A long-term trial was established in Frick, Switzerland (47◦30
N, 8◦01 E) involving the following factors: tillage, fertilization and
biodynamic preparations. A detailed description of the field trial is
given by Berner et al.(2008) and Gadermaier et al.(2012). The mean
annual air temperature and mean annual precipitation at this site
are 8.9 ◦C and 1000 mm, respectively. The trial was set up during
the fall of 2002 on an organic farm with the field being tilled conventionally
during preceding years. The soiltype atthe field site is a
Stagnic Eutric Cambisol with a mean clay and silt content of 45 and
33%, respectively and a pHH2O of 7.1. The organic carbon content of
the soil in the upper 10 cm induced by tillage is 2.27 and 2.67% Corg
in conventional(CT) and reduced (RT)tillage, respectively (Table 1).
The soil is poorly drained and prone to water-logging during winter
and spring. In 2011 winter spelt (Triticum spelta L., cv. ‘Ostro’) was
grown. Spelt was the third crop of a six-year crop rotation including
winter wheat, an oat-clover intercrop, sunflower, winter spelt,
a two-year grass-clover ley, a winter pea cover crop (only in the
RT system) and silage maize. To destroy the grass clover sward in
reduced tillage, it was necessary to change the traditional cropping
system, to clean the sward and let it dry in September, to sow winter
peas in autumn and to cut it as green manure at end of April
before maize. In the conventional system the sward was ploughed
in spring (Krauss et al. 2010). The crop rotation is currently in its
second cycle. All crops are being grown in compliance with the
Swiss standards for organic agriculture (Bio Suisse 2012), fulfilling
the EU regulation (EEC) No. 834/2007.