REDUCTION OF AMMONIA EMISSIONS AFTER APPL ICATION OF LIQUID CATTLE MANURE ON ARABLE LAND AND GRASSLAND - COMPARISON OF WIDE SPREAD APPLICATION, APPLICATION IN NARROW BANDS AND INJECTION

The influence of different application techniques (broadcast applicati on, application in narrow band and injection) of liquid cattle manure on NH3-N-emissions were measured. On grassland emissions declined from 38-74 % after broadcast application to 7-23 % of applied NH4+-N after injection, which on arable land gave respective values ranging from 6 .1 to 0 %. The ammonia emissions after injection on grassland depended on dry matter content and the pollution by liquid manure,. the grass next to the injection slot. After injection on arable land, lowest emi ssions were Observed after covering the injection slot with soil (flat injection). Compared to broadcast application, application in narrow bands reduced NH3-N-emissions only in one experiment. In contrast, NH3 -N-losses were greater after application in narrow bands to winter whe at (50 cm height) during flowering, to spring barley stands at tilleri ng, and to grassland. Incorporation of liquid manure by a disc harrow 30 hours after broadcast application to frost-killed mustard crops sto pped further NH3-N-emissions, but was too late for substantial reducti on of losses.