Transcript Soil Nutrition - Silver Sage FFA

Plant Nutrition
Mrs. Gill
Pee-Cycling
http://www.npr.org/blogs/thesalt/2014/0
7/31/336564120/should-we-return-thenutrients-in-our-pee-back-to-the-farm
Major Nutrition
 3 Major Elements
 oxygen (O)
 hydrogen (H)
 carbon (C)
 Considered to be non-fertilizer
nutrients and make up 96% of plant’s
tissue
 Acquired through natural processes
from air and water
Macro Elements
 Divided into two groups, macro and micro
 Macro
 Nitrogen – N
 Phosphorus – P
 Potassium – K
 Calcium - Ca
 Magnesium - Mg
 Sulfur - S
Micro Elements
Chlorine – Cl
Iron - FE
Manganese – Mn
 Boron – B
Micro Elements Cont..
Zinc – Zn
Copper – Cu
Nickel – Ni
Molybdenum - Mo
Soil tests
 Determines which nutrients
are present and which are
deficient for growing a variety
of crops
Soil Sampling
(Simplified)
 Take random samples from the area to represent the
area you want to test
 Mix all of the samples together
 Complete the soil test info sheet
 Mail the sample and info sheet to a reputable lab
 Usually a University Extension Program
 Analyze results and make production decisions
Plant Requirements
 large amounts of major
elements
 relatively small amounts of
minor elements
Fertilizer
 Any material added to a growing
medium that provides nutrients for
plants
 Vary in what they contain, how they
are applied, and the function they
serve
Commercial fertilizers
 The fertilizer analysis shows
% or pounds per cwt. (100#)
of the three major elements in
large numbers on the
container or bag
 Nitrogen (N), phosphate (P),
and potassium (K) or Potash
Commercial fertilizers
 5-10-5
 5% N, 10% P, 5% K
 remaining 80% is filler
 NP&K are always listed in
that order.
Fertilizer Forms
•
•
Liquids
-
Salty so they dissolve in water
-
Sprayed on root zone or as a foliar
application
-
Have high tendency to ‘burn’ plants
-
Are usually short-lived
Granules
-
Most common form
-
Heavy pellets don’t drift too far
-
Can be slow-release
Fertilizer Forms
•
Tablets and Spikes
-
Large compressed items that are pushed into the soil or
placed in a hole
-
Expensive for the amount of nutrient they contain
-
Release nutrients very slowly over time
•
Several months to more than a year
Nutrient Solutions
 Nutrients in solution are measured in
parts per million or PPM.
 Fertilizer rates can be taken from tables
in reference books or to instructions with
their injector system, or growers can
calculate the amount of fertilizer needed
to reach a desired PPM.
An example problem might call for 200
PPM nitrogen.
 The chosen fertilizer is calcium nitrate
with an analysis of 15-0-0.
 A rule of thumb in calculating PPM is
that 1 ounce of anything in 100 gallons
H2O equals 75 PPM.
 Problem: Wanted, 200 PPM N 15-0-0
Calcium Nitrate
 Multiply the percent of the nutrient in the
given fertilizer by 75.
 .15 N × 75 = 11.63 PPM N (if 1 oz added
to 100 gallons) 200 divided by 11.63 = 17.2
oz of fertilizer needed in 100 gallons to get
200 PPM.
 If the injector system delivers 1:100 (one
gallon concentrate mixed with 99 gallons
water for a total of 100 gallons), 17.2 ounces
of fertilizer is needed for each gallon of
concentrate.
 If the tank holds 30 gallons of concentrate,
516 ounces (32.25 pounds) of fertilizer is
needed to deliver 200 PPM
Choosing a Fertilizer
 Things to consider
 Nutritional need
 Application method
 Price
 Availability
 Personal Preference
 Safety/Environmental Concerns
 Placement is critical—GPS systems
Nitrogen
 has most noticeable effect on
plants
 encourages above ground
vegetative growth
 regulates use of other
elements
 Leaches easily
Too much Nitrogen
 lowers disease resistance
 weakens stem because it
promotes long, soft growth
 lowers fruit quality
 delays maturity
 increased susceptibility to cold
Symptoms of Nitrogen
Deficiency
 yellow or light green color
 stunted root and top growth
Nitrogen Deficiency in
Corn
Phosphorous
 held tightly by soil particles
 not easily leached
Phosphorous
 encourages cell division
 flowers and seeds don’t form
without it
 hastens maturity, offsetting
quick growth caused by
nitrogen
Phosphorous
 encourages root growth
 makes K more available
 increases disease resistance
 improves quality of grain,
root and fruit crops
Insufficient Phosphorus
 susceptibility to cold
 susceptibility to plant diseases
 poor quality fruit and seeds
Symptoms of Phosphorus
Deficiency
 purple color on underside of
leaves
 reduced flower fruit and seed
production
Potassium
 Works with Nitrogen and
Phosphorus to improve plant
growth
 development of chlorophyll
 efficient use of CO2
Potassium
 increases disease resistance
 encourages healthy root
systems
 essential for starch formation
Insufficient Potassium
 leaves appear dry and
scorched with irregular yellow
areas on the surface
Lime
 CaCO3- Calcium Carbonate
 acts as a plant food
 affects soil acidity
 soil acidity affects availability
of plant food elements
Is Soil Alive?
 ¼ teaspoon of fertile soil
contains approximately:
- 1 Earthworm
- 50 Nematodes
- 52,000 Algae
- 111,000 Fungi
- 2,920,000 Actinomycetes
- 25,280,000 Bacteria
Earthworms
 Decompose organic matter
 Mix plant litter with soil
 Tunneling helps with aeration of the soil
Nematodes
 Examples are:
 Roundworms, threadworms, hair
worms
 Consume other microbial
organisms which help regulate
the microbial population
 Also found in the roots of the
plants
Algae
 Contain chlorophyll (photosynthetic)
 Soil algae are too small to be seen with
the naked eye, but in large numbers can
give the surface a green color
 They favor damp soil that is exposed to
the sun
 Help with the formation of soil
structure
Fungi
 Examples:
 Mushrooms, mold, mildew, rusts, yeasts
 Grow on dead and decaying tissue
 Primary agent of organic matter decay
 Make nutrients available by
decomposing organic matter.
Actinomycetes
 Rod-shaped form of bacteria
 Can live under drier conditions than
bacteria, very abundant in sod
 One of the most important agents in
the soil for decomposing and breaking
down cellulose
 Its what gives freshly tilled soil its
smell
Bacteria
 Most numerous and MOST
IMPORTANT!
 Diverse metabolism aides in breaking
down organic chemicals like pesticides
 Can also degrade inorganic materials
 Fix Nitrogen so it can be used by plants
Why do we need microorganisms
in Agriculture?
 Decay plant residue
 Fix nitrogen
 Break down nutrients needed by plants
 Break down cellulose
 Finally, much of the soil is not available to
the plants until the microbes break it down