Soil, Plant Nutrition & Roots
description
Transcript of Soil, Plant Nutrition & Roots
![Page 1: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/1.jpg)
Soil, Plant Nutrition & RootsChapters 29, 30,
24
![Page 2: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/2.jpg)
Exam 1 Avg = 86.4%
![Page 3: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/3.jpg)
Soils and Plant Nutrition• Plants require nutrients from soil• In eastern US, 200 yr to form 2 cm
topsoil (even slower in western where arid)
• What is soil? • A mixture of:
• Mineral particles (sand, silt, clay)• Decomposing organic matter (humus)• Air• Water• Living Organisms humus
![Page 4: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/4.jpg)
Mineral Particles• Sand 0.05-2.0 mm• Silt 0.002-0.05 mm• Clay < 0.002 mm• Clay soils
• soil water holding capacity, but all water not available for plants
• infiltration rates so runoff• Loamy soils
• even mixture of particle sizes
• best for agricultural
siltsand
clay
![Page 5: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/5.jpg)
Many soils in southeastern Nebraska were formed in parent materials deposited by the glaciers, usually referred to as glacial drift, glacial till or glacial outwash.
Much of the parent material deposited in ancient times has been covered by windblown material. The windblown silty material is called loess. It covers most of Nebraska to varying depths, except in the Sandhills and western portions of the Panhandle.
![Page 6: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/6.jpg)
Where does soil come from?
• Weathering of parent material (bedrock)
• Soil horizons• O horizon
• organic, few cm thick• humus – organic decay products• contained within A horizon in
some classifications• A horizon
• topsoil, 10-30cm thick• greatest physical, chemical, and
biological activity• B horizon
• subsoil, larger particles, 30-60cm
• leaching from A horizon by water percolation
• iron oxide, clay particles, little organic material
• mixed with A horizon when plowed
• C horizon• soil base• partially weathered parent
material, 90-120 cm
![Page 7: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/7.jpg)
Soil Forming Factors• Parent material• Climate• Living organisms• Topography• Time
Extent of North American glaciation
![Page 8: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/8.jpg)
2008 Iowa Floods
June 2008 Rainfallhttp://www.srh.noaa.gov
Cedar Rapids Iowahttp://www.treehugger.com
Soil erosion20 tons/acre40,000lbs/acreSome farms in Iowa have no topsoil remaining(Mary Skopec, Iowa DNR)
![Page 9: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/9.jpg)
Essential Elements for Plants
Macronutrients (9)• required in greater amounts• What do these macronutrients do?
C, H, O - basic organic constituentsN, K, Ca, P - oh my gosh, some very essential
organics: amino acids, nucleotides, ATP, NADPH, cell wall, regulatory, osmoregulation
Mg, S - chlorophyll, electron transport chain, amino acids
chlorophyll
Required for normal growth & reproductionNo other element can replaceDirect or indirect action in plant metabolism
![Page 10: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/10.jpg)
Magnesium deficiency Iron deficiency
Chlorosis
![Page 11: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/11.jpg)
amine group
![Page 12: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/12.jpg)
![Page 13: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/13.jpg)
![Page 14: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/14.jpg)
![Page 15: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/15.jpg)
![Page 16: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/16.jpg)
Essential Elements (continued)
Micronutrients (8)• required in lesser quantities
Fe, Mn, Cu, Zn, B, Mo, Cl, Ni• What do these micronutrients do?
essential for enzyme function, organ and organelle function, photosynthesis
Manganese: involved in photosynthetic reaction in which oxygen is produced from waterCopper: associated with enzymes involved in redox reactionsIron: component of enzymes involved in the transfer of electronsEtc…..
![Page 17: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/17.jpg)
Plant Growth Medium for fern gametophytes (C-fern)
• MacronutrientsNH4NO3, KH2PO4, MgSO4, CaCl2
• MicronutrientsMnSO4, CuSO4, ZnSO4, H3BO3, (NH4)6Mo7O24, FeSO4
![Page 18: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/18.jpg)
Nickel
![Page 19: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/19.jpg)
Roots
• Roots are 50-80% of plant biomass in prairie
• Plants “forage” for dilute nutrients in environment
![Page 20: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/20.jpg)
Root functions
• Anchor plant into ground• Storage of energy reserves• Absorption of water and dissolved
minerals from soil• Conduction of water and dissolved
nutrients to shoot
![Page 21: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/21.jpg)
Taproot System
• First root formed is the radicle
• In dicots, radicle grows into taproot
• Branch roots grow from taproot
![Page 22: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/22.jpg)
Fibrous Root System
• Mostly in monocots• Extensive mass of
similarly sized roots• Radicle short-lived,
replaced by adventitious root system• adventitious means
not belonging to• roots growing from
stem
![Page 23: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/23.jpg)
Root Structure• Root cap
• protection from desiccation, lubrication, water and nutrient absorption
• Zone of Cellular Division • densely packed cells
undergoing mitosis• Zone of Elongation
• growing cells• Zone of Maturation
• differentiating cells
![Page 24: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/24.jpg)
![Page 25: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/25.jpg)
Epidermis: • one cell thick, usually no
cuticle; absorbs waterCortex:
• just interior to epidermis, waxy protective layer
• parenchyma tissue: most of cortex, often contains starch
• endodermis: tightly packed cells with casparian strip
Stele: • tissue inside cortex• pericycle: interior to
endodermis - a meristem for branch roots
• vascular bundle: xylem as a cross with phloem in armpits
Monocot Root
Dicot Root
![Page 26: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/26.jpg)
![Page 27: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/27.jpg)
Dicot - young stele
Dicot - mid-aged stele
Dicot - old stele
Endodermis change through aging
![Page 28: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/28.jpg)
Casparian Strip
• integral band-like portion of primary wall and middle lamella in endodermal cells
• lignin and suberin “valve”
• regulates water because water • must move
symplastically through the endodermal cells
• through plasmdesmata between cells
• rather than apoplastically
• through intercellular spaces
![Page 29: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/29.jpg)
Casparian Strip
![Page 30: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/30.jpg)
![Page 31: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/31.jpg)
Root hairs
![Page 32: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/32.jpg)
due to molecular structure
OH H
-
++
a polar molecule - excellent solvent
adhesion
hydrogen bondingbetween water molecules
between water and other molecules
cohesion
O
HH
-
++
OH
H
-
++
OH
H
-
++
tensile strength
capillarity - from cohesion and adhesion
Unique Properties of Water
![Page 33: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/33.jpg)
![Page 34: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/34.jpg)
![Page 35: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/35.jpg)
Leaf Anatomy
H2O
![Page 36: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/36.jpg)
• 85-95% of plants is water
• 95% of H20 taken up by plant transpired back into atmosphere
![Page 37: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/37.jpg)
cohesion and adhesion cause water to rise in plants
as water evaporates from the leaf surface,
a column of water
is pulled upward from the soil water
Cohesion-tension theory
![Page 38: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/38.jpg)
![Page 39: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/39.jpg)
vessel elementstracheid
![Page 40: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/40.jpg)
Size comparison of xylem elements
Note distribution of pits in walls of all xylem elements (tracheids and vessels)
![Page 41: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/41.jpg)
pits
perforation plate (end walls)
![Page 42: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/42.jpg)
Problems with water movement
• air bubbles• cavitation
• water column rupture
• embolism• filling with air or
water vapor• solution
• move water around embolism
![Page 43: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/43.jpg)
Is there a limit to water column?
• How tall are the tallest trees?
• What are the tallest trees?
![Page 44: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/44.jpg)
Tallest Tree• Coast Redwood
• Sequoia sempervirens
• Redwood National Park California
• Height = 116m (379.1 feet) named Hyperion; Steve Sillett, Humboldt State U.
• Estimated Age = 2,000+ yrs
Save the Redwoods League
![Page 45: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/45.jpg)
Giant Redwood -Sequoiadendron giganteum
• Top: lithograph showing a party of 32 people dancing on the stump of the Discovery Tree, North Calaveras Grove
• Bottom: 30-foot section of the General Noble Tree, which was displayed at the Columbian Exposition in Chicago in 1893 and later at the Mall in Washington, DC; it was subsequently taken to the US government's Arlington Experiment Farm, where it was "misplaced"
http://en.wikipedia.org/wiki/Image:Giant_sequoia_exhibitionism.jpg
![Page 46: Soil, Plant Nutrition & Roots](https://reader035.fdocuments.in/reader035/viewer/2022081505/56816696550346895dda7c52/html5/thumbnails/46.jpg)
Transpiration and Productivity
• Leaves adapted for photosynthesis• abundant stomata• large number vein endings
• Tradeoff • CO2 in - photosynthesis • H2O out - transpiration
• H2O limits biomass production in most areas
• Evapotranspiration• transpiration & soil
evaporation• problematic in arid areas