Nitrogen is a major component of chlorophyll, the compound by which plants use the sun’s energy to produce sugars
from water and carbon dioxide (i.e., photosynthesis). Nitrogen also plays a role in the growth of tissues and cells found
within the plant It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants
wither and die. Nitrogen is very moble if N is lacking it will move from older leaves into the younger leaves this will
show as yellowing of the old leaves first. If a soil test gives you a recommended amount of nitrogen to apply it is
usually divided into three separate applications across the growing season
Excessive nitrogen can give you bloated lush plants that are more susceptible to sucking insects such as aphids,
whiteflies, leafhoppers, etc. as well as foliar and soilborne diseases such as powdery mildew, root rot, Pythium, scab,
blight, and other pathogens. It can also reduce or stop flowering
Nitrate is the form of nitrogen most easily used by plants. Nitrate is an anion making it highly leachable it is readily
absorbed by the plant and does not need to undergo any further conversion in the soil as is the case with urea and
ammonium. N helps with the uptake of cations, such as K, Ca and Mg. The conversion of nitrates to amino acids
occurs in the leaf. .This process is fuelled by solar energy, which makes it an energy-efficient process.
Ammonium taken in by plants is used directly in proteins. This form is not lost as easily from the soil. Ammonium has
to be converted into organic N compounds in the roots. This process is fueled by carbohydrates, which are at the
expense of other plant life processes, such as plant growth and fruit fill.
Urea lowers ph, is fast-acting but can easily burn plants, so it’s used in smaller amounts In general, urea will provide the
most nitrogen at the lowest cost. Urea may be mixed with other fertilizers or may be applied on its own. For plants that
love acidic soils, urea is one of the top fertilizers for acidifying soils. When urea is placed on the surface of the soil, a
chemical reaction takes place that changes the urea to ammonium bicarbonate. The ammonium will convert into a gas,
which is then lost if not protected. This means that urea should be mixed in with the soil for maximum effectiveness.
Disadvantages of Urea. As a result of the chemical reaction that takes place when urea is applied to the soil, special care
must be taken to ensure that the nitrogen is not lost when the ammonium evaporates. This can make urea
impractical for gardeners dealing with large plots of land. The high solubility of urea also makes dry storage conditions
Enables photosynthesis (energy transformation) Builds nucleic acids, proteins, and enzymes, facilitates root growth
strengthens stems and stalks Improves flower formation and seed production.P promotes crop uniformity and can
contribute to earlier maturity. P increases disease resistance Improves overall crop quality and facilitates nitrogen
fixation abilities of legumes
Differences in the initial chemical reaction between various commercial P fertilizers in the soil become minor over time
(within weeks or months) and are minimal as far as plant nutrition is concerned. Phosphorus is an anion, it will usually
combine with Iron or Aluminum and act as a cation. If soils are too acidic,|phosphorus reacts with iron and aluminum which makes it unavailable to plants if soils are too alkaline, phosphorus reacts with calcium and also becomes inaccessible.
Excess of phosphorus interferes with the uptake of other elements, such as iron, manganese, and zinc and may inhibit the
formation of mycorrhizae, organic forms of fertilizers seem to have a less inhibitory effect on mycorrhizae than inorganic
soluble fertilizers. Over-fertilization with phosphorus is common and many growers apply unnecessarily high amounts
of phosphorus fertilizers, especially when compound NPK fertilizers are used and manure. Phosphorus moves very little
in most soils possible only one to two inches from the application site, crops seldom absorb more than 20 percent of
phosphorus fertilizer during the first season after application. Samples that are taken from the topsoil will usually indicate a
higher amount of phosphorus than samples that are taken from the subsoil. The location from which soil samples are
taken can affect the results considerably. Your soil sample must be from the plants growing zone Without movement
little soil phosphorus is lost by leaching. This fixed, residual phosphorus remains in the rooting zone and will
be slowly available to succeeding crops. Soil erosion can carries P into waterways.
You can easily get levels of Phosphorus to high and it can take many years to bring it back down. P is returned to
the soil by decaying plant material and manure if you plant a cover crop and remove all of the material from the area
it will help bring down P because it is trapped in that crop. Animals and humans do not digest P very well and it can
return to the soil by their manure and urine possible 60% of consumed P is excreted in urine. Recommendations for
applying manure is usually based on the level of P that you currently have not the amount of nitrogen or potassium
so as not to bring levels of P to high
Phosphorus fertilizers are manufactured from rock phosphate, but rock phosphate is rarely used as a fertilizer
because of its low availability to plants, transport cost is also high plants can only take up phosphorus dissolved
in the soil solution, and since most of the soil phosphorus exists in stable chemical compounds, only a small
amount of phosphorus is available to the plant at any given time N P K
Superphosphate (OSP) 0% 21% 20%
Finely ground rock phosphate is treated with sulfuric acid to yield super-phosphate. About 85–90% of phosphate in super-phosphate is water-soluble.
Concentrated Superphosphate (CSP) 0% 45% 45%
The reaction of phosphoric acid with finely ground rock phosphate yields super-phosphate
Monoammonium Phosphate (MAP) 11% 49% 48%
It can be placed in close proximity to germinating seeds without concern for NH3 damage. However, MAP used in foliar
spray or added to irrigation water shouldn’t be mixed with calcium or magnesium fertilizers.
Diammonium phosphate (DAP) 18% 47% 46%
It is manufactured by reacting phosphoric acid and ammonia and contains two ammonia molecules. In alkaline soil
conditions, one of the ammonia molecules in DAP will revert to ammonia, making it an excellent fit for low pH or
alkaline soil. DAP itself is alkaline with a high pH, exceeding 7.5.
Potash refers to potassium compounds and potassium materials. The name derives from pot ash, the first way
of manufacturing potassium carbonate was extracted by leaching the ashes or burnt plants in big iron pots to dissolve
out the soluble components, evaporation of the solution produced potash.
On July 31, 1790, President George Washington signed the first patent ever issued in the United States. It was granted
to Samuel Hopkins for a new process and apparatus for making potash, America’s first industrial chemical.
K is needed for nutrient uptake, it improves the movement of other nutrients throughout the plant, develops a better
root system helps in providing consistent growth of fruits, improved color, resistance to drought, and provides insect and
disease protection. Approx sixty enzymes perform complex chemical reactions in plants all of them need K to perform
their tasks. Some of these enzymes are needed for the production of proteins and starch and play a role in photosynthesis
K regulates the opening and closing of stomata and therefore regulates CO2 uptake
The uptake of K can be reduced by too much magnesium and/or calcium mainly in high ph soils with low ph higher
than normal levels of other cations, including hydrogen (H), aluminum (Al) and iron (Fe), among others can compete
with K for entry into the plant, and/or create soil conditions that lower the ability of K to be absorbed
Potassium Sulfate 0-0-50 + 18% sulfur (this type of sulfur doesn’t change ph) also known as Sulfate of potash (SOP)
is considered a premium-quality potash. It contains two key nutrients for growing crops: potassium and sulfur It is a
white 100% water-soluble solid and can be used in irrigation lines or incorporated into soil Granular Potassium
Sulfate cannot be used in irrigation water and must be applied directly to the soil
Monopotassium Phosphate 0-52-34
Monopotassium Phosphate fertilizer contains 52% Phosphorous and 34% Potassium and can be 100% water-soluble..
It can be used in irrigation lines and directly applied to the soil
Potassium Chloride KCI 0-0-60 also known as (MOP) Muriate of potash
Not recommended for Giant Pumpkins can cause splitting and may cause the fruit to mature early, and contains larger
amounts of chloride but it has been used
Potassium Nitrate also is known as Nitrate of potash or saltpeter 13.7 – 46 – 0
Crystalline in form and white in color. Colorless and Odorless Water-soluble and chloride-free it provides essential nitrogen in the most efficient nitrate form. Ideal for plants that are sensitive to Chloride and high salinity.
Called secondary nutrients calcium (Ca), sulfur (S) and magnesium are just as important as the primary N-P-K. They
are called secondary because the plant uses a lower quantity of them than the N-P-K , in some plant tissues magnesium
levels can be almost as high as phosphorus most important role of magnesium is as the central atom in the chlorophyll
molecule, chlorophyll absorbs light in the red (long wavelength) and the blue (short wavelength) regions of the visible
light spectrum. Greenlight is not absorbed but reflected, making the plant appear green this carries out the process of
photosynthesis. Many enzymes in plant cells require magnesium, and it is also used by plants for the metabolism of
carbohydrates and in cell membrane stabilization
Calcium is responsible for holding together the cell walls of plants a deficiency will cause new growth to be distorted
because of weak cell walls, it will be worse in tissues fed principally by the phloem rather than the xylem, such as in
‘blossom end rot’ of watermelon, pepper, and tomato fruit, and maybe the cause of thin walls in pumpkins, especially at
the blossom end, but this theory is still in debate
Xylem (XY-limb) The basic function of xylem is to transport water along with nutrients from roots to stems and leaves,
movement is one direction from the roots through the canopy
Phloem (flow-M) is the vascular tissue responsible for the transport of soluble organic compounds mainly sugars from
the leaves to the sink tissues such root cells, developing flowers and fruit. Other molecules such as proteins are also
transported throughout the plant via the phloem. Movement can be in both directions
Nitrogen and magnesium are mobile in the plant, they can move to the more critical areas, but once calcium is fixed in
the tissues it will not move, new growth relies on current viable supplies of calcium from the roots through the Xylem, this
is effected by transpiration Transpiration is low in young leaves, in enclosed tissues, and in fruit. Calcium flows along
through the xylem with water, high humidity, cold and dry conditions may result in calcium deficiency.
Transpiration is the process of water movement through a plant and its evaporation from leaves, stems, and flowers.
Only a small amount of water taken up by the roots is used for growth and metabolism over 90 % will be lost by
transpiration and guttation (drops of xylem sap on the tips or edges of leaves of some vascular plants,)
Calcium has many roles , helps in the process of other nutrients, strengthens cells walls making them less susceptible to
disease. Helps against heat stress and the regulation of the stomata, Participates in enzymatic and hormonal
processes. Promotes proper plant cell elongation, bigger cells mean bigger fruit it improves root growth and
stimulates microbial activity, encourages nitrogen (N)-fixing bacteria that form nodules on the roots to capture
atmospheric N gas
The most common calcium sources are calcium nitrate, calcium chloride, lime, gypsum, calcium chelates and some
If you need Nitrogen and calcium use calcium nitrate
If you need sulfur and calcium–use Gypsum
If you need magnesium and calcium–add Dolomite.
If you need trace minerals and calcium–use Azomite.
If you need phosphorus and calcium–use Soft Rock Phosphate or bone meal
There are many other types of calcium products some, using the name CalMag
Sulfur is a vital part of all plant proteins and certain plant hormones. Sulfur comes in many forms the types used for
the garden are Sulfate-Sulfur(SO42) which is the only form of sulfur that plants can utilize. Plants can absorb sulfur by
their roots but it must be in the form of Sulfate which does not change the PH of the soil. The sulfate form is
water-soluble, and being an anion is readily leachable
Elemental Sulfur(So) is used to lower PH
Elemental Sulfur will lower the PH of soil but only while it is being broken down by biological activity, this isn’t possible
when the soil temperature is below 55F, or when the soil is waterlogged. When elemental sulfur breaks down it lowers
PH and turns into Sulfate sulfur which the plant can use. Elemental does not dissolve in water
A sulfur deficiency can look similar to a Nitrogen def with yellowing of the leaves, nitrogen will usually affect older
leaves first while sulfur shows in the youngest leaves. Heavy use of manure can lock up sulfur due to high Phosphorus
levels. Sandy soils are usually low in sulfur while organic matter holds sulfur. Without enough sulfur, plants cannot
efficiently use nitrogen and other nutrients to their full potential.
Most commercial fertilizers do not provide enough sulfur, Epsom’s salts can be used to provide magnesium and sulfur
Dusting Sulfur is elemental sulfur, it is one of the oldest fungicides and pesticides, it can be used in organic gardens
if regulations are followed Dusting home gardens can be done with an inexpensive “blower” or use Wettable sulfur that
can be sprayed on, Wettable sulfur it is dusting sulfur formulated with additional ingredients to make it mixable with
water,but it does not dissolve. Some crops can be damaged so investigate before using
Micronutrients (or trace minerals): iron (Fe), manganese (Mn) Zinc (Zn), and copper (Cu) boron (B), chlorine (Cl),
molybdenum (Mo), nickel (Ni)
Applying nutrients such as iron(Fe), manganese (Mn) Zinc (Zn), and copper (Cu), directly to the soil is inefficient
because in soil solution they are present as positively charged metal cations and will readily react with oxygen and/or
negatively charged hydroxide anions (OH-). If they react with oxygen or hydroxide ions, they form new compounds that
are not available to plants. Both oxygen and hydroxide ions are abundant in soil and soilless growth media Chelating
agents such as amino acids, citric acid glucoheptonates, and other organic acids are able to tear away a mineral
(chelate) and hold onto it inside its structure. This protects the metal ion from other soil compounds, the structure is
strong enough for protection but weak enough to be broken down by the plant by exudate’s otherwise the plant cannot
use it. In the soil, plant roots can release exudates that contain natural chelates if the nutrient is close to the root. The
value of a synthetic chelated micronutrient lies in their ability to move freely with other nutrients through the soil
solution for rapid effective uptake by the root system.
Products should be marked as chelated fertilizer or have ingredients such as, EDTA, DTPA and EDDHA.
Chelated Zinc EDTA
Zinc (Zn) is taken up by plants as the divalent Zn+2 cation. It was one of the first micronutrients recognized as
essential for plants and the one most commonly limiting yields. For 1000sq ft of space, the amount used will probably
require well under one pound of product. Zinc is responsible for activating the enzymes which help in the synthesis of
protein in the formation of chlorophyll and conversion of starches to sugar. Plants absorb zinc as an ion through their
foliage as well as their roots. High pH may limit availability. Zinc can stay in the soil for long periods so do at least one soil
test per year Zinc is immobile meaning that lack of zinc shows its symptoms on new leaves first.
Chelated Manganese EDTA
Most likely for 1000sqft of garden you would need well under 8 oz but this amount must be determined by a soil test
Manganese (Mn) functions primarily as part of enzyme systems in plants. It activates several important metabolic
reactions and plays a direct role in photosynthesis. Manganese accelerates germination and maturity while increasing
the availability of phosphorus (P) and calcium (Ca). Manganese is used as a primary contributor to most biological
processes like nitrogen assimilation, metabolism, respiration, and photosynthesis. It is also vital in pollen germination,
the growth of pollen tube, resistance to root pathogens and root cell elongation. Plants absorb manganese as an ion
through their foliage as well as their roots. Manganese is mobile a deficiency will likely to be seen in older leaves first.
A non-chelate would be Manganese Sulfate
Chelated Iron DTPA
Iron (Fe) is essential for crop growth and food production. Plants take up Fe as the ferrous (Fe2+) cation.
Iron is a component of many enzymes associated with energy transfer, nitrogen reduction and fixation, and lignin
formation. Pour uptake of iron can be due to excess amounts of clay in the soil,ph is too high The phosphorus content
of the soil is too high or overly wet or compacted soil. Chelated Iron DTPA is more suitable than Chelated Iron EDTA
since it is 100% more efficient from a pH level of 6 and above Chelated Iron EDTA is better suited to lower pH soils.
Foliar applications may be more effective than to soil. NON-chelate iron would be Ferrous sulfate
Chelated Copper EDTA and nonchelate Copper Sulfate
You may never have to supplement copper and only add copper if its recommended by a reliable soil test, in almost all
cases it will be a very small amount needed for 1000sqft possible less than 1/2 ounce. Copper can be deadly to plants
even in small quantities. Swine and dairy manure can raise copper levels to toxic levels and the problem can persist
for an extended period of time and is difficult to correct because of copper’s low solubility in water. Fungicides can also
contain copper with repeated use even they can bring soil levels of copper to high The use of compost may help lower
copper in soils
Boron 11% mule team borax and Boric Acid
Not a chelated nutrient boron is important but like copper can be very toxic for plants. A reliable soil test should be
used before applying. A 1000sqft garden may only need 1/2 ounce or less. Boron is needed for the structural and
functional integrity of plant cell membranes, keeps a balance between starch and sugar and is critical to normal cell
division, protein formation, and nitrogen metabolism. Boron is used with calcium in cell wall synthesis and is essential
for cell division, the two work together Calcium and boron are immobile elements. once set in place within the plant,
they will not be translocated to other areas. Boron helps get calcium to where it is needed. Most home gardeners use
11% Mule Team Borax manufactured as laundry detergent and is allowed in organic gardens with Restrictions. It can
be purchased at grocery stores and home centers
In almost all cases Chloride does not need to be supplemented, usually, you want to avoid adding it.
Chloride is an essential micronutrient that all crops require It plays an important role in plants, including
photosynthesis, osmotic adjustment, and suppression of plant disease. However, it is often associated with salinity
damage and toxicity that will reduce yield and give leaves a scorched or burned appearance. The toxicity results from
accumulation of chloride in the leaves. Chloride can also cause leaf damage when deposited on leaves in overhead
irrigation Excess chloride can build up in the soil from swimming pool runoff, irrigation water, or excess soil salts
Chlorine (Cl) converts to chloride (Cl-) in the soil and is absorbed by plants in this form. Chloride toxicity is most
common in irrigated, dry regions, near seas and roads frequently treated with salt. Chloride levels can be reduced with
the use of gypsum less is needed in sandy soils, more in heavy clay soils. Chloride is an anion it is completely soluble
and very mobile making it easier to leach out of soils. In extreme cases like along roadways deiced by chloride, it can
become toxic to aquatic life and impacts vegetation and wildlife.
Cucurbits(include cucumbers, melons, watermelons, pumpkins, squash, and many others.) and non-legume plants
have a higher demand for molybdenum than most other crops but of all the essential micro-nutrients or trace elements,
molybdenum (Mo) is required in the smallest amount by plants. A seed may contain enough Mo to provide the plant with
all of its Mo needs. It is most available in neutral or alkaline soils and least available below a PH of 6. Molybdenum is
an essential component in two enzymes that convert nitrate into nitrite (a toxic form of nitrogen) and then into ammonia
before it is used to synthesize amino acids within the plant. It also needed by symbiotic nitrogen-fixing bacteria in
legumes to fix atmospheric nitrogen Feeding with mostly nitrate fertilizer will induce a molybdenum deficiency sooner
than feeding with ammoniacal fertilizer.
Many good soil tests do not give you Mo readings and you can usually get enough Molybdenum from water-soluble and
some controlled-release fertilizers. Very little molybdenum needs to be applied to correct a deficiency. Molybdenum
toxicity is very rare
I would not bother trying to supplement Nickel
Nickel (Ni) was added to the list of essential plant nutrients late in the 20th century. Since nickel is needed in such small
quantities and more research needs to be done, it is not added to most fertilizers. It can be found as a contaminant in
fertilizer and the irrigation water and it is often found in animal waste. Nickel can also be applied as a single element application as nickel sulfate or in a chelated form. Use caution as little nickel is needed to correct a deficiency.
Nickel is important in plant N metabolism because it is a component of the urease enzyme. Without the presence of Ni,
urea conversion is impossible. It is required in very small amounts, with the critical level appearing to be about 1.1 ppm
Without nickel, toxic levels of urea can accumulate within the tissue forming necrotic legions on the leaf tips