Life cycle assessment nitrogen cycles

Brentmp, F., Kiisters, J., Kuhlmarm, H., I.ammel, J., 2001. Application of the life cycle assessment methodology to agricultural production an example of sugar beet production with different forms of nitrogen fertilisers. Eruopean Journal of Agronomy 14, 221-233. 

Singh S, Bakshi BR. Accounting for the biogeochemical cycle of nitrogen in input-output life cycle assessment. Environ Sci Technol 2013 47(16) 9388—96. 

Most LCAs are performed only xmtil Step 2, since impact assessment and interpretation involve many more qualitative assumptions. In this case, LCA are called life cycle inventories (LCIs). This latter is a tool required to estimate the direct and indirect inputs of each step of a biofuel pathway. The results are the use of resources (eg, energy consumption) and the environmental emissions (eg, CO2, sulfur oxides, nitrogen oxides). LCIs permit the assessment of impact categories, such as climate change, photooxidant formation, acidification, eutrophication, ecotoxicity and human toxicity, and the depletion of biotic and abiotic resources. These factors of the LCI will be converted into environmental damages. Various indicators can be derived from these mechanisms at intermediate levels (midpoints) or damage levels (endpoints) after normalization, often weighting approaches. 

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