Source of nutrients
Organic source:
- Organic fertilizers are natural materials of either plant or animal origin, including livestock manure, green manures, crop residues, household waste, compost,and woodland litter.
- Organic fertilizers include both plant and animal bi-products.
- They are slow acting.
- Organic nitrogen fertilizers include oil cakes, fish manure, dried blood from slaughter houses etc.,whereas organic phosphorus fertilizers are from bone meal and organic potassium from cattle dung ash,wood ash, leaf mould, tobacco stems and water hyacinth.
Advantages
Organic fertilizers mobilize existing soil
nutrients.
They increase physical and biological
nutrient storage mechanisms in soils,
mitigating risks of over-fertilization.
They helps to release nutrients at a slower
and consistent rate.
They help to retain soil moisture, reducing
the stress due to temporary moisture stress.
They improve the soil structure.
They help to prevent top soil erosion.
Disadvantages
It require large amounts to be applied to have desirable effects.
Transporting large amount of fertilizer incurs higher costs, especially with slurry and manure.
The composition of organic fertilizers tends to be more complex and variable than a
standardized inorganic product.
More labor is needed to compost organic
fertilizer, increasing labor costs.
Unavailability of seed for green manures is one of the major limitations.
Green manures must occupy land at a time
when other food crops could be grown.
Inorganic source
Inorganic (or mineral) fertilizers are fertilizers mined from mineral deposits with little processing (e.g., lime, potash, or phosphate rock), or industrially manufactured through chemical processes (e.g., urea).
Inorganic fertilizers vary in appearance
depending on the process of manufacture.
The particles can be of many different sizes
and shapes (crystals, pellets, granules, or
dust).
Inorganic fertilizer could be classified into
three based on the nutrient composition as
follows:
1. Straight fertilizers:
These are fertilizers which contain and supply one or single nutrient element only.
They could be nitrogenous,phosphatic or potassic fertilizers supplying nitrogen, phosphorus or potassium, respectively.
2. Complex/Compound fertilizers:
These are fertilizers which contain two or more nutrient elements usually combined in a homogeneous mixture by chemical interaction.
Complex NPK fertilizers have the advantage of having each nutrient in each granule.
3. Fertilizer blends or mixed fertilizers:
These are fertilizers formed by physically
blending mineral fertilizers to obtain
desired nutrient ratios.
Two or more of the separate fertilizer carriers or straight fertilizers are mixed to obtain the desired nutrient ratios. Examples are NPK 15-15-15, NPK 20-10-10 etc.
Advantage and disadvantage of inorganic fertilizer
Organic manure
• Organic manure are bulky in nature and supply nutrients in small quantities and organic matter in large quantities.
Importance and scope:
• Organic manure provides all the nutrients that are required by plants but in limited quantities.
• It helps in maintaining C:N ratio in the soil and also increases the fertility and productivity of the soil.
• It improves the physical, chemical and biological properties of the soil.
• It improves both the structure and texture of the soils.
• It increases the water holding capacity of the soil.
• Due to increase in the biological activity, the nutrients that are in the lower depths are made available to the plant.
Types
Bulky:
This consists of the slow acting organic
manures with large quantities of organic
matter.
Examples are cattle, sheep, poultry, pig, goat,horse manures, compost, green manures, and sewage, sludge.
Concentrated :
This consists of the quick acting organic
manures with small quantity of organic matter.
Examples are groundnut cake, castor cake,
bone meal, blood meal, horn meal, wood ash,cotton and linseed Meal.
Chemical fertilizers
• Fertilizers are defined as materials having
definite chemical composition with a high
analytical value that supply essential plant
nutrients in available form.
• They are usually manufactured by
industries and sold with a trade name.
• They are commonly synthetic in nature and also called as chemical fertilizers/
inorganic fertilizers/commercial fertilizers
other than lime and gypsum.
Types of chemical fertilizers
1. Nitrogenous fertilizers:
• Nitrogen is the first fertilizer element of the macronutrients usually applied in
commercial fertilizers.
• Nitrogen is a very important nutrient for
plants and it seems to have the quickest and
most pronounced effect.
• In the case of nitrogenous fertilizers,
nitrogen may be in the ammonical, nitrate
(or a combination thereof) or amide form.
• Nitrogen content in urea: 46%
2. Phosphatic fertilizer
• Phosphorus is the second fertilizer element after N and it is an essential constituent of every living cell and for the nutrition of plant and animal.
• It takes an active part in all types of
metabolism of plant. Phosphate present in
phosphatic fertilizers may be in the water
soluble form or citrate soluble form.
• The sum of water soluble and citrate soluble values is termed as available phosphates.
• Phosphorus content in SSP = 16 %, DSP =
32% and TSP = 48%
3.Potassic fertilizer
• Potassium is the third fertilizer element.
• Potassium acts as a chemical traffic
policeman, root booster, stalk strengthener,
food former, sugar and starch transporter,
protein builder, breathing regulator, water
stretcher and as a disease.
• The potassium content in Muriate of
Potash = 60%
Micronutrients
• Micronutrients are those which required by plants in very minute quantities by plants but they have equal role as that of primary nutrients.
• They govern most of the physiological as
well as biochemical reactions of plant
growth and development.
• The most important micronutrients are iron, manganese, zinc, copper, molybdenum,chlorine, boron and nickel.
• Fe carrying fertilizers: Ferrous sulphate, Ferric sulphate.
• Boron carrying fertilizer: Borax, Boric acid.
• Manganese carrying fertilizer: Manganese
sulphate.
• Zinc carrying fertilizer: Zinc sulphide, Zinc
oxide.
• Molybdenum carrying fertilizer: Sodium
Molybdate, Ammonium molybdate.
• Copper carrying fertilizer: Copper sulphate.
Biofertilizer
• Bio fertilizers are cultures of microorganisms (bacteria, fungi, algae).
• They benefits the soil and plants growth by providing N & P and also brings about the rapid mineralization of organic materials in soils.
• They are capable fixing N, solubilizing and mobilizing the phosphorus and mineralizing organic matter in soil.
• Their incorporation improves the physical and biological properties of soils.
• e.g. Azotobacter, Blue Green Algae, Rhizobium,Azospirillum, Phosphate Solubilizng Biofertilizer (PSB), Azolla, etc.
Benefits
• Germination increase up to 20 percent.
• Improved seedling emergence and growth.
• Increase yield from 10 to 40 percent. - Improve the quality of fruit and keeping quality.
• Saving of 25 to 35 percent inorganic fertilizers.
• Increase the availability and up take of N and P in plants.
• Improve the status of soil fertility maintain good soil health and crop productivity.
Thank you all dear Friends
Note is provided by Senior Instructor Of TRIVENI SECONDARY SCHOOL AG BRANCH
NAME: Krishana Poudel.
Distributor student
Name: Bibash Lamichhane.
