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 essential to all living systems, which makes the nitrogen cycle one of Earth's most important nutrient cycles. Eighty percent of Earth's atmosphere is made up of nitrogen in its gas phase. Atmospheric nitrogen becomes part of living organisms in two ways. The first is through bacteria in the soil that form nitrates out of nitrogen in the air. The second is through lightning. During electrical storms, large amounts of nitrogen are oxidized and united with water to produce an acid that falls to Earth in rainfall and deposits nitrates in the soil.