Page 29 - Introduction to Agriculture by: Aqleem Abbas
P. 29
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