Transcript Fertilizing
Fertilizing
Plant Material Maintenance
Fertilizing
Essential elements
Nutrient deficiency symptoms
Fertilizer forms
Interpreting labels
Application techniques
17 Essential Elements (Nutrients) for
Woody Plant Growth
Elements Derived From Air and
Water
Carbon (C)
Oxygen (O)
Hydrogen (H)
Soil - Macronutrients
Nitrogen (N)
Phosphorous (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Soil - Micronutrients
Boron (B)
Chlorine (Cl)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Nickel (Ni)
Zinc (Zn)
Nutrient Deficiencies
Lack of either macro or micro nutrients will impede normal plant
growth.
Not enough in the soil
In the soil, but unavailable
Symptoms will appear on different parts of the plant. Interpret these
symptoms.
Some common nutrient deficiencies and the symptoms:
Nitrogen deficiency
Older leaves (bottom of plant) begin to
yellow. Remainder of plant generally a
lighter green than normal.
Nitrogen
is mobile in the plant and can be
translocated to new, young leaves.
Nitrogen can be mobile in the soil.
Phosphorous deficiency
Leaves often dark green.
Veins, petioles, and lower surfaces may
become reddish – purple colored.
Sparse, distorted foliage.
Phosphorous
is mobile in plants.
Phosphorous is immobile in the soil.
Potassium deficiency
Marginal and interveinal chlorosis followed
by scorching moving inward between the
main veins.
Leaf curling
Potassium
is highly mobile in plants.
Potassium is immobile in the soil.
Iron deficiency
Interveinal
Chlorosis: Veins stay green, but area
between veins turns yellow.
Common on pin oak, red maple and river birch.
Due to high pH soil.
Common problem in Iowa, especially on trees planted
where original topsoil has been removed. (New
subdivisions)
Iron cannot be translocated.
Organic Fertilizer
Organic fertilizer
Derived
from plant and animal products.
Blood meal, bone meal, manure & sewage sludge.
fert. released slowly – avoids plants from
being burned.
Generally more expensive than chemical fert. on the
basis of amount of nutrients supplied.
Organic fert can work as a soil amendment at the
same time.
Organic
Ex. Milorganite
Inorganic Fertilizer
Manufactured chemical fertilizer.
Much more concentrated than organic.
Can
burn plants with too much fert, especially if using
a fast release form.
Less expensive.
Carbon (C) : Nitrogen (N) Ratio
The ratio of carbon atoms to nitrogen
atoms.
Soil microorganisms use nitrogen to
metabolize (breakdown) carbon.
Certain types of organic matter are very
high in carbon:
Sample C:N of various types of organic matter:
Sandy loam (fine)
Humus
Food scraps
Alfalfa hay
Grass clippings
Rotted manure
Sandy loam (coarse)
Vegetable trimmings
Oak leaves
Leaves, varies from
7:1
10:1
15:1
18:1
19:1
20:1
25:1
25:1
26:1
35:1 to 85:1
Peat moss
Corn stalks
Straw
Pine needles
Farm manure
Alder sawdust
Sawdust weathered 3 years
Newspaper
Douglas fir bark
Sawdust weathered 2 months
58:1
60:1
80:1
60:1 to 110:1
90:1
134:1
142:1
170:1
491:1
625:1
Nitrogen Robbing
Organic matter with excess C:N ratios (or
excessive amounts of organic matter) can
create problems.
To continue decomposition the soil
microorganisms will draw nitrogen out of
the soil making it unavailable to plants.
Fertilizer Forms
Liquids
Easy
application (tank mix or hose end sprayer).
Potential to burn plants if mixed too strong, or too
much applied.
Soluble Powder
Dissolves
readily in water (apply just like liquid).
Generally less expensive than liquid.
Fertilizer Forms
Granular
Most
common and widely used form.
Slow release forms available.
Prolongs release of nutrients
Decreases burning potential
Fertilizer Labels
Analysis
Shows
type of nutrients and amount.
Nitrogen – Phosphate – Potash
N-P-K
10-5-5
Gives the percentage of each in the fertilizer.
10% Nitrogen, 5% Phosphate, 5% Potash
Use conversion factors to find % phosphorous and
potassium.
Conversion Factors
To convert phosphate to phosphorous (P):
Multiply
%phosphate by .44
To convert potash to potassium (K):
Multiply
%potash by .83
Osmocote fertilizer label
What’s the analysis of the fertilizer?
19-5-8
What percentage of the fertilizer is N?
19%
What percentage of the fertilizer is
phosphate (P2O5)?
5%
What percentage of the fertilizer is potash
(K2O)?
8%
What percentage of the fertilizer is actual
phosphorous (P)?
5
x .44 = 2.2%
What percentage of the fertilizer is actual
potassium (K)?
8
x .83 = 6.64%
How long is this fertilizer supposed to last
at 70 degrees F.?
8-9
months
Does this fertilizer contain any
micronutrients?
Yes
How many forms of N are in the fertilizer?
3
6.60%
Ammoniacal Nitrogen
5.70% Nitrate Nitrogen
6.70% Urea Nitrogen
Application Methods
Broadcast on the soil surface
Most soils supply adequate amounts of nutrients with the exception of N.
Effective method for applying N.
Placed in holes in the soil
P, K and other nutrients of low solubility benefit from incorporation.
Core, punch, or drill holes.
6 inches deep, 2-3 feet apart.
Application methods continued
Injected into the soil under pressure
High pressure hydraulic sprayer.
6 inches deep.
150-200 psi pressure.
Sprayed on foliage
Placed in holes in tree trunks
Micronutrient implants.
Placed in xylem.
Holes approx. ½ inch in diameter.
Plug holes.
Injected into the trunk
Micronutrients.
Mauget, Wedgle.
Broadcast Application of
Fertilizer
Fertilizer Application in Holes
Injecting Fertilizer into the Soil
150-200 psi
Foliar Fertilizer Spray
Misting sprayer suitable
for foliar feeding
Systemic Tree Implants
Microinjection:
How to use Mauget
Microinjection:
Wedgle direct inject system
Macroinjection
Fertilizer Math
Remember that a 20 -10 -10 fertilizer, for example, contains only 20%
actual N on a weight basis. A useful calculation for determining how many
pounds of fertilizer to apply is:
pounds of fertilizer = application rate of the nutrient in pounds
percentage of that nutrient in the analysis
If you want to apply nitrogen at the rate of 2 pounds per 1,000 square feet to
an area measuring 300 square feet how many pounds of 20 – 10 – 10
fertilizer should be applied:
pounds of fertilizer = application rate of the nutrient in pounds
percentage of that nutrient in the analysis
pounds of fertilizer =
10
1,000
x = 3 pounds
=
x
300
2 = 10 pounds of fertilizer
.20
The End