 Reproductive
parts
• Flowers
• Fruit
• Seeds
 Vegetative
• Stems
• Leaves
• Roots
• Tubers
parts
Food/Feed
• Grains/Grasses
• Fruits
• Vegetables
Shelter
Ornamentals/Decor
Entertainment

Flowers
FRUITS
• Broccoli, cauliflower,
artichokes, capers, pansies, ...

Fruits
• Apples
• Oranges, lemons, grapefruit,
•
•
•
•
•
tomato
Squash, pumpkin
Peaches, nectarines, plums,
olives, mangoes
Berries
Beans, peas
Cucumber, banana
VEGETABLES

Veggies
• Carrots, parsnips, turnips
• Potatoes, yams
• Lettuce, herbs
• Celery, onions, chives
GRAINS
 Barley
 rye
 oats
 wheat
 millet
 spelt
 quinoa
 amaranth
 corn
GRASSES
 Alfalfa
 Timothy
 Clover
 Rye
grass
 Trees
= Shelter
 Corn
maze
What do plants need to grow?
Plant needs:
•
•
•
•
•
sunlight
water
carbon dioxide
nutrients (N, phosphorus)
warm temp
Because
different ecosystems have varying
conditions the level of plant productivity varies.
• Warm, wet areas tend to have the highest productivity.
• Cold, dry areas tend to have the lowest.
Is
this a rule?
What have humans done to alter productivity
in some areas?
 Today
we rely heavily on about 20 different
species – wheat, rice, corn, and potatoes being
the most common.
The
closer humans are to the producer,
the more usable energy we consume
The
further we are down the food chain,
the less energy we receive from the
producers
 Human
population is increasing rapidly!
• Due to decrease in death rate with medical and scientific
advancements
 We
are consuming the earth’s natural environment to
feed ourselves
 We
are also using up resources for convenience
• Ex: cotton, tobacco, domestic pets (birds, fish, etc)
 We
are destroying natural ecosystems
• Burn forests, drain wetlands, pave highways, build golf courses
Just
because an area has high productivity
does not mean that anything will grow
there. Why not?
Plants
and animals introduced from other
areas of the world may be vulnerable to
pests, diseases, and weather fluctuations.
 Clearing
areas for agriculture results in a loss
of biodiversity by removing natural habitat.
• Biodiversity is the variety (diversity) of species
within a given ecosystem.
 Some
plants may also outcompete native
plants/animals which also lessens species
diversity.
• What are possible consequences of lower species diversity?
• Whay might a large drop in producer output do to other
trophic levels?
 By
selecting plants with desired characteristics,
scientists have been able to produce also reduced
the genetic variety of crops.
 Plants
selected for rapid growth and desired
aesthetic qualities may not be ideally suited to
withstand disease an other negative
environmental conditions.
 Monocultures
– where humans mass produce a
particular type of food
 This
decreases biodiversity and increases pests
• Ex: Population of aphids can become out of
control when their food source is grown as a
monoculture
• Ex: Wheat Rust article
 Pesticides
are used to kill
pests but are designed to
not harm plants or
humans
 Biological
Magnification:
• once pesticides enter a food
chain, its concentration
increases as it moves through
the food chain
• Ex: DDT in food chain
Compounds given to plants with the
intention of promoting growth.
Fertilizers can be organic
(composed of organic matter, i.e. carbon based),
or inorganic
(containing simple, inorganic chemicals).
They can be naturally-occurring compounds such
as peat or mineral deposits,
or manufactured through natural processes
(such as composting)
or chemical processes (commercial fertilizer).
Fertilizers typically provide, in varying proportions:
3
Major Plant Nutrients:
• Nitrogen
• Phosphorus
• Potassium
 Secondary
Plant Nutrients
• Calcium
• Sulfur
• Magnesium
 and
sometimes trace elements (or micronutrients) with a
role in plant nutrition:
• boron, chlorine, manganese, iron, zinc, copper and molybdenum.
 Nitrogen
 Phosphorus
 Potassium
 Calcium
 Sulphur
 Magnesium
• oxygen
• hydrogen
• Carbon
*These are available from the
environment
• Each nutrient plays an important role in plant survival
and health.
• Nutrients don't stay long in the soil and have to be
replenished regularly.
• Fertilizer is the means of supplying these nutrients.
Fertilizer is available in two types:
liquid and
granular
Choose the one that meets your needs in
the form that is easiest for you to use.
 fast-acting
 quickly
absorbed
 require
application every 2-3 weeks
 Most
are concentrates, mixed with
water prior to application
applied
dry and must be watered in
easier
to control because you can actually
see how much fertilizer you are using and
where it is being dispersed
produced
in two different formulations,
quick-release and slow-release.
SLOW-RELEASE

There are two main types
known as water-insoluble
nitrogen (WIN), available
for specific applications:
1.
Sulfur coated, which lasts
for about 8 weeks.
Polymer coated, lasting
about 12 weeks.
QUICK-RELEASE


Typically lasts for 3-4
weeks, depending upon the
temperature and the
amount of rainfall.
For general use, these
water-soluble nitrogen
fertilizers (WSN) are also
known as commodity or
field grade fertilizers.
2.
*Both time estimates may vary
depending upon the amount
of rainfall.
 The
three numbers (often called NPK) on a
fertilizer package tell you the percentage of the
primary nutrients' makeup by weight.
 The three main components are:
• Nitrogen (symbol N) for leaf development and vivid
green color.
• Phosphorous (symbol P) for root growth
• Potassium (symbol K) sometimes called potash, for root
development and disease resistance.
For
example, a bag marked "16-4-8"
contains:
•
•
•
•
16 percent nitrogen,
4 percent phosphorous and
8 percent potassium.
The other 72 percent is usually inert filler
material, such as clay pellets or granular
limestone.
To
know how much of each is in the
bag, multiply the percentage by the
size (weight) of the bag.
• Example:
A 50-lb. bag of 10-10-10 contains ....
5 pounds each of nitrogen, phosphorus and
potassium.
 There
may also be secondary or minor
elements in the formula.
 Don't
feel short-changed by the presence of
the so-called inert material in the fertilizer
bag. Its purpose is to help distribute the
fertilizer evenly and prevent chemical burn
 Weed
and Feed is a common term which refers
to fertilizer that contains weed killer for
broadleaf weeds such as dandelions or grassy
weeds like crabgrass.
 Look on the label for a list of weeds that can
be treated with the product.
 The two types are:
• Pre-emergents
• Post-emergents
 Pre-emergents
are
weed killers which
must be applied before
the weeds germinate.
 They are ineffective if
the weeds are already
actively growing.
 Pre-emergent weed
killers are often mixed
with fertilizer and are
applied early in the
season.
 Post-emergents
are
contact killers.
 They
are effective only
if the weeds are
already actively
growing.
 They will not kill
weeds that have not yet
germinated.
 The
timing of application of pre-and postemergents is critical for success.
• Applying these products too early or too late is essentially a
waste of time.
 If
sowing grass seed is also in schedule, make
sure that there is the proper time interval
between applying weed and feed and sowing.
 Read the package carefully before selecting to
be sure which product fits your needs.
 Starter
fertilizers and winterizers provide
extra phosphorus for root growth. Starter
fertilizers are applied to provide a boost to
newly seeded lawns. Winterizers are used as a
last fall feeding to promote off-season root
growth.
 Non-synthetic
organic fertilizers, soil
conditioners and soil additives are also widely
used.
 Because they lack some added ingredients to
slow the nutrient release, these products may
have to be applied more frequently.
 As with synthetic products, apply properly and
with caution.
Some of the most commonly used are:







Green sand — from sedimentary marine deposits. Contains potassium and iron.
Blood meal — a byproduct of the meat packing industry. Steamed and dried, it
is high in phosphorous.
Compost — one of the best all around garden materials for soil improvement.
Cottonseed meal — a byproduct from cotton processing. This is a good source
of nitrogen.
Fish emulsion — a fish processing byproduct. Mild, nontoxic, and organic, fish
emulsion is good for use with tender plants that may suffer fertilizer burn. Yes,
it does smell like fish.
Super phosphate — rock phosphate combined with sulfuric acid to produce
phosphorus in a form easy for plants to uptake.
Manure — for soil conditioning. "Hot" manures such as horse, pig and poultry
are high in nitrogen and need composting to prevent burning plants. "Cold"
manures like cow, sheep or rabbit can be added directly to the soil.
Do a Soil Test
 Just because the soil looks rich and dark
doesn't mean that the nutrients are all there.
 Soil nutrients can become depleted over time
and need a boost.
 A soil test is the key. The soil test tells you
what is already there (so you don't add more),
and what is missing.
• Lime is used for raising pH (make it more more
alkaline).
• Sulfur lowers soil pH (making it more acidic).
 Over-application
of fertilizer is a common
occurrence.
 Too
much product applied faster than the
plant can absorb it wastes fertilizer and harms
the plant.
 Always
apply fertilizer at the proper time. Do
not apply slow-release fertilizer late in the
growing season.
 You
don't want to boost foliage growth with
nitrogen-heavy fertilizers prior to the dormant
season.
 Each
species of plant needs a different mix of
nutrients.
 Rotation of plantings allows you to get the
most from your garden soil.
 Intercropping is the planting of different
varieties within a close vicinity.
 Using principles of companion planting,
intercropping lets plants natural qualities
complement each other.
 Crops
that are planted with the specific
intended purpose of being worked back into
the soil are known as green manure.
 These
cover crops are chosen for their
nutrient value and are used by serious home
gardeners as well as commercial agricultural
growers.
 Excess
product from fertilized areas has to go
somewhere.
 That somewhere is either down into the
ground, affecting the water table or running
off to affect nearby areas.
 That runoff could eventually end up in the
water supply downstream.
 Always follow package directions regarding
proper attire, application procedures and
safety precautions.
1.
They developed an
industrial method of
fixing nitrogen to
produce artificial
fertilizers
2.
Planted crops (legumes,
ex. clover) to increase
the nitrates in the soil
Burning fossil fuels which causes
nitrogen compounds to enter the
atmosphere and return to earth in
the rain (aka acid rain).
Nitrogen saturation – not all nitrogen is used by
organisms.
Extra nitrogen in forests:
 damages tree roots,
 stunts tree growth,
 kills conifers needles.
 The extra nitrogen is increasing the acidity of
the soil.
Nitrogen-containing gases are released from
industrial smokestacks, power plants and
vehicle exhaust.
Lakes: became acidified killing organisms that
live in there
Maple trees: acid draws the nutrients out of the
soil which stunts tree growth.
Runoff is carried from farms,
industry and cities to the
water




Increased plant growth because of increased
nitrates
Some plants underwater stop producing O2
because not enough photosynthesis occurs
Death of plants increases decomposer #s which
decreases the O2 levels (cellular resp)
Decreased O2 levels kills fish
Increased nitrates increases algal growth (bloom).
When algae die, decomposers increase in # which
decreases O2 levels, which kills fish
Explain how adding nitrogen-containing
fertilizers to fields can affect its
biodiversity of grass species.
Increased nitrogen can only be taken
advantage of by a few grass species
to increase their growth. Other
species will die off.
 Nutrient
Cycles in a closed system work
efficiently when there is a balance between what
is entering the system vs. what is leaving.
 What
if something changes the balance of the
nitrogen cycle?
• Part of the cycle is shut down
• Part of the cycle slows down or speeds up
• More or less demands are made of the cycle
• Nutrients may become “stuck” in one part of the cycle
 Engineer
a Crop: Transgenic
Manipulation
 Farmer's Dilemma
 Bt Corn
 Should We Grow GM Crops?
 Soil
qualities
 pH
 Nutrient
levels
 Fertilizers
 Deep tillage
 Crop rotation