NITROGEN---Can purchased in 4 FORMS
1. Nitrate of soda NaNO3
*a highly soluble & quickly available
*tends to reduce soil acidity
*It has 16% Nitrogen
2. Ammonium Nitrate NH4NO3
* Not a soluble
*Available over a longer period of time
*Contains 33% Nitrogen
3. Ammonium Sulfate NH4SO4
*Available slowly
*Leaves soil acidic
*Good for plants that grow well in very acidic soil
*21% Nitrogen
4. Urea formaldehyde
*Original form of Nitrogen
*More slowly available than the inorganic
*contains 38% Nitrogen
NITROGEN—is the Major Plant food that is most noticeable effects on plants sooner
A.
B.
C.
D.
Encourages above ground vegetation -=gives dark green leaves
Tends to produce soft tender growth—Great for Lettuce
Tender Growth makes plants taste better
Nitrogen helps to regulate the use of other major elements
TOO MUCH NITROGEN:
1.
2.
3.
4.
Lowers plants resistance to diseases
Weakens the stem because of long soft growth
Lowers the quality of the fruit-causing them to be too soft to ship
Delays maturity or hardiness of tissues, thus increase winter damage to plant
NOT ENOUGH NITROGEN:
1. Yellow or light Green
2. Stunted in roots and top growth
Nitrogen : is lost through soil easily
*It is water soluble & is not held by the soil particles because of the charges of the
Particles involved.
*Soil Particles –Have a Negative Charge
*Ammonium Form of Nitrogen has a Positive charge & is held by negatively
Charged soil particles
*Nitrate Nitrogen is leached quickly because of the Negative charge—However
Organic Matter does tend to hold insoluble that is released slowly into the
soil.
Nitrogen --Should Not be used in EXCESS for 2 Reasons
1. It is quickly Lost from soil through leaching –especially in Sandy soil
2. It can DAMAGE plants if applied in too great of amounts—Some plants
such as Legumes ( beans & peas) manufacture their own Nitrogen.
PHOSPHORUS:
Purchased in the following forms:
Superphosphate 20% Phosphate
Treble superphosphate 46% Phosphate
Rock Phosphate -25-35% Phosphate
Ammonium Phosphate 48% Phosphate
PHOSPHOROUS:
*Is Present in some extent in All Soils
*Phosphorus is held tightly to soil particles
*therefore not easily Leached from soil
PHOSPHORUS AFFECTS ON PLANTS:
1.
2.
3.
4.
5.
6.
7.
It encourages plant cell division
Flowers & seed do not form without phosphorus
It Speeds up Maturity thereby offsets the quick growth caused by Nitrogen
It encourages Root Growth & development of strong root system
It make Potash (Potassium) more easily available
It increases the Plants Resistance to Disease
Improves quality of Grain , Root & Fruit Crop
Phosphorous is held very Tightly ty SOIL PATICLE
IT DOESNOT CAUSE DAMAGE TO FIELD GROWN PANTS –if in EXCESSIVE AMOUNT
HOWEVER: CONTAINER GROWN PLANTS- can be Damaged by excessive
Phosphorous..
It can dehydrate (dry out) plant roots by pulling water from the roots
LOW PHOSPHORUS: in sufficient results in:
1.
2.
3.
4.
5.
Purple color on under surface of leaves
Reduced flower, fruit & seed production
Susceptibility to cold injury
Susceptible to plant disease
Poor quality fruits & Seeds
POTASSIUM: common sources
1. Muriate of potash 60% Potash
2. Sulfate of Potash 49% Potash
3. Nitrate of Potash 44% of Potash
POTASSIUM
*Is rarely in soil in sufficient amounts to harm plants
*Potassium modify both fast, soft growth of Nitrogen & the Early Maturity of
Phosphorus
PRESENT OF POTASSIUM IS ESSENTIAL FOR:
1.
2.
3.
4.
5.
INCREASE PLANTS RESISTANCE TO DISEASES
IT ENCOURAGES A STRONG, HEALTHY ROOT SYSTEM
IT IS ESSENTIAL FOR STARCH FORMATION
IT IS NEEDED FOR THE DEVELOPMENT OF CHLOROPHYLL
IT IS ESSENTIAL FOR TUBER DEVELOPMENT
Because it is a major element is generally added to soil
SOIL TEST IS RECOMMENDED
POTASSIUM DEFFIENCY APPEARS:
1. As a marginal yellowing
2. Scorching on edges of leaves on the lower portion of the plants
LIME: CaCO3
*Lime acts as a plant food & as a material that affects soil acidity
*In turn it affects the availability of other plant food elements\
LIME furnishes : Calcium ---Which is one of the most important of the secondary food
Elements
CALCIUM is IMPORTANT IN THE FORMATION OF PLANT CELL WALLS AMONG OTHER –
Just like bones.
SOIL ACIDITY (PH)
Most plants grow best in
5.6-7.0 ph
7.0 ph is Neutral –Not ACID or ALKALINE
1-14
Lower than 7 indicate ACID SOIL
Higher than 7 indicates ALKALINE SOIL