Q1: Urea is a __________ fertiliser.

ANS:A - nitrogenous

Urea is a nitrogenous fertilizer. Urea is one of the most widely used nitrogen fertilizers in agriculture. It contains a high concentration of nitrogen, making it an essential source of nitrogen for plant growth. When applied to the soil, urea undergoes hydrolysis, breaking down into ammonia and carbon dioxide. The ammonia then reacts with water in the soil to form ammonium ions, which are readily taken up by plant roots and utilized for protein synthesis and other metabolic processes. Therefore, urea is primarily valued for its nitrogen content and its role in providing a vital nutrient for plant growth. The term "nitrogenous" refers to substances or compounds that contain nitrogen or are rich in nitrogen. In the context of fertilizers, "nitrogenous" describes fertilizers that provide nitrogen as the primary nutrient for plant growth. Here's an explanation of why urea is considered a nitrogenous fertilizer:

1. Nitrogen Content: Urea is composed of carbon, nitrogen, oxygen, and hydrogen atoms. However, its most significant component is nitrogen, which typically accounts for about 46% of its weight. This high nitrogen content makes urea an excellent source of nitrogen for plants.
2. Nitrogen Importance: Nitrogen is an essential nutrient for plant growth and development. It plays a crucial role in various physiological processes, including photosynthesis, protein synthesis, enzyme production, and the formation of chlorophyll. Adequate nitrogen supply is necessary for plants to achieve optimal growth, yield, and overall health.
3. Nitrogen Transformation: When urea is applied to the soil, it undergoes hydrolysis, a chemical reaction in which water breaks down urea molecules into ammonia (NH3) and carbon dioxide (CO2). The ammonia subsequently reacts with water in the soil to form ammonium ions (NH4+), which are readily absorbed by plant roots and utilized for growth and metabolism.
4. Versatility: Urea is versatile and can be used in various agricultural settings and cropping systems. It can be applied to the soil as a granular fertilizer, sprayed as a liquid solution, or incorporated into blends with other fertilizers to provide a balanced nutrient supply to plants.