Midterm Flashcards
three particle sizes typically found in the mineral matter of soils
sand (.05-2mm)
silt (.002-.05mm)
clay (smaller than .002mm)
Why is air needed in soil
keep it light
allow the roots to burrow down in it
how can you improve the condition of soil to allow more air to be contained within a soil profile
add sand (or perlite in potting soil) which increases porosity
what value do soil microbes add to the quality of the soil
add nutrients
why is understanding good soil health important for someone who is considering a career in working with plants
good soil results in healthy plants and to have a successful career, ones plants must be healthy
clay
the smallest soil particle
horizon
a layer of soil
loam
mixture of different soil particles
organic matter
animals and plants
permeability
water moving downward in the soil
porosity
voids or openings in the soil
structure grade
how defined or clearly shaped a soil ped is
structure type
the shape in which soil pets are formed
if a soil appears to be of poor quality because plants do not grow well, is hard as a rock when dry and the water stands on the surface and does not soak into the soil when it rains what is the problem
the soil has too much clay resulting in saturated soil and a lack of porosity
in order to add air space/porosity sand should be added
to help with water availability silt should be added
Agronomy
the specialization of ag concerned with the theory and practice of field-crop production and soil management
THE SCIENTIFIC MANAGEMENT OF LAND
soil conservation researcher
soil scientist
crop farmer- corn, soybeans, wheat
Arboriculture
growing and caring for trees in urban cities
also, cultivation of woody plants particularly those used for decoration and shade
tree trimmer
christmas tree farmer
landscaping
Botany
the science of plants
museum historian
plant researcher-DNA research
Plant researcher- environment of plants
floriculture
the cultivation of plants and their flowers
wholesale fresh flower market
florist
flower grower
forestry
the sciences, arts and business practices of crafting, conserving and managing natural resources on land designated as forests
horticulture
the science of agriculture that relates to the cultivation of gardens or orchards including the growing of vegetables, fruits, flowers, and ornamental shrubs and trees
extension agent
food
ornamental flower arrangements
orchard
grove of fruit or nut trees
arial spray service technician
fruit stand
apiary
three crops grown in our local area
apples
vegetables
tobacco
two factors that determine why certain crops are grown in area and not northern Canada
temp
soil quality
corn is usually considered a: food fiber fuel medicine aesthetic
food and fuel
how do plants benefit animals in terms of gas exchange during photosynthesis
plants turn the carbon dioxide that animals exhale into oxygen that animals need to survive
soil has 4 components that make up the whole:
45% mineral components, 5% organic matter, and 50% bet air and water
sand
.05-2 mm round shape gritty feel adds porosity reduces water holding capacity
silt
.002- .05 mm round shape but very small to detect flour-like smooth but not sticky moderate porosity helps water holding capacity
clay
less than .002 mm flat or platy cannot be seen with the naked eye sticky when wet (ribbon test) bad for porosity(fit together tightly because they r so small) locks in water and plants can't use it (need sand/silt for water availability)
when soil particles cling together in an arrangement known as a – it is called —
ped; structure
two considerations must be made for soil structure
structure type
structure grade
structureless types
MASSIVE & SINGLE GRAIN
two extremes in terms of effects on permeability
neither present great conditions
massive structureless type
compact coherent soil not separated into peds of any kind
usually in clayey soils
structure grade
determines soil quality– stronger grade = better quality
how strongly the ped is held together
four grades of structure
strong, moderate, weak, and structureless
good structure provides more or less aeration/ pore space
more
—– is important for forming soil structure
organic matter
effective depth
the zone which plant roots can easily grow (the deeper the better)
barriers for root growth are caused by
massive soils dense soil structure poor internal drainage abrupt texture changes between horizons gravely and large sands
areas with high rainfall cause soils to become – because water leaches — — away
acidic; hydroxyl ions
however in arid (desert) regions the lack of rainfall can cause the other extreme in soil chemistry:
salinity
soil salts combine with common soil elements:
magnesium calcium chloride sulfates sodium (obviously) fertilizer
how salt accumulates in farmland
occur naturally from weathering of parent material (original bedrock below soil)
dry conditions allow salt to accumulate because
salt is not leached downward by rainfall
poor drainage causes water to
not filter through the soil and be evaporated leaving salts behind
fertilizer and some irrigation water contains salt compounds; plenty of water is needed to
flush salts from plant pots
plants have varied — to salt levels based on species but generally high salt content will affect:
tolerance;
water uptake & availability of nutrients
how to fix the problem/ adjust salinity on farmland:
improve drainage
supply ample irrigation
apply gypsum
add mulches
how to fix the problem/ adjust salinity in greenhouses
easier to manage if you monitor salinity levels and:
use overhead irrigation methods
neutralize salinity in potting media at the time of mixing
use organic fertilizers (manure/ compost)
salinity can be monitored by
measuring the electrical conductivity of soil (because salt conducts electricity)
environmental factors which influence where certain crops grow include:
frost free periods/ growing season
mean average temp
rainfall
relationship bet plants and animals
animals eat plant material
plants restore oxygen to the air animals breathe
decaying animal products support plant life in the form of nutrients
plants use the energy from the sunlight to convert raw materials from earth into:
carbs
fats
oils
plants use – – from the air and convert it into –
carbon dioxide; oxygen
the process of food production and – — is called:
gas conversion; photosynthesis
some ways humans use plant material
food feed for livestock fiber fuel medicine aesthetic value
current issues facing the supply of plant products include:
global human population
demand for biofuels
urban growth
water resources
some solutions for plant producing issues include:
alternative energy (wind, solar, water) crops that need less water (genetically modified)
two principals that define soil and water relationships (determine quality of soil) are;
permeability
water holding capacity
permeability
the rate water moves through soil
depends on:
texture, structure, organic matter (porosity)
pores in the soil are created by:
roots and other organic matter (decaying substances)
animals
soil particle size & fit
rapid permeability rate
texture: sand and silts
structure: strong/ well defined
porosity: porous
slow permeability rate:
texture: clays
structure; weak and massive
porosity: not porous
water holding capacity is
the availability of water retained by soil particles
water holding capacity mainly depends on
texture
water holding capacity is improved by
organic matter
high water holding capacity
texture: silts, loams and clays
organic matter: present
low water holding capacity
texture: sands
organic matter: absent
plants – use all soil water
can’t
available water is
free for the plant’s use
unavailable water is
held too tightly by clay particles and surface tension
saturated soils
have excessive water that will run off, increasing erosion concerns
why are there so many types of industries involved with plants
plants are thoroughly involved with many aspects of our everyday life
&
there are many areas of plants to be studied
landscape management
to beautify terrain with the plantings of trees, shrubs and flowering herbs; walks with ornamental features such as rock drives, gardens, bog gardens, water fountains, pools etc
landscape designer
landscaper
topiaries
nursery
any place for plants, shrubs and trees are grown either for transplanting or as grading stocks
greenhouse manager
nursery greenhouse
bartlett
research
all effort directed toward increased knowledge of natural phenomena and the environment and toward the solution of problems in fields of science. this includes basic applied research; much of the agricultural productivity of the US is directly the result of applying research
DNA technician
drought resistance
genetically altering a plant
willow tree and aloe are examples of
medicine from plants
fuel from plants (list 4)
trees
sugarcane
compress fossilized plants
corn
fiber from plants (list 8)
cotton silk hemp flax straw grass
why are a large number of cattle an hogs raised in the midwest
much more land which is unpopulated and it is hard to grow plants
single grain ped rate of permeability & structure grade
rapid; structureless
granular ped rate of permeability & structure grade
moderate; moderate
blocky ped rate of permeability & structure grade
moderate; moderate
platy ped rate of permeability & structure grade
very slow; strong
prismatic ped rate of permeability & structure grade
moderate; weak
massive ped rate of permeability & structure grade
very slow; structureless
tilling soil using a tractor and plow would be detrimental to soil structure in what way?
it would destroy whatever soil structures are there and would result in poor balance in soil drainage/absorption
why does structure grade contribute to soil quality
determines water flowability, which, in turn, greatly affects the growth of plants
ped types
single grain, granular, blocky, platy, prismatic, massive
how do differences in soil characteristics affect the diversity and quantity of soil organisms
a soil richer in moisture and nutrients will have more organisms that a poor, dry soil
why would a desert soil contain fewer soil organisms than a rainforest soil? list three reasons
more moisture would allow more organisms to survive
high content of organic matter would provide more food
smaller ped size/ more pores allow for more movement
best test of soil when checking for porosity, permeability and water holding capacity
run a measured amount of water through the soil, tracking how long it takes, how much water is absorbed, and how much makes it through
trade-off between increasing permeability and improving water holding capacity
if water travels through the soil too quickly the plant might not have a chance to get the water it needs; if it holds too much the ground will eventually flood causing erosion
can you have too much organic matter in soil
yes with too much organic matter soil will lack nutrients as well as air and water space
problems with very rocky soil
too much pore space causing water to move through too quickly and the plant will not be able to get the water it needs
ph determines:
the availability of certain nutrients
with a low ph a plant will not be able to absorb:
phosphorus which will lower the productivity of the plant
chemical nature of basic substance
high concentration of hydrogen
how do u adjust the ph level of soils
add lime to make soil more alkaline and sulfur to make it more acidic
what affect would a high or low ph have on a famers crop
nutrients would be unavailable
rain or irrigation water will leach out elements causing the soil to become:
acidic
what will happen if you over-fertilize with a chemical fertilizer
salinity level will rise and could result in the death of plants
how do you correct high salinity levels
water plant from overhead
if crops are not growing normally, and lack green color,and then fertilizer is added but leaves the problem worsening , explain why PH could be a contributing factor
an incorrect pH level will result in crops not being able to get the nutrients they need. too much fertilizer will alter PH
What does a continuous overdose of fertilizer do to the soil
ph level will worsen, salinity level could rise, and crops will eventually die by lack of nutrients
how do you prevent a high salinity content in soil or potting media
water container from overhead
wash salts through the soil column
