Mineral Nutrition - 7 Flashcards

1
Q

Define mineral nutrition

A

study of how plants obtain and use mineral nutrients

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2
Q

Half of the energy in agricultural production is expended on what

A

nitrogenous fertilizers

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3
Q

Crops use what amount of the applied fertilizer and where does the remaining go

A

less than half
leach into surface water/ groundwater, absorb to soil particles or contribute to air pollution

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4
Q

What are plants the traditional means of and proving useful for what

A

traditional means of recycling animal wastes and useful for removing deleterious materials from toxic-waste

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5
Q

Define essential element

A

is an intrinsic component in the structure or metabolism of a plant. It is necessary for the completion of the plants life cycle and suffers if in limited supply

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6
Q

What two groups are essential minerals classified into

A

macronutrients and micronutrients
according to relative concentrations in plant tissues

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7
Q

What is the other way essential minerals can be classified by

A

according to biochemical role and physiological function into 4 groups

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8
Q

Explain group 1 of essential nutrients by biochemical role

A

nutrients that are part of carbon compounds (N and S)
create organic compounds (ex. amino acids, nucleic acids)

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9
Q

Explain group 2 of essential nutrients by biochemical role

A

Important in energy storage or structural integrity (P, Si, and B)
present in plant tissues where elemental group is covalently bound to an organic molecule

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10
Q

Explain group 3 of essential nutrients by biochemical role

A

Nutrients that remain in ionic form (K, Ca, etc.)
(important as enzyme cofactors, regulating osmotic potentials, controlling membrane permeability).

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11
Q

Explain group 4 of essential nutrients by biochemical role

A

nutrients involved in redox reactions (Fe, Mn, etc.)
important in reactions involving electron transfer

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12
Q

Why is the biochemical classification arbitrary

A

because many elements serve several functions and should belong in multiple groups

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13
Q

Crop plants commonly contain only relatively small amounts of ______

A

nonessential elements

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14
Q

Define nutrient solution

A

provides all of the elements needed for plants to grow without soil or organic matter

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15
Q

Define hydroponics

A

techniques of growing plants with their roots immersed in a nutrient solution without soil

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16
Q

What does successful hydroponic culture require

A

a large volume of the nutrient solution or frequent adjustments of the nutrient solution to account for uptake by roots and changes in pH

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17
Q

a sufficient supply of _____ to the root system is crucial in hydroponics

A

oxygen

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18
Q

Define nutrient film growth system

A

another form of hydroponic culture that involves growing plants in a trough and letting solution flow over the roots. it ensures ample supply of oxygen

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19
Q

Define aeroponics

A

a modification of hydroponics which involves misting roots with nutrients solution and no substrate is required

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20
Q

What is another approach aside from hydroponics and aeroponics that supply intermittent amounts of nutrient solution

A

ebb and flow system

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21
Q

What are the 4 various types of solution culture systems

A
  1. hydroponic growth system
  2. nutrient film growth system
  3. aeroponic growth system
  4. ebb-and-flow system
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22
Q

Define Hoagland solution

A

a formulation used for nutrient solutions that contains all known mineral elements needed for rapid plant growth

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23
Q

Define chelate and what problem it helps solve in nutrient solutions

A

they prevent loss of nutrients due to precipitation
ex. iron is provided as a chelate

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24
Q

Why can diagnoses of deficiencies in soil-grown plants be complex (3)

A
  1. deficiencies may occur in multiple elements at the same time in different plant tissues
  2. deficiencies or excess of one element may affect the status of other elements (connected)
  3. some symptoms look similar to disease symptoms induced by viruses
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25
What is an important clue to diagnose deficiencies and how
the extent to which an element is mobile in plants ex. N, P, and K can move readily from leaf to leaf and therefore symptoms show up in older leaves first whereas B, Fe, and Ca are immobile and symptoms show up in younger leaves first
26
Group 1 minerals
Nitrogen and Sulfur
27
Explain nitrogen as a mineral deficiency
required in greatest amount inhibits plant growth shows up as chlorosis (yellow leaves) in older leaves
28
Explain sulfur as a mineral deficiency
amino acids, coenzymes and vitamins essential for metabolism similar to nitrogen!!!, chlorosis and inhibits growth. young leaves first, immobile
29
Explain phosphorous as a mineral deficiency
integral component, sugar phosphates (respiration and photosynthesis) and phospholipids (membranes), ATP, etc. deficiency in stunted growth, dark green, necrotic spots (dead spots on leaves), older leaves may die, can produce excess anthocyanin (purple colouration)
30
What minerals are in Group 2
Phosphorous, Silicon, and Boron
31
Explain Silicon as a mineral deficiency
adequate silicon show enhanced growth, fertility, and stress resistance lodging (falling over), fungal infection, reinforcement of cell walls and can lesson toxicity of other metals
32
Explain boron as a mineral deficiency
elongation, nucleic acid synthesis, hormone responses, membrane function and cell cycle regulation deficiency = black necrosis of young leaves, terminal buds, loss of apical dominance, abnormal fruits, fleshy roots and tubers
33
What minerals are in Group 3
potassium, calcium, magnesium, chlorine, zinc, sodium, iron , manganese, copper, nickel, and molybdenum
34
Explain Potassium as a mineral deficiency
regulating osmotic potential, activates enzymes in respiration and photosynthesis chlorosis, develop into necrosis at leaf tips and margins, leaves curl, and appear on mature leaves
35
Explain calcium as a mineral deficiency
structural cell walls, secondary messenger, binds to calmodulin necrosis of young meristematic regions (tips), young leaves appear deformed, meristematic regions die prematurely
36
Explain Magnesium as a mineral deficiency
activation of enzymes for respiration, photosynthesis, and synthesis of DNA and RNA chlorosis between leaf veins, older leaves first, senescence and premature leaf abscission (natural detachment)
37
Explain chlorine as a mineral deficiency
water-splitting reactions of photosynthesis, required for cell division wilting, leaf chlorosis and necrosis, bronze-like colour, deficiency is rare because are highly soluble and generally available
38
Explain Zinc as a mineral deficiency
enzymes require Zn, may be required for chlorophyll biosynthesis reduction in internodal growth (two nodes of a stem) therefore display rosette habit (short, bunchy), occur because loss ability to produce amounts of auxin, chlorosis in older leaves
39
Explain sodium as a mineral deficiency
CAM plants require for regenerate PEP chlorosis and necrosis, fail to form flowers, many C3 benefit from low concentration of sodium, stimulate growth through enhanced cell expansion and can partly substitute for potassium as osmotically active solute
40
Explain iron as a mineral deficiency
synthesis of chlorophyll-protein complexes, involved in electron transfer, reversible oxidation interveinal chlorosis, younger leaves
41
Explain maganese as a mineral deficiency
activate enzymes, required in photosynthetic reaction of O2 into water interveinal chlorosis with small necrotic spots, younger or older leaves
42
Explain copper as a mineral deficiency
enzymes involved in redox, reversible oxidation, plastocyanin initial symptom = dark green leaves with necrotic spots, twisted or malformed, may drop prematurely and be sterile
43
Explain nickel as a mineral deficiency
urease requires it, nitrogen-fixing organisms require for hydrogen uptake accumulate urea show leaf-tip necrosis, require small amounts of nickel so deficiencies are rare
44
Explain molybdenum as a mineral deficiency
components of enzymes, nitrogenase, and others general chlorosis between veins and necrosis of older leaves, associated with nitrogen fixation and assimilation therefore may bring nitrogen deficiency
45
what are the mobile mineral elements
Nitrogen, potassium, magnesium, phosphorus, chlorine, sodium, zinc, and molybdenum
46
What are the immobile mineral elements
calcium, sulfur, iron, boron, and copper
47
Define soil analysis
the chemical determination of nutrient content in a soil sample from the root zone
48
Define plant tissue analysis
analysis of concentrations of mineral nutrients in a plant sample
49
Define deficiency zone
range of mineral concentrations below the critical concentration - yield response is anticipated
50
Define adequate zone
range of mineral concentrations beyond which further addition no longer increases yield or growth
51
Define critical concentration
minimum concentration of a mineral nutrient in a plant sample that is correlated with maximum growth or yield
52
Define toxic zone
range of concentrations of a mineral nutrient in excess of the adequate zone - yield or growth declines
53
Define/Explain circular economy
the recycling of mineral elements - crops absorb, humans and animals consume crops, and crop residues and manure return to nutrients of the soil
54
Mineral availability is affected by _____
soil pH
55
Define mineralization
the break down of organic compounds in order for plants to acquire the nutrients from residues, done by small soil microorganisms
56
What 6 factors does mineralization depend on
1. temperature 2. water 3. oxygen availability 4. pH 5. type and 6. number of microorganisms in the soil
57
What benefits do residues from organic fertilizers provide (3)
1. improve soil structure 2. enhance water retention during drought 3. increase drainage in wet weather
58
Define foliar application and what benefit does it provide
plants absorbing mineral elements applied to leaves as a spray. reduce lag time between application and reuptake, important for rapid growth
59
Explain what the liquid phase of soil consists of
constitutes the soil solution held in pores between the soil particles. contains dissolved mineral ions serving as the medium for ion movement to root surface.
60
Explain what the gaseous phase of soil does
oxygen, carbon dioxide, nitrogen dissolved in the soil solution. roots exchange gases with soils through air-filled pores between soil particles
61
What does the solid phase of soil do
the inorganic particles of the solid phase provide reservoir
62
Define symbiosis in terms of mineral nutrition
some specialized microorganisms form alliances with plants for their mutual benefit for nutrients
63
soil particles have predominantly ____ charges on their surfaces
negative
64
soils are characterized by ______
particle size
65
mineral cation, such as ___ and ____ are absorbed to the ____ surface charges of soil particles. why is this cation absorption important
NH4+ and K+ negative important factor for soil fertility
66
minerals that are absorbed on the surface of soil particles provide a mineral reserve availability to the roots, how?
because they are not readily leached when soil is infiltrated by water therefore providing the reserve.
67
mineral nutrients on the soil particles can be replaced by what process
cation exchange
68
Define cation exchange capacity and what it is dependent on
degree in which soil can absorb and exchange ions dependent on soil type
69
how to mineral anions behave to the negative charge on the soil particles
they are repelled and remain dissolved in the soil solution
70
Explain phosphates affects on absorption of mineral nutrition
phosphate ions bind to soil particles and can form insoluble compounds. therefore, phosphates are tightly bound at both high and low pH which can limit plant growth. organic acids are released in large amounts to release phosphate binding to soil particles
71
What is gypsum and what are its affects
gypsum is formed by sulfate and Ca2+ (CaSO4). slightly soluble but releases sufficient amounts of calcium for plant growth.
72
why is pH an important property of soils
because affects growth of plant roots and soil microorganisms
73
what pH is root growth favoured
5.5-6.5 slightly acidic
74
soil pH determines...
availability of soil nutrients
75
What are the major factors that lower soil pH (3)
1. decomposition of organic matter (CO2 is produced and release hydrogen ions which lowers pH) 2. ammonium assimilation by plants and microbes 3. amount of rainfall
76
How can hydrogen ions affect leaching
they displace ions from surfaces of soil particles and may remove by leaching and leave more acidic soil
77
How can weathering of rock affect leaching
they release ions into the soil but because of low rainfall, ions do not leach, soil remains alkaline (basic)
78
when excess minerals are present in soil, soil is ____ which _____ plant growth
saline (salt stress) inhibit
79
why can excess minerals be a major problem is arid and semi-arid regions
because rainfall is insufficient to leach them from soil layers
80
What is another problem that can results from excess minerals in the soil
the accumulation of heavy metals which can cause severe toxicity in plants and humans
81
plants developed what 3 things to obtain nutrients from the soil
1. extensive root systems 2. form symbioses with mycorrhizal fungi 3. produce and secrete protons or organic anions into the soil
82
what does plant proliferation (rapid production of cell) depend on
availability of water and minerals in immediate environment around root (rhizosphere)
83
Define fibrous root structure
in monocots, is formed when primary roots are joined by adventitious roots
84
Define tap root system
this system forms in eudicots and secondary growth can increase the diameter of the main root
85
for species with poorly developed root hairs, what may play a significant role in uptake of nutrients
hyphae of arbuscular mycorrhizal fungi
86
nutrients move to the root surface within the soil by ____ and ____.
bulk flow (by water) and diffusion (high to low conc)
87
plant nutrient absorption becomes independent of ____, while diffusion rates limit _____
transpiration rates the movement of nutrient to root surface
88
What results when diffusion is too slow to maintain high nutrient concentrations near the root
nutrient depletion zone forms adjacent to the root surface
89
What two factors is the effectiveness of roots in mining minerals from the soil determined by
the rate at which they remove nutrients from the soils rate of root growth into un-depleted soil
90
roots sense the belowground environment through ____, ____, ____, and ___ to guide their growth toward soil resources
gravitropism, thigmotropism, chemotropism, and hydrotropism
91
What are the two main types of mycorrhizal symbioses
arbuscular mycorrhizae and ectomycorrhizae
92
mycorrhizae ____ plant root system and influence what
modify influence plant mineral acquisition
93
Define arbuscular mycorrhizal fungi and their function
they develop outside the root of their host, highly branched system of hyphae. they invade cortical cells to deliver phosphate in exchange for carbohydrates
94
how are roots colonized by ectomycorrhizal fungi clearly distinguishable
they grow slowly and appear thicker and highly branched
95
Define hartig net
hyphae surrounding cells instead of penetrating
96
what do ectomycorrhizal fungi enable host plants to do
allow host plants to access organic sources of nutrients, to avoid competition, and grow in highly organic forest soils that contain low inorganic nutrients
97
What is the function of hyphae
they extend reach of roots and facilitate acquisition of nutrients
98
arbuscular mycorrhizae vs. ectomycorrhizae is what role they play
arbuscular = increase uptake of mineral nutrients, phosphorous ectomy = obtaining nitrogen from organic sources
99
what do plants provide to the fungi
carbohydrates
100
What does the mutualist relationship between plants and fungi require (4)
1. uptake of a nutrient from the soil by the fungi 2. long-distance transport through fungal hyphae 3. release from fungus to the apoplastic zone 4. uptake by plant plasma membrane (ATP may be required)