SPREADING OF FARMYARD MANURE TO LEY WITH DIFFERENT METHODS - YIELD AND SILAGE QUALITY

A three-year field experiment was conducted with solid (about 740 kg/m (3), 20% DM) and semi-solid (about 870 kg/m(3), 18% DM) dairy cattle m anure to determine the effects of application technique (one-step and two-step spreaders), manure rate (25 and 40 t/ha), and subsequent irri gation (15 mm water) on forage yield, nitrogen removed in yield and si lage quality at the second harvest. The used spreaders was JF, type AV 50, and Hill HS8-2000 (both one-step spreaders) and JF, type ST70-H, m odified (two-step spreader). Field plots fertilized with farmyard manu re together with mineral fertilizer (FYM+NPK) were compared with contr ol plots with solely mineral fertilizer. The effect of FYM+NPK on yiel d, in comparison with mineral fertilizer, was inconsistent and varied between years. The use of manure to silage crops, however, negatively affected the silage quality. Irrigation with 15 mm water immediately a fter spreading reduced the ammonia emission from manured plots by up t o 30%, but had no positive effect either on forage yield or on silage quality. In year two, high application rate (40 t/ha) seemed to have a negative effect on both yield and silage quality (p < 0.05). In gener al, there were no significant differences in yields or silage quality that could be related to application techniques. To reduce the risk of damage caused by covering and/or scorching, a low rate of manure is p referable to a high rate, thereby reducing contamination of the silage crop.