Het 'VELD'-project: een gedetailleerde inventarisatie van de ammoniakemissies en -concentraties in een agrarisch gebied

During the period June 2002 till September 2003 the pilot project VELD was carried out in the vicinity of the village of Vragender, in the eastern part of the Netherlands. All agricultural activities were administrated and the resulting ammonia emission was calculated. The ammonia concentration in the air was measured at 50 sites within the Vragender pilot area. Comparison of calculated and measured ammonia concentrations in general revealed a good correlation. However, during the period of manure application in spring 2003 a large discrepancy was found. Main reasons for this is an underestimate of the ammonia emissions during manure application under dry and sunny weather conditions and a reduced dry deposition of ammonia during the manure application period