1. Fertilizers

2. Fertilizers
Based on the type of improvement desired for the soil quality, fertilizers are divided in three categories: 1. Organic: enrich the soil with one or more nutritional elements absorbed by plants; 2. Amendments: any organic or inorganic substance that can provide the plant with the elements necessary for growth; 3. Corrective: as the name implies, these are any substance that is capable of modifying or improving the chemical composition of soil. For example, they are used to change the pH of soil to desired levels.

3. The most essential requirements for plants are water and sunlight
The most essential requirements for plants are water and sunlight. Then there are the nutritional requirements: • Macronutrients: Nitrogen (N), Phosphorous (N), Potassium (K), and Calcium (Ca); • Micronutrients: Iron, Copper, Manganese, Zing, and Sulphur, which plants assimilate from the soil.

4.  Natural fertilizers are organic products that have been extracted from living things or from the earth. They can be either plant-derived or animal-derived. Some examples would be mushroom manure,, cottonseed meal, kelp meal, poultry or horse manure (aged) and compost.
In general, natural fertilizers contain lesser amounts of N-P-K than their synthesized counterparts, so you need to use more of them to supply the plant with the required amount of nitrogen, phosphorus or potassium.
Natural fertilizers add vital organic matter, they also improve soil texture — an important advantage
Organic fertilizers add humus to the soil and help in better water retention and aeration of soil.
Also provide food to soil organisms like earthworms, bacteria and fungi.
Donot pollute the environment and are not toxic.

5. Synthetic fertilizers are those composed of the synthesized chemicals of nitrogen, phosphorus and potassium.

7. Important nutrients (NPK)
Nitrogen :
Phosphorous
Potassium

8. TYPES
Chemical, or inorganic, fertilizers are those produced industrially and are nutritionally balanced by mixing macro and micronutrients in proportions based on desired plant requirements.
There are various types of chemical fertilizers, such as:
1. Nitrogen-rich, that promotes stem and leaf growth, and is suitable for evergreens and grasses;
• Urea
Ammonium sulphate
Ammonium nitrate
Sodium nitrate

9. 2. Phosphorous-rich, that stimulate root growth and is thus suitable for plant early growth. It is indicated mostly for flowering plants;
- deficiency causes stunted growth and graying of leaves.
Calcium dihydrogen phosphate
Ammonium hydrogen phosphate
Ammonium phosphate
Di-ammonium phosphate

10. 3. Potassium-rich, that stimulates flower and fruit growth, and the formation of the lignifying protective layer of stem;
- deficiency causes leaves to die early.
Potassium nitrate
Potassium chloride
Potassium sulphate

12. Manufacture of urea