1. Soil Nutrients
Olga S. Walsh
Assistant Professor
Soil Nutrient Management
Montana State University
Western Triangle Agricultural Research Center

2. Nutrients and plant growth
o Plant’s sufficiency range = range of nutrient necessary to meet
plant’s nutritional needs and maximize growth
o Nutrient levels outside of a
plant’s sufficiency range cause
crop growth and health to
decline due to either a
deficiency or toxicity
Mc Cauley et al., 2009

3. Mobile and Immobile Nutrients
BLA BLA
BLA BLA
Roger Bray, “A Nutrient Mobility Concept or Soil-Plant Relationships. 1954.
Soil Science.

4. MT soils:
Common deficiencies /toxicities
• Most common: N and P
• Sometimes – K, S
• Micronutrient deficiencies are fairly
uncommon with deficiencies of B, Cl, Fe, and
Zn occurring most often
• Toxicities – uncommon, result of over-
fertilization

5. Essential plant nutrients
Total of 16 essential nutrients
3 Macronutrients from air and water: Carbon, Hydrogen,
Oxygen (C, H, O)
13 MACROnutrients from soil:
3 Primary nutrients - Nitrogen, Phosphorus and
Potassium (N, P, K)
3 Secondary nutrients - Calcium, Magnesium and Sulfur
(Ca, Mg, S)
7 MICROnutrients - Iron, Manganese, Zinc, Copper, Boron,
Molybdenum, and Chlorine (Fe, Mn, Zn, Cu, B, Mo, Cl)

6. Essential plant nutrients
Deficiency disrupts plant’s growth and
reproduction
Deficiency can be prevented or corrected only by
supplying the element
Nutrient is directly involved in the nutrition of
the plant

7. Macronutrients

8. Nutrients from air and water
Carbon, Hydrogen, Oxygen
Base of all organic molecules, building blocks
for growth
Absorbed as CO2
Combined with H and O
Transformed into carbohydrates in leaves in the
process of photosynthesis

9. Essential Macronutrients
 N, P, K
Needed in greater amounts for growth
Lacking from soil first
Greater response

10. N deficiency
 Light green upper (young) leaves
Yellow lower (older) leaves

11. Essential Macro nutrients: P
 Catalyses biochemical reactions
Component of DNA (genetic memory)
Component of energy molecules
Key element in photosynthesis

12. P deficiency
 Dark purple discoloration on the leaf tips, advancing
down the leaf
Stunted plants with fewer shoots

13. Essential Macro nutrients: K
 Photosynthesis and movement of nutrients
Protein synthesis
Activation of plant enzymes
Regulation water use

14. K deficiency
 Marginal chlorosis and necrosis on older leaves
Shorter internodes, stunting

15. Essential Secondary nutrients
 Ca, Mg, S
Needed in moderate amounts

16. Essential Secondary nutrients: Ca
 Cell structure, membranes
Nutrient uptake
Reaction to negative environmental factors
Defense against disease

17. Ca deficiency
Poor root growth, stunted dark rotting roots
Symptoms – in new growth (necrotic spots in young leaves),
leaves collapse before unrolling

18. Essential Secondary nutrients:
Mg
Chlorophyll formation
Light-absorbing pigments
Amino acids and proteins
Resistance to drought and disease

19. Mg deficiency
Pale green, chlorotic young leaves
Folded or twisted leaves
Symptoms similar to drought

20. Essential Secondary nutrients: S
 Component of amino acids and proteins
 Component of enzymes and vitamins
 Formation of Chlorophyll

21. S deficiency
Seedlings: pale yellow
chlorosis on young leaves
S deficient leaf (left)
normal (right)

22. Micronutrients

23. Micronutrients
 Fe, Mn, Zn, Cu, B, Mo, Cl
Needed in very small amounts
Involved in metabolic reactions as part of
enzymes (reused, not consumed)
Can be corrected with a fraction of pound
per acre rate

24. Iron (Fe)
Respiration
Photosynthesis
Enzymatic Activator
Chlorophyll Synthesis

25. Fe deficiency
Failure to produce sufficient chlorophyll
Interveinal chlorosis, green/yellow stripes
New leaves turn white

26. Manganese (Mn)
Component of various enzyme systems for:
• energy production
• protein synthesis, and
• growth regulation

27. Mn deficiency
Interveinal chlorosis
 Brown necrotic spots on leaves
White/gray spots on leaves
 Premature leaf drop and delayed maturity

28. Zinc (Zn)
Respiration
Photosynthesis
Enzymatic Activator
Chlorophyll Synthesis

29. Zn deficiency
First appear on middle-aged and old leaves
Muddy gray-green leaf color
Leaves appear drought stressed,
with necrotic spots

30. Copper (Cu)
 Catalyst in photosynthesis and respiration
 Constituent of enzymes
 Involved in building and converting amino acids to
proteins
 Carbohydrate and protein metabolism
 Plant cell wall constituent

31. Cu deficiency
 Leaf tip die-back followed by a twisting or wrapping
of the leaves
 Delayed maturity
 Stunted, misshapen heads

32. Boron (B)
Cell wall strength and development
Cell division
Fruit and seed development
Sugar transport

33. B deficiency
 Saw tooth effect on younger leaves
Pale, “water-soaked” new shoots
Head sterility

34. Molybdenum (Mo)
Conversion of nitrates (NO3 ) into amino acids
in the plant
Conversion of inorganic P into organic forms
in the plant
Protein synthesis
Sulfur metabolism

35. Mo deficiency
 Stunted plants
Flowering/Seed formation affected
Hollow stems
Brittle, discolored leaves

36. Chloride (Cl)
Photosynthesis
Stomata regulation
Gas and water balance in cells
Nutrient transport (K, Ca, Mg)
Disease resistance

37. Cl deficiency
Physiological Leaf Spot Syndrome
White to brown spots on leaves
Starts in lower leaves at tillering
Similar to tan spot, smaller spots, no “halo”

38. Micronutrient deficiency
High soil pH (uptake decreases as pH increases) –
all but Mo
MT typical pH = 7-8, varies from 4.5 to 8.5
Low organic matter
MT typical OM = 1-4%
Cool, wet weather

39. Micronutrient products
Citri-Che Crop Mix 1 (N, S, Cu, Mn, Zn)
Gainer High Phos (N Nitrogen, Phosphate,
Potash, Sulfur, Boron, Copper, Iron, Manganese,
Molybdenum and Zinc

42. Acknowledgements
• Information is based on Montana State
University’s Extension Module 9 by McCauley
et al, 2009:
http://landresources.montana.edu/NM/Modu
les/Module9.pdf