Plain-English field handbook
Diagnosis and Field Records
The LRN learning loop
- Observe: look at soil cover, moisture, roots, leaf colour, pests, heat, and recent weather.
- Choose one test: mulch, living cover, water timing, reduced disturbance, crop mix, or record keeping.
- Protect the plant first: keep stems clear, avoid waterlogging, and do not bury fresh wet material against roots.
- Wait and record: give the system time to respond before adding another correction.
- Scale only after evidence: repeat in a second small area before making it a farm-wide practice.
Do not diagnose from one leaf
A yellow leaf can mean nutrient shortage, waterlogging, root damage, pest pressure, old age, shade, pH issue, salt stress, or disease. One symptom is a clue, not a conclusion.
Good diagnosis asks: where is the symptom, how fast did it appear, what changed recently, what is the soil moisture, what is the weather, and whether neighboring plants show the same pattern.
The five checks
Water: too dry, too wet, or irregular.
Roots: damaged, compacted, shallow, rotting, or overheated.
Soil: bare, crusted, salty, sour-smelling, compacted, or low organic matter.
Biology: no residue breakdown, no visible soil life, disease pressure, or pest imbalance.
Nutrition: likely deficiency or excess, ideally confirmed by soil or plant tissue testing in commercial systems.
EC and salts
Electrical conductivity, or EC, is a way to estimate soluble salts in water or soil solution. High salts can make it hard for roots to take up water and can injure sensitive roots.
Do not treat EC as a magic number without context. Crop tolerance, irrigation water, soil texture, drainage, fertilizer history, and climate all matter.
Record format
Use the same simple template every time: date, plot, crop, weather, soil moisture, mulch, symptom, suspected cause, action taken, photo, and follow-up result.
The value is not in writing beautifully. The value is in noticing patterns before they become expensive.
Do This in the Field
- Create a field record for three plants: healthy, weak, and average.
- Photograph each from the same angle every week.
- Write one action only, then wait long enough to see whether it worked.
- After 30 days, summarize what you learned.
Field Record
- Date and weather: note rain, heat, wind, irrigation, and unusual stress.
- Soil surface: bare, covered, crusted, moist, dry, compacted, or loose.
- Root-zone clue: new feeder roots, earthworm channels, smell, fungal strands, or lack of activity.
- Plant response: leaf colour, wilting, new flush, flowering, pest pressure, disease signs, or recovery.
- Next action: one small change, one control area, and the date you will check again.
Common Mistakes to Avoid
- Turning LRN into a fixed recipe instead of a field observation system.
- Adding too much mulch or fresh organic matter directly against stems.
- Changing water, inputs, mulch, crop mix, and pruning at the same time, then not knowing what worked.
- Calling a practice successful before comparing it with an untreated or differently treated area.
- Making nutrient, disease, or commercial decisions without records, local testing, or repeated observation.
Self Check
- Why is one leaf not enough for diagnosis?
- What does EC roughly indicate?
- What fields belong in a useful farm record?
Answer Guide
- Why is one leaf not enough for diagnosis?
Answer guide: connect your answer to a visible field sign, a likely cause, a low-risk test, and the record you will keep before scaling the practice. - What does EC roughly indicate?
Answer guide: connect your answer to a visible field sign, a likely cause, a low-risk test, and the record you will keep before scaling the practice. - What fields belong in a useful farm record?
Answer guide: connect your answer to a visible field sign, a likely cause, a low-risk test, and the record you will keep before scaling the practice.
Evidence Anchor
This lesson is based on the local LRN source documents listed in the bibliography and cross-checked against soil health, agroecology, cover-crop, rhizosphere, and natural farming references. Where a claim depends on local conditions, the lesson asks for observation, comparison, or testing.
Use this handbook as a base for field decisions, not as a substitute for soil tests, water tests, pest diagnosis, disease diagnosis, or local agronomic advice when the risk is high.
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