nitrogenous fertilizers

7/29/2019 Nitrogenous Fertilizers

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Nitrogenous Fertilizers:Types of Nitrogenous Fertilizers:According to the manner in which their nitrogen is combined with other elements, the

nitrogenous fertilisers are divided into four groups; nitrate, ammonia, and ammonium salts,

chemical compounds containing nitrogen in the amide form, and plant and animal by-

products.

I. Inorganic Nitrogenous Fertilizers

Inorganic substances containing large amount of nitrogen come under this category. It is

further divided into following groups according to the form of nitrogen they contain.

1. Nitrate fertilizers (NO3- ): Nitrogen present in these fertilizers are in nitrate form,NO3

-which are rapidly dissociated to release NO3

-ions and readily absorbed by the

plants. Nitrate ions highly reactive and mobile are susceptible to losses due to

leaching and under water-logged conditions by denitrification. They are alkaline in

their residual effect in soil. Following are the nitrate fertilizers:

S.

No.

Fertiliser % N

1 Sodium nitrate (NaNO3) 16%N

2 Calcium nitrate Ca(NO3) 2 15.5%N

1. Ammonium fertilizers (NH4+): Ammonium fertilizers are soluble in water and, assuch, absorbed on the soil colloids and thus protected from being washed away by

run off or by leaching. Some crops like rice, sugarcane, tuber crop, seedlings directly

utilize ammonium form of these fertilizers. The absorbed ammonium ions on soil

collections are transformed to nitrate slowly and taken up by most of the crops. They

are acidic in their residual effect in soil. Following are the ammonium fertilizers:

S.

No.

Fertiliser % N

1 Ammonium Sulphate(NH4)2SO4 20.6%N

2 Ammonium ChlorideNH4CL 25%N

3 Ammonium phosphate---NH4 (H2PO4) 20%N

4 Anhydrous ammonia --NH3 82%N

5 Ammonia Solution --NH3 in water 20 to 25%N

2. Nitrate and Ammonium fertilizers (Nitrate, NO3- and ammonium, NH4+ ): Thesefertilizers contain nitrogen in both nitrate (NO3

-) and ammonium forms (NH4

+). The

nitrate nitrogen is readily available to plants for immediate need, whereas

ammonium nitrogen becomes available to plants at a later stage, when it is


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transformed by microbiological process to nitrate. They are soluble in water and

suitable for most of the crops and soils. They are acidic in its residual effect.

S.

No.

Fertiliser % N

1 Ammonium nitrate---NH4NO3 33 to 34%N

2 Calcium Ammonium Nitrate (CAN)

Ca(No3) 2NH4NO3

25%N

3 Ammonium Sulphate Nitrate (ASN)

(NH4) 2SO4NH4NO3

26%N

II. Organic Nitrogenous Fertilizers:

These fertilizers contain nitrogen in organic form. These include plant and animal by-

products.

These fertilizers are relatively slow-acting but they supply nitrogen for a longer

period.

1. Amide Fertilizers (Amine, NH2 or amide, CN2): These fertilizers contains nitrogen inorganic compounds as amideNH2 or ---- CN 2 , not directly available to plants, as

such , but quickly converted by soil microbes to ammoniacal and nitrate form and

then utilized. Amide fertilizers are:

S.

No.

Fertiliser % N

1 Urea CO(NH2) 2 46%N

2 Calcium cyanamide CaCN2 21%N

2. Slow release nitrogenous fertilizers: These are newly developed fertilizers whichrelease nitrogen in soil very slowly so that it may be available to the plants for longer

period of time. Use of these materials result in better utilization of applied nitrogen

by the growing crop plants and reduces losses.

S.

No.

Fertiliser % N

1 Urea-form (Urea+Formaldehyde) 38%N

2 Oxamide H2NCO--CONH2 31.8%N

3 Isobutylidinediurea (IBDU) (Urea+Isobutylaldehyde)(CH3) 2----

CH=CH(NH---CO---NH2) 2

32.2%N

4 Crotonilidinediurea (CDU)(Urea+acetaldehyde) 32% N

5 Guany1 urea (GU) 37% N

6 N-lignin (Ammonified lignin) 18% N

7 Sulphur coated urea (SCU) 36 to 40% N

8 Metal-ammonium phosphate Me.NH4PO4 x H2O

If Me is Mg 8.3%N" Fe 7.5%N


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" Cu 7.2%N

" Zn 7.8%N

" Mn 7.5%N

" Co 6.1%N

9 Nutricate, Osmocate Mixed fertilizers

coated

with various resin

containing release

controlling agents,

additives

Raw Materials :The fertilizers are compound fertilizers composed of primary fertilizers and secondary

nutrients.The raw materials, in solid form, can be supplied to fertilizer manufacturers in bulk

quantities of thousands of tons, drum quantities ,or in metal drums and bag containers.

Primary fertilizers include substances derived from nitrogen, phosphorus, and potassium.

Various raw materials are used to produce these compounds. When ammonia is used as the

nitrogen source in a fertilizer, one method of synthetic production requires the use of

natural gas and air. The phosphorus component is made using sulfur, coal, and phosphate

rock. The potassium source comes from potassium chloride, a primary component of

potash.

Secondary nutrients are added to some fertilizers to help make them more effective.

Calcium is obtained from limestone, which contains calcium carbonate, calcium sulphate,

and calcium magnesium carbonate. The magnesium source in fertilizers is derived from

dolomite. Sulfur is another material that is mined and added to fertilizers. Other mined

materials include iron from ferrous sulfate, copper, and molybdenum from molybdenum

oxide.

The Manufacturing Process :Fully integrated factories have been designed to produce compound fertilizers. Depending

on the actual composition ofthe end product, the production process will differ from

manufacturer to manufacturer.


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Nitrogen fertilizer component :Ammonia is one nitrogen fertilizer component that can be synthesized from in-expensive

raw materials. Since nitrogen makes up a significant portion of the earth's atmosphere, a

process was developed to produce ammonia from air. In this process,

natural gas and steam are pumped into a large vessel. Next, air is pumped into the system,

and oxygen is removed bythe burning of natural gas and steam. This leaves primarily

nitrogen, hydrogen, and carbon dioxide. The carbon dioxideis removed and ammonia isproduced by introducing an electric current into the system. Catalysts such as magnetite

(Fe3O4 ) have been used to improve the speed and efficiency of ammonia synthesis. Any

impurities are removed fromthe ammonia, and it is stored in tanks until it is further

processed.

While ammonia itself is sometimes used as a fertilizer, it is often converted to other

substances for ease of handling. Nitric acid is produced by first mixing ammonia and air in a

tank. In the presence of a catalyst, a reaction occurs which converts the ammonia to nitric

oxide. The nitric oxide is further reacted in the presence of water to produce nitric acid.


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Nitric acid and ammonia are used to make ammonium nitrate. This material is a good

fertilizer component because it has a high concentration of nitrogen. The two materials are

mixed together in a tank and a neutralization reaction occurs, producing ammonium

nitrate. This material can then be stored until it is ready to be granulated and blended with

the other fertilizer components.

Phosphorousfertilizer component :To isolate phosphorus from phosphate rock, it is treated with sulfuric acid, producing

phosphoric acid. Some of this material is reacted further with sulfuric acid and nitric acid to

produce a triple superphosphate, an excellent source of phosphorous in solid form.

Some of the phosphoric acid is also reacted with ammonia in a separate tank. This reaction

results in ammonium phosphate, another good primary fertilizer.

Potassium fertilizer component :Potassium chloride is typically supplied to fertilizer manufacturers in bulk. The manufacturer

converts it into a more usable form by granulating it. This makes it easier to mix with other

fertilizer components in the next step.


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Advantages of Organic Fertilizers :Organic fertilizers have been known to improve biodiversity (soil life) and long-term

productivity of soil, and may prove a large depository for excess carbon dioxide.Organic nutrients increase the abundance of soil organisms by providing organic matter andmicronutrients for organisms such as fungal mycorrhiza, (which aid plants in absorbing

nutrients), and can drastically reduce external inputs of pesticides, energy and fertilizer, at

the cost of decreased yield.

Disadvantages of Organic Fertilizers : Organic fertilizers may contain pathogens and other disease causing organisms if not

properly composted

Nutrient contents are very variable and their release to available forms that theplant can use may not occur at the right plant growth stage

Organic fertilizers are comparatively voluminous and can be too bulky to deploy theright amount of nutrients that will be beneficial to plants

More expensive to produce No so handy to apply in the soil

Advantages and Disadvantages of UsingInorganic Fertilizers :Inorganic fertilizers are also known as synthetic or artificial fertilizers. These kinds of

fertilizers are manufactured. Inorganic fertilizers do not need a certain time to be broken

down or decomposed before usage because these contain nutrients that can be readily

absorbed by plants.

Advantages of Using Inorganic Fertilizers : Works immediately:Inorganic fertilizers are usually given as a rescue treatment to plants th at are

malnourished, unhealthy or even dying. Inorganic fertilizers are appropriate in this situation

because the nutrients needed by the plants are readily available. In comparison, using an

organic fertilizer would mean that the plant has to wait until the components of the organic

fertilizer have been broken down first into its primarynutrients. By then, the plant could be

dead already.


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Contains all necessary nutrients that are ready to useInorganic fertilizers are designed to give plants all the nutrients-Nitrogen, Phosphorous and

Potassium that they need in appropriate proportions and amounts. Hence, plants do not get

more of one can of nutrient over the other. Instead it has a balance of all the nutrients it

needs and are readily available at a given time. Adding inorganic fertilizers into the soil to be

planted makes the soil ideal for planting as it is already enriched with nutrients.

AffordableYou do not have to spend much on buying an inorganic fertilizer because it is relatively

cheap. Of course, it is not as cost-effective when compared to using compost. Yet, for theconvenience that it gives you when it comes to caring for your plants, an inorganic fertilizer

is a very good deal already.

Convenient to useIt takes awhile to make your own organic fertilizer. Though the process is relatively easy to

do, still you need to delegate enough time to do the task and wait for the decomposition

part to take place. It takes a while. With an inorganic fertilizer, you save a lot of time and

effort. Inorganic fertilizers are quite cheap and even easier to use and prepare. They are

available at almost every gardening store.

The Disadvantages of Using InorganicFertilizers: Leeching happensInorganic fertilizers contain nutrients that have been broken down already into the most

basic of its components for easy absorption by the plants. Yet, it can also be washed away

easily when watering or irrigating the plants. This is called leeching. Leeching happens very

often as you water your plants. Hence, a lot of the fertilizer goes to waste. Nitrogen is one of

the elements that easily get washed away since it usually settles below the roots of the

plants quickly. This is called leeching, and it happens very often. When youre using

inorganic fertilizers you need to pay special attention to the roots of the plant when youre

watering it and not over water the area so that youre not encouraging the leeching of the

nutrients in the soil.


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Some are not affordableGenerally, inorganic fertilizers are inexpensive. Yet, some specially formulated inorganic

fertilizers come at a cost that are considerably higher than most.

Accumulation of toxic wastesInorganic fertilizers are not entirely composed of the nutrients needed by the plants. It also

contains salts and other compounds. These are not absorbed by the plants so they are left

behind in the soil and build up over time. When found in large amounts in the soils, these

compounds can alter the chemistry of the soil that makes it less ideal for planting. Often

times, the soil needs to be neutralized using other substances to return it to a normal state

that is suitable for planting. Furthermore, these toxic compounds may also get washed away

when you water your plants and seep into groundwater. It has been reported that the toxic

wastes from fertilizers contaminating the water we drink is bad for the health.

Too much is not a good thingFertilizers are good sources of nutrients for plants. However, too much of it can also be

harmful to the plants. Applying the fertilizer directly to the plants may burn the delicate

plant structures such as the roots. This could affect the over-all development of the plant.

Inorganic fertilizers have both good and bad points. Should you consider using them, better

maximize and the advantages and try to prevent all its avoidable disadvantages.

nitrogenous fertilizers

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