Page 29 - Introduction to Agriculture by: Aqleem Abbas

Introduction to Agriculture Notes prepared by: Aqleem Abbas

Secondary nutrients
Ca, Mg, S

Are secondary nutrients these are present in soil to some extent. Therefore these nutrients are called
secondary nutrients.

Nitrogen

Nitrogen is most important in all over the world

Cell division and cell enlargement

Important for vegetative growth.

Present in enzymes and proteins.

It is important for the protoplasm formation.

Nitrogen Is important for plumbness of seeds

Chlorophyll formation

Greenery of plants depends on nitrogen.

Deficiency symptoms of nitrogen

Leaves of plant become yellow due to deficiency of nitrogen. This process is called chlorosis.

Cell development and cell enlargement stops than plant has stunted growth.

Deficiency of nitrogen causes decrease in no of tillers and inflorescence and also decrease in protein.
Similarly quality of sed.

Excess of nitrogen

When nitrogen increases than the optimum will delay crop maturity.

Excess of nitrogen will increase plant height. It will cause lodging.

Excess of nitrogen in fiber crops decrease the fiber quality.

Excess of nitrogen in fodder crops is toxic to animals. Excess of nitrates cause cancer.

Excess of nitrogen is not economical to the farmers.

Excess of nitrogen increases impurities in sugar.

Phosphorous

Phosphorous is second most important nutrients after nitrogen. It is component of energy rich
compounds. Phosphorous is also component of RNA and DNA. Phosphorous application to crops can