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Book of Abstracts

11th IFOAM
Scientific Conference
11-15 August 1996
Copenhagen, Denmark

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Yield Patterns after Organic or Mineral Fertilization S19

Raupp, J.

Institute for Biodynamic Research, Brandschneise 5, D-64295 Darmstadt

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In order to optimize cropping systems in organic farming an understanding of the crop specific yield developing processes is needed. Within the limits of climate and soil conditions, these processes can be directly influenced by agronomic techniques, mainly by fertilization. Because of the central role of farmyard manure for fertilization in organic farming, a field trial was started in 1980 with the following treatments: i) composted cattle manure and liquid manure (CM), ii) the same, but with all biodynamic preparations (CMBD), iii) mineral fertilizer (MIN). Each treatment is given in three different amounts equivalent to 0.9, 1.4 and 1.8 livestock units per hectare (calculation for MIN based on equivalent total nitrogen contents).

Yields of all crops showed different patterns and levels depending upon either manure or mineral fertilization. In years with favourable conditions as regards climatic factors spring wheat yields in the manure treatments were only around 80% of the yield of the mineral fertilized plants. Under worse conditions, however, spring wheat was more effective with manure achieving yields up to 120% of the mineral fertilized plants. Winter rye yields after manure application were only 60-80% of the mineral fertilization in all years.

The different efficiency of both fertilization systems against unfavourable environmental conditions will be discussed taking into account other effects of organic vs. mineral fertilization on soil and plant development observed in this experiment. Findings concerning C- and N-dynamics and amino acid contents in the soil (see also contributions from Scheller, Bachinger & Raupp) are also presented to this conference. In some cases the biodynamic preparations were able to improve the resistance of spring wheat against unfavourable environmental conditions.