SUMMARY
Introduction: Composted manure (CM) is an alternative to nutrient recycling, and can improve or maintain soil fertility by replacing conventional fertilization. The objective of the study was to evaluate the characteristics and chemical composition of the soil, percentage of infection of the arbuscular mycorrhizal fungus (AMF) in the root, agronomic characteristics of the plant, growth rate in the crop, nutrient accumulation and productive yield, in response to the E and Glomus intraradices (CM) in forage corn.Method: Six levels of organic fertilization were evaluated (15, 30 and 45 t ha-1 of E, 15, 30 and 45 t ha-1 of EM), one of chemical fertilization (QF: 160-60-30 kg) ha-1 of NPK), and a control (without fertilizing: WF), in two crop cycles (Cycle, SS: spring-summer and AW: autumn-winter). E and G. intraradices were used. The variables studied in the soil were: pH, electrical conductivity (EC), organic matter (OM), N, P, K, Ca, cation exchange capacity (CEC), number of spores; in the plant: accumulation of nutrients (N, P, K, Ca), percentage of infection in root, height, number of leaves and dry matter (DM); in the crop: growth rate of the crop (GRC), yield of forage in green matter (GM t ha-1) and dry matter (DM t ha-1).Results: With the exception of the K in soil and the CEC, the Treatment, Cycle and the interaction of both factors affected (P <0.05) the variables that defined the chemical composition of the soil (pH, EC, OM, N, P, Ca), the accumulation of plant nutrients (N, P, K, Ca) and forage yield in GM and DM. In OI, QF presented the lowest OM content; in SS, an increase in E (from 15E to 45E) allowed to increase the OM (P< 0.05). The N in soil was higher in AW in relation to SS in all treatments (P< 0.05). In AW, 30EM presented the highest accumulation of plant nutrients (N, P, K and Ca) with respect to the rest of the treatments (P< 0.05). In both cycles, SS and AW, 30EM had the highest forage yield in DM (P< 0.05).Discussion or Conclusion: The chemical composition of the soil, plant and forage maize yield were affected by the use of E alone or in combination with M during the SS and AW cycles. The use of 30EM represents a better fertilization option with relation WF and QF because the plant had more forage production in MS during the SS and AW. The use of G. intraradices in combination with E contributes to optimize the use of soil nutrients by the plant. The results obtained are important to increase the quality and quantity of feed corn.