Chapter 29 Plant Nutrition and Soil
• Sun, Water, Nutrients necessary
• CO2 and H20 into organic
compounds
• Synthesize all required amino acids,
vitamins, using inorganic nutrients
from environment.
• Evolution designed for efficient
uptake of raw material and
distribution
Plant Nutrition and soil
• Essential Elements
• Functions of
Essential Elements
• The soil
• Nutrient cycles
• Nitrogen and
Nitrogen cycle
• The Phosphorus
Cycle
Nitrogen cycle
Plant Nutrition and Soils
Plant Nutrition- involves the uptake from the
envrionment of all the raw material required for
1. Essential biochemical processes (metabolism and
growth)
2. Distribution within the plant
More than 60 chemical elements identified
Not all essential (gold, silver, lead, mercury, arsenic,
uranium)
Phytoremediation- the removal of contaminants
The fungus Boletus parasiticus
Forms Ectomycorrhizae on the
Roots of a red pine (Pinus resinosa)
Increase uptake of water and
Phophorus
Also Protects against pathogenic
Fungi and nematodes
Essential Elements
Criteria
• Needed for life
cycle
and/or
• Essential for parts
i.e. Mg in chlorophyll
Nitrogen in protein
• 17 essential
Essential elements
• Necessary for plant growth
• In the absence plant displayed characteristic abnormalities
of growth, or deficiency symptoms, reproduction
• In 1880 established that at least 10 essential
• Essential elements/minerals (inorganic nutrients)- Carbon,
hydrogen, oxygen, potassium, calcium, magnesium,
nitrogen , phosphorus, sulfur and iron
• By the 1950’s added seven more, manganese, zinc, copper,
chlorine, boron, molybdenum, and nickel
The essential elements can be divided
into Micronutrients and Macronutrients
• Micronutrients- trace elements equal or less than
100 mg/kg
• Macronutrients – require large amounts above 100
mg/kg
• Nutrient sometimes greater in conc. Than soil thus
have to use energy
• Certain plant species are chars. By specific
elements
Plants of the
mustard
family i.e.
Wintercress
use sulfur
Synth.
Mustard oil
Horsetail silicon into cell walls
Making it indigestible for herbivores
Functions of Essential Elements
• Essential elements: Functions and
Defieciency symptoms Table 29-2
Nutrient Deficiency symptoms Depend on
functions and mobility of essential elements
• Chlorosis Fig. 29-3- loss or reduced development
of chlorophyll
• Magnesium, essential for chlorophyll
– Younger leaves vs. older leaves
– Depends on phloem
– Phosphorus, potassium and nitrogen are also phloemmobile (appear in older first)
– Iron and calcium are phloem immobile (appear in
younger first)
– Sulfur and zinc intermediate in mobility
Deficiency of magnesisum a phloem mobile element in
Maise- older leaves more affected than younger
Sorghum - Deficiency of iron a so
called phloem immobile element
results in symptoms of chlorosis in
younger leaves
The soil
• Primary nutrient
medium for plants
• Root systems
(fibrous anchor)
• Weathering of rock
produce the
inorganic nutrients
Fibrous roots that bind and
anchor prairie soil
Three major soil types
• Coniferous- acidic little accumulation of
humus is leached of minerals
• Cool temperate deciduous decay is more
rapid, leaching less, soil more fertile
• Grasslands, almost all plant dies each year
organic material returned to soil- highly
fertile soil, often black in color
Soil consist of layers called Horizons
Living organisms of
the A horizon
Microbes, small mammals, earthworms
Ants