ASPECTS OF MYCORRHIZAL ASSOCIATION WITH THREE PLANT SPECIES IN AGROFORESTRY SYSTEMS IN THE AMAZON

Abstract

Agroforestry Systems (Portuguese acronym, SAF) encompass diverse plant species coexisting within the same space, influenced by factors such as fertilization and water availability, shaping the occurrence and diversity of soil microorganisms, including Arbuscular Mycorrhizal Fungi (AMF). This study aimed to assess the diversity, colonization, and density of AMF in the roots of plant species from two SAF areas: one subjected to green manure, biofertilizers, compost fertilizer, limestone application, and artificial irrigation (SAF-1), and the other without such interventions (SAF-2). Both SAFs harbored the species Mariri (Banisteriopsis caapi), Castanheira (Bertholletia excelsa), and Tapiririca (Tapiririca guianensis). Samples of rhizospheric soil and roots were collected for physical-chemical analysis, isolation, and identification of AMF, as well as quantification of spore density and percentage of colonization. Significant differences were observed in organic matter content, being high in SAF-1 and medium in SAF-2, while phosphorus content was high in SAF-1 and low in SAF-2. The occurrence of four distinct orders of AMF, Archaeosporales, Glomerales, Diversisporales, and Gigasporales, was noted, albeit with varying richness. Spore density was significantly higher in SAF-1 with intervention, attributed to elevated phosphorus and organic matter content. Conversely, mycorrhizal colonization was greater in SAF-2 without intervention, owing to phosphorus deficiency favoring colonization formation.