the damage it is intended to remedy.
- Quenched biochar application at 1.5–2.5 t ha−1, charged with compost extract, fulvic acid, fish amino acids and paramagnetic basalt powder, then cured 14–21 days under breathable tarp until thermal stability indicates microbial colonisation of the pore structure.
- Fungal and microbial inoculation at ≥100,000 viable propagules m−2, with indigenous microbial inoculum and saprophytic decomposer slurry applied beneath mulch.
- Succession cover polyculture — a twelve-species cocktail combining taproot drillers, nitrogen-fixing legumes, fungal-biomass builders and pollinator/dynamic accumulators. Bare soil is never left exposed.
- Organic armour. A 5–10 cm carbonaceous mulch to suppress evaporation, buffer temperature swing and shield soil biology from UV.
Analytical Framework & Stability Proof
Composite index construction · controller constraint sets · Lyapunov argument7.1 Composite Restoration Index
No single variable constitutes soil health. The programme therefore constructs a composite Restoration Index (RI) from z-scored, directionally normalised endpoints, weights fixed a priori rather than fitted to the observed data, so that the index cannot be reverse-engineered to produce a desired result:
$z_i^{*}$ is the directionally normalised z-score of endpoint $i$ (sign-corrected so that higher is always better); $w_i$ is the pre-specified weight; $k = 8$ for the primary index.
| Endpoint | Domain | Weight $w_i$ | Rationale |
|---|---|---|---|
| Bioavailable Pb (inverse) | Contaminant | 0.20 | Primary safety endpoint |
| Redox potential $E_h$ (target band) | Function | 0.18 | Master diagnostic of aeration |
| Water-stable aggregates | Physical | 0.15 | Structure & erosion resistance |
| AMF root colonisation | Biological | 0.14 | Symbiotic function |
| Microbial biomass C | Biological | 0.11 | Active community size |
| Cation exchange capacity | Chemical | 0.09 | Retention buffer capacity |
| Respiration flux | Biological | 0.07 | Metabolic activity |
| Organic carbon | Chemical | 0.06 | Substrate & structure |
| Total | 1.00 |
7.2 Controller Constraint Set
The controller's admissible action set is a convex polytope rather than an unconstrained action space. This single design decision is what converts a machine learning controller from a hazard into a safety instrument:
with $E_{\max} = 1.2$ V cm−1 and $\dot{E}_{\max} = 0.1$ V cm−1 min−1. Any action proposed by the learned policy is projected onto $\mathcal{K}$ before actuation; a projection onto a compact convex set is idempotent and cannot produce an out-of-bounds command 28.
7.3 Lyapunov Stability of the Closed Loop
The programme's central theoretical claim is that the constrained closed loop cannot run away. The argument is stated in full below; it is deliberately elementary, and elementary is the point — an esoteric proof that reviewers decline to check provides no safety assurance.
Statement. Let the plant be $\dot{\mathbf{x}} = \mathbf{A}\mathbf{x} + \mathbf{B}\mathbf{u}$ with $\mathbf{A}$ Hurwitz. Let the feedback be $\mathbf{u} = -\mathbf{P}\mathbf{x}$, with $\mathbf{P} \succeq 0$ chosen so that $\mathbf{A} - \mathbf{B}\mathbf{P}$ is Hurwitz. Let the admissible set be $\mathcal{K}$ as in Section 7.2, compact and convex, containing the origin. Then all state trajectories are ultimately bounded: there exist $R_{\mathrm{bound}} > 0$ and $T > 0$ such that $\|\mathbf{x}(t)\| \le R_{\mathrm{bound}}$ for all $t \ge T$, independent of the policy used within $\mathcal{K}$.
where $\mathbf{Q} \succ 0$ solves the Lyapunov equation $\mathbf{A}^{\top}\mathbf{Q} + \mathbf{Q}\mathbf{A} = -\mathbf{I}$, and $\alpha > 0$ follows from the Hurwitz property of the closed-loop matrix. Since the projected disturbance term is bounded on the compact set $\mathcal{K}$:
Setting $\dot{V} < 0$ for all $\|\mathbf{x}\| > R_{\mathrm{bound}}$ yields the ultimate invariant bound:
The state enters and remains in the ball of radius $R_{\mathrm{bound}}$. Because the argument holds for any control law mapping into $\mathcal{K}$ — including a mis-specified, stochastic, or adversarially perturbed policy — runaway oscillation and out-of-bound actuation are precluded by construction rather than by tuning. $\blacksquare$
It guarantees bounded states, not desirable states. A system can be perfectly stable and perfectly useless. Boundedness is a safety property; it is a necessary but emphatically not sufficient condition for restoration success. H4 addresses efficacy, and is tested empirically.
7.4 Controller Action Matrix
The rule-based fallback controller — the one the system reverts to if H4 fails — operates on the following state machine. It is specified in full so that the fallback is auditable without reference to the learned policy.
| Condition | Class | Action | Rationale |
|---|---|---|---|
| $E_h > +500$ mV | OXIDATIVE | Halt field; irrigate to field capacity; drench fulvic at 1:500 | Suppresses nitrification and oxidation fronts 12 |
| $E_h < +150$ mV | HYPOXIC | Stop irrigation; resume aeration; raise field to 0.3 V/cm | Fe/Mn oxide dissolution releases sorbed metals 13 |
| VWC > 45% | SATURATED | Gate all field actuation; hold | Pre-conditions for short-circuit current |
| Cassette load > 85% | BREAKTHROUGH | Reverse polarity; schedule cassette exchange | Avoids remobilisation of captured metals |
| Root Pb > 0.5 mg/kg | TOXICITY | Full stop; deploy chelation flush to sandbox only | Plant-protection override |
| All conditions nominal | NOMINAL | Policy dispatch (learned, else linear ramp) | Normal closed-loop operation |
The TOXICITY and SATURATED rows are hard interlocks: they override the learned policy entirely, including the project's target trajectory. No learned policy may act while an interlock is asserted.
Work Packages & Programme Timeline
Six work packages over 36 months, with three gated decision pointsThe programme is organised into six work packages sequenced so that each gate is a genuine decision point — at each gate the programme can legitimately stop, redirect, or continue on the basis of accumulated evidence. A programme with no stopping rules is a programme that cannot be held to account.
| WP | Title | Months | Primary output | Gate criterion |
|---|---|---|---|---|
| WP1 | Baseline & Facility Commissioning | 1–9 | Non-invasive WP0 baseline across 6 varietal classes; controlled-environment facility commissioned if acquired | Feasibility; acquisition funding; facility acceptance (Scenario A/B selection) |
| WP2 | Media Characterisation | 4–14 | Pilot column capacity data; validated kinetic model; OSI→$E_h$ transfer re-fitted | GATE 1 capacity ≥60 mg/kg |
| WP3 | Controlled-Environment Deployment | 9–26 | Operate 144 instrumented vessels; execute factorial across varietal classes (H1) | GATE 2 H1 falsifier not triggered |
| WP4 | Pedogenesis & Succession | 12–33 | Biochar + AMF + cover polyculture trajectory across varietal classes | Mid-term RI trajectory |
| WP5 | AI Surrogate & Control Validation | 15–36 | Trained surrogate; digital twin; held-out generalisation (H7); stability in HIL (H5) | GATE 3 stability + compliance verified |
| WP6 | Supervised Field Deployment & Verification | 24–36 | Certified system deployed on island surface under supervision; open dataset; papers | GATE 4 H8 compliance = zero violations |
8.1 Gate Criteria & Stopping Rules
Continue if pilot-column working capacity ≥60 mg Pb kg−1 and nZVI passivation <70% at 21 days. Redirect if capacity is 30–60: substitute slag or bimetallic media. Stop if capacity <30: revert to excavation.
Absolute stop if root-zone bioavailable Pb exceeds the paired control by >15% at $p<0.05$ (the H1 falsifier). Continue otherwise. This gate is evaluated on a single pre-specified statistic and is not subject to committee discretion.
Pass if hardware-in-the-loop testing finds no trajectory escaping the invariant set. Conditional pass (rule-based controller retained) if the learned policy fails to meet the 15% energy criterion. H6 termination is automatic if no respiration response at month 24.
Risk Register & Mitigation
Twenty identified risks on a 5×5 likelihood–impact matrixRisks are scored on a 5×5 matrix (likelihood × impact) and each carries a named owner and a trigger threshold that initiates the mitigation — not a vague intention to monitor. Select any cell below to inspect the risks assigned to it.
| ID | Risk | L | I | Score | Trigger threshold | Mitigation | Owner |
|---|---|---|---|---|---|---|---|
| R1 | Phytotoxicity from electrode front migration | 3 | 5 | 15 | Root Pb >0.5 mg/kg, or AMF colonisation fall >20% in 30 d | Immediate field halt; chelation flush to sandbox; Gate 2 evaluation | Field Lead |
| R2 | Reaction front breakthrough → metal re-mobilisation | 3 | 4 | 12 | Cassette load >85%, or sandbox effluent Pb >0.3 mg/kg | Polarity reversal; scheduled cassette exchange; nZVI top-up | Process Eng. |
| R3 | nZVI rapid passivation → capacity shortfall | 4 | 3 | 12 | Passivation >70% at 21 d in pilot | Media substitution: slag, bimetallic particles; Gate 1 redirect | Lab Lead |
| R4 | Freeze–thaw artefact misread as treatment effect | 4 | 3 | 12 | Control plots diverge >1σ during winter | Seasonal covariate in mixed model; VWC gating of actuation | Data Lead |
| R5 | Property acquisition not funded; target site unavailable | 2 | 5 | 10 | Acquisition funding not committed by month 6 | Programme continues on Scenario B or C (§2.1.2) — mechanism and H1/H3/H8 preserved; H7 generalisation deferred | Exec. Director |
| R6 | Regulatory permit denial or delay | 2 | 4 | 8 | NYSDEC comment cycle exceeds 90 d | Permit matrix initiated in WP1; pre-application meeting in month 2 | Compliance Lead |
| R7 | Sensor fouling / drift biasing telemetry | 4 | 2 | 8 | Calibration drift >10% on reference check | Fortnightly calibration; redundant ISFET; automatic data flagging | Instrumentation |
| R8 | AMF inoculation failure in field | 3 | 3 | 9 | Colonisation <25% at month 18 | H3 falsifier; re-dose with adapted local inoculum (§4) | Biology Lead |
| R9 | Learned policy underperforms fixed schedule | 3 | 2 | 6 | Energy saving <15% at Gate 3 | Automatic reversion to rule-based controller; no schedule impact | Control Lead |
| R10 | Power interruption during energised treatment | 2 | 3 | 6 | Outage >4 h during active phase | UPS + generator; auto-ramp on restart (no step change) | Site Ops |
| R11 | Drought lowers conductivity below threshold | 2 | 3 | 6 | VWC <18% for 5 consecutive days | Supplementary irrigation to field capacity before energising | Field Lead |
| R12 | Unanticipated baseline contamination severity | 2 | 3 | 6 | Baseline total Pb >3× modelled estimate | Re-scale design; revise capacity model; draw budget contingency | Project Lead |
| R13 | Equipment procurement delay | 3 | 2 | 6 | Any critical-path item >8 weeks late | Dual-source key instrumentation; 8-week float retained on WP3 | Procurement |
| R14 | Adverse weather / flood event on island | 2 | 4 | 8 | Stage-action flood warning for the St. Lawrence basin | Raise cassettes; de-energise; storm-drainage survey in WP1 | Site Ops |
| R15 | Adverse findings published — sponsor/reputational risk | 2 | 3 | 6 | Gate 2 stop triggered | Pre-agreed publication policy: null results published with equal prominence | Exec. Director |
| R16 | AI surrogate fails to generalise across varietal classes | 4 | 3 | 12 | Held-out $R^{2} < 0.50 | Declared class-specific; substrate features ($K_d$, CEC, $\phi$) added; per-class models trained (H7 fallback) | AI Lead |
| R17 | Controller issues an out-of-envelope command | 1 | 5 | 5 | Any single logged $\mathcal{K}$ violation | AI layer disabled; rule-based fallback restored; gate failed pending root cause (H8) | AI Lead / Safety |
| R18 | Controlled-environment facility failure (climate, power, biosecurity) | 2 | 4 | 8 | Set-point deviation >1 °C or >3% VWC for >4 h | Redundant HVAC and UPS; alarm escalation; vessel-level data loss assessed before restart | Facility Eng. |
| R19 | Introduced weed seeds, pathogens or root pathogens in source soil | 2 | 4 | 8 | Species recorded on receipt from outside the island | Quarantine handling; heat treatment of imported material; disinfection between varietal classes; containment per NY agriculture law | Biosafety Officer |
| R20 | Training/validation data leakage inflates AI performance | 3 | 4 | 12 | Random rather than grouped train/test split, or shared mother batch | Split by vessel and mother batch, never randomly; holdout classes sealed until Gate 3; split manifest published | Data Lead |
L = likelihood, I = impact, each 1–5; Score = L × I. R15 exists because a programme that publishes only positive results has already failed as science, irrespective of its technical merits.
Governance, Ethics & Regulatory Compliance
Permitting matrix · advisory board · data and publication policy10.1 Regulatory & Permitting Matrix
The programme is scoped to avoid regulated-activity thresholds wherever scientifically possible. This is a deliberate design choice, not an oversight: a research programme that requires fewer exemptions is faster, cheaper, and more likely to complete.
| Domain | Authority | Applies? | Action |
|---|---|---|---|
| Water discharge (Clean Water Act / NPDES) | NYSDEC / EPA Region 2 | NOT APPLICABLE | Zero-discharge design: all process liquor reclaimed |
| Solid waste (RCRA) | NYSDEC | CONDITIONAL | Spent cassettes characterised; disposal via licensed facility if TCLP-exceeding |
| Ground disturbance / coastal zone | NYS DEC / Town of Alexandria Bay | REQUIRED | Permit matrix in WP1; minimal-footprint installation design |
| Endangered species / habitat | USFWS | SCREENING | Pre-project screening; no listed species expected on an existing disturbed parcel |
| Research involving human subjects | IRB | NOT APPLICABLE | No human-subjects research; no biospecimen collection |
| Live animal use | IACUC | NOT APPLICABLE | No animal research; soil fauna sampled non-destructively |
| Unmanned aerial vehicle operation | FAA (Part 107) | CONDITIONAL | Remote ID, Part 107 compliance, no flight over persons or water without notice |
| Electrical installation & grid tie | NY Authority Having Jurisdiction | REQUIRED | GFCI protection, weather-rated enclosures, licensed electrician sign-off |
Permitting determinations are provisional and must be confirmed with the relevant authority before ground disturbance. Nothing in this table constitutes legal advice.
10.2 Governance Structure
10.3 Ethics, Publication & Data Policy
- Pre-registration. Hypotheses, primary endpoints, exclusion criteria and the analysis plan are registered before WP2 completes, so that the analysis cannot be retrofitted to the data.
- Null-result parity. Negative findings are published with the same prominence as positive findings. This is contractual, not aspirational (risk R15).
- Selective reporting audit. All measured endpoints appear in the publication regardless of the direction of the result.
- Data release. De-identified telemetry, laboratory data and analysis code are released under an open licence within 12 months of each gate (see Section 15).
- Stewardship commitment. The island is treated as a long-term research asset, not a development site. No construction beyond what the research requires.
Budget & Resource Model
Indicative 36-month cost envelope · carbon co-benefit projectionAll monetary values are order-of-magnitude planning estimates for programme structuring, not quotations. They exclude property acquisition. Final budgeting requires vendor quotes and will be revised at WP1.
| Category | Low | Expected | High | % of total |
|---|---|---|---|---|
| Personnel (PI, 2 research staff, field tech, 0.3 FTE data, 0.5 FTE ML engineer) | $372,000 | $462,000 | $565,000 | 37.8% |
| Controlled-environment facility (HVAC, 144 instrumented vessels, growth space) | $180,000 | $248,000 | $330,000 | 20.3% |
| Instrumentation & telemetry mesh | $95,000 | $128,000 | $165,000 | 10.5% |
| Reactive media & consumables (nZVI, biochar, LDH) | $70,000 | $96,000 | $140,000 | 7.9% |
| Laboratory analysis (ICP-MS, sequencing, assays) | $120,000 | $165,000 | $210,000 | 13.5% |
| MSD installation & electrical | $55,000 | $78,000 | $105,000 | 6.4% |
| Biological inputs & amendments | $28,000 | $39,000 | $52,000 | 3.2% |
| Permitting, legal & compliance (incl. biosecurity) | $22,000 | $33,000 | $48,000 | 2.7% |
| Publication, open data & dissemination | $22,000 | $31,000 | $44,000 | 2.5% |
| Travel, equipment servicing | $20,000 | $28,000 | $38,000 | 2.3% |
| Contingency (10%, driven by risks R12, R3, R18) | $84,000 | $113,000 | $142,000 | 9.2% |
| TOTAL (36 months) | $1,068,000 | $1,421,000 | $1,839,000 | 100% |
cost (36 mo)
expected case
experimental vessels
facility share
11.1 Carbon Co-Benefit Projection
Restoration produces a measurable carbon co-benefit. The model below is a first-order projection based on IPCC Tier 1 stock-change factors for mineral soil, modified for the biochar carbon-fixing pathway 3031. Adjust the parameters to test sensitivity; the output is deliberately conservative and should be treated as an order-of-magnitude estimate, not a verified offset.
Sequestration credited is the net change against the untreated control, not the gross stock. Credit against purchased offsets is not assumed: no recognised framework currently applies to this pathway, so the figure is a research co-benefit rather than a tradable instrument.
Dissemination & Anticipated Impact
Publication plan · open data · practitioner pathways| Output | Venue | Timing | Audience |
|---|---|---|---|
| Baseline characterisation dataset + site model | Repository (Zenodo/Figshare), DOI | Month 12 | Pedology community |
| Media characterisation & validated kinetic model | Journal of Hazardous Materials; Geoderma | Month 18 | Remediation chemists |
| BACI field trial & Restoration Index results | Soil Biology & Biochemistry; Applied Soil Ecology | Month 30 | Soil ecologists |
| Constrained control architecture & stability proof | IEEE Transactions (control systems) | Month 34 | Control engineers |
| Integrated final report + raw data | Open repository, CC-BY | Month 36 | All |
| Practitioner protocol (replicable field method) | Extension service; open handbook | Month 36 | Farmers & agronomists |
12.1 Intended Impact
A remediation method that discharges no secondary liquid waste and retains native soil carbon — removing the principal objection to in-situ electrokinetic treatment.
An operational, falsifiable definition of pedogenic function, and an open BACI dataset from a well-characterised insular system — both rare resources.
Avoided excavation, hauling and disposal cost, plus retained productive land value — the comparison against which the $1.08M programme cost must be justified.
Limitations, Falsifiers & Adversarial Review
The case against this programme, stated by the programmeA proposal that does not articulate its own weaknesses has not been reviewed. The seven objections below are, in the authors' assessment, the strongest arguments against this programme. Each is stated at full strength, followed by the response — and, where the response is weak, that is acknowledged.
The objection. Terms like “pedogenic function” and “bio-cybernetic” are not standard constructs. Defining success with a bespoke index assembled to move in the intended direction is a well-known route to self-confirming results.
Response — partly conceded. The composite index is a genuine vulnerability, addressed by fixing weights a priori, pre-registering the analysis, reporting every measured endpoint regardless of significance, and reporting full sensitivity to weighting. But the deeper objection stands partly: the index has no external validator. The programme's response is that its individual components are independently validated — redox potential, aggregate stability and mycorrhizal colonisation each have established meanings in the literature — and the index is a convenience for statistical power, not a claim of new science.
The objection. Electrokinetic remediation is a four-decade-old technology with well-documented limitations: high energy cost, poor performance in soils of low permeability and high buffering capacity, and diminishing returns under sustained operation. Presenting it as novel invites the reasonable suspicion that the limitations are being omitted.
Response — partially conceded. The limitations are real and are not omitted; they are the reason the design is what it is. The MSD cassette exists to contain them, and the constrained controller exists because unconstrained operation is both wasteful and phytotoxic. The claim under test is not “electrokinetics works” but “electrokinetics can be made microbiologically non-hostile and materially efficient when the collection geometry and the control law are designed together.” That is a narrower, more defensible claim — and a less commercially exciting one.
The objection. Soil behaviour in an instrumented container is not soil behaviour in a field. The programme may produce a system that works beautifully on its own substrate and fails in the first real season — the classic laboratory-to-field transfer failure.
Response — conceded, and staged to address it. The transfer claim is deliberately not made in the controlled phases. Six varietal classes spanning the hydraulic and textural range are used precisely to reduce the artificiality of any single substrate, and WP6 places the certified system on the island surface under supervision as an explicitly separate test. The programme claims mechanism and cross-substrate generality from the controlled work, and open-field performance only from WP6. Overclaiming transfer is treated here as a scientific failure, not a presentational one.
The objection. Soil AI is a crowded field of models that perform well on random train/test splits and collapse under honest validation. Cross-substrate transfer is known to be hard, and a fitted neural network presented as “AI-driven soil revival” may be dressing a regression in unfamiliar terms 35. If the AI does not work, is the programme refuted, or merely rebranded?
Response — conceded on the science, defused on the programme. H7 is written to expect failure: its null hypothesis is that cross-class performance is no better than a per-class fit, and its fallback is an honest declaration of class-specificity rather than a re-tune until the headline metric improves. Data splitting is by vessel and mother batch, never random, with held-out varietal classes sealed until Gate 3 (risk R20). Critically, no hypothesis depends on the AI being clever: H1, H3 and H8 are testable with rule-based control. If the model is worthless, the programme loses a tool and reports that it has done so — it does not lose a result.
The objection. Learned controllers can produce unpredictable behaviour, encode spurious correlations from a 36-month single-site record, and are difficult to certify — problems documented in safety-critical applied machine learning 32.
Response — accepted by design. This is why the learned policy is never the safety mechanism. The constraint projection, the rule-based fallback, the hard interlocks and the Lyapunov bound are all independent of the learned component. If H4 fails, the programme loses an efficiency optimisation and nothing else. The system is deliberately architected so that the most fashionable element is also the most removable.
The objection. If baseline contamination is severe enough to justify a dedicated programme, the residual toxicity after partial treatment may remain above phytotoxic thresholds, making productive restoration impossible regardless of technique.
Response — unresolved until WP0. This objection cannot be answered in advance, and the authors will not pretend otherwise. It is the reason WP1 baseline characterisation precedes any treatment commitment, and the reason Gate 1 can terminate the programme cheaply and early. If the baseline is beyond the reach of in-situ treatment, the honest outcome is termination in year one rather than three wasted years.
The objection. Sub-Faradaic bioelectric effects on soil microbial activity are frequently asserted on the basis of a small, methodologically weak literature, frequently adjacent to commercial claims for “electroculture” equipment. Including H6 in a funded programme risks lending it unearned credibility.
Response — accepted in full. H6 is retained only as a rigorously sham-controlled, small-scale test with a pre-specified null and an automatic termination rule at month 24. It consumes a minor fraction of the budget. No conclusion will be drawn unless the effect survives blinded, sham-controlled, power-adequate replication. If anyone believes this programme is promoting H6, they have misread Sections 3.2 and 4.
13.1 Residual Limitations
- Statistical power. Twenty plots per treatment across four blocks gives limited power for small effect sizes. The programme is powered for the large effects it hypothesises, not for subtle ones; a null result must be read as a confidence interval, not as proof of absence.
- Unmeasured legacy contaminants. The fourteen-endpoint battery may miss contaminant classes not included in the baseline, such as persistent organics. A broader screening scan is recommended at WP1.
- Equipment maturity. Commercially available reactive media and ISFET assemblies are not purpose-built for this application; some development effort is assumed.
- Model transferability. The kinetic parameters in Section 3.3 are literature-derived and site-specific only after WP2 validation. Pre-validation model output is illustrative only.
- Climate confounding. Thirty-six months spans two complete seasonal cycles, which is the minimum at which seasonal covariates are estimable. More would be better; the design does not claim otherwise.
- Analyst degrees of freedom. Pre-registration mitigates but does not eliminate discretion in exploratory analysis. All exploratory analyses are labelled as such and reported separately from confirmatory results.
Conclusions
What will be known, and what will notThe Terra Vivens Sanctae Mariae programme proposes a falsifiable test of whether electrokinetic remediation and biological restoration can be made mutually compatible through physical decoupling, and whether a constrained closed loop can operate that decoupled system materially efficiently.
The scientific contribution is not a new remediation technology. Electrokinetic remediation has existed for four decades, and mycorrhizal pedogenesis has been understood for longer still. The contribution is the coupling — an architecture that treats the antagonism between the two as a design problem to be solved rather than a constraint to be accepted, together with the measurement discipline to determine whether the solution actually works.
14.1 Expected Contributions
- An operational definition of pedogenic function expressed as a pre-registered, weight-specified composite index over independently validated endpoints — and, more valuably, a full sensitivity analysis showing how much such indices depend on weighting choices.
- A quantitative assessment of whether physical decoupling of electrolysis fronts and field from a root zone is achievable, and at what cassette geometry.
- A validated reactive-media formulation with published working capacity and passivation kinetics for a St. Lawrence lowland soil.
- An open, well-characterised BACI dataset with 36 months of high-frequency telemetry from a hydrologically bounded site — a resource of standalone value to the modelling community.
- A reusable, safety-certified control architecture in which the learning component is provably bounded and provably removable.
- A published negative or null result on H6, should that be the outcome — contributing to a cleaner picture of the sub-Faradaic bioelectric literature than currently exists.
14.2 Closing Statement
The organisation approaches this programme as an ecological trust and a research instrument, and it approaches the St. Mary's Island property as an opportunity rather than a prerequisite. The science is testable whether or not the purchase completes, and the three scenarios in Section 2.1.2 exist so that no single funding decision can determine whether the programme proceeds. The organisation's first obligation is to the integrity of the result, and its second to the site — and both are served by the same design choice: to specify in advance what would prove the approach wrong, and to stop if it does.
Terra Vivens Sanctae Mariae — The Living Soil of Saint Mary
“Earth Inspired Self Contained Self Reliant Systems”
Data Management & Open Science
FAIR data · open code · reproducible analysisData lifecycle
- Collection. All telemetry routed through MQTT to a time-series store with automatic calibration-flag insertion; no manual edits to raw streams.
- Provenance. Every derived variable carries a machine-readable lineage record linking it to the raw sensor series and the code version that produced it.
- Quality control. Automated range, rate-of-change and cross-sensor consistency checks; flagged data are retained and marked, never silently dropped.
- Analysis. All analysis in version-controlled, containerised environments; the exact image digest is published with each release.
- Release. CC-BY 4.0 data, MIT-licensed code, DOI-archived at each gate.
FAIR compliance summary
| Principle | Implementation |
|---|---|
| F — Findable | DOI + repository metadata + keyword indexing |
| A — Accessible | Open protocol; no proprietary formats retained |
| I — Interoperable | CF/NetCDF conventions, standard vocabularies, SI units |
| R — Reusable | CC-BY licence, full provenance, published code |
The BACI design and georeferenced sampling template are released as a reusable protocol so that the design is transferable even where the site-specific results are not.
Glossary & Appendices
Terminology, notation, and protocol referencesGlossary of Terms
| Term | Definition as used here |
|---|---|
| $E_h$ (redox potential) | Electrical potential of a soil relative to a standard hydrogen electrode; the master indicator of oxidation–reduction status and, through it, of Fe/Mn oxide stability and metal bioavailability. |
| AMF | Arbuscular mycorrhizal fungi — root-colonising fungi forming arbuscules for nutrient exchange; the principal symbiotic guild in this programme. |
| MSD | Modular Sandbox Detoxification — the permeable reactive barrier cassette architecture that spatially decouples the electric field and captured metals from the root zone. |
| EK-PRB | Electrokinetic Permeable Reactive Barrier — the underlying class of technology; MSD is a modular, replaceable realisation of it. |
| nZVI | Nanoscale zero-valent iron — a strong reductant and metal sorbent; prone to passivation in oxidising soils. |
| LDH | Layered double hydroxide — an anionic exchange material used to capture oxyanions (arsenate, chromate) that cation-targeting media miss. |
| DTPA | Diethylenetriaminepentaacetic acid — a chelating extractant used to operationally define the plant-available (bioavailable) metal pool. |
| CEC | Cation exchange capacity — the total negative-charge-buffering capacity of a soil for positively charged ions. |
| WSA | Water-stable aggregates — the fraction of soil structure surviving wet sieving; a proxy for physical resilience. |
| BACI | Before–After–Control–Impact — a quasi-experimental design separating treatment effect from natural temporal change. |
| RI | Restoration Index — the pre-specified weighted composite of the eight primary endpoints. |
| PPO | Proximal Policy Optimization — a model-free reinforcement-learning algorithm used for the non-safety-critical control policy. |
| BIBO | Bounded-input bounded-output — a stability property guaranteeing state trajectories stay within a finite set for bounded inputs. |
| PEMF | Pulsed electromagnetic field — tested here only under H6, at low intensity and with sham controls. |
Notation
$E$ electric field (V cm−1) · $c$ dissolved concentration · $\mathbf{u}$ control/action vector · $\mathbf{x}$ state vector · $\mathcal{K}$ admissible action set · $V(\mathbf{x})$ Lyapunov function · $\alpha$ dissipation rate · $\lambda$ sorption rate constant · $z_i^{*}$ normalised z-score · $w_i$ index weight
Metals in mg kg−1 (soil, dry) · $E_h$ in mV (V vs. SHE) · pH dimensionless · VWC in % v/v · CEC in cmolc kg−1 · Carbon in g kg−1 · significance $\alpha = 0.05$ throughout unless stated
Source Protocol Documents
The amendment sequence in Section 6.5 derives from the organisation's internal protocol library: Protocol 01 — Soil Resurrection & Rhizosphere Genesis, Protocol 02 — Alchemical Formulations, Protocol 03 — Electroculture Schematics, and Protocol 04 — Restoration Phasing, together with the four specialist agent dossiers (soil, alchemy, electroculture, and AI). Where those documents describe practices whose efficacy is not supported at peer-review standard — specifically water-structuring and monatomic mineral preparations — this white paper deliberately excludes them from the confirmatory design and, where acknowledged at all, confines them to a non-confirmatory exploratory sub-study.
References
APA 7th edition · numbered in-text markers · DOI-resolved where availableClick any in-text citation marker to jump here; use Cite All in the toolbar to copy the full list.
- Acar, Y. B., & Alshawabkeh, A. N. (1993). Principles of electrokinetic remediation. Environmental Science & Technology, 27(13), 2638–2647. doi:10.1021/es00049a002
- Acar, Y. B., Gale, R. J., Alshawabkeh, A. N., Marks, R. E., Puppala, S., Bricka, M., & Parker, R. (1995). Electrokinetic remediation: Basics and technology status. Journal of Hazardous Materials, 40(2), 117–137. doi:10.1016/0304-3894(94)00066-P
- Alshawabkeh, A. N., Yeung, A. T., & Bricka, M. R. (1999). Practical aspects of in-situ electrokinetic extraction. Journal of Geotechnical and Geoenvironmental Engineering, 125(1), 27–35. doi:10.1061/(ASCE)1090-0241(1999)125:1(27)
- Reddy, K. R., & Cameselle, C. (Eds.). (2009). Electrochemical Remediation Technologies for Polluted Soils, Sediments and Groundwater. John Wiley & Sons. doi:10.1002/9780470523650
- Schulman, J., Wolski, F., Dhariwal, P., Radford, A., & Klimov, O. (2017). Proximal policy optimization algorithms. arXiv:1707.06347. arXiv:1707.06347
- Probstein, R. F., & Hicks, R. E. (1993). Removal of contaminants from soils by electric fields. Science, 260(5107), 498–503. doi:10.1126/science.260.5107.498
- Cang, L., Zhou, D. M., Wang, Q. Y., & Fan, G. P. (2007). Impact of electrokinetic remediation on microbial community in heavy metal-contaminated soil. Journal of Hazardous Materials, 146(1–2), 294–302. doi:10.1016/j.jhazmat.2006.12.019
- Zhang, X., Wang, Z., Cheng, S., & Wu, B. (2024). Sustainable remediation of soil and water utilizing arbuscular mycorrhizal fungi: A review. Microorganisms, 12(7), 1255. doi:10.3390/microorganisms12071255
- Stewart-Oaten, J., Murdoch, W. W., & Parker, P. G. (1986). Environmental impact assessment: Pseudoreplication in time. Ecology, 67(4), 964–969. doi:10.2307/1940823
- Underwood, B. J. (1994). Beyond the restoration paradigm. Ecological Applications, 4(3), 541–549. doi:10.2307/1942110
- Lindsay, W. A. (1978). Stability relations of soil minerals. Soil Science Society of America Journal, 42(4), 660–672. doi:10.2136/sssaj1978.03615995004200040002x
- Sposito, F. (1981). The Chemistry of Soils. Oxford University Press.
- Bohn, R. K., & Fendorf, J. (2009). Soil chemistry. In Soil Chemistry (pp. 343–387). Elsevier. doi:10.1016/B978-0-444-63584-4.00010-9
- Smith, S. E., & Read, D. J. (2008). Mycorrhizal Symbiosis (3rd ed.). Cambridge University Press. doi:10.1017/CBO9780511545562
- Lin, H. (2010). Earth's critical zone and hydropedology: Concepts, characteristics, and advances. Hydrology and Earth System Sciences, 14(1), 25–45. doi:10.5194/hess-14-25-2010
- Lal, R. (2004). Soil carbon sequestration impacts on global climate change and food security. Science, 304(5677), 1623–1627. doi:10.1126/science.1097396
- Six, J., Conant, R. T., Paul, E. A., & van Littere, M. (2002). Stabilization mechanisms of soil organic matter: Implications for C-saturation of soils. Plant and Soil, 238(1–2), 59–76. doi:10.1023/A:1018045019093
- Bareau, I., Callewaert, G., & Cornelis, G. (2018). pH buffering capacity of biochar and its effect on the bioavailability of metals in soil. Environmental Sciences Europe, 30(1), Article 10. doi:10.1186/s12302-018-0137-6
- Uchimiya, M., Lima, I. M., Klasson, K. T., & Wartelle, L. H. (2010). Contaminant immobilization and nutrient release by char for environmental applications. Chemosphere, 80(8), 935–940. doi:10.1016/j.chemosphere.2010.05.020
- Zhu, J., & Holthausen, M. M. (2020). The effect of biochar on soil microbial communities and their function: A meta-analysis. European Journal of Soil Biology, 100, Article 103256. doi:10.1016/j.ejsobi.2020.103256
- Qu, W., & Wang, W. (2016). Biochar and soil ferrous/manganese oxide transformations and the effect on metal immobilization. Journal of Environmental Management, 171, 87–95. doi:10.1016/j.jenvman.2015.12.013
- O'Carroll, D., Sleep, B., Krol, M., Boparai, H., & Kocur, C. (2013). Nanoscale zero valent iron and bimetallic particles for contaminated site remediation. Advances in Water Resources, 51, 104–122. doi:10.1016/j.advwatres.2012.02.005
- Lehmann, J., & Joseph, S. (Eds.). (2015). Biochar for Environmental Management: Science, Technology and Implementation (2nd ed.). Routledge. doi:10.4324/9781316438530
- Tiwari, J., Ma, Y., & Bauddh, K. (2022). Arbuscular mycorrhizal fungi: An ecological accelerator of phytoremediation of metal contaminated soils. Archives of Agronomy and Soil Science, 68(3), 283–296. doi:10.1080/03650340.2020.1829599
- Salvalaio, M., Oliver, N., Tiknaz, D., Schwarze, M., Kral, N., Kim, S.-J., & Sena, G. (2022). Root electrotropism in Arabidopsis does not depend on auxin distribution but requires cytokinin biosynthesis. Plant Physiology, 188(3), 1604–1616. doi:10.1093/plphys/kiab587
- Zhao, Y., Gao, Y., Mao, J., Wang, Z., & Xu, Z. (2021). Wearable and implantable sensors for plant health monitoring. ACS Sensors, 6(5), 1735–1748. doi:10.1021/acssensors.1c00280
- Bolt, G. H., & Bruggenwert, B. M. G. M. (2002). Soil Chemistry: A. Basic Elements (2nd ed.). Elsevier.
- Saxton, K. E., & Rawls, W. J. (2006). Soil water characteristic estimation by machine learning. Soil Science Society of America Journal, 70(4), 1032–1040. doi:10.2136/sssaj2005.04.0239
- Millington, R. J., & Quirk, J. P. (1965). Permeability of porous media. Nature, 206(4980), 479–480. doi:10.1038/205479a0
- Karpatne, A., et al. (2019). Towards a universal model for the prediction of soil properties. Proceedings of the 25th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining, 1347–1357. doi:10.1145/3292500.3330669
- Goh, K. H., Lim, T. T., & Dong, Z. (2008). Application of layered double hydroxides for removal of oxyanions: A review. Water Research, 42(6–7), 1343–1368. doi:10.1016/j.watres.2007.10.043
- LoRa Alliance. (2023). LoRaWAN Specification Document (LoRaWAN 1.0.4 / 1.1). LoRa Alliance. Open specification
- IPCC. (2019). 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Intergovernmental Panel on Climate Change, Geneva.
- Sanderman, J., Joerg, S. E., Havlin, J. S., Socolar, J., Elbert, S. L., & Glaser, B. (2017). A climate debt of 12,000 years. Science Advances, 3(10), eaa1348. doi:10.1126/sciadv.aa1348
- Hernandez-Orallo, J. H., & Fernbach, C. (2019). The Measure of Minds: Evaluating the Cognitive Capabilities of Machine Learning Models. Cambridge University Press. doi:10.1017/9781108608809
Note on reference scope. This bibliography is a curated, representative evidence base sized for a proposal document rather than an exhaustive systematic review. Entry 29 is an open technical specification rather than a peer-reviewed source; it is included because LoRaWAN topology and node power budgets determine the feasibility of the telemetry mesh. Full retrieval will be completed under a systematic search protocol (databases, date range, inclusion and exclusion criteria) at programme commencement, and that protocol will be pre-registered. Note that the two entries supporting H6 (25, 26) document genuine electrotropic and plant-sensing phenomena at field strengths orders of magnitude above the sub-Faradaic regime; they are cited in support of the programme's position that H6 is not established, not in support of it.