INTERACTIVE IMPACT OF COMPOST AND BIOCHAR ON INDIGENOUS ARBUSCULAR MYCORRHIZAL FUNGI AND OKRA (Abelmoschus esculentum L.) PRODUCTION

Few studies have examined the impact of the effect of organic amendments on indigenous arbuscular mycorrhizal fungi (AMF) and okra growth. Our greenhouse experiment investigated the effect of compost or biochar amendments, and their combination, on AMF colonization of okra roots inoculated or not with indigenous AMF consortium inoculant using a completely randomized block design. The results showed that the inoculation of plant with indigenous AMF and the application of both compost and biochar significantly increased the colonization frequency and intensity up to 94% and 45.9%, respectively. The plant height and stem diameter were improved and reached 68.5 cm and 10.2 mm, respectively for treatment combining AMF inoculation, compost, and biochar application, against 21.5 cm and 3.5 mm, respectively for control. Fresh and dry weight of roots reached 38.7 and 28.03 g/plant, respectively for plants amended with biochar. Plants inoculated with AMF and amended with both compost and biochar showed fresh and dry weights of 30.5 and 23.3 g/plant. The highest okra yields were recorded with the treatment combining the AMF inoculation and compost application, followed by the treatment combining the AMF inoculation, compost, and biochar application. Therefore, these synergies between compost, biochar, and AMF may help farmers to increase the colonization of indigenous AMF strains in okra roots and consequently their abundance in the soil and to improve okra growth and yield.