Plant Nutrition Flashcards
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what is a pitcher plant large enough to catch a rat?
Nepenthes Rajah
N. Rajah environment?
lives in unproductive soil and uses carnivory to obtain nutrients such as calcium, potassium, and phosphorus
where do plants obtain most of their water and minerals?
upper layers of soil
how is soil classified?
size, from large to small; called sand silt, clay
soil horizons
how soil is stratified
topsoil
consists of mineral particles, living organisms, and humus (decaying organic material)
what prevents soil from leaching out out through groundwater?
cations binding to soil particles
humus
builds a crumbly soil that retains water but is still porous
topsoil
contains bacteria, fungi, algae, and other protists, insects, earthworms, nematodes, and plant roots
cause of 1930s American Dust Bowl
soil mismanagement
what % of farmland has reduced productivity globally?
30%
sustainable agriculture
goal is to use farming methods that are conservation-minded, environmentally safe and profitable
what % of global freshwater use is
devoted to agriculture
75%
primary source of irrigation water
75%
primary source of irrigation water
aquifers
land subsidence
caused by depletion of aquifers
fertilization
replaces mineral nutrients that have been lost from the soil
what are commercial fertilizers enriched in?
nitrogen, phosphorus, potassium
what does soil pH affect?
availability of minerals
phytoremediation
biological, nondestructive technology that reclaims contaminated areas
why are some areas unfit for agriculture?
soil or groundwater contamination
80%-90% of plants free mass is what?
water
4% of plant’s dry mass is?
inorganic substances
96% of plant’s dry mass is from what?
CO2 assimilated during photosynthesis
how many essential element for plant life cycle?
17
what are the nine nutrients?
carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium
what plants need to sodium?
C4 and CAM
diagram of leaves and what they’re deficient in
green: healthy
purple outline: phosphate-deficient
orange-yellow outline: K-deficient
orange-yellow center: N-deficient
smart plants
blue tinge indicates when nutrient deficient (phosphate) has occurred
plants and soil microbes have what type of relationship?
mutualistic: dead plants provide energy, and secretions from living roots support nearby microbes
rhizosphere
layer of soil bound to plants roots, contains bacteria that act as decomp/nitrogen-fixers
rhizobacteria do what?
produce hormones, produce antibiotics, absorb toxic metals, make nutrients more available
why does rhizosphere have high microbial activity
sugars, amino acids, and organic acids secreted by roots
what does the nitrogen cycle do?
transform nitrogen and nitrogen-containing compounds from gas to usable forms
nitrogen fixation
conversion from n2 tro nh3
nodules (along a legume’s roots)
composed of plant cwlls “infected” by nitrogen-fixing rhizobia bacteria
bacteriods
within root nodule, formed by rhizobia
crop rotation
takes advantage of agricultural benefits of symbiotic nitrogen fixation
non-legume crop rotation
A non-legume such as maize is planted one year,
and the next year a legume is planted to restore
the concentration of fixed nitrogen in the soil
mycorrhizae
mutualistic associations of fungi and roots; secrete growth factors
two types of mycorrhizae types
ectomycorrhizae, arbuscular mycorrhizae
how old are mycorrhizae?
date 460 million years ago, may have helped plants colonize land (start = parasitism)
ectomycorrhizae
mycelium of the fungus
forms a dense sheath over the surface of the root
—> do not penetrate root cells
ectomycorrhizae occur in what % of plant families?
10%; including oak, walnut, birch, willow, eucalyptus
arbuscular mycorrhizae
microscopic fungal
hyphae penetrate the cell wall to form branched
arbuscules within root cells
arbuscular mycorrhizae occur in what % of plant species?
85%; including grains and legumes
garlic mustard
invasive species that slows growth of other
plants by preventing the
growth of mycorrhizal fungi
epiphyte
grows on another plant and obtains water
and minerals from rain
how do carnivorous plants obtain nitrogen?
by killing and digesting mostly insects
how do farmers promote mycorrhizae?
inoculate seeds with fungal spores
