Plant Nutrition Flashcards
(32 cards)
This process replaces mineral nutrients that have been lost from the soil.
Fertilization
How much of a plant’s mass is composed of water?
80-90%
How much of a plant’s dry mass is composed of inorganic vs. carbon dioxide converted into sugars
4% inorganic
96% co2 converted to sugars via photosynthesis
How many chemical elements have been discovered in the inorganic nutrients in plants? How many are essential nutrients?
50 overall
17 essential
What are the 9 macronutrients? Why are they called macronutrients?
carbon, oxygen, hydrogen, nitrogen, phosphorus, sulphur, potassium, calcium, magnesium
called macro bc the plants need them in large quantities
Which 3 macronutrients are the most abundant? Why?
Carbon, oxygen, hydrogen.
b/c they make up the backbone of sugars
What are the 8 micronutrients? Why are they micronutrients?
chlorine, iron, nickel, manganese, boron, zinc, copper, molybdenum.
micro bc plants need them in relatively small quantities
what is the largest contributor to phosphate runoff in manitoba?
the city of winnipeg
what type of ions can be lost from soil by leaching? why?
ones that are negatively charged, as they will not bind to the negatively charged soil
describe the cation exchange in soil.
- roots acidify soil by releasing CO2 and H+ ions.
- CO2 reacts with H2O to produce H2CO3, releasing H+ upon dissociation
- H+ ions neutralize negative charge of the soil, causing the mineral cations to be released into soil solution.
- roots absorb the released minerals
what does a mobile nutrient deficiency affect?
the older parts of a plant more than the young ones
what are the mobile nutrients?
nitrogen, phosphorus, potassium, magnesium, chlorine, zinc, molybdenum
what does a less mobile nutrient deficiency affect?
the younger parts of a plant more than the older ones.
what are the less mobile nutrients?
calcium, sulphur, iron, boron, copper
why do plants turn yellow when they have a nutrient deficiency?
because of the breakdown of chloroplasts
what does a phosphate deficiency look like?
reddish purple on the edges of the leaves
what does a potassium deficiency look like?
drying on tips and edges of leaves
what does a nitrogen deficiency look like?
yellowing that starts at tip and moves down middle of the leaf.
what does a magnesium deficiency look like?
whitish appearance of veins, with purple colour on underside of lower leaves
what is the layer of soil surrounding a plant’s roots called?
rhizosphere
what lives in rhizosphere?
free living rhizo-bacteria
describe the relationship between plants and rhizobacteria.
rhizobacteria depend on nutrients secreted by plants and in turn, help enhance plant growth by producing antibiotics and chemicals.
how do bacteria play a role in the nitrogen cycle?
bacteria can transform atmospheric nitrogen into NO3- or NH4+, the only forms that plants can absorb nitrogen as.
describe how nitrogen fixing bacteria form swellings along a legume’s roots, and how that is beneficial.
there are swellings called nodules along the legume’s roots that are inhabited by nitrogen fixing bacteria that take on a form called bacteriods.
the plant will send signal to bacteria which takes that as a sign to start forming nodules. the plant will then give the bacteria carbon in exchange for nitrogen.
