Companion cropping in dry areas increase of plant diversity and nitrogen or decrease of soil water?

With the intensification of agriculture, the resilience of production systems decreases and ecosystem services are lost. In Austria, this intensification leads to a simplified crop rotation with the three most commonly used crops winter wheat, winter barley and grain maize, which account for 41% of the cultivated area. On the other hand, diverse crop systems can increase yield stability and soil fertility by preserving soil fauna. One way to increase crop diversity is to use companion cropping. Companion crops are grown along with the main crop in a mixture and provide soil cover, nutrient delivery, and can reduce dependence on nitrogen fertilizers. However, increasing spring drought can lead to competition for water resources and yield losses, which will be exacerbated by climate change. The development of adapted production measures, such as the choice of companion crops (frost-killed or winter-hardy), seeding rates and fertilizer management are of particular interest to the agricultural sector with the background knowledge of the possible water competition and the current fertilizer costs. For this purpose, a 3-year field trial is being conducted at the experimental farm of the University of Natural Resources and Life Sciences, Vienna, in Gross-Enzersdorf.