Colonization of arbuscular mycorrhizae in Bothriochloa pertusa (L) A. Camus pasture

Objective. Evaluate in situ the colonization of arbuscular micorrhizae, in grass roots colosuana in function of the physical and chemical characteristics of the soil, in cattle farms of four agroecological areas of the savannah physiographical sub region. Materials and methods. The determination of the colonization percentage was done in colored roots. In order to establish the differences between average colonization percentages between areas, a completely random design was used. To determine the differences between areas, the Tukey test was used to the nearest 5%. The physical and chemical variables and colonization percentages in the tested farms were characterized through the main component analysis technique, and the farms were classified through agglomerative cluster analysis. Results. The ANOVA showed significant differences (p-value=0.02359) between the colonization average percentages between areas. The Tukey test revealed that areas 2 and 4 showed the least colonization percentages and are statistically the same, while areas 1 and 3 had the maximum colonization values. The main component analysis showed high colonization percentages of HMA in farms with moderate phosphorous and Nitrogen contents; low sodium and moderately alkaline pH. The agglomerative cluster showed 5 groups of farms related to decreasing colonization percentages in the presence of clay to sandy-loam structure. Conclusions. This is the first regional and national level on the effect of physical-chemical parameters of soil on arbuscular mycorrhizal colonization in Colosuana grass roots.