Quantitative Determination Of Functional Bacteria Associated With Biogeochemical Cycles In Rhizospheric Soils Of Cofee Cultivation (Coffea Arabica)

Abstract

The microbiota present in the soil is usually diverse and plays a vital role in the cycling and availability of nutrients for plants, being one of the potential indicators of soil quality. The objective of this work was to determine the population densities of the entire microbial groups and cultivable functional bacteria associated with the biogeochemical cycles of the soil of the coffee biosphere in the municipality of Lourdes, Norte de Santander. Three farms were sampled, and two rhizome soil samples were taken on each farm at a depth of 20 cm. Total microbial groups were counted on plates in Nutrient Agar (AN), Rose Bengal Agar (ARB), and Oat + Nystatin Agar (ANA) media. For the quantification of cellulose, starch, protein, chitin, and phosphorus solubilizing bacteria, selective media and plate count were used and, by the NMP method, a symbiotic bacteria that fix atmospheric nitrogen and nitrifying bacteria. In turn, correlations were determined between the density of the functional groups found and the specific physicochemical properties of the soils. The results showed statistically significant differences (p>0.05) in the population density variable in the total microbial groups. Similarly, statistically significant correlations (p≤0.05; ≤0.01) were observed between the population density of some functional groups and the physicochemical properties of rhizosphere soils. The soil nutrients presented the most correlation in this work were Na, Ca, and P, followed by OM and K.