Long-term successional dynamics of an inoculum of arbuscular mycorrhizal fungi (AMF) associated with the maize rhizosphere (from traditionally managed agroecosystems in Los Tuxtlas, Veracruz, Mexico), was followed in Bracchiaria comata trap cultures for almost eight years. The results indicate that AMF diversity is lost following long-term subculturing of a single plant host species. Only the dominant species, Claroideoglomus etunicatum, persisted in pot cultures after 13 cycles. The absence of other morphotypes was demonstrated by an 18S rDNA survey, which confirmed that the sequences present solely belonged to C. etunicatum. Members of Diversisporales were the first to decrease in diversity, and the most persistent species belonged to Glomerales.

Excessive inorganic fertilizers applied to pineapple crops in Mexico cause the progressive degradation and pollution of soils in the short- and long-term, and they also increase production costs. An alternative to reduce excessive fertilization is its partial substitution by nutrition and growth enhancing arbuscular mycorrhizal fungi (AMF). The goal of this research was to compare the effect of AMF inoculation combined with different fertilizer doses and full chemical fertilization on pineapple yield variables in a commercial plantation. We used a randomized block design with six treatments: a non-inoculated control with 100% chemical fertilization, and five treatments with AMF inoculation and fertilization doses of 0%, 25%, 50%, 75%, and 100% chemical fertilization. There were four replicates of each treatment containing 30 plants in each experimental unit (plot). We measured the dry weight of the D-leaf 9 months after planting, and the root mycorrhizal colonization percentage, yield, and fruit quality after 18 months. Mycorrhizal inoculation equated to 100% chemical fertilization already when combined with 25% fertilization and surpassed it when combined with 50% fertilization in most of the yield variables measured. The fruit mass and organoleptic variables were significantly higher in mycorrhizal plants with 50% fertilization than in the non-inoculated control and the treatments inoculated with AMF and combined with 0%, 25%, 75%, and 100% of a dose of chemical fertilizer. Inoculation with mycorrhizal fungi in the field could reduce chemical fertilizer application by 50%, with no yield loss and with improved fruit quality.