Micorrizas arbusculares en plantaciones de Theobroma cacao y su relación con los parámetros fisicoquímicos del suelo en el cantón Macará, Provincia de Loj

Abstract

Abstract: Arbuscular mycorrhizal fungi (AMF) are essential for nutrient uptake in cacao and for mitigating cadmium toxicity in soils. This study evaluated the relationship between AMF colonization and diversity and soil physicochemical parameters in cacao plantations in Macará, Ecuador. Between 499 and 833 spores/100 g of soil were identified, with 40 morphotypes dominated by the genera Glomus and Acaulospora. Root colonization ranged from 10% to 40%, with no significant differences between farms. The soils had a moderately acidic pH (5.7 to 6.3) and organic matter between 4.6% and 7.9%, indicating healthy soils. Cadmium in roots showed a moderate-to-high correlation with mycorrhizal colonization (r = 0.73), indicating a key role of AMF in its immobilization. In some cases, cocoa beans exceeded the export limit (0.6 mg/kg). Furthermore, spore counts were positively correlated with phosphorus (r = 0.95) and organic matter (r = 0.81), suggesting that these soil properties favor mycorrhizal activity.