Question

Ideal NPK ratio for Indian soils is______?
A. \[8:4:2\]
B. $4:2:1$
C. $9:5:3$
D. $2:1:0.5$

Answer 1

Hint:As we all know that NPK value or ratio is related to the nutrients present in the fertiliser which are labelled on the packets in terms of Nitrogen, Phosphorus and Potassium amount present in that fertiliser.

Complete step-by-step answer:As we have discussed that the soil may not contain all the nutrients which are required for the growth of various crops. We also know that there are a total of six nutrients which are primarily required by the plants from the soil and these are carbon, hydrogen, oxygen, nitrogen, phosphorus and potassium. Therefore the soil with limited nutrients is provided with nutrients from outside using fertilisers.
These fertilisers are labelled with NPK ratio giving information about the content of nitrogen, phosphorus and potassium. The ratio of NPK found in Indian soils is about $4:2:1$. These values are present in terms of percentage to their weight in the fertilisers.
The Nitrogen is advantageous for the plants as they use it for the growth of leaves, flowering and fruit bearing ability. Phosphorus is used for the development of roots, seeds, fruits and flowering purposes and finally the Potassium which we know enhances the overall growth of plants and helps in making the plant tolerant to extreme conditions.

Therefore, the correct answer is (B).

Note:Remember that the plants generally require large quantities of Nitrogen, Phosphorus and Potassium for their proper growth. Without enough nitrogen, plant growth becomes slow and plants may turn pale, Phosphorus absence makes the roots of plants very weak and thus no flowering and fruiting take place.