Denitrification nitrogen losses

Nowicki, B.L., Kelly, J.R., Requintina, E., and van Keuren, D. (1997) Nitrogen losses through sediment denitrification in Boston Harbor and Massachusetts Bay. Estuaries 20, 626-639. 

Nitrogen is returned to its atmospheric form by the action of denitrifying bacteria such as Pseudomonas thiobacillus and Micrococcus denitriflcans. The process is referred to as denitrification and represents the major mechanism of nitrogen loss in the overall nitrogen cycle whereby various forms of nitrogen in the soil revert to the N2 form. The reactions and their energetics are given below ... 

The major modes of nitrogen losses from the Bay of Bengal are sedimentary denitrification and burial. Note that the estimate for sedimentary denitrification (3 Tg N year ) is based on only one measurement at the outer shelf off Chennai (Naik, 2003), while the burial in sediments was computed from the carbon burial using a C N value of 10. 

The reduction of nitrate via nitrite to ammonia occurs in soils at low rates (Rosswall, 1982). If it were possible to stimulate the reduction of nitrate to ammonia and then its incorporation into the organic matter (reaction 4), large nitrogen losses resulting from denitrification could be prevented so that a high fertility status could be maintained. 

The main nitrogen losses from marshes are caused by denitrification and detrital export and sedimentation sinks. Denitrification has been reported to be the major cause of nitrogen loss from marshes. Although the potential for denitrification is very high in the reduced marsh soil, the level of in situ denitrification depends on the availability of nitrate. Nitrate must be either formed through nitrification of ammonium or supplied from an extrinsic source such as tidal input, wet deposition, or groundwater flow. 

The excesses of nitrogen application over crop uptake in the individual years from 1977 to 1986 were read from Figure 4 of Sylvester-Bradley et and subjected to the rules. Neither the leaching nor the denitrification losses seemed particularly large (Table 4), given that these were aggregate values for ten years, and the amount of nitrogen that was remineralized and then leached seemed very unlikely to be important. 

The interest in gaseous losses of nitrogen from soil is now extensive and includes the well established community of soil scientists concerned with losses of fertilizer-applied nitrogen by nitrification and denitrification. More recently, interest in ammonia losses from plants and soil has been stimulated by the very large emissions from intensive cattle production in the Netherlands and their... 

K. A. Smith and J. R. M. Arah, Losses of Nitrogen by Denitrification and Emissions of Nitrogen Oxides from Soils, The Fertiliser Soeiety, 1990, Proeeedings No. 299. 

Rolston, D. E. (1981). Nitrous oxide and nitrogen gas production in fertilizer loss. In "Denitrification, Nitrification, and Atmospheric Nitrous Oxide" (C. 

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