Some good plant nutrition info fo dat ass (got it off wiki):
Plant nutrition
Main article:
Plant nutrition
Plant nutrition is the study of the
chemical elements that are necessary for plant growth. There are several principles that apply to plant nutrition. Some elements are directly involved in plant
metabolism. However, this principle does not account for the so-called beneficial elements, whose presence, while not required, has clear positive effects on plant growth.
A nutrient that is able to limit plant growth according to
Liebig's law of the minimum, is considered an essential plant nutrient if the plant cannot complete its full life cycle without it. There are 17 essential plant nutrients.
Macronutrients:
Micronutrients (trace levels) include:
Macronutrients
Calcium
Calcium regulates transport of other nutrients into the plant and is also involved in the activation of certain plant enzymes.
Calcium deficiency results in stunting.
Nitrogen
Nitrogen is an essential component of all proteins.
Nitrogen deficiency most often results in stunted growth.
Phosphorus
Phosphorus is important in plant
bioenergetics. As a component of
ATP, phosphorus is needed for the conversion of light energy to chemical energy (
ATP) during photosynthesis. Phosphorus can also be used to modify the activity of various enzymes by
phosphorylation, and can be used for
cell signaling. Since ATP can be used for the
biosynthesis of many plant
biomolecules, phosphorus is important for plant growth and
flower/
seed formation.
Potassium
Potassium regulates the opening and closing of the
stoma by a potassium ion pump. Since stomata are important in water regulation, potassium reduces water loss from the leaves and increases
drought tolerance.
Potassium deficiency may cause necrosis or interveinal chlorosis.
Silicon
Silicon is deposited in
cell walls and contributes to its mechanical properties including
rigidity and
elasticity
Micronutrients
Boron
Boron is important in sugar transport,
cell division, and synthesizing certain enzymes.
Boron deficiency causes necrosis in young leaves and stunting.
Copper
Copper is important for photosynthesis. Symptoms for copper deficiency include chlorosis. Involved in many enzyme processes. Necessary for proper photosythesis. Involved in the manufacture of lignin (cell walls). Involved in grain production.
Chlorine
Chlorine is necessary for
osmosis and
ionic balance; it also plays a role in
photosynthesis.
Iron
Iron is necessary for photosynthesis and is present as an enzyme cofactor in plants.
Iron deficiency can result in interveinal
chlorosis and
necrosis.
Manganese
Manganese is necessary for building the
chloroplasts.
Manganese deficiency may result in coloration abnormalities, such as discolored spots on the
foliage.
Molybdenum
Molybdenum is a cofactor to enzymes important in building amino acids.
Nickel
In
higher plants, Nickel is essential for activation of
urease, an enzyme involved with
nitrogen metabolism that is required to process urea. Without Nickel, toxic levels of urea accumulate, leading to the formation of necrotic lesions. In
lower plants, Nickel activates several enzymes involved in a variety of processes, and can substitute for Zinc and Iron as a cofactor in some enzymes.
Sodium
Sodium is involved in the regeneration of
phosphoenolpyruvate in
CAM and
C4 plants. It can also substitute for potassium in some circumstances.
Zinc
Zinc is required in a large number of enzymes and plays an essential role in
DNA transcription. A typical symptom of zinc deficiency is the stunted growth of leaves, commonly known as "little leaf" and is caused by the oxidative degradation of the growth hormone
auxin.
Processes
Plants uptake essential elements from the
soil through their
roots and from the air (mainly consisting of nitrogen and oxygen) through their
leaves. Nutrient uptake in the soil is achieved by
cation exchange, wherein
root hairs pump
hydrogen ions (H+) into the soil through
proton pumps. These hydrogen ions displace
cations attached to negatively charged soil particles so that the cations are available for uptake by the root. In the leaves,
stomata open to take in carbon dioxide and expel
oxygen. The carbon dioxide molecules are used as the carbon source in photosynthesis.
Although
nitrogen is plentiful in the Earth's atmosphere, relatively few plants engage in
nitrogen fixation (conversion of atmospheric nitrogen to a biologically useful form). Most plants therefore require nitrogen compounds to be present in the soil in which they grow.
Plant nutrition is a difficult subject to understand completely, partially because of the variation between different plants and even between different species or individuals of a given
clone. Elements present at low levels may cause deficiency symptoms, and toxicity is possible at levels that are too high. Furthermore, deficiency of one element may present as symptoms of toxicity from another element, and vice-versa.
Carbon and oxygen are absorbed from the air, while other nutrients are absorbed from the soil. Green plants obtain their carbohydrate supply from the carbon dioxide in the air by the process of
photosynthesis.
