Transcript 6.9 Macronutrients and Micronutrients in Plants

Macronutrients and
Micronutrients in Plants
Zivuku . M
Objectives
• List the macro and micronutrients in plants.
• Explain the fundamental underlying nutrients
requirements in plants.
• Discuss the roles of major and micronutrients
in plants.
• Outline the consequences of inadequate
supply of some nutrients in plants.
Classification of the Essential
Nutrients for Plant Growth
Macronutrients
C, H, O from air and water
N, P, K, Ca, Mg, S from soil
Primary Secondary
Micronutrients
Fe, B, Mn, Cu, Zn, Mo, Cl, Ni from soil
Essential Major Elements – Plants/Animals
• Major Plant Nutrients
Major Animal Nutrients
•
•
•
•
•
•
•
•
•
•
•
•
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Sulfur (S)
Calcium (Ca)
Phosphorus (P)
Potassium (K)
Magnesium (Mg)
Sodium (Na)
Chlorine (Cl)
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Essential Trace Elements – Plants/Animals*
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Trace Plant Nutrients
Boron (B)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Chlorine (Cl)
Nickel (Ni)
Essential for Some Plants
Cobalt (Co)
Silicon (Si)
Sodium (Na)
Vanadium (V)
Trace Animal Nutrients
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Arsenic (As)
Chromium (Cr)
Cobalt (Co)
Flourine (F)
Iodine (I)
Nickel (Ni)
Selenium (Se)
Silicon (Si)
Tin (Sn)
Vanadium (V)
* Plants will not only absorb essential plant and animal elements, but many
non-essential elements found in soils are also found in plant tissue ash.
Nutrient Levels in Plants
• Terms used to describe nutrient levels in plants:
• Deficient – when the concentration of an essential element is low
enough to severely limit yield
• Critical range – nutrient concentration in plant below which a yield
response occurs when the essential nutrient is added
• Sufficient (optimal) – nutrient concentration range when the yield
will not increase when more of the essential nutrient is added, but
plant tissue concentration can increase
• Excessive (toxic) – when the concentration of an essential, or nonessential, element is high enough to reduce plant growth and yield
(a)
(b)
Figure 2.5. Typical dose-response curves for (a) essential elements (macronutrients & micronutrients)
and (b) non-essential elements. (Alloway,1995, p. 31)
Macronutrients
Elements
Functions
Deficiency Symptom
Potassium
(K)
•Potassium is absorbed by plants in larger
amounts than any other mineral element
except nitrogen and, in some cases, calcium.
•Helps in the building of protein,
photosynthesis, fruit quality and reduction of
diseases.
•Potassium is supplied to plants by soil
minerals, organic materials, and fertilizer.
Older leaves may wilt, look
scorched.
Interveinal
chlorosis begins at the base,
scorching inward from leaf
margins.
Elements
Functions
Deficiency Symptom
Calcium
(Ca)
•Calcium, an essential part of plant cell wall
structure, provides for normal transport and
retention of other elements as well as strength
in the plant. It is also thought to counteract the
effect of alkali salts and organic acids within a
plant.
•Sources of calcium are dolomitic lime,
gypsum, and superphosphate.
•New leaves (top of plant)
are distorted or irregularly
shaped. Causes blossom-end
rot.
Elements
Functions
Magnesium •Magnesium is part of the chlorophyll in all
(Mg)
green plants and essential for photosynthesis.
It also helps activate many plant enzymes
needed for growth.
•Soil minerals, organic material, fertilizers,
and dolomitic limestone are sources of
magnesium for plants.
Deficiency Symptom
•Older leaves turn yellow at
edge leaving a green
arrowhead shape in the
center of the leaf.
Elements
Functions
Deficiency Symptom
Nitrogen
(N)
• Nitrogen is a part of all living cells and is a
necessary part of all proteins, enzymes and
metabolic processes involved in the synthesis
and transfer of energy.
• Nitrogen is a part of chlorophyll, the green
pigment of the plant that is responsible for
photosynthesis.
• Helps plants with rapid growth, increasing
seed and fruit production and improving the
quality of leaf and forage crops.
• Nitrogen often comes from fertilizer
application and from the air (legumes get their
N from the atmosphere, water or rainfall
contributes very little nitrogen)
•General yellowing of older
leaves (bottom of plant).
•The rest of the plant is often
light green.
Elements
Functions
Deficiency Symptom
Phosphorus
(P)
•Like nitrogen, phosphorus (P) is an essential
part of the process of photosynthesis.
•Involved in the formation of all oils, sugars,
starches, etc.
•Helps with the transformation of solar
energy into chemical energy; proper plant
maturation; withstanding stress.
•Effects rapid growth.
•Encourages blooming and root growth.
•Phosphorus often comes from fertilizer,
bone meal, and superphosphate
•Leaf tips look burnt,
followed by older leaves
turning a dark green or
reddish-purple.
Elements
Functions
Deficiency Symptom
Sulphur (S) •Essential plant food for production of protein. Younger leaves turn yellow
•Promotes activity and development of first, sometimes followed by
enzymes and vitamins.
older leaves.
•Helps in chlorophyll formation.
•Improves root growth and seed production.
•Helps with vigorous plant growth and
resistance to cold.
•Sulfur may be supplied to the soil from
rainwater. It is also added in some fertilizers
as an impurity, especially the lower grade
fertilizers. The use of gypsum also increases
soil sulfur levels.
Micronutrients
Elements
Functions
Deficiency Symptom
Copper
(Cu)
•Important for reproductive growth.
•Aids in root metabolism and helps in the
utilization of proteins.
•Leaves are dark green,
plant is stunted.
Elements
Functions
Deficiency Symptom
Iron (Fe)
•Essential for formation of chlorophyll.
Yellowing occurs between
•Sources of iron are the soil, iron sulfate, iron the veins of young leaves.
chelate.
Elements
Functions
Deficiency Symptom
•Manganese
(Mn)
•Functions with enzyme systems involved in
breakdown of carbohydrates, and nitrogen
metabolism.
•Soil is a source of manganese.
•Yellowing occurs between
the veins of young leaves.
Pattern is not as distinct as
with iron. Palm fronds are
stunted and deformed, called
"frizzle top.“ Reduction in
size of plant parts (leaves,
shoots, fruit) generally. Dead
spots or patches.
Elements
Functions
Deficiency Symptom
Molybdenu
m (Mo)
•Helps in the use of nitrogen
•Soil is a source of molybdenum.
•General yellowing of older
leaves (bottom of plant). The
rest of the plant is often light
green.
Elements
Functions
Deficiency Symptom
Zinc (Zn)
•Essential for the transformation of
carbohydrates.
•Regulates consumption of sugars.
•Part of the enzyme systems which regulate
plant growth.
•Sources of zinc are soil, zinc oxide, zinc
sulfate, zinc chelate.
•Terminal leaves may be
rosetted, and yellowing
occurs between the veins of
the new leaves.
Elements
Functions
Deficiency Symptom
Boron (B)
•Helps in the use of nutrients and regulates Terminal buds die
other nutrients.
•Aids production of sugar and carbohydrates.
•Essential for seed and fruit development.
•Sources of boron are organic matter and
borax
Objectives
• Know the definition of element, compound,
macronutrient and micronutrient.
• Know the 16 essential nutrient elements.
• Learn how to use the "Key to Nutrient
Disorders ".
Important Definitions
• An element is a pure chemical that contains
only one type of atom.
• A compound is a molecule that contains one
or more elements.
Essential Elements
• The 16 elements required by plants are obtained from
the soil, water and air.
• Thirteen of these elements must be supplied by the soil.
• Six of the soil elements required by plants are needed in
relatively large amounts and are usually added to the soil
through fertilizer or lime. These are called
macronutrients.
• The remaining 7 elements supplied by soil are required in
very small amounts and are termed micronutrients.
Macronutrients
• Macronutrients are
needed in relatively
large amounts by
plants.
Element
Oxygen
Hydrogen
Carbon
Nitrogen
Phosphorus
Sulfur
Potassium
Calcium
Magnesium
Symbol
O
H
C
N
P
S
K
Ca
Mg
Source
Air/Water
Air/Water
Air/Water
Soil
Soil
Soil
Soil
Soil
Soil
Macronutrients – Form Used By Plants
Nutrient
Carbon
Oxygen
Hydrogen
Nitrogen
Phosphorus
Potassium
Calcium
Magnesium
Sulfur
Form Used
CO2
Charge on the
H2O
molecule
H2O
NO3-, NH4+
H2PO4 & HPO42K+
Ca2+
Mg2+
SO4-
Micronutrients
• Macronutrients are
needed in relatively
small amounts by
plants.
• They are usually
supplied by
fertilizers.
Element
Iron
Manganese
Boron
Molybdenum
Copper
Zinc
Chlorine
Symbol
Fe
Mn
B
Mo
Cu
Zn
Cl
Source
Soil
Soil
Soil
Soil
Soil
Soil
Soil
Micronutrients – Form Used By Plants
Nutrient
Iron
Manganese
Boron
Molybdenum
Copper
Zinc
Chlorine
Form Used
Fe2+
Mn2+
H2B03MoO42Cu2+
Zn2+
Cl-
Charge on the
molecule
Nutrient Deficiency Symptoms
• Nutrient deficiency symptoms usually appear
on the plant when one or more nutrients are
in short supply.
• In many cases, deficiency may occur because
an added nutrient is not in the form the plant
can use.
• Deficiency symptoms for specific elements are
included on the "Key to Nutrient Disorders".
Nutrient Deficiencies
• Every soil is not susceptible to the same
nutrient deficiencies.
• For example, coarse-textured soils low in
organic matter are susceptible to sulfur
deficiencies whereas sulfur is usually in
adequate supply in clayey soils or soils high in
organic matter.
Macronutrient Deficiencies & Soils
Element
Soil Factor Causing Deficiency
N&K
Excessive leaching on coarse-textured low organic matter soils
P
Acid low organic matter soils
Cold wet soils such as occurs during early spring
Newly cleared soils
S
Excessive leaching on coarse-textured low organic matter soils
in areas where air pollution is low (minimal levels of SO2 in the
air)
Ca & Mg
Excessive leaching on coarse-textured low organic matter soils
Soils where large amounts of K have been applied
Micronutrient Deficiencies & Soils
Element
Soil Factor Causing Deficiency
Fe
Poorly drained soils, Low organic matter soils, pH>7.0, Soils
high in P
Zn
Cold wet soils low in organic matter and highly leached, High
pH soils (pH>7.0), Soils high in P, Exposed subsoils
Cu
Peat and muck soils, High pH, sandy soils, Soils heavily
fertilized with N
B
Excessive leaching on coarse-textured low organic matter soils,
Soils with pH>7.0
Mn
Excessive leaching on coarse-textured low organic matter soils,
Soil with pH>6.5
Mo
Soils high in Fe oxides, high adsorption of molybdenum, Soil
cropped for a long time
Deficiency Symptoms - N
• General chlorosis.
• Chlorosis progresses from
light green to yellow.
• Entire plant becomes
yellow under prolonged
stress.
• Growth is immediately
restricted and plants soon
become spindly and drop
older leaves.
http://plantsci.sdstate.edu/woodardh/soilfert/Nutrient_Defici
ency_Pages/soy_def/SOY-N1.JPG
Deficiency Symptoms - P
• Leaves appear dull, dark
green, blue green, or redpurple, especially on the
underside, and especially
at the midrib and vein.
• Petioles may also exhibit
purpling. Restriction in
growth may be noticed.
http://www-unix.oit.umass.edu/~psoil120/images/tomatox2.jpg
http://www.ext.vt.edu/news/periodicals/viti
culture/04octobernovember/photo3.jpg
Deficiency Symptoms - K
• Leaf margins tanned,
scorched, or have necrotic
spots (may be small black
spots which later coalesce).
• Margins become brown and
cup downward.
• Growth is restricted and die
back may occur.
• Mild symptoms appear first
on recently matured leaves.
http://www.ipm.iastate.edu/ipm/icm/files/images/antonio004f.jpg
Deficiency Symptoms - Ca
• Growing points usually
damaged or dead (die
back).
• Margins of leaves
developing from the
growing point are first to
turn brown.
http://hubcap.clemson.edu/~blpprt/acid_photos/BlossomEn
dRot.JPG
Deficiency Symptoms - Mg
• Marginal chlorosis or chlorotic
blotches which later merge.
• Leaves show yellow chlorotic
interveinal tissue on some
species, reddish purple
progressing to necrosis on
others.
• Younger leaves affected with
continued stress.
• Chlorotic areas may become
necrotic, brittle, and curl
upward.
• Symptoms usually occur late in
the growing season.
http://quorumsensing.ifas.ufl.edu/HCS200/images/deficiencie
s/-Mgcq.jpg
Deficiency Symptoms - S
• Leaves uniformly light green, followed by yellowing
and poor spindly growth.
• Uniform chlorosis does not occur
http://www.ces.ncsu.edu/plymouth/cropsci/grap
hics/sulfur2.jpg
http://www.ag.ndsu.nodak.edu/aginfo/entomolo
gy/ndsucpr/Years/2007/june/7/soils.jpg
Deficiency Symptoms - Cu
• Leaves wilt, become
chlorotic, then necrotic.
• Wilting and necrosis are
not dominant symptoms.
http://images.google.com/url?q=http://ipm.ncsu.edu/Scoutin
g_Small_Grains/Grain_images/fig4.jpg&usg=AFQjCNE2vzRwrq
p65VR_xKRlo2LQOgWI3g
Deficiency Symptoms - Fe
• Distinct yellow or white
areas appear between
veins, and veins
eventually become
chlorotic.
• Symptoms are rare on
mature leaves.
http://bexartx.tamu.edu/HomeHort/F1Column/2003Articles/
Graphics/iron%20chlorosis.jpg
Deficiency Symptoms - Mn
• Chlorosis is less marked
near veins.
• Some mottling occurs in
interveinal areas.
• Chlorotic areas eventually
become brown,
transparent, or necrotic.
• Symptoms may appear
later on older leaves.
http://www.ca.uky.edu/HLA/Dunwell/KHC/110-122.JPG
Deficiency Symptoms - Zn
• Leaves may be abnormally small and necrotic.
• Internodes are shortened.
http://agri.atu.edu/people/Hodgson/FieldCrops/
Mirror/Nutrient%20Def_files/slide24.jpg
http://plantsci.sdstate.edu/woodardh/soilfert/Nutr
ient_Deficiency_Pages/corn_def/CORN-ZN1.JPG
Deficiency Symptoms - B
• Young, expanding leaves
may be necrotic or
distorted followed by
death of growing points.
• Internodes may be short,
especially at shoot
terminals.
• Stems may be rough,
cracked, or split along the
vascular bundles.
http://www.canr.msu.edu/vanburen/ffc12.jpg
Crops Highly Susceptible to Deficiencies
Element
Crops
Mn
Soybean, Small Grain & Peanuts
Cu
Wheat & Corn
Zn
Corn
Mo
Soybeans & Cauliflower
B
Alfalfa, Apples, Peanuts, Tobacco & Tomatoes
Fe
Ornamentals, Fruit Trees, Soybeans, Grain
Sorghum & Some Grasses