"vitamins" for lawns

For human beings, there are vitamins.
For example, the well known "VITAMIN C"...
How many times our mother or the doctor told us "you need vitamin C to cope with the cold winter and with flu" ?
Or, generally speaking, you need vitamins and dietary mineral for your good health.
The same things occur with plants.
In this case, we talk about chemical elements (iron, nitrogen, ecc.), salts, etc.
Those substances are in the ground.
plants take them from the ground they are in, to grow up healthy and strong.
Now comes my question:
accordingly to this argument, may we use some chemical products in order to improve our lawn ???
I guess we can.
For example, in some gardening-shops or gardening-store, they sell a product to use in spring to improve the lawn. Probably to get the grass more green...
I don't know...
Neither do I know whether this product is a liquid or a dust...
But my real questions are three.
1. Which substances are they ? Iron ? Magnesium ? Nitrogen ??? (I must say that the grass of my lawn is "Festuca arundinacea").
2. Should we use this kind of products in any case or ONLY if needed ???
3. If we should use them IN ANY CASE, when should we use them ? In winter ? In spring ? In summer ? In autumn ?
If we should use them ONLY if needed, how can we "work out" that they are needed ??? Maybe when the grass is getting yellow ??? Maybe when the grass is dying ??? In which cases ???
Pardon me my english (as you can see I am not british :D) and thanks to those who will reply.
Regards.

 

Hi Maksim

Grass, like any plant will grow better if fed a correctly balanced fertiliser. All garden shops will sell "lawn feed". Some are for use all year round, others are specially formulated for spring or autumn. Use one of these at the right time and you should improve the health of your grass. A healthy and vigorous grass will withstand wear better as well as looking better.

I would suggest that it is best to feed any grass no matter how it looks. But it is better to do it while the grass is healthy rather than waiting until it looks distressed.

 

In addition to the above-answer (whose user I thank), I try to self-answer my questions.
This subject goes on the topic: "Plant nutrition".
Probably has been talked about in other threads in this forum. Threads about "FERTILIZERS".
I report some meaningful excerpts from wikipedia on the topic "Plant nutrition".
Wikipedia says:

"There are 16 essential plant nutrients. Carbon and oxygen are absorbed from the air, while other nutrients
including water are obtained from the soil. Plants must obtain the following mineral nutrients from the soil:
The three primary macronutrients: nitrogen, phosphorus, and potassium.
The three secondary macronutrients such as calcium(Ca), sulfur (S), magnesium (Mg).
The macronutrient Silicon (Si).
The micronutrients or trace minerals: boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo) selenium (Se), and sodium (Na).".
"The macronutrients are consumed in larger quantities and are present in plant tissue".
"Micronutrients are present in plant tissue in quantities measured in parts per million".
"Plants uptake essential elements from the soil through their roots and from the air (mainly consisting of nitrogen and oxygen) through their leaves."
"In the leaves, stomata open to take in carbon dioxide and expel oxygen. Green plants obtain their carbohydrate supply from the carbon dioxide in the air by the process of photosynthesis."
"Though 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. These can either be supplied by decaying matter, nitrogen fixing bacteria, animal waste, or through the agricultural application of purpose made fertilizers."
"Nutrients are moved inside a plant to where they are most needed. For example, a plant will try to supply more nutrients to its younger leaves than its older ones. so when nutrients are mobile, the lack of nutrients is first
visible on older leaves. However, not all nutrients are equally mobile. When a less mobile nutrient is lacking, the younger leaves suffer because the nutrient does not move up to them but stays lower in the older leaves. Nitrogen,
phosphorus, and potassium are mobile nutrients, while the others have varying degrees of mobility."

"FUNCTION OF NUTRIENTS."
CARBON, HYDROGEN, OXYGEN AND PRYMARY MACRONUTRIENTS.

"CARBON forms the backbone of many plants biomolecules, including starches and cellulose. Carbon is fixed through photosynthesis from the carbon dioxide in the air and is a part of the carbohydrates that store energy in the plant.
HYDROGEN also is necessary for building sugars and building the plant. It is obtained almost entirely from water.
OXYGEN is necessary for cellular respiration. Cellular respiration is the process of generating energy-rich adenosine triphosphate (ATP) via the consumption of sugars made in photosynthesis. Oxygen gas is produced as a by-product from this reaction.
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. ...
Since ATP can be used for the biosynthesis of many plant biomolecules, phosphorus is important for plant growth and
flower/seed formation.
POTASSIUM regulates the opening and closing of the stomata 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.
NITROGEN is an essential component of all proteins. Nitrogen deficiency most often results in stunted growth."

A FEW AMONG OTHER NUTRIENTS (SECONDARY MACRONUTRIENTS AND MICRONUTRIENTS).

"CALCIUM regulates transport of other nutrients into the plant. ... Calcium deficiency results in stunting.
MAGNESIUM is an important part of chlorophyll, a critical plant pigment important in photosynthesis. ...
Magnesium deficiency can result in interveinal chlorosis.
SILICON contributes to mechanical properties including rigidity and elasticity.
IRON is necessary for photosynthesis. Iron deficiency can result in interveinal chlorosis and necrosis."

SODIUM, is a particular issue.
It is usually considered as a bad element (SALTY SOILS).
However in northern Europe, where it is very rare, is considered very important and is supplied along with fertilizers, expecially in pastures to enrich the cattle food.
There are world-maps that indicate the soil regions in the world (GLOBAL SOIL REGIONS).

As far as a lawn is concern, I have bought myself tWo kind of fertilizers.
One of them, is for the grass "first sowing".
Its content is - basicly - NITROGEN and PHOSPHORUS PENTOXIDE (P2O5) in the form of water-soluble little spheric
white and orange pills.

As Wikipedia says, "due to its high reactivity, phosphorus is never found as a free element in nature on Earth".
Actually, in nature PHOSPHATES are found. They are salts of phosphoric acid.
In organic chemestry, there are ORGANOPHOSPHATES. They are esters of phosphoric acid.
P2O5 cames from the reaction with the oxygen in the air, "by burning elemental phosphorus with sufficient supply of air", as Wikipedia says.
The lebel on this fertilizers box, says:
IN SPRING a product with a high content of NITROGEN is needed for the leaves and stems growth.
IN SUMMER a product with a high content of POTASSIUM is needed for the leaves to regulate the water consumption and bear high temperatures.
IN AUTUMN a product with a right balance of NITROGEN and POTASSIUM is needed for the plant to manage to store sugars and carbohydrates.
FOR THE FIRST SOWING, a product with a right content of PHOSPHORUS is needed to supply an immediate amount of
energy.
FOR "RECOVERING", a product with a right content of NITROGEN is needed for the plant to recover/retrieve after a
long stressfull period.

The other fertilizer that I bought, is for lawns to get more "green and strong".
Its content is NITROGEN, AMMONIA, BLOOD UREA NITROGEN, PHOSPHORUS PENTOXIDE (P2O5) and POTASSIUM OXIDE (K2O) in the form of water-soluble little spheric white pills.