Isabgol (Plantago ovata) and lentil (Lens culinaris) intercrop responses to arbuscular mycorrhizal fungi inoculation

ABSTRACT Intercropping medicinal plants with grain legumes provides an excellent opportunity for small-scale farmers to generate more income and move towards sustainable cropping systems. The effect of arbuscular mycorrhizal fungi (AMF) inoculation on yield, quality and nutrient uptake of isabgol and lentil, when grown as monocrops or in various intercropping ratios, were evaluated. Inoculation with AMF resulted in positive effects on AMF root colonisation, yield components and seed yields (significant for lentils only) of both crops, especially in the intercropping systems, as well as in the nutrient uptake in isabgol. The highest seed yields of isabgol (743 kg ha−1) and lentil (684 kg ha−1) were obtained when these species were grown as monocrops and inoculated with AMF. The highest mucilage content (20.9%) and swelling factor (16.9 ml) of the isabgol seeds were found when the two secies were grown in the intercropping ratio of 2I:2L (2 rows isabgol: 2 rows lentil) and treated with AMF. Regarding the composition of the isabgol seed mucilage, the highest concentrations of galacturonic acid (9.0%), galactose (11.8%), glucuronic acid (18.3%), and xylose (39.0%) were recorded in intercropping with AMF treatment. AMF inoculation also increased soil basic microbial respiration, soil substrate-induced respiration and soil microbial biomass carbon. Overall, the highest land equivalent ratio (LER = 1.67) was recorded in the 4I:2L intercropping pattern with AMF inoculation. The results indicated that intercropping of isabgol and lentil together with AMF inoculation was an effective system to increase the use efficiency of resources for smallholder farmers in semi-arid regions.