Plants require essential nutritional elements for their growth and development, including phosphorus, but this in the soil is usually deficient and slow in mobility, so biological practices must be used to make the uptake of this element by plants more efficient, for which, mycorrhizal symbiosis could greatly contribute to the uptake of phosphorus. The symbiosis becomes more effective when the soil contains low levels of phosphorus in the soil, however, these low contents do not favor the development of the corn crop. In response to this, this research was proposed, which was developed in semi-controlled conditions at the University of Córdoba, warm climate, in which different doses of phosphorus were evaluated (0, 5, 10, 20, 30, 40, 50 kg/ha) and the degree of colonization and vegetative development of the corn crop was evaluated in a soil with low nutritional supply and especially phosphorus (5 mg/kg). Corn of the ICA V 109 variety was used, in a complete randomized design, seven treatments with three repetitions were evaluated. The variables height, stem diameter, leaf area, wet and dry biomass and degree of colonization (mycorrhization) were evaluated. It was found that phosphorus is a limiting element in the growth of the corn plant and also influences the degree of mycorrhizal colonization. It was concluded that phosphorus fertilization has an inverse effect on mycorrhizal colonization in corn cultivation in edaphoclimatic conditions of Montería-Colombia. However, the amount of phosphorus available in the soil is directly proportional to the growth of this cultivar.