Nutrient Requirements

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Nutrient Requirements

• September 28 29

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What is a nutrient?

• Is it plant food? (think photosynthesis)
• Plant nutrient (essential element)
• Chemical element which is essential for proper
  plant growth and reproduction
• 3 criteria
• Required for plant to complete its life cycle
• No other element substitutes
• All plants require that element
• Nonessential elements examples
• Silicon, sodium
• Cobalt (in nitrogen fixing plants)

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What Nutrients do Plants Need?

• Carbon
• Hydrogen
• Oxygen

• Nitrogen
• Phosphorous
• Potassium
• Calcium
• Magnesium
• Sulfur

• Iron
• Manganese
• Copper
• Zinc
• Molybdenum
• Boron
• Chlorine
• Nickel

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What Nutrients do Plants Need?

• N
• P
• K
• Ca
• Mg
• S

• Fe
• Mn
• Cu
• Zn
• Mo
• B
• Cl
• Ni

• C
• H
• O

C. HOPKiNS CaFe Mighty Good
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Macronutrients -most important -large amounts
Micronutrients -trace elements -smaller amounts
Air and/or Water
Soil
Soil

• C
• H
• O

• N
• P
• K
• Ca
• Mg
• S

• Fe
• Mn
• Cu
• Zn
• Mo
• B
• Cl
• Ni

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Nutrient Deficiencies
?

• When do deficiencies occur?
• Foliage (leaves) symptoms
• Chlorosis yellowing in portions of the plant
• Necrosis localized cell death
• Lack of new growth
• Accumulation of anthocyanin (pigment) redi
  purple color
• Stunting
• If catch deficiency early
• Symptoms are nutrient specific
• If catch deficiency late
• Symptoms may intensify and look like other
  nutrients

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Nutrient Deficiencies Hunger Signs

• Stunting yellowing of older leaves
• Pale green / yellow green leaves towards bottom
  of plant

• N
• P
• K
• Ca
• Mg
• S

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Nutrient Deficiencies Hunger Signs

• N
• P
• K
• Ca
• Mg
• S

• Stunting purplish foliage

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Nutrient Deficiencies Hunger Signs

• Tip and marginal leaf browning

• N
• P
• K
• Ca
• Mg
• S

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Nutrient Deficiencies Hunger Signs

• N
• P
• K
• Ca
• Mg
• S

• Dieback of growing tip blossom end decay

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Nutrient Deficiencies Hunger Signs

• Splotchy interveinal yellowing of older leaves
• Possible leaf curl

• N
• P
• K
• Ca
• Mg
• S

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Nutrient Deficiencies Hunger Signs

• N
• P
• K
• Ca
• Mg
• S

• Yellowing of newer leaves
• Symptoms not as frequently noticed

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Effect of pH

• What is pH?
• Degree of acidity or alkalinity
• pH is a measure of the H ion concentration
• pH -logH
• Florida soils
• South limestonepH 8.0
• Statewide pH 5.0 or lower
• What does pH have to do with nutrient supply to
  plants?

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Effect of pH

• pH affects the availability of nutrients
• Different nutrients will be in forms that are
  available or unavailable to plants at different
  pHs
• Just because the nutrient is present in the soil
  does not mean you cannot have a deficiency
• Presence ? Availability

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Effect of pH
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Effect of pH

• What if your pH is too low?
• Add Lime
• Limestone (mostly calcium)
• Dolomite (better has calcium and magnesium)
• Best to apply 2-3 months in advance of planting
  due to slow reaction time
• Plow or spade into soil
• What if your pH is too high?
• Add Manganese
• Add sulfur if soil if too much lime was added

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Nutrient Cycling

• Plant uptake
• Return to soil
• Loss due to leaching and erosion
• Plant uptake

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Nutrient Cycling

• Plant uptake
• Return to soil
• Loss due to leaching and erosion
• Plant uptake
• Difference between this scenario and a garden?

Crop Removal
Fertilizer Inputs
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Nutrient Supply

• Chemical (inorganic) fertilizers
• Numerous dry and liquid forms
• Supply specific nutrients
• Natural (organic) fertilizers
• Animal manures
• Plant manures (compost)
• Dried blood...
• Most supply micronutrients

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Nutrient Supply

• Q Which nutrients are in a bag of
  fertilizer?
• A Look at the label
• (N-P-K)
• Amounts of other nutrients will be specified.

(Potassium)
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Lawn Fertilizers

• Pay attention to the label
• May have wrong proportions of nutrients for
  vegetables
• May contain herbicides
• Best to avoid using lawn fertilizer in the garden

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Rate of Application

• Applying more fertilizer than needed may cause
  some nutrients to leach
• Particularly a problem with Floridas soils
• Solutions
• Do not over-apply fertilizers (Follow
  recommendations)
• Split desired rate into at least 2 applications
  for N K
• Incorporate in soil
• Side dress as plant grows
• Apply with fruit development

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Methods of Application

• Broadcasting
• On soil surface
• Banding
• 2 to side and below seed
• Sidedressing
• During the season, 6-10 from plant
• Starter Solutions
• Stimulate young transplant growth
• Foliar Fertilization
• On leaf surface (micronutrients)
• Fertigation
• Incorporated into irrigation water

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Fertilizer Leaching

• A few things to know
• N readily leaches from any soil
• K is prone to leach from sandy (Florida) soil
• Most other nutrients stay in the soil

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Over-fertilization

• Excessive vegetative growth
• Fertilizer burn
• Nutrient toxicities

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How much fertilizer ( lime) to apply?

• Best answer Base it on a soil test
• Soil Testing
• From random spots through your garden, dig a
  spade-full of soil and place it in a bucket
• Mix several (all) samples together
• Fill soil-testing bag to marked line with mixed
  soil
• Request a soil test (pH nutrients) for the crop
  garden

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Soil Testing Dont guess, soil test!

• Soil test
• Is a measurement of the soil properties by
  chemical and/or physical measurement based on a
  soil sample
• Basic principle
• A representative sampled area is taken and
  chemical analysis assess the nutrient status of
  the entire area
• Done to check the availability of plant nutrients
  in the soil

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Fertilizer Application

• General Guidelines
• Apply 4 lbs of 6-6-6 fertilizer per 100 ft2
• Later, apply 2 lb of 15-0-15 per 100 ft2
• For beans and peas, apply half the above amounts

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Fertilizer to be applied

• Apply 8 pounds of 10-10-10 micros
• Spread evenly over all 3 beds
• Avoid over-applying close to plants
• Apply 3 pounds of Epsom Salt

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Presentation References

• Barker, A.V. and D.J. Pilbeam. 2007.
  Introduction. In Barker, A.V. and D.J. Pilbeam
  (eds.). Handbook of Plant Nutrition. CRC Press,
  Taylor and Francis Group, LLC, Boca Raton, FL.
• Schroeder,C.B. Seagle, E.D.Felton, L.M. Ruter,
  J.M. Kelley, W.T. and G. Krewer. 2004.
  Olericulture-Vegetable Production, p.512-541. In
  Introduction to Horticulture. 4th ed. Pearson
  Education by Prentice Hall Interstate Publishing
  Company, Upper Saddle River, NJ.
• Simonne, E.H. and G. J. Hochmuth. 2007. Soil and
  Fertilizer Management for Vegetable Production.
  p. 3-15. In Olson, S.M. and E. Simonne (eds.)
  Vegetable production handbook for Florida.
  University of Florida, IFAS Extension.
• Stephens, J.M. 1999. Vegetable Gardening in
  Florida, University Press of Florida,
  Gainesville, Fl.
• Swaider, J.M. and G.W. Ware. 2002. Producing
  Vegetable Crops. 5th ed. Interstate Publishers,
  Inc., Danville, IL.

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Todays Field Questions for Garden Notebook

• What is a plant nutrient?
• When do nutrient deficiency symptoms occur?
• Why is nutrient presence not equal to nutrient
  availability?