An adequate and balanced supply of nutrients is essential for yields and yield quality. In six crops cultivated in parallel, the Demo trial vividly demonstrates the effects of different organic and mineral fertilisers as well as deficiency symptoms under inadequate supplies of nitrogen, phosphorus and potassium.
Originally designed as a comparison of conventional and organic farming systems, today the DOK trial serves as a platform for a wide variety of scientific studies. Biodynamic (D), bioorganic (O) and conventional (K; German: konventionell) treatments are used to study aspects of soil fertility, productivity, climate impact and the resilience of agricultural systems.
Tillage and fertilisation are crucial for the quality and functionality of soils. The Oberacker trial demonstrates the effects of no-till and ploughing, combined respectively with the GRUD/PRIF and Kinsey fertilisation concepts, on six crops cultivated in parallel. In addition to a focus on crop performance, there is a strong emphasis on the investigation of chemical, physical and biological soil properties.
The R4B trial was set up in Wallbach (canton of Aargau) in 2018 as a multi-year precision trial to optimise both the impact on yield and the nitrogen use efficiency of recycled fertilisers in organic cropping systems. In addition, effects on soil and product quality as well as nitrate leaching, ammonia losses and climate impact are being studied. The recycled fertilisers used in this trial are biogas slurry with co-substrate, solid digestate, and compost made from solid digestate, each with and without the addition of biochar.
Besides fertilisation, the nutrient supply of arable crops depends strongly on soil and climate conditions. The STYCS trials are designed to investigate the influence of site characteristics on the soil nutrient content necessary for optimal yields on seven sites in Switzerland. The findings contribute to the improvement of fertilisation recommendations.
Since 1949, the influence of mineral and organic fertilisation and their combination on yields and yield quality as well as on soil quality parameters has been investigated in Switzerland’s longest-running experiment. The time series covering more than 70 years of measurements permit the evaluation of the sustainability and climate impact of different fertilisation approaches.