ACS CCN1 study guide
ACS CCN1 · Work through your exam, one topic at a time.
The ACS Certified Crop Nutritionist (CCN1) is a professional credential for agronomists, crop consultants, fertilizer and nutrient-management advisers, extension staff, and farm managers who make nutrient recommendations. It signals that the holder can reason from soil and tissue data to a defensible nutrient plan that balances crop yield, cost, and environmental risk. The ACS CCN1 study guide has 8 sections and about 2,526 words.
01Soil Fertility and Plant Nutrition Fundamentals
Candidates must separate soil fertility (the capacity of soil to supply nutrients in available forms) from nutrient availability (the fraction actually plant-accessible at a given pH, moisture, and temperature). Know the 17 essential elements, the macronutrient/micronutrient split, and the distinction between mobile nutrients (N, K, Mg - deficiency shows on older leaves) and immobile nutrients (Ca, Fe, B - deficiency shows on new growth).
306 words, about 2 min02Nutrient Sources
Know the major source categories: commercial inorganic fertilizers, organic amendments (manure, compost, biosolids), legume biological nitrogen fixation, and recycled crop residues. For organic sources, understand that nutrient availability depends on mineralization rate, which is driven by C:N ratio, moisture, temperature, and incorporation.
295 words, about 1 min03Fertilizer Materials and Soil Amendments
Understand fertilizer grade notation (N-P₂O₅-K₂O), how to read a label, and the properties of common materials: urea (46-0-0, volatile if surface-applied without incorporation), ammonium nitrate, ammonium sulfate (acidifying, supplies S), MAP/DAP (P sources with different N contents and pH effects), muriate vs sulfate of potash, and micronutrient chelates vs sulfates. Know amendment functions: lime raises pH and supplies Ca/Mg; gypsum supplies Ca and S without raising pH and can improve sodic soil structure; elemental S acidifies slowly via microbial oxidation.
285 words, about 1 min04Soil Testing, Plant Tissue Analysis, and Interpretation
Know the soil-testing workflow: representative sampling (proper depth, cores per composite, avoiding atypical spots), lab extraction methods (e.g., Bray-1 and Olsen for P, ammonium acetate for K and CEC), and how results map to soil test categories (very low to very high) that drive recommendations. Understand that different extractants give different numbers and are not interchangeable.
282 words, about 1 min05Nutrient Management Planning and Application Methods
A nutrient management plan matches nutrient supply to realistic yield goals while minimizing loss. Know the planning components: realistic yield goal, soil test-based rates, credits (legumes, manure, residual), timing, placement, and the 4Rs (right source, right rate, right time, right place).
265 words, about 1 min06Environmental Stewardship and Nutrient Loss Prevention
Understand the major loss pathways and their drivers: nitrate leaching (soluble, moves with water, worst in sandy soils and high-rainfall periods), denitrification (anaerobic, waterlogged soils, warm temps), volatilization (ammonia loss from surface urea or manure, favored by high pH, warmth, and moisture), runoff and erosion (P attached to sediment, plus soluble P), and P loss driving eutrophication. Know best management practices: cover crops, buffers, reduced tillage, timing applications to avoid rain, incorporation, and avoiding application on frozen or saturated ground.
278 words, about 1 min07Crop-Specific Nutrition and Yield Quality Management
Different crops have distinct nutrient demands and quality drivers. Know that legumes fix N via rhizobia and respond mainly to P, K, S, and pH rather than N; grasses (corn, wheat) are heavy N feeders; and high-value crops (potatoes, vegetables) are sensitive to micronutrients and to balance among nutrients.
269 words, about 1 min08Regulatory, Safety, and Professional Ethics
Understand the regulatory and safety framework around nutrient management: confined animal feeding operation (CAFO) rules, nutrient management plan requirements, setback distances from waterways and wells, recordkeeping mandates, and worker protection and fertilizer storage/handling safety (including anhydrous ammonia hazards, PPE, and emergency response). Know professional ethics: honest recommendations, avoiding conflicts of interest, accurate recordkeeping, and protecting client and environmental interests.
546 words, about 3 min