Nitrogen fertilizer fate

Birds and animals are tagged so that their wanderings and ultimate fate can be followed. To do the same for nitrogen fertilizer, we use the heavy isotope of nitrogen, as a tag or label . This is a safe isotope to use because it is not radioactive. The of the label is taken up by the crop, incorporated in the soil s... 

Figure 1 Fate of N-labelled nitrogen fertilizer applied to a winter wheat erop. (Taken from Maedonald et...

The fate of the nitrogen fertilizer applied in spring was assumed by harvest... 

Table 4 Fate of nitrogen fertilizer applied in exeess of erop uptake in England and Wales, 1977-1986. Caleulated using the assumptions listed in the text...

Box 4. The Fate of Nitrogen Fertilizer in North America (After Howarth et al, 2002) When nitrogen fertilizer is applied to a field, it can move through a variety of flow paths to surface and grounds waters (Fignre 24). 

Soil represents the final destination for industrial residues and for biological and nonbiological processes. It is possible to obtain mathematical models for the transformation of chemical products in the soil, e.g., the fate of thiocarbamate herbicides in the system, the effect of atrazine on denitrification, and the effect of atrazine on the transformation of a nitrogen fertilizer (urea).31 The chemical-physical model of the behavior of the herbicides in the air-water-solid system is presented in Figure 3.1. 

Fig. 2.50 Fate of applied nitrogen fertilizers to farmland data from Moller und Schiefer-...

Rachhpal-Singh, Kirk GJD. 1993b. A model for predicting fhe fate of nifrogen fertilizer in lowland ricefields. II. Predicted dynamics of inorganic carbon, nitrogen and acidity in the soil and floodwater. Journal of Soil Science 44 285-297. 

Breland T. A. and Hansen S. (1998) Comparison of the difference method and 15N technique for studying the fate of nitrogen from plant residues in soil. Biol. Fertility Soils 26(3), 164-168. 

What is the fate of anthropogenic Nr The immediate fate for the three anthropogenic sources is clear NO from fossil-fuel combustion is emitted directly into the atmosphere R-NH2 from rice and legume cultivation is incorporated into biomass NH3 from the Haber-Bosch process is converted primarily into commercial fertilizer applied to agro-ecosystems to produce food. However, httle fertilizer nitrogen actually enters the human mouth in the form of food in fact, most created Nr is released to environmental systems (Smil, 1999). 

Paul and Clark (11), pp. 147-158. Denitrification is also a particularly effective way of removing that fraction of fertilizer nitrogen that reaches estuary and shelf waters see Nixon, S. W., et al. 1996. The fate of nitrogen and phosphorus at the land-sea margin of the North Atlantic Ocean. Biogeochemistry 35 141-180. Dissolved nitrate in ground waters with low... 

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