Crss 4590 - Exam 3

P uptake

hats and lats, taken up as Pi

P transport

xylem or phloem, easily tanslocated

P functions

ATP, phospholipids and enzyme production

P storage

kept in cytoplasm as Pi, phytic acid, or polyphosphate

P deficiency

purpling

P toxicity

uncommon

K uptake

through K+ channels by way of electrochemical gradient

K transport

xylem, phloem mobile, easily translocated

K function

opening. and closing of stomata, enzyme production

K storage

in vacuole

K deficiency

stunted growth

K toxicity

uncommon

S uptake

taken in as SO4-2

S transport

cotransported with 3H+

S functions

stinky oils to stop predation

S storage

in vacuole

S deficiency

young leaf chlorosis

S toxicity

localized, mostly from atmospheric S

Ca uptake

Ca++, taken up in root tips

Ca transport

in xylem, not phloem mobile!

calluose

Ca is immobile in phloem. if present it can clog sieve plates

this can also be used as a scab if some plates are fucked up

Mg uptake

competes with K, inefficient

Mg transport

phloem mobile when carried with H+ antiporter

Mg function

central atom for chlorophyll and rubisco

Mg storage

stored as phytate

Mg deficiency

older leaves, interveinal chlorosis

Fe uptake (3 strategies)

strategy 1 non-grasses:

Plant releases H+, making Fe3 soluble. Fe3 is assimilated into Fe2, which is then taken into cells via iron transporter

strategy 2 grasses:

plant releases PS. PS binds to Fe3, creating PS-Fe3 which is then brought into the plant by YS1

Strategy 3 rice:

can do a combination of 1 or 2 because they grow in waterlogged soil

Fe functions

respiration and photosynthesis

Fe storage

chloroplast

Fe deficinecy

whitening of leaves

Fe toxicity

bronze speckles

Mn functions

release of O in photosynthesis

Mn deficiency

decreased photosynthesis

Mn toxicity

stunted leaf growth

Zn uptake

non-specific ion transporters

Zn transport

through xylem as Zn3+

Zn function

catalytic component of 300+ enzymesZ

Zn deficiency

short internodes

Zn toxicity

reduced root and shoot growth

Cu uptake and transport

taken up and transported with amino acids

Cu deficiency

reduced photosynthesis

Cu toxicity

root spinout

Ni uptake

competes with other metals

Ni function

cofactor for urea synthesis

Ni deficiency

mouse ear disorder

B movement

immobile unless bound to sorbitol

B function

pollen, new cell synthesis

B deficiency

misshapen leaves

B toxicity

very easy to reach toxicity if treating deficiency, basically no luxury consumption

S cycle (2)

available in terrestrial or atmospheric

terrestrial can be leached, must be mineralized and converted to sulfate to be taken up by the plant

S in soils

.06-10%, 95% in OM where plants can take up mineral form but organic S is acififying

S movement through soil

diffusion if just a lil small, mass flow if higher quantity is present

Adsorbed S

Al and Fe oxides

self-liming reaction of gypsum

OH is released, sulfate takes its place, the unsatisfied negative charge from this reaction generates CEC and raises pH, gypsum moves deeper into the soil profile

reduction of inorganic sulfur

sulfite ←→ sulfur ←→ sulfate

S mineralization

C:S ratio <200 immobilization, >400 mineralization

S volatilization

SO4 released into the atmosphere is converted to SO4-2 and is brought back into the soil

two options for synthetic S fertilizers

gypsum: non-acidifying

aluminum sulfate: acidifying

Ca in soils

.7-1.5%, taken up and leached as Ca+2

mineral forms of Ca

gypsum and calcite

soil solution Ca movement

moves by mass flow

Ca % saturation on CEC

60-80%, kicked off by Al at low pH

Ca fertilizers

gypsum, raises pH

triple superphosphate, no affect on pH

Mg in soils

.7-1.5%, taken up and leached as Mg+2

mineral forms of Mg

serpentine and biotite

soil solution Mg movement

mass flow

Mg % saturation of CEC

5-40%, kicked off by Al at low pH

Mg fertilizers

dolomite, raises pH

So-Pho-Mag, no affect on pH

Fe, Zn, Cu, Mn availability in soil

more available in lower pH

Fe chelates, what contains chelates

increase solubility and transport of Fe

found in manure, synthetic form available

how to increase soil Zn and what restricts it

broiler litter increases, P restricts availablity

Zn deficiencies

Turkey, India, sub-saharan Africa, biggest nutrient issue, leads to 800,000 deaths

Zn production

20 years in reserves, 85% imported

Cu deficiencies

neutral and calcareous soils, strong Fe and Al adsorption

Cu production

40 years in reserves, 35% imported

Mn deficiencies

neutral and calcarous soils

Mn production

42 years in reserves, 100% imported

B deficiencies

neutral and calcarous soils, increased by high K fertilizers

B organic source

mineralization of OM

B production

100 years in reserves, net exporter

Cl deficiencies

low water-extractable soil Cl-

Cl fertilizers

Al chloride

Mo availability

in high pH (anion!)

Mo deficiencies

adsorbed by Al and Fe oxides

Mo fertilizers

ammonium molybdate → soil, seed, or foliar application

Mo production

58 years in reserves, U.S. net exporter

Ni adsorption

Ni+2

Ni production

37 years in reserves, 60% imported

Beneficial elements

cobalt: N-fixing microorganisms

sodium: turgor and growth

silicon: structure of cell walls