Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

functions midterm > chapter 37: soil and plant nutrition > Flashcards

chapter 37: soil and plant nutrition Flashcards

1
Q

What is soil horizons?

A

Layers where soil is stratified.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a soil solution?

A

Water and dissolved minerals in pores between soil particles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the basic physical properties of soil?

A

Texture and composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the different soil particles from largest to smallest?

A

Sand, silt and clay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens after lots of rain?

A

Water drains from larger spaces in soil and smaller spaces retain water because of attraction to clay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are loams?

A

They are the most fertile topsoils, containing equal amounts of sand, silt, clay, bacteria, fungi, algae, protists to decompose organic materials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the different types of soils?

A
  1. Sandy soils: don’t retain enough water
  2. Clayey soils: they retain too much water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is soil composition made of?

A

inorganic (mineral) and organic chemical components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are inorganic components needed?

A

Because cations (K+, Ca2+) adhere to negatively charged soil particles, preventing leaching out of soil by prelocating groundwater.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the mechanism of cation exchange in soil?

A
  1. Roots acidify soil solution by releasing CO2 from respiration and pumping H+ in soil
  2. CO2 reacts with H2O and forms H2CO3 releasing H+
  3. H+ in soil solution neutralizes negative charge of soil particles causing release of mineral cations
  4. Roots absorb the released cations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is humus?

A

It is an organic component that builds crumbly soil that retains water but is still porous, increasing soil capacity to exchange cations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the consequences of agriculture?

A
  1. Depletes mineral content of soil
  2. Taxes water reserves
  3. Encourages erosions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the primary source of irrigation?

A

Underground water reserves called aquifers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What causes sinking of land?

A

Depletion of aquifers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is salinization?

A

Concentrations of salts in soil as water evaporates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is fertilization?

A

replaces mineral nutrients that have been lost from soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are examples of organic fertilizers?

A
  1. Nitrogen
  2. Phosphorus
  3. Potassium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are algal blooms?

A

excess minerals leached from soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does adjusting pH cause?

A

Affects cation exchange, cations are more available in slightly acidic soils (H+ ions displace cations)

20
Q

How can erosion be reduced?

A
  1. Planting trees as windbreaks
  2. Terracing hillside crops
  3. Cultivating in a contour pattern
  4. Practicing no-till agriculture
21
Q

What is phytoremediation?

A

It is biological, nondestructive technology reclaims contaminated areas,

22
Q

What contributes to plant growth?

A
  1. Water: (80-90%) plants fresh mass
  2. Inorganic substances: 4% plants dry mass
  3. CO2 assimilated into carbohydrates: 96% plants dry mass.
23
Q

What macronutrient deficiency is a plant that has chlorolysis at tips of older leaves?

A

Nitrogen - NO3- or NH4+ deficient

24
Q

What macronutrient deficiency is a plant that is developing very slowly?

A

Phosphorus - H2PO4-, HPO42- deficient

25
Q

What macronutrient deficiency is a plant that has mottling of older leaves with drying leaf edges?

A

Potassium - K+ deficient

26
Q

What macronutrient deficiency is a plant where chlorosis between veins is seen in older leaves?

A

Magnesium - Mg2+ deficient

27
Q

What macronutrient deficiency is a plant where general chlorosis happens in young leaves?

A

Sulfur - SO42- deficient

28
Q

What macronutrient deficiency is a plant where crinkling of young leaves and death of terminal buds happens?

A

Calcium - Ca2+ deficient

29
Q

What macronutrient deficiency is a plant wilting with poor growth?

A

Hydrogen - H2O deficient

30
Q

What macronutrient deficiency is a plant with poor growth?

A

Oxygen and/or Carbon - CO2 deficient

31
Q

What micronutrients are present in plants?

A
  1. Boron
  2. Chlorine
  3. Manganese
  4. Iron
  5. Nickel
  6. Copper
  7. Zinc
  8. Molybdenum
32
Q

What is the role of micronutrients?

A

They function as cofactors, nonprotein helpers in enzymatic reactions.

33
Q

What is a research method done to know which chemical elements are essential to plants?

A

Hydroponic cultures

34
Q

Why is aluminum toxic?

A

It damages roots and reduces crop yield

35
Q

What are smart plants?

A

They are plants that warn farmer of nutrient deficiency.

36
Q

What type of relationship do plants and microbes have and why?

A

They have a mutualistic relationship
Dead plants provide energy needed bu soil-dwelling microorganisms. The secretions from living roots of sugars, amino acids support many microbes in near-root environment.

37
Q

What is the rhizosphere?

A

Layer of soil closely surrounding plant roots where rhizobacteria thrive.

38
Q

What are endophytes?

A

Nonpathogenic bacteria that live between cells of host plant tissues.

39
Q

How do rhizobacteria and endophytes help plants?

A
  1. produce chemicals (this stimulates plant growth)
  2. produce antibiotics (protects roots from diseases)
  3. absorbs toxins like metals
  4. Increases nutrients
40
Q

How is the nitrogen cycle involved in plants?

A

The Atmosphere releases fixed nitrogen (N2) where 2 things can happen:

  1. nitrogen fixing bacteria convert it to NH3 (ammonia) and then H+ from soil makes NH4 (ammonium)
    Nitrifying bacteria can then convert to NO2 (nitrite) and then NO3 (nitrate)
  2. denitrifying bacteria convert N2 to NO3 (nitrate)

Plants absorb only NO3 and NH4 .

41
Q

What are nodules?

A

They are composed of plant cells “infected” by nitrogen fixing Rhizobium

42
Q

Why is crop rotation important?

A

Agricultural benefits of symbiotic nitrogen fixation.

43
Q

What is mycorrhizae?

A

A mutualistic association of fungi and roots.

44
Q

What are the advantages of the different parties in mycorrhizae?

A
  • The fungus gets suger
  • The host plant; because fungus increases surface are for water uptake, gets more mineral absorption
  • mycorrhizal fungi secretes growth factors that stimulate root growth and branching.
45
Q

What are 3 unusual adaptations of nonmutualistic ways?

A
  1. epiphytes: grow on other plants, getting water and minerals from rain
  2. parasitic plants: absorbs sugars and minerals from living host plant
  3. carnivorous plants: photosynthetic but obtain nitrogen by killing / digesting insects.

functions midterm (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions