Holiday Weather. Less rain and more sun is the main theme during the third month of the year, and a very popular time to visit Madrid, as the fleeting spring season begins. You can expect an average temperature of around 10Â°C during March, which actually reaches a very pleasant 16Â°C on a good day, and goes down to an average low of 4Â°C in th...
The nitrogen cycle is the process by which nitrogen is converted from organic to inorganic forms; many steps are performed by microbes. Learning Objective. Key Points. Nitrogen is converted from atmospheric nitrogen (N2) into usable forms, such as NO2-, in a process known as fixation.
The Nitrogen Cycle. Nitrogen is also key in the existence of ecosystems and food chains. Nitrogen forms about 78% of the air on earth. But plants do not use nitrogen directly from the air. This is because nitrogen itself is unreactive, and cannot be used by green plants to make protein. Nitrogen gas therefore, needs to be converted into nitrate compound in the soil by nitrogen-fixing bacteria in soil, root nodules or lightning. To understand the cycle better, let us consider the diagram below: 1.