Lecture 21 Flashcards Preview

Plant Science > Lecture 21 > Flashcards

Flashcards in Lecture 21 Deck (22):
1

what is the definition of plant nutrition

uptake from environment of all required raw material, distribution of materials within the plant, use of materials in metabolism and growth

2

what makes an element essential

needed for plant to complete its life cycle, part of any molecule/constituent that is essential to plant, deficiency symptoms appear if element is absent

3

what are the many roles of essential elements

structural, enzymatic, regulatory, and ionic

4

what are some nutrient deficiency symptoms

most associated with shoot, necrosis, chlorosis, phloem-mobile elements

5

what is necrosis

localized tissue death

6

what is chlorosis

loss or reduced chlorophyll

7

what is phloem-mobile elements

(Mg, P, K, N) show up in old leaves vs. immobile elements (Fe and Ca) show up in new leaves

8

what does the soil provide the plant with

support, inorganic nutrients, water, suitable gaseous environment for roots

9

what are the soil horizons

A horizon (topsoil), B horizon, C horizon, and bedrock

10

what are soil horizons

vary by amount of living and dead organic matter, and porosity, structure, and the extent of weather of bedrock

11

what is water potential

measured as pressure units in soil, plant, and air; indication of amount of water held in soil; below minimum threshold, plant will wilt

12

what are nutrient cycles

biogeochemical cycles; 17 essential elements for plants; dependent on recycling of nutrients; may be global or localized

13

what are the three main processes of nutrient cycling

ammonification, nitrification, assimilation

14

what is ammonification

plants can take up ammonium

15

what is nitrification

plants take up nitrate

16

what are some losses of nitrogen from soil

harvest and removal of plants, soil erosion, burning plants, leaching

17

why is nitrogen fixation important

all living organisms depend on this process, just as they depend on photosynthesis for their energy

18

what is assimilation

evidence that many plants take up organic compounds directly

19

what are two things that impact the nutrient cycles and effects pollution

human population growth and acid rain

20

why is plant nutrition research important

to overcome soil deficiencies and toxicities

21

how is plant nutrition research being done

select and develop varieties of plants rather than amending soil; phytoremediation; manipulate biological N fixation

22

what is the phosphorus cycle

in the curst, localized cycling, amount of P required by plants small compared with N, P has low solubility and mobility, is often the limiting nutrient