A. Panse et al., EFFECT OF COMBINED SLURRY AND MINERAL FER TILIZATION ON YIELD FORMATION, YIELD COMPONENTS AND NITROGEN EFFICIENCY OF WINTER-WHEAT, Zeitschrift fur Pflanzenernahrung und Bodenkunde, 158(3), 1995, pp. 221-229
From 1984/85 to 1987/88 field trials were conducted on the experimenta
l farm Roggenstein in order to examine the efficiency of pig slurry ap
plied at different developmental stages of winter wheat combined with
different dosage and distributions of mineral N-fertilizer. On the ave
rage over 4 years maximum grain yield by applying exclusively mineral
N-fertilizer has been achieved with 120 kg N/ha, with the optimal amou
nt of N-fertilizer at the 3 developmental stages being 40 kg N/ha, res
pectively. Decreased yields induced by a reduced mineral N-fertilizati
on could be compensated by application of 20 m(3)/ha or 40 m(3)/ha slu
rry either at the beginning of the growing period. EC 30-31 or EC 33-3
5 developmental stages. However, mineral fertilizer equivalents calcul
ated on the oasis of the NH4-N-content of slurries for each year range
d from 25 to 79 in dependence of application date and prevailing, weat
her conditions. Regarding the effect on yield components, no differenc
e between slurry and mineral N-fertilizer were observed. The mediocre
and very variable efficiency of slurry-N leads to the conclusion, that
the use of slurry in cereal production may be of limited value for ag
ronomic as well as for ecological reasons, as long as no efficient and
cost-effective application techniques are available.