Nutrition & Root-Zone Chemistry
Essential elements, nutrient uptake, pH, EC, alkalinity, nutrient interactions, deficiencies, toxicities, and root-zone chemistry.
Published lessons
These pages are organized here by subject. The permanent THC-ENC IDs remain stable behind the scenes even when a clearer display title is used.
Essential Elements and the Criteria for Essentiality
Classify plant-essential elements by source and quantity while distinguishing essentiality from usefulness, abundance, and fertilizer marketing.
Nitrogen Forms, Uptake, and Metabolism
Trace nitrate and ammonium from solution through uptake and assimilation while controlling total nitrogen, form, pH effect, and crop response separately.
Phosphorus Function and Overapplication Risk
Explain phosphorus in energy transfer, nucleic acids, and membranes while separating correction of deficiency from unsupported bloom-booster escalation.
Potassium and Osmotic Regulation
Connect potassium to osmotic adjustment, stomata, enzyme activation, and charge balance without treating high K as a universal flower-quality lever.
Calcium Transport and Growing-Tissue Disorders
Explain why calcium disorders often reflect transport and root-zone conditions rather than simple absence from the fertilizer formula.
Magnesium, Chlorophyll, and Enzyme Function
Relate magnesium to chlorophyll and metabolism while diagnosing older-leaf interveinal chlorosis through measured system context.
Sulfur and Sulfur-Containing Metabolism
Trace sulfate uptake into sulfur amino acids and cofactors while separating sulfur nutrition from aroma claims and acidification effects.
Iron Availability and Chlorosis
Explain iron in electron transfer and chlorophyll formation while diagnosing young-leaf chlorosis through pH, redox, chelation, roots, and tissue evidence.
Manganese, Zinc, Copper, and Molybdenum
Differentiate four essential micronutrients by function, uptake chemistry, symptom logic, and toxicity risk without diagnosing from color alone.
Boron, Chloride, and Nickel
Explain the essential trace functions and narrow management margins of boron, chloride, and nickel while accounting for water and fertilizer background.
Nutrient Mobility and Symptom Location
Use tissue age and symptom distribution as diagnostic evidence while separating phloem mobility, xylem delivery, and root-zone mobility.
Solution pH and Root-Zone pH
Measure and interpret solution and root-zone pH as distinct, logarithmic indicators tied to a defined sampling method and pH trajectory.
Alkalinity, Hardness, and Acid Requirement
Separate alkalinity from pH and hardness, then calculate water-treatment need from laboratory chemistry under a controlled safety procedure.
Electrical Conductivity and Salinity
Use EC as a temperature- and method-defined indicator of total ionic conductivity while separating it from specific nutrient concentration and crop diagnosis.
PPM Scales and Why EC Is More Transferable
Distinguish true mass concentration from meter-derived TDS or ppm displays and standardize nutrient records in direct units.
Nutrient Antagonism, Synergy, and Ratio Myths
Interpret nutrient interactions through absolute supply, chemistry, transport, and plant response instead of pursuing a universal ratio.
Fertigation Mixing Order and Precipitation Risk
Build a verified fertigation solution without concentrating incompatible salts, losing nutrients to precipitates, or creating avoidable worker and equipment hazards.
Runoff, Pour-Through, Slurry, and Tissue Testing
Select, standardize, and interpret root-zone and plant tests without comparing values generated by incompatible methods.
Deficiency, Toxicity, and Root-Cause Diagnosis
Run a differential diagnosis that distinguishes inadequate supply, unavailable supply, excessive supply, transport failure, and non-nutrient look-alikes.
Nutrient Records, Trend Review, and Corrective Action
Convert fertility measurements into a controlled decision system with traceable formulas, trend limits, deviations, corrective action, and effectiveness review.