TY  - GEN
ID  - orgprints14554
UR  - http://orgprints.org/14554/
TI  - DOK-Versuch (Langzeituntersuchung zu biologisch-dynamischen, organisch-biologischen und konventionellen Landbausystemen)
N2  - An understanding of agro-ecosystems is key to determining effective farming systems. Here we report the 21-year study of agronomic and ecological performance of bio-dynamic, bio-organic, and conventional farming systems in Central Europe. We found crop yields to be 20 % lower in the organic systems, although input of fertiliser and energy was reduced by 34 ? 53 %  and pesticide input by 97 %. Enhanced soil fertility and higher biodiversity found in organic plots may render these systems less dependent on external inputs.
Definition of the problem:
	Soils are well buffered systems and an adaptation of the soil - plant relationship from high-input to low external input farming practices may last decades. For instance, soil nutrient stocks are frequently huge in European soils and a normalisation after conversion to organic low-input systems needs time. Also the adaptation of the soil micro-flora to altered chemical soil conditions presumably occurs only after a prolonged period of time upon conversion from high-input to low-input farming. Therefore, long-term trials are essential to assess the agronomic performance of low-input production systems and a focus should be put on studying the underlying soil processes.
Project aims:
-	to analyse the long-term agronomic performance of a Swiss wheat cultivar under organic and integrated farming systems (continued) 
-	to investigate the interrelations of soil properties and plant growth in different farming systems
Experiments:
-	to perform a system comparison experiment with organic and integrated farming (continued, running since 1978)
-	to assess soil chemical, physical and biological properties
-	to determine nitrogen and phosphorus dynamics related processes in the soil-plant ?microorganisms - system
-	to study the soil - plant interface
Methodology:
Soil microbial biomass analyses, enzyme activities, characterisation of microbial populations (Biolog, PLFA, DNA), assessment of mycorrihizal root colonisation and diversity by molecular tools, isotope tracer and dilution techniques.
AV  - none
KW  - System comparison
KW  -  bio-dynamic farming
KW  -  organic farming
KW  -  conventional farming
KW  -  soil fertility
KW  -  soil quality
KW  -  carbon cycling
KW  -  mycorrhizal symbiosis
KW  -  system performance
KW  -  long-term
KW  -  P cycling
KW  -  N dynamics
KW  -  Bodenfruchtbarkeit
KW  -  DOK
ER  -