Soil nutrients

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

2. Nutrients and plant growth Plant’s sufficiency range = range of nutrient necessary to meet plant’s nutritional needs and maximize growth 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 CO 2 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 (NO 3 ) 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

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