Succession Soils

What This Tool Does For You

The Field Assessor is a nine-test soil check you can do yourself, in your own field, with no purchased equipment beyond a spade and some water. It takes between 45 and 75 minutes. At the end, it gives you a score out of 100 and a short list of what to fix — in order of what will make the biggest difference first.

The key word there is order. Most farms spend money on fertiliser and biological inputs before fixing the things that make those inputs worthless. This tool finds the bottlenecks first.

What You Need Before You Start

• Spade or garden fork
• Straight-sided tin or ring, minimum 10 cm diameter (an open-ended tin can works)
• Two 200 mL measures of water (use a cold-drink bottle)
• Stopwatch or phone timer
• Tape measure
• A glass of water (for the slake test)
• Dark-coloured tarpaulin or shade cloth (for the earthworm count)

Pick your sampling spot

• Choose a representative area — not the worst or best patch. Pick the middle of a typical block.
• For orchards: sample in the midrow, not directly under the drip line or under the tree canopy.
• Don't assess immediately after rain. Wait at least 48 hours. Soil should be moist but not waterlogged.
• Run three separate spots per field and enter them as three separate assessments, then compare.

Why the Order Matters — The Gateway Model

The Field Assessor uses a gateway-gated scoring model. The first two tests — bare earth and infiltration — are abiotic gateways. If either one fails, your total score is locked to zero. This reflects a biological reality: if water cannot enter the soil, or if the surface is unprotected, no biological input will establish a functioning ecosystem.

1. Tier 1 — Abiotic Gateways (must pass). Bare earth and infiltration are binary gates. If either fails its threshold, every biological score is suppressed to zero.
2. Tier 2 — Fungal Maturation (65 pts). Rhizosheaths, aggregate stability, and soil insect diversity show whether the fungal network is establishing.
3. Tier 3 — Active Biology (30 pts). Earthworms, nodulation, and soil smell respond once the physical and fungal foundations are in place.
4. Tier 4 — Trailing Indicators (5 pts). Rooting depth improves last, after compaction is relieved and biology has restructured the soil profile.

The Nine Tests — Step by Step

Uncovered soil is eroding soil. If bare earth exceeds 50%, the gateway fails and your total score is locked to zero.

1. Walk a straight 20-metre line through your sample area.
2. At every metre mark (20 points total), look directly at the ground below your feet. Is it covered — by mulch, living plants, dead leaves, or old crop residue — or bare soil?
3. Count your bare points. Bare Earth % = (bare count ÷ 20) × 100.

% Bare	What it means	Gateway
30% or less	Gateway passes — soil is adequately protected	PASS
30 – 50%	Marginal — gateway passes but cover needs attention	MARGINAL
More than 50%	Gateway fails — score locked to zero until fixed	FAIL

Water is your transport system. If infiltration is below 5 mm/hr, the gateway fails and your total score is locked to zero.

1. Drive the 150 mm ring 3–5 cm into the soil. Firm the edges so water can't sneak around the outside.
2. Pre-wet: Pour 450 ml of water into the ring. Wait for it to fully absorb (this is the initial flush — untimed).
3. Measure: As soon as the first pour is absorbed, pour a second 450 ml and start your timer.
4. Stop the timer the exact moment the surface water vanishes. Record the time in minutes and seconds — the app calculates mm/hr automatically.

Rate (mm/hr)	What it means	Gateway
50+ mm/hr	Excellent — highly porous, healthy soil	PASS
25 – 50 mm/hr	Good — typical for well-structured loams	PASS
10 – 25 mm/hr	Moderate — some compaction or heavy texture	PASS
5 – 10 mm/hr	Slow — marginal, address compaction	MARGINAL
Below 5 mm/hr	Critical — severe compaction, high runoff risk. Score locked to zero.	FAIL

A sheath of soil clinging to fine roots is evidence of fungal hyphae and root mucilage — the biological glue that holds the soil food web together.

1. Gently pull a grass plant or small cover crop from the soil. Do not shake or brush the roots.
2. Hold the root system over your hand or a dark surface. Look at the fine roots.
3. Assess how much soil is sticking to the fine root hairs along the length of the roots.

What you see	What it means	Rating
Dense soil sheath coating fine roots	Strong fungal network	✓ Good
Soil clinging to some roots, patchy	Moderate fungal activity	⚠ Moderate
Minimal soil adhesion — roots mostly clean	Low fungal activity	✗ Low
No soil adhesion at all	Biology very suppressed	✗ Problem

Tells you how well your soil holds together when it gets wet — which is what matters when rain hits.

1. Take an air-dry clod of soil about the size of a golf ball (3–4 cm across). It must be dry.
2. Lower it gently into a glass of still, clear water. Don't drop it — lower it slowly.
3. Watch for 5 minutes without touching the water.

What happens	What it means	Rating
Clod holds its shape after 5 min	Strong aggregates — good organic matter and biology	✓ Strong
Clod partly breaks apart, 1–5 min	Moderate structure	⚠ Moderate
Clod collapses within 1 minute	Weak structure — low organic matter	✗ Weak

A diverse soil invertebrate community means a functioning food web. High diversity equals high resilience.

Do this test at the same time as the earthworm count (Test 6) — same pit, no extra digging.

1. As you break apart soil clods for the earthworm count, watch for other invertebrates — beetles, centipedes, millipedes, ants, mites, slaters, spiders, fly larvae.
2. Count the number of different types you find — not individuals.
3. Record the number of different types and enter it in the app.

Different types found	What it means	Rating
5 or more types	High biodiversity — healthy food web	✓ Excellent
3 – 4 types	Moderate diversity — recovering	✓ Good
1 – 2 types	Low diversity	⚠ Low
0 — nothing at all	Soil fauna severely suppressed	✗ Problem

Earthworms are your fastest sign that the soil is recovering. They respond to good management within one to two seasons.

1. Dig a square hole 30 cm × 30 cm × 30 cm deep. Pile the soil onto your tarpaulin or shade cloth.
2. Break apart every clod by hand and count every earthworm — including small ones.
3. Multiply your count by 11 to get an approximate count per square metre, or just enter the raw count — the app does the conversion.

Worms in 30×30 cm hole	Per m² (approx)	Rating
More than 2	More than 20	✓ Good
1 – 2	10 – 20	✓ Acceptable
0 – 1	5 – 10	⚠ Low
0	Less than 5	✗ Very low

Note: Do this test when the soil is moist and not too hot. Summer midday or after long drought gives low counts regardless of management.

Nitrogen-fixing bacteria live inside nodules on legume roots. Active nodules mean free nitrogen being made in your soil right now.

If there are no legumes in your sample area, score this test zero and note "no legumes present" in the app.

1. Find a legume plant — clover, vetch, lucerne, or beans. Carefully dig it up to expose the full root system.
2. Count the nodules — the small round or oval bumps attached to the roots.
3. Break one nodule open. If the inside is pink or red, it is actively fixing nitrogen. White or green inside means it is not working.

What you see	What it means	Rating
Many nodules (10+), pink/red inside	Active nitrogen fixation	✓ Good
Some nodules (5–10), mixed colour	Partial fixation	⚠ Moderate
Few nodules (fewer than 5)	Low fixation	⚠ Low
No nodules, or all white/green inside	No nitrogen fixation	✗ Problem

The fastest diagnostic in this entire test. Healthy soil has a specific earthy smell.

1. Take a fresh handful of moist soil from 5–10 cm depth.
2. Cup it in both hands and smell it immediately — the smell fades within a minute of exposure to air.

What it smells like	What it means	Rating
Earthy, rich, sweet (like fresh rain on dry ground)	Healthy aerobic biology	✓ Good
No real smell — neutral	Low biology — soil is not very active	⚠ Low activity
Sour, sulphurous, like rotten eggs	Waterlogged, anaerobic	✗ Problem
Chemical, synthetic, sterile	High synthetic input history	✗ Problem

That earthy smell comes from geosmin, produced by healthy aerobic bacteria called Streptomyces. No smell means no Streptomyces.

Shallow roots mean shallow access to water and nutrients. Rooting depth is a trailing indicator — it improves last, after compaction is relieved and biology has restructured the soil profile.

1. In your 30 cm soil pit (from the earthworm test), look at the profile wall.
2. Find the deepest fine (fibrous) root you can see. Measure the depth with your tape measure.
3. For orchards, look in the midrow — you're looking at the cover crop or grass roots, not the tree taproot.

Root depth	What it means	Rating
40 – 60 cm	Good depth — plant can access a large soil volume	✓ Good
20 – 40 cm	Moderate — often means some compaction layer below	⚠ Moderate
More than 60 cm	Deep roots — check for excess leaching below	✓ / Watch
Less than 20 cm	Very shallow — almost always caused by compaction	✗ Problem

Understanding Your Total Score

After you enter all nine results, the app checks the two gateways first. If both pass, it calculates a total score out of 100 from the remaining seven indicators. If either gateway fails, your score is locked to zero.

Score	Band	What it means
0 – 39	Critical	Major biological gaps. Focus on Tier 2 indicators — fungal network is not yet established.
40 – 69	Building	Fungal foundation forming. Continue building biological diversity and structure.
70 – 100	Functioning	Soil ecosystem working well. Focus on monitoring and fine-tuning.

How the 100 points are distributed:

• Tier 1 — Gateways (Tests 1–2): Bare Earth, Infiltration — Pass/Fail (no positive points)
• Tier 2 — Fungal Maturation (Tests 3–5): Rhizosheaths, Slake Test, Insect Score — 65 pts
• Tier 3 — Active Biology (Tests 6–8): Earthworms, Nodulation, Soil Smell — 30 pts
• Tier 4 — Trailing (Test 9): Rooting Depth — 5 pts

What to Do With Your Results

1. Fix any gateway failures first. Gateway penalties have the biggest impact on your score. Resolving these gives the greatest improvement.
2. Work the tiers in order. Once gateways pass, focus on Tier 2 (fungal maturation) before chasing Tier 3 or 4 scores.
3. Repeat the assessment in 6 months. Soil changes are slow. Measure again after you've implemented your first fixes.
4. Share your results with your consultant before booking a consultation — it gives them your baseline data.