The Role of Soil Organic Matter and Manures in Sustainable Nutrient Cycling - Sustainable Management of Soil Organic Matter - page 294

are reported here. Attention focuses on the question of whether there are
fundamental differences between farmyard manure and mineral fertiliza-
tion as regards soil fertility indicators, crop yield and the soil's function as a
carbon sink or source.

Materials and Methods

A long-term field trial on a sandy orthic Luvisol with 590 mm precipitation
per year and 9.5 C annual mean temperature is being carried out to

compare three types of fertilizer: (i) composted farmyard manure (CFM);
(ii) composted farmyard manure with application of all biodynamic
preparations (CFMBD); and (iii) mineral fertilization (MIN, i.e. calcium
ammonium nitrate, super phosphate and potassium magnesia). Production
and use of the preparations were described by Steiner (1924) for the first
time. Further details are given by, for instance, Koepf (1981). Each type of
fertilizer is applied at three different levels, corresponding to a total nitrogen
content of 60, 100 and 140 kg ha −1 N to wheat and rye and 50, 100
and 150 kg ha −1 N to potatoes. The nine treatments are implemented
identically in four replicates on four fields with four different crops. This
gives 36 plots in each of the four fields. Manure is applied before sowing or
planting, mineral fertilizer is applied to spring wheat and potatoes before
sowing and planting, and to winter rye in spring. To cereals, a part of the
nitrogen amount in the medium and high fertilization treatments (20 and
40 kg ha −1 N) is applied during tillering as liquid manure in CFM and
CFMBD or as calcium ammonium nitrate in MIN. The legume crop
remains unfertilized in all treatments. The nutrient amounts applied yearly
with the mineral and manure treatments are listed in Table 4.10.1.
Straw of the MIN plots remains on the field, but is removed from the
CFM and CFMBD plots. Crop rotation is red clover ( Trifolium pratense
L.), alternatively Persian clover ( Trifolium resupinatum L.), spring wheat
( Triticum aestivum L.), potatoes ( Solanum tuberosum L.) and winter rye
( Secale cereale L.). The trial has been under way with this design since
1985/86. It started in 1980 with the aim of investigating the effects of
fertilization on food quality (Abele, 1987). Therefore, from 1980 to 1984,
the trial had the same treatments at a higher level of manure fertilization
and a different crop rotation. Except for fertilization, all other elements of
cultivation are the same in all treatments and follow normal organic farming
practices. More details of the trial have been published earlier by Bachinger
(1996) and by Raupp (1996).
Where statistical requirements were fulfilled, analyses of variance were
calculated, taking type and level of fertilizer as fixed effects and replicates
and years as random. In the tables, mean values of the main effects with
different letters are significantly different ( P < 0.05). The least significant

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