Introduction

For satisfactory crop growth and production, there is a need of proper nutrition to the crop as there are 16 elements that are essential for the growth of plant. These 16 elements are derived from the soil, present in the form of inorganic salts. 94-95% of plant material contains carbon, hydrogen and oxygen. Other 6% contain other nutrients such as calcium, phosphorous, nitrogen etc.

Any compound which contains one or more chemical elements that may be present in organic or inorganic form is known as fertilizers. These fertilizers may be natural or synthetic. In agricultural activities, Fertilization are used to increase the efficiency and better quality of product recovery.

Role of Nitrogen in Plant

For the successful growth of plant, nitrogen element plays a vital role because of the protein and chlorophyll are the essential constituents of the plants. Less than 5% of inorganic nitrogen (NH4, NO2, and NO3) in soil that are absorbed by most of the plants. To maintain the nutritional condition of different cropping systems, Inorganic and organic fertilizers are applied to the crops. In an organic agricultural system, the quantity of nitrogen, phosphorous, calcium, magnesium and potassium are increased by the continuous application of manure. After applying the organic fertilizers to the soil, Inorganic nitrogen is released and absorbed by the plants during the beginning of mineralization. Therefore, mineralization rate is controlled by several factors such as agricultural management, microorganism, soil properties, temperature water content and type of organic fertilizer.

Once, agricultural system is treated by the nitrogen fertilizer that is directly absorbed by the plants. This absorbed fertilizer converts into various different forms by the oxidation process. Through the leaching, volatilization and denitrification, excess nitrogen is lost in ionic or gaseous form. Nitrogen fertilizer is carried away by runoff or leaches into the soil with water, if it is not absorbed by the plants. As the large quantity of the nitrogen fertilizer is applied due to which the phytoavailability of nitrogen pool increases and cause the potential threat to the surrounding environment. It shows the close relationship between the excessive nitrogen fertilizers and environmental problems i.e., eutrophication, greenhouse effect, and acid rain (Liu et al., 2014).

A significant role is played by the soil and climate condition in uptake and utilization of Nitrogen. Hence, before conducting any experiment to know the response of nitrogen on the growth and productivity of diverse crop species, the condition of soil and climate of any particular region must be considered. There are some advantages of nitrogen as follows:

• Nitrogen give the dark green color to the plants,

• Promote leaves stem, and other vegetables part’s growth and development.

• Stimulate Root growth

• Improve fruit quality

• Enhance the growth of leafy vegetables

• Increase the protein content of fodder crops (Leghari et al., 2016).