Nitrogen reservoirs nitrate

The rank order of size of the reservoirs of nitrogen on earth are atmospheric N2, nitrate in sea water, and organic nitrogen of the biosphete and soils (Sverdrup et al., 1942), Nitrite and free ammonium are rare by comparison. Nitrate is also found at low concentrations in soils and fresh water. NO is extremely rare in the environment and when detected in sea water is typically at concentrations of less than 1 nM (Ward and Zafiriou, 1988). 

Between the filter and the nitrator a reservoir of compressed air, fitted with a safety valve set for 4 atm pressure, should be installed. In the event of any breakdown in the compressor and any pause in the in-flow of compressed air, a steel cylinder filled with compressed nitrogen (or carbon dioxide) kept ready for this emergency should be used to supply gas to the stirrer pipe. While stirring is interrupted the supply of glycerine to the nitrator must be stopped. 

Weeds host pathogens and nematodes and use soil nutrients. One example is pigweed, a luxuriant extractor of soil nitrogen that causes nitrate deficiencies in the sugarcane plant. Weedy grasses serve as an alternate hosts and reservoirs for systemic viruses, and they harbor insects that carry diseases to sugarcane. Rats find shelter in weedy fields. Because stalk juice alone does not provide an adequate diet, rats are attracted to weed seeds as a source of protein. 

Only a small percentage of the chlorine released by photolysis of CFCs is present in the active forms as Cl or CIO, however. Most of it is bound up in reservoir compounds such as hydrogen chloride and chlorine nitrate, formed respectively by hydrogen abstraction (equation 10) from methane and addition (equation 11) to nitrogen dioxide. Slow transport of these reservoir species across the tropopause, followed by dissolution in tropospheric water and subsequent rain-out, provide sink processes for stratospheric chlorine. 

The chemical form of the nitrogen depends on the reservoir. In the atmosphere, except for trace amounts of N2O, NO, NH , and organic N, it occurs as N2. In oceans and soils, it primarily occurs as organic nitrogen, nitrate, and ammonium. 

The amount of carbon present in soil is closely related to the CO2 content of the atmosphere. But atmospheric CO2 is regulated mainly by the ocean rather than by soil (see Section 2). The amount of nitrogen in the soil also does not influence the N pool in the atmosphere because the atmosphere is a huge reservoir regulated mainly by the ocean (Butcher efal, 1992). Nevertheless, the soil has a tremendous influence on the nitrate load of the rivers (see Section 3). 

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