Pilot sustainability study comparing growth characteristics of mung bean (Vigna radiata) in German indoor and outdoor environments

Pulses are neglected crops in Germany. To meet sustainable development goals and decrease global carbon emissions, there is a need for a sustainable agricultural system. During the current changing climate environment, there is a particular emphasis on developing pulses for the regional production of proteinaceous micronutrient-rich food. It is conceivable that established popular pulse crops from the Global South are options also in Middle Europe, such as the popular Asian Vigna radiata (green gram, mung bean), which is unknown and not agronomically exploited in Germany. First open questions are whether mung bean plants can be grown to maturity in outdoor conditions in Germany and whether the growth cycle can be completed with successful yield. Here, we present a pilot study using an Indian variety from Odisha, an area with temperate winter conditions, comparable with German summer. We compared growth of mung bean from seedling stage to maturity in a German indoor and outdoor environment. We repeated the experiment four times spanning between April and September 2022. Additionally, we investigated whether and to which extent growth dynamics, flowering, fruiting and seed micronutrient contents were affected by differing soil-sand ratios. Thereby, we were able to define the most suited time window for cultivation of mung bean in German outdoors and the soil-to-sand ratios for optimal growth and yield. This study is useful for planning future field testing and genetic selection experiments to identify the most suited mung bean varieties for cultivation and improved breeding in Germany.