Nitrate Leaching under Arable Crops
Our multi-year trials with arable crops aim to quantify the amount of nitrate leached from the soil with a particular form of agricultural management. Here, the focus is on examining various farming systems (PEP, organic farming), cover crops (with different sowing and ploughing times), tillage (plough, mulch seed), fertilisation variants (reduced and increased nitrogen fertilisation) and soil types.
Co-workers: Ernst Spiess, Volker Prasuhn, Clay Humphrys, Karin Meier-Zimmermann, Frank Liebisch
Nitrate Leaching under Vegetable Crops
Since 2017, the Ly12 facility has been used to study the level of nitrate leaching under a vegetable crop rotation, as well as the influence of crop-residue management (leaving crop residues on the lysimeters vs. removal of same) on losses. This trial is being conducted within the ‘NitroGäu’ research programme for the nitrate project in the ‘Gäu-Olten’ region (canton of Solothurn).
Co-workers: Ernst Spiess, Clay Humphrys, Reto Neuweiler, Volker Prasuhn, Frank Liebisch, Karin Meier-Zimmermann
Optimal Use of Recycling Fertilisers in Organic Farming (Recycle4Bio)
The production and use of recycling fertilisers from biogas facilities are steadily increasing throughout Switzerland; however, many questions regarding the medium-term impact on yields and nitrogen use-efficiency and losses remain unanswered. In addition, data from multi-year field trials on the pros and cons of the combination of recycling fertilisers and biochar is lacking.
The aim of the project is to investigate and optimise the impact on yield as well as the nitrogen-use efficiency of recycling fertilisers in organic production systems. The effects on soil- and product quality and on nitrate leaching will also be examined. To this end, a multi-year precision trial with different recycling fertilisers (biogas slurry with co-substrate, solid digestate and compost produced from the latter) with or without the addition of biochar, was set up. At the same time, the processes with liquid fertilisers were tested for source-specific nitrate leaching in 12 vessels of the Ly72 facility by means of 15N stable isotope labelling.
This is a joint project of the Research Institute of Organic Agriculture (FiBL) and Agroscope, sponsored by the Federal Office for Agriculture.
Co-workers: Jochen Mayer, Michael Scheifele, Else Bünemann (FiBL), sowie Feld- und Labortechniker von FiBL und Agroscope
Assessment of micropollutant degradation using multi-element compound-specific isotope analysis
In this SNSF Sinergia project, a new method was developed for detecting the breakdown of plant-protection products in groundwater. Agroscope made the Ly12 facility available for this purpose. After application, various PPPs and their metabolites were analysed in the soil water and the seepage water.
The project was conducted together with the Centre for Hydrogeology and Geothermal Energy of the University of Neuchatel (D. Hunkeler), EAWAG (T. Hofstetter, H.P. Kohler) and the Munich Helmholtz Centre (M. Elsner).
Co-workers: Volker Prasuhn, diverse Externe
SNF: Assessment of micropollutant degradation using multi-element compound-specific isotope analysis