Mycorrhizal Abundance and Its Interaction with Cereal Root Traits and Crop Productivity in Organically Managed Cereal/Legume Intercropping

Mixed cropping may positively affect soil fertility and soil biological activities, such as those related to mycorrhizal colonization intensity (M%), which plays a vital role in the plant nutrient cycle and can improve tolerance to drought and pathogens. This plant and soil fungi symbiosis helps to reduce dependency on chemical fertilizers, promotes sustainable agricultural practices, and minimizes environmental impacts. However, field studies that clearly assess the effects of cereal/legume intercropping on mycorrhizal intensity and relate it to plant productivity, yield quality, and plant adaptation to climate change are lacking. This field experiment was conducted to assess the effects of cereals/legume intercropping on mycorrhizal colonization, and to explore its interaction with physical cereal root parameters and crop yield. Three main crops, spring barley, oat, and field pea, were grown as monocultures. For the spring barley and oat, the study also included two different fertilization levels (with and without organic fertilizers) and legume intercropping (field pea and red clover). The intercropping had a significant impact on spring barley and oat root length, diameter, and specific root length. The general average of root length and diameter was higher in oat-pea and barley-pea cropping systems. The most significant effect in root architecture parameters observed in red clover was when it was intercropped with barley or oat. The establishment of field pea intercrop significantly increased M% in spring barley and had a positive effect on the grain yields of both spring barley and oat. Meanwhile, red clover intercropping enhanced M% and grain yield in oats but had no such effect in barley. In both spring barley and oat, M% was positively correlated with grain yield.