Question

Name two fertilizers supplying N, P, K to crops.

Answer 1

Hint: Nitrogen, phosphorus, and potassium come under macronutrients for plants. Macronutrients require large amounts and it is essential for plant growth which cannot be replaced by other elements.

Complete Answer:
Compost and manures are two organic fertilizers supplies N, P, K to plant whereas NPK 15-15-15 and NPK 25-4-2 are synthetic fertilizers.

Additional information:
Organic fertilizers like compost and manure are prepared from blood meal, bone meal, cotton seeds, and also by feces of cattle and humans. Organic fertilizers work slowly but it cannot cause any harmful effect to plants and soil. These fertilizers form by decomposition and degradation by microorganisms. NPK value in compost varies from 2-2-1 to 3-2-1 and manure NPK values range from 3-2-1 to 6-4-3. NPK fertilizers aren’t able to kill weeds of lawn due to its slow effect but it is considered a sustainable resource.
Synthetic fertilizers are chemical fertilizers available in the form of solid granules and liquid. It acts fastly on the plant which leads to fast growth and development in the plant. It readily fulfills the deficiency of nutrients therefore it is considered the best choice for farming. These fertilizers are used directly or by mixing with water.
Before using fertilizers it is important to know the composition of elements in soil because low composition leads to deficiency while high composition leads to toxicity. Nitrogen and phosphorus are mobile elements whereas phosphorus is an immobile element therefore it is considered to use fertilizer before sowing seed so that it can easily get a transfer into the plant.

Note: Nutrient deficiency leads to yellowing of leaves, different types of spots on leaves, shunting growth, slender stem, early leaf fall, and many more. The mycorrhizal association is also useful to facilitate the nutrient from root to soil.