Fall is rapidly approaching, and a new semester is starting at the University of Bonn. As usual, the summertime was marked by many field activities where colleagues can apply and learn a lot with practice as well as promote team spirit! This year we established the first intercrop project trial in Campus Klein-Altendorf (CKA), which is part of the network of field experiments of the IntercropVALUES project. Field trials are a fundamental tool for scientists and practitioners to test a new method and measure its performance against a controlled condition.

Picture above: fava bean and two spring wheat cultivars.

In the case of IntercropVALUES, scientists aim to assess the crop performance and key ecosystem services (ESS) of intercrops versus sole crops in various experiments located in and outside of Europe. Moreover, emissions of nitrous oxide (N2O), a relevant greenhouse gas, from intercrops and sole crops during growth and the months after harvest will be measured in selected experiments.

The field trial located at CKA is comprised of 14 treatments and tests sole crops (fava bean and two spring wheat cultivars) and the in-row mixture of both crops at different levels of mineral nitrogen (N) fertilization. To quantify N losses, N leaching, N2O emissions, and crop N uptake as well as other ESS such as crop biomass growth and yield and deep percolation of soil water are monitored.

Picture above: installation of sensors to monitor soil moisture.

Picture above: box with bottles for collection and quantification of N leaching.

Preliminary results of the first season which was characterized by very dry conditions indicate that the soil moisture in the upper soil layers was higher in the intercrop compared to both sole crops. This may be one of the reasons for the enhanced productivity in terms of biomass in the intercrops vs. the sole crops. Especially the spring wheat plants profited from the lower competition for the limited water in the mixture.

Picture above: measurements of gaseous emissions in a fava bean plot.

These results will be underpinning information for developing and improving models to simulate soil health indicators, and ecosystem services and to understand the resilience of the system to climate change and its variability. The network of field experiments together with CICS partners across Europe make the results more robust and closer to farmers’ reality.

This news item was written by Sabine Seidel and the IntercropVALUES team at the University of Bonn, Germany.