Nitrogen flows on organic and conventional dairy farms: a comparison of three indicators
Artikel i vetenskaplig tidskrift, 2017

This paper analyzes nitrogen (N) flows on organic and conventional dairy farms in Sweden, and compares three indicators for the N pollution associated with the milk: (1) the farm-gate N surplus, (2) the chain N surplus, and (3) the N footprint. We find that, compared to indicators based on N surplus, the N footprint is a more understandable indicator for the N pollution associated with a product. However, the N footprint is not a replacement for the often-used farm-gate N surplus per unit area, since the two indicators give different information. An uncertainty analysis shows that, despite the large dataset, 1566 conventional and 283 organic farms, there is substantial uncertainty in the indicator values, of which a large part is due to possible bias in estimates of biological N fixation (BNF). Hence, although the best estimate is that conventional milk has 10–20% higher indicator values than organic, it is conceivable that improved estimates of BNF will change that conclusion. All three indicators simplify reality by aggregating N flows over time and space, and of different chemical forms. Thus, they hide many complexities with environmental relevance, which means that they can be misleading for decision-makers. This motivates further research on the relation between N surpluses and N footprints, and actual environmental damages.

surplus

indicators

balance

footprint

nitrogen

milk

budget

uncertainty

Sweden

dairy

NUE

organic

conventional

Författare

Rasmus Einarsson

Chalmers, Energi och miljö, Fysisk resursteori

Christel Cederberg

Chalmers, Energi och miljö, Fysisk resursteori

Jonatan Kallus

Chalmers, Matematiska vetenskaper, Tillämpad matematik och statistik

Chalmers, Matematiska vetenskaper

Göteborgs universitet

Nutrient Cycling in Agroecosystems

1385-1314 (ISSN)

1-14

Drivkrafter

Hållbar utveckling

Ämneskategorier

Miljö- och naturvårdsvetenskap

Jordbruksvetenskap

Miljövetenskap

DOI

10.1007/s10705-017-9861-y

Mer information

Skapat

2017-10-07