Kingrow1
Well-Known Member
Nitrogen (N)
Why do plants need Nitrogen?
Protein is essential for all living organisms, and is required for growth and development. Nitrogen is one of
the main elements in protein. Nitrogen is also a component of nucleic acid, DNA, RNA, genes,
chromosomes, enzymes, chlorophyll, secondary metabolites (alkaloids), and amino acids. Nitrogen
accounts for about 1 to 6 % of plant dry matter, depending on the species.
What happens when Nitrogen is not available to plants?
Nitrogen deficiency slows down the growth and development of plants. The plants appear stunted with
light green lower leaves, while the upper leaves remain green. With prolonged N deficiency, yellowing
(chlorosis) of older or lower leaves occurs. This is followed by leaf tip death and leaf margins developing a
brown discoloration (necrosis). In some instances the leaves fall off. The plant stems become woody.
Source of Nitrogen Fertilizers
NAME RATE COMMENTS
Protein is essential for all living organisms, and is required for growth and development. Nitrogen is one of
the main elements in protein. Nitrogen is also a component of nucleic acid, DNA, RNA, genes,
chromosomes, enzymes, chlorophyll, secondary metabolites (alkaloids), and amino acids. Nitrogen
accounts for about 1 to 6 % of plant dry matter, depending on the species.
What happens when Nitrogen is not available to plants?
Nitrogen deficiency slows down the growth and development of plants. The plants appear stunted with
light green lower leaves, while the upper leaves remain green. With prolonged N deficiency, yellowing
(chlorosis) of older or lower leaves occurs. This is followed by leaf tip death and leaf margins developing a
brown discoloration (necrosis). In some instances the leaves fall off. The plant stems become woody.
Source of Nitrogen Fertilizers
NAME RATE COMMENTS
Ammonium Nitrate
200 – 300 ppm Single N (33%) source; lowers substrate pH
Ammonium Sulfate
200 – 300 ppm Excellent source of N (21%) and S (24%)
Ammonium Chloride
200 – 300 ppm Source of N (25 %) and Cl-(66%);
high concentration may cause foliar injury
Potassium Nitrate
200 – 300 ppm Source of N (13%) and K (44%)
Monoammonium Phosphate
200 – 300 ppm Source of N (10%) and P (50-52%)
Diammonium Phosphate
200 – 300 ppm Source of N (19%) and P (46-53%)
Urea
200 – 300 ppm Single source of N (45%);
cheap, but will lower substrate pH
Calcium Nitrate
200 – 300 ppm Source of N (15%) and Ca (22%);
will increase the substrate pH
will increase the substrate pH
Phosphorous (P)
Why do plants need Phosphorous?
Phosphorus provides energy in the form of ATP and NADPH for plant metabolism (photosynthesis and
respiration). Additionally, it is a component of DNA, RNA, nucleotides and cell membrane.
What happens when Phosphorous is not available to plants?
Initially, plants appear darker green with reduced growth affecting the leaf size and stem thickness. As the
deficiency continues, the older, lower leaves develop irregular spots of brown to dark brown dead tissue. In
some plants, reddish to purple pigmentation may appear on the under or upper surface of leaf margins,
lower leaves, and stems. Eventually, leaf death of older leaves may occur. In most cases, lack of
phosphorus delays flowering in plants.
Source of Phosphorous Fertilizers
NAME RATE COMMENTS
Monoammonium Phosphate
Phosphorus provides energy in the form of ATP and NADPH for plant metabolism (photosynthesis and
respiration). Additionally, it is a component of DNA, RNA, nucleotides and cell membrane.
What happens when Phosphorous is not available to plants?
Initially, plants appear darker green with reduced growth affecting the leaf size and stem thickness. As the
deficiency continues, the older, lower leaves develop irregular spots of brown to dark brown dead tissue. In
some plants, reddish to purple pigmentation may appear on the under or upper surface of leaf margins,
lower leaves, and stems. Eventually, leaf death of older leaves may occur. In most cases, lack of
phosphorus delays flowering in plants.
Source of Phosphorous Fertilizers
NAME RATE COMMENTS
Monoammonium Phosphate
30 ppm Source of N (10%) and P (50-52%)
Diammonium Phospate
30 ppm Source of N (19%) and P (46-53%)
Monobasicpotassium phosphate
30 ppm P (23%) K (28%)
Dibasicpotassium phosphate
30 ppm P (18%) K (45%)
Phosphoric acid 10 ppm Single P source (P2O5 -54%)
Phosphoric acid 10 ppm Single P source (P2O5 -54%)
Potassium (K)
Why do plants need Potassium?
Unlike nitrogen and phosphorus, potassium is not a component of plant organic matter. Potassium is
important for movement of sugars, starch formation, pH stabilization, drought tolerance, cell turgor,
enzyme activation, and regulation of stomata opening and closing.
What happens when Potassium is not available to plants?
The leaves of potassium deficient plants are small and dark green. The plants have short internodes
resulting in compact plant appearance. These symptoms are followed by a sudden development of irregular
necrotic tissues along the leaf margins and tips of lower, older leaves and eventually covering whole
leaves, making the leaves appear scorched. Also, leaves curl downwards.
Source of Potassium Fertilizers
NAME RATE COMMENTS
Potassium chloride
Unlike nitrogen and phosphorus, potassium is not a component of plant organic matter. Potassium is
important for movement of sugars, starch formation, pH stabilization, drought tolerance, cell turgor,
enzyme activation, and regulation of stomata opening and closing.
What happens when Potassium is not available to plants?
The leaves of potassium deficient plants are small and dark green. The plants have short internodes
resulting in compact plant appearance. These symptoms are followed by a sudden development of irregular
necrotic tissues along the leaf margins and tips of lower, older leaves and eventually covering whole
leaves, making the leaves appear scorched. Also, leaves curl downwards.
Source of Potassium Fertilizers
NAME RATE COMMENTS
Potassium chloride
200 ppm Source of K (60%) and Cl
Potassium nitrate
200 ppm Source of K (44%) and N (13%)
Potassium sulfate
100 ppm Source of K (50%) and S (18%)
Potassium hydroxide
50 ppm Single source of K (75%)
Potassium thiosulfate
200 ppm Source of K (25%) and S (17%)
Monobasic potassium phosphate
200 ppm Source of K (28%) and P (23%)
Dibasic potassium phosphate 100 ppm Source of K (45%) and P (18%)
Dibasic potassium phosphate 100 ppm Source of K (45%) and P (18%)
Calcium (Ca)
Why do plants need Calcium?
Calcium is required for cell wall structure and cellular signaling. Calcium is important in cell division, cell
expansion, building of cell walls, stomatal regulation, and cold tolerance.
What happens when Calcium is not available to plants?
Unlike other nutrients, lack of calcium generally affects the growing points and young leaves of the plants.
The young leaves are often twisted or wrinkled. The growth is reduced with tiny black spots appearing
around the mid-leaf area of young leaves and on the tips of very young leaves. In some cases, these black
spots appear on the growing points. Abortion of flowers or flower buds is common if calcium is unavailable
during flowering. During fruiting, lack of calcium can result in fruit cracking, water soaked tissues or
blossom end rot (tomato).
Source of Calcium Fertilizers
NAME RATE COMMENTS
Calcium nitrate
Calcium is required for cell wall structure and cellular signaling. Calcium is important in cell division, cell
expansion, building of cell walls, stomatal regulation, and cold tolerance.
What happens when Calcium is not available to plants?
Unlike other nutrients, lack of calcium generally affects the growing points and young leaves of the plants.
The young leaves are often twisted or wrinkled. The growth is reduced with tiny black spots appearing
around the mid-leaf area of young leaves and on the tips of very young leaves. In some cases, these black
spots appear on the growing points. Abortion of flowers or flower buds is common if calcium is unavailable
during flowering. During fruiting, lack of calcium can result in fruit cracking, water soaked tissues or
blossom end rot (tomato).
Source of Calcium Fertilizers
NAME RATE COMMENTS
Calcium nitrate
200 ppm Calcium source 22%
Calcium chloride
200 ppm Calcium source 36%
Calcitic limestone
3 g per liter
of substrate Calcium source 32%
Dolomitic limestone
3 g per liter
of substrate Calcium source 22%
Hydrated lime
1.5 g per liter
of substrate Calcium source 46%
Gypsum
3 g per liter
of substrate Calcium source 23%
of substrate Calcium source 23%
Magnesium (Mg)
Why do plants need magnesium?
Magnesium is a core component of chlorophyll (pigment of photosynthesis). Magnesium is also important
in enzyme and cofactor reactions. It is involved in the metabolism and movement of carbohydrates and
stabilizing cell membranes.
What happens when magnesium is not available to plants?
Normally magnesium deficiency symptoms appear in lower, older leaves with chlorosis of greenish yellow
to yellowish green developing along the leaf margins and tips, which progresses inward between the leaf
veins. As the deficiency prolongs, necrosis develops between the veins and the leaves curl downwards.
Eventually, leaf and plant death may occur if the magnesium deficiency continues.
Source of magnesium Fertilizers
NAME RATE COMMENTS
Magnesium nitrate
Magnesium is a core component of chlorophyll (pigment of photosynthesis). Magnesium is also important
in enzyme and cofactor reactions. It is involved in the metabolism and movement of carbohydrates and
stabilizing cell membranes.
What happens when magnesium is not available to plants?
Normally magnesium deficiency symptoms appear in lower, older leaves with chlorosis of greenish yellow
to yellowish green developing along the leaf margins and tips, which progresses inward between the leaf
veins. As the deficiency prolongs, necrosis develops between the veins and the leaves curl downwards.
Eventually, leaf and plant death may occur if the magnesium deficiency continues.
Source of magnesium Fertilizers
NAME RATE COMMENTS
Magnesium nitrate
50 ppm Magnesium source 9%
Magnesium sulfate
50 ppm Magnesium source 10%
Magnesium chloride
50 ppm Magnesium source 25%
Potassium magnesium sulfate
25ppm Magnesium source 11%
Dolomite
3 g per liter Magnesium source 8-20%
Magnesium oxide 1 g per liter Magnesium source 50-55%
Magnesium oxide 1 g per liter Magnesium source 50-55%
