Anbau und Düngung von Winterraps (Brassica napus L.) im Ökologischen Landbau

Summary

At the experimental farm Wiesengut in Hennef (Germany) in 2007/8 four different
cultivation methods of rapeseed and an application of fertiliser in springtime were
tested in order to manage weeds, to reduce nitrogen losses during wintertime and to
enhance grain yield. Cultivation methods tested included i. narrow row distance (12
cm), no mechanical weed control; ii. wide row distance (24 cm), mechanical hoeing;
iii. rapeseed sown in double rows intercropped with buckwheat (Fagopyrum
esculentum Moench) sown in double rows, row distance 12 cm, no mechanical weed
control; iv. rapeseed sown in double rows and left double rows free, row distance
12 cm, mechanical hoeing. In a two factorial completely randomised block design
these treatments were fertilised (I. 80 kgN/ha as PPL, Potato Protein Liquid) and not
fertilised (II.) in March 2008 at EC 30. In contrast to the hypothesis treatment iii.
(rapeseed intercropped with buckwheat) did not control weeds efficiently nor
enhanced nitrogen uptake before winter. Grain yield was significantly lower in this
treatment compared to all other treatments. The most cost-efficient treatment i.
controlled weeds effectively. Grain yield was not significantly lower in this treatment
compared to the more cost-intensive treatments (ii. & iv.) where hoeing was
performed. Across treatments calculated, application of PPL increased grain yield
significantly.