Transcript AGRI 101 Introduction to Agriculture

AGRI 101
Introduction to Agriculture
Agriculture
Science, art, or practice of
cultivating soil producing crops, and
raising livestock, and the preparation
and marketing of the resulting
products
Agriculture
Horticulture
**most diverse and interesting field**
Landscape Design
Landscape Construction
Landscape Maintenance
Nursery Production – field and container
Greenhouse Production – Tropical Foliage,
flowering potted plants, cut flowers
Agriculture
Horticulture (cont’d)
Pomology
Small fruits
Tree fruits and nuts
Olericulture
Turf/Golf Course
Agriculture
Agronomy – Field Crops
Corn, soybeans, wheat, tobacco
Fiber crops
Forages
Forestry
Soils erosion and fertility
Harvesting & Production of timber
Management of Wild Areas
Urban Forestry (horticulture)
Agriculture
Animal Sciences
Cattle
Dairy, beef
Poultry
Sheep/Goats
Horse
Swine
Agriculture
Plant sciences
Animal sciences
Economic Sciences
Mechanical/Engineering Sciences
Soil Sciences
World Wide
World’s surface area = 112 billion A
Cropland is 3-4%
Remainder is ice, water, mountains, etc.
World Land Area 32 b A
29% of entire planet’s surface
The most popular photograph in history,
taken from Apollo 17.
World Wide
World Land Area 32 b A (29% of
World Total)
11.5 b A Agricultural - 36% of Land Total
3.5 b A Cropland - 11% of Land Total
8 b A grazing - 25% of Land Total
10.6 b A forest – 33% of Land Total
Remainder Desert or Ice or Mountains
United States,
Number of Farms (1000)
2600
2500
2400
2300
2200
2100
2000
1900
1800
1975
1980
1985
1990
1995
2000
2005
United States,
Average Farm Size (A)
460
450
440
430
420
410
400
1975
1980
1985
1990
1995
2000
2005
World Population
Thomas Malthus
Essay on the Principle of Population in
1798
Human population increases
geometrically
Resources increase arithmetically
Therefore, POPULATIONS WILL
GROW UNTIL THEY CRASH
Thomas Malthus
Predicted
Land Degradation
Massive Famine
Disease
War
Has this happened?
Where?
Malthus’s Predictions
USA & Developed Countries
Predictions Delayed by Technology
Fertilizer – more yield per acre
Irrigation – more yield per acre and opened
more land in arid regions
Green Revolution Crops (Breeding)
Human Birth Control
Education of Women
World Population Growth
pop (billions)
12
10
8
6
4
2
0
0
500
1000 1500 1600 1700 1800 1830 1960 1999 2050
year
Causes for World Population
Growth
DDT/Malaria
Childhood immunizations
Education of females
Green Revolution Crops
Use of fertilizers and pesticides
Religious Beliefs – large families,
contraception
World Population
How many people can the earth
support?
Who Knows, possibly 20 Billion
Conclusion:
There has been a famine in the world
almost every year since WWII
Human Suffering
Political Instability
Causes are
Manmade
Natural
Consider
World >> 6,000,000,000 persons
Entire world depends on 25 crops of
which
3 – 5 are heavily relied upon
Risk mass starvation
Susceptible to disease/insect damage
Irish Potato Famine
Reliance on one food
1.5 A fed family of six, would take 8
A of wheat for same level!
1845 cool, wet summer
Potato blight fungus imported from
South America by mistake
Spread by spores throughout country
without notice
Irish Potato Famine
When they dug tubers in the fall, half the
crop was rotted
Theories of the day
Static electricity from new steam locomotives
Mortiferous vapors from volcanoes
Tubers contracted dropsy
Tubers continued to rot but they did
nothing to stop it
Irish Potato Famine
Lasted from 1845 to 1851
Hunger, disease, weakened bodies
Death from dysentery and others
Causes of Famine
Irish Potato Famine
Russian Famine
African Famines
Consecutive years of below average rain
Political redistribution of land or food
aid
Robert Mugabe, Pres. Zimbabwe land reform
Reducing Famine
Diversify food supplies
Keep food reserves safe
Population control
Political stability
Better transportation, highways and
ports
Education, better economic outlook
CHINA
1.28 Billion persons in 2002
5X U.S.
20% of world’s population
Land area slightly less than U.S.
10% Arable land vs. 19% in U.S.
China
1979 decided to limit pop to 1.2 B by
2000
One child per couple policy
Couples rewarded money, vacation,
more land to farm
One child children get better
education, housing, jobs
India
Family planning less aggressive
947 million, .947 Billion persons
Expected to reach 2 Billion by 2025
and become the world’s most populous
nation
Name the top 3 World Crops
Rice
Corn
Wheat
What do they have in common?
All grasses!!
We have low diversity for
Pest Resistance
Nutrition
Green Revolution
Feeding the Growing World
Green Revolution
The most significant development of
agriculture of the 20th century
Dr. Norman Borlaug
1970 Nobel Peace Prize
Landrace Varieties
Tall
Leafy
Large root system
Evolved to compete under high pest
pressure and marginal production
areas
Landrace Wheat
Green Revolution Wheat
Green Revolution Varieties
Physical Changes to Plants
Shorter plants
Smaller leaves
Stronger stems
Smaller root systems
Results of G.R. Crops
More plants/acre = higher yield
India exports wheat now, not starving
BUT
Less competitive plants = more need
for weed control, herbicides
Genetic variability gone
More fertilizer to produce higher
yields
G.R. Crops
Bottom Line
Millions now fed
Requires more management and inputs
Has been criticized for this but
Soils
Not just Dirt
Soil Importance
Agriculture
Construction
Depository for waste
Beauty
What is soil?
Minerals from weathered rock
Organic matter
Decaying plants
Decaying animals
Decaying microbes
Water
Air
Living Organisms
Functions of Soil
1.
2.
3.
4.
Provide physical support for plants
Provide nutrients
Provide water
Support biological activity of
microbes, earthworms, etc.
Soil Profile
Vertical cross section showing
horizons or layers
Horizons determine value and use of
land
A
0 – 25 in. Roots, highest biological
activity, microbes, OM
B
25 – 36 in. Accumulation from A,
more mineral, less OM, less oxygen,
less biological activity
C
36 + in. Weathered parent rock
BEDROCK
Nutrients aka Fertilizer
Macronutrients – used in large
quantities
Nitrogen – N – promotes leafy green
growth
Phosphorous – P – promotes flowering
Potassium – K – promotes root growth
and cold hardiness
Macronutrients
Appear on the fertilizer label
Always appear in order N – P – K
20 – 20 – 20
N P
K
0 – 60 – 0
33 – 0 – 0
Micronutrients
Trace elements
Needed in smaller quantities
Mg
Mn
Cu
Fe
B
Mo
Zn
Macronutrients and
Micronutrients
CHOPKNS CaFe Mg
CuZn BMo Cl Mn
Know them for the exam
Organic vs. Inorganic Ferts.
Organic – not wholesome and pure
Denotes source of elements
Organic – derived from living organisms
Compost, sea weed, fish emulsion,
manure
Organic vs. Inorganic Ferts.
Inorganic – does not mean evil or
wrong
Designates source – processing or mining
N – natural gas
P and K - mined
Organic Ferts.
Organic Ferts low in nutrients
Manure <2% N
Inorganic > 30% N
Cost per pound of N?
Ease of Application?
Bonus with Organic – Adds OM
Slow Release Ferts.
Organic – manure rots over time
Inorganic – engineered to be slow
release
Osmocote
Various particle sizes are
coated with various
thickness of a resin
coating.
Osmocote
Thin coating breaks down first
Thicker coating breaks down last
Availability
All nutrients are available based not
only on amount applied but also the
pH
Availability
Environmental Concerns
Runoff into surface waters
Leaching through soil profile into
groundwater
Biological Nitrogen Fixation
78% of atmosphere is nitrogen gas
Inert
Unusable as macronutrient
Biological Nitrogen Fixation
2 ways nature converts nitrogen gas to
usable form
1. Lightning
2. Rhizobium bacteria
Found in symbiotic relationship with
plants in legume (bean) family
2. Peas, redbud, alfalfa, locust, soybean,
wisteria
1.
Biological Nitrogen Fixation
Rhizobium found in root nodules
Free nitrogen, transportation,
application
Rhizobium nodules on roots
Black alder seedlings growing without N fertilizer
Left: not growing with bacteria
Right: with bacteria
Physical Properties of Soils
Physical Properties of Soils
1. Color – indicates parent material,
amount of OM, aerobicity or not of
soil, clay content
2. Texture – proportion of
sand:silt:clay
Soil Texture Triangle
What texture of
soil is
20% Clay
15% Sand
65% Silt?
Agents of Soil Erosion
1. Wind - Dust Bowl, 1930’s Great Plains
2. Water – Impact of raindrops, running
water
3. Biological – cattle overgrazing
4. Temperature – changes in soil
chemistry, mainly a problem in the
tropics
Soils and Fertility in
Horticulture
Types of Soils & Media
Native Soils
Soilless Media
Sing. Medium, pl. Media
Hydroponics
Tissue Culture
Sand/Gravel Culture
Bag Culture
Soilless Media
Used in Container Nursery
Production
All Greenhouse Crops
Foliage
Flower production
Potted flowering plants
Soilless Media
Field Soil is NOT used in containers
Soil structure is destroyed
Loss of pore space; long capillary
tubes in soil that allow water and
gasses to be exchanged are destroyed
when placed into a pot
Poor aeration
Poor drainage
POOR PLANT PERFORMANCE!!
Components of Soilless Media
Sand – adds weight to hold the pot
upright and adds porosity.
Little water holding or CEC capacity
Components of Soilless
Media
Sand
Bark - creates a lightweight portion
that adds porosity
Little water holding or CEC capacity
Components of Soilless
Media
Sand
Bark
Peat - holds water like a sponge with a
high CEC
Components of Soilless
Media
Sand
Bark
Peat
Compost – Less expensive alternative to
peat that holds water, has a high CEC,
and decomposes to N and P among
others.
Components of Soilless
Media
Sand
Bark
Peat
Compost
Vermiculite –
Vermiculite is a sterile, lightweight mica
heated to approximately 1800 degrees F
plate-like structure expands, allowing it to
retain large quantities of air and water
Vermiculite
Components of Soilless
Media
Sand
Bark
Peat
Compost
Vermiculite
Perlite
produced by heating volcanic rock to
approximately 1800 degrees F
sterile, lightweight, porous material
Perlite - Coarse
Tropical Foliage Plant
Production
Hydroponic Production
Hydroponic Production
Field Nursery
Container Nursery
Container Plant Production
Container Tree Nursery
Soilless Media
Commercial Media
Soilless Media Mixers
Soilless Media Plug Trays and
Filling Machine
Peat Harvest
Importance of Crop Plants
“Plants are only important if like
breathing or eating”
Top 4 List
Why crops are important
4. Primary producer in the food chain
3. Animals depend on them
2. Fossil Fuels
1. Humans use them for food, medicine,
fiber, building materials, oxygen,
aesthetics, waxes, perfumes, etc.
Plant Life Cycles
Annual – a plant that completes its life
cycle in one season
•Winter Annual – germinates in fall,
establishes crown and root system in fall,
overwinters, flowers and dies in spring.
Vegetative Phase in Fall
Sexual Phase in Spring
Winter wheat, annual bluegrass, henbit,
chickweed
Plant Life Cycles
Annual –
•Winter Annual
•Summer Annual – germinates in spring,
grows in summer, flowers, sets seed, and
dies before winter.
Vegetative Growth in Spring/Summer
Sexual Growth in Late Summer/Fall
Impatiens, beans, corn, sunflower, begonia
Plant Life Cycles
Perennial – a plant that lives for more than
one year, is herbaceous, and regrows each
year from a perennating structure
Hosta, daylily, iris, some ferns, heucheras,
coneflower, vinca groundcover
Distinct from shrubs-woody <10’, mult.stems
trees – woody >10’ main trunk
Plant Life Cycles
Biennials – Bi = two, ennial = years
Intermediate life cycle between
annuals and perennials
Live for two years with distinct
growth patterns for each year
Plant Life Cycles
Year 1 – grow vegetatively
Leaves, stems, roots
Usually grow in a rosette
Year 2 – grow reproductively (sexually)
Send up flower stalk
Set seed
Die
Hollyhocks, cabbage, carrots
Climate vs. Weather
Climate includes temperature,
precipitation, humidity, sky conditions,
wind, and atmospheric pressure
Climate is the average conditions over a
long period
Weather is the current and temporary
atmospheric conditions
Difference is time span
Climate Types
Macroclimate describes the conditions
over a relatively large area i.e. a portion of
a state or county
Local climate refers to more localized
conditions i.e. a valley or mountain
Microclimate is the conditions around a
plant or leaf
Microclimate can be modified by us to grow
marginally hardy plants
Modifying Cold Temps
Modifying Temperatures
Frost Protection
Most effective and widely used is mist
irrigation
Can prevent damage down to 20F, but usually
only to the upper 20’s
As the temp drops below freezing, ice forms,
releases heat of fusion
Freezes and Frosts
Radiational Freeze – calm conditions,
radiational cooling, not a blanket of
cloud cover to hold in heat
Radiational Freeze
Sunset beginning a cold, clear night
Freezes and FrostsDamage Control
Radiational Freeze
1.
Reduce outgoing radiation
Hotcaps
Row cover
Flooding (cranberries)
Foams
Straw covering (must be removed)
strawberries
Artificial fog
Row Cover with Tomatoes
Freezes and FrostsDamage Control
Radiational Freeze
2. Add heat
Smudge pots
Utilize the temperature inversion with
fans or helicopters
Overhead irrigation- water gives off heat
when it freezes (80cal/g). Must
constantly add water. As long as liquid
water is present, the temp. remains at 0 F
Temperature Inversion
CALM NIGHT
Warmer Air, ie. 36 F
Crop Will FREEZE!!!
Very Cold Air, ie. 30 F
Temperature Inversion
Mix Air
Air Mixture is Now 34 F and the Crop is Safe!
Freezes and Frosts
Advective Freeze
Large, cold air mass moves in from
Canada
Associated with windy conditions
Freezes and FrostsDamage Control
ADVECTIVE FREEZE
Not much you can do.
Vegetative (Asexual)
Propagation
Vegetative Propagation
Making more plants without sex
(seeds)
A form of ‘cloning’ that has been
practiced for centuries
Includes all techniques from rooting a
houseplant in a glass of water to
grafting fruit trees to tissue culture
Techniques of Asexual Prop.
Divisions
Herbaceous perennials – hosta,
daylily, liriope
Cuttings
Leaf cuttings- African
Violets
Stem cuttings- Crape
Myrtle
Root cuttingsBlackberries
Layering
Houseplants,
strawberry
Grafting – roses, fruit
and nut trees
Budding – fruit and
nut trees
Tissue Culture –
ornamentals, most
agronomic crops
Vegetative Propagation
Advantages:
-all offspring are clones
(plants derived
from the same parent plant by asexual means and are
genetically identical)
-some plants can’t be propagated
by seed
-can decrease time to flower
Vegetative Propagation
Disadvantages:
-can only propagate a few from each
parent (except tissue cultures)
-requires a lot of labor
-Diseases can be easily transmitted
Totipotency
Plant cells contain all
the genetic
information needed
to regenerate a
complete organism
Totipotency allows
stem or leaf cuttings
to grow roots and
vice versa
Allows the
regeneration of
entire plants from a
single cell
Totipotency
Chrysanthemum stem
cuttings freshly
harvested from the stock
plant
Cuttings will be dipped in a
hormone to facilitate
rooting and stuck into
propagation tray
Totipotency
Stem grows root cells and
roots after several weeks
Production tray full of
rooted cuttings
Illustrated Examples of
Asexual Propagation
DIVIDING CLUMPS
DIVIDING CLUMPS
DIVIDING CLUMPS
OFFSETS
Hen and Chicks
BULBS
HARDWOOD/SOFTWOOD
CUTTINGS
LEAF CUTTINGS
Leaf bud
Leaf petiole
Leaf blade
Leaf Section
LEAF CUTTINGS
African Violet Leaf Cuttings
Leaves are cut from the
plants and planted leaf
to leaf in 10 x 20 trays
filled with violet
potting soil.
After about 4 to 6 weeks in
the 10 x 20 trays small
plantlets start appearing on
the stems of the rooted
cuttings.
African Violet Leaf Cuttings
When the sprouting plantlets
have taken over the 10 x 20 tray
it's time to start breaking them
apart and putting them into a
roomier container.
Four inch pots are allowed
to grow pot to pot until the
plants get bigger.
African Violet Leaf Cuttings
A four inch violet is taped
for shipping. The tape
stops soil from falling out
of the pot during transit.
LAYERING
roots are formed on a stem
before it is removed from the
parent plant
the stem is cut below the new
root system and planted
LAYERING
(Important Points)
similar to cuttings
advantages (water, nutrients, disease)
hard to root plants
accumulation of photosynthates and
hormones
encourage by bending, girdling, or wounding
etiolation
shoot elongation in the absence of light
natural means of reproduction
strawberry runners, Bermuda grass stolons, hen and chic
offsets
PHYSIOLOGY
LAYERING WOODY PLANTS
remove a ring of bark
(removing phloem and cambium)
xylem remains intact
plant)
(water continues to move up the
accumulation of
photosynthates and
hormones
LAYERING
Tip
Simple
Compound/Serpentine
AIR LAYERING
LAYERING
continued
Mound / Stool
layer
Trench Layer
WHY GRAFTING OR BUDDING?
cannot be propagated by other means
decrease time to flower and fruit
change variety of existing, mature tree
special forms (dwarf trees, tree roses, weeping cherry, etc.)
obtain desirable traits of rootstock
(disease resistance, adaptation, etc.)
repair damage
PHYSIOLOGY of GRAFTING
Scion
Root Stock
Cambium
GRAFTING TYPES
(Stock and Scion Same Sizes)
Whip or Tongue Graft
Saddle Graft
Splice Graft
GRAFTING
(Stock and Scion Different Sizes)
graft
graft
graft
Wedge
Cleft
Side
APPROACH GRAFTING
APPROACH GRAFTING
GRAFTING
(TO REPAIR DAMAGE)
Brace Graft
Bridge
Graft