Root growth in biopores of spring wheat, faba bean and intercropping system

Enhancing root systems, especially through utilization of biopores, can improve crop access to essential resources as climate change effects intensify. In this context, intercropping, also known as mixed cropping emerges as a promising technique to facilitate root growth into deeper soil layers, optimizing water and nutrient extraction and providing a resilient and sustainable solution to agricultural challenges. While crop mixtures have the potential to increase yield compared to sole crops, little is known about their impact on root growth in biopores. Therefore, a study was conducted with the aim of quantifying the root length density and biopore usage of spring wheat and faba bean in pure stands and mixtures. The trial was established at the Campus Klein-Altendorf (CKA), the experimental research farm of the University of Bonn in Germany. Crops were analyzed for root mass, root length density (RLD), biopore usage by roots, and yield parameters. Roots were sampled by soil monolith and profile wall methods up to 70 and 100 cm, respectively. The mean RLD in mixture was highest in top soil (10-20 cm) while for lower depth levels of 40-70 cm, spring wheat exhibited significantly higher root growth than faba bean. Meanwhile, in biopores, faba bean root share was higher than spring wheat and mixture. Mixture showed lowest root share in biopores at 40-50 cm but this share was higher than spring wheat at 60-70 cm, but differences were not statistically significant. The results indicated that the faba bean uses biopores more excessively for root growth than spring wheat. Values of Land Equivalent Ratio (LER) index >1 confirmed the productivity advantage of mixture over sole crops. Overall, the results indicated better yet insignificant root growth for mixtures in biopore and higher crop yield in mixtures.