Entec nitrogen fertilizer delays nitrification of ammonium with the ammonium-stabilizer DMPP (3,4-dimethyl pyrazole phosphate) for 4-10 weeks according to environmental conditions. Field trials at Geisenheim, Germany, were initiated in spring 2000 with asparagus Eposs. The sandy soil was enriched with farmyard manure and bio-compost. Entec was applied on 21 June 2001 and ammonium sulfate salpeter (ASS) was used as control. Both fertilizers had 26% N and treatment rates were 45 kg N/ha.