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.
Excretion and decay then return the nitrogen to the soil as ammonia, which is converted back to nitrate by bacteria. Nitrogen fixation-a process carried out by certain algae and soil bacteria whereby atmospheric nitrogen is incorporated to form nitrogen-based organic compounds. A crucial part of the nitrogen cycle. Nivation-the expansion of a hollow through freeze-thaw under a patch of snow and the subsequent washing out of the debris by meltwater. Nivation hollow-a circular depression in the ground, usually seen in periglacial areas, that has been created by nivation. Node-in a transport network, a point where links join.