An integrated microbiological analysis of the soil and rhizosphere of Agave spp. under minimum technological input farming systems

The expansion of arid and semi-arid regions, consequent to the intensification of desertification processes attributable to global warming, exerts a deleterious effect on agricultural production of energy crops, with current estimates indicating that a further 23% of global agricultural areas will suffer from desertification by 2100, precipitating crises in these sectors. Agave species have the capacity to thrive in these marginal environments characterized by aridity and elevated temperatures. These plants can serve as a source of biomass for the production of biofuels, a process that mitigates the environmental impacts of the transport sector while promoting the utilization of drylands, thereby eliminating competition with food crops. Given the paucity of knowledge regarding the soil microbiota and rhizosphere in minimal technological input Agave plantations, the objective of this study was to evaluate the microbiological and chemical soil properties of Agave sisalana and Agave hybrids (H11648 and H400f) farming systems. The analyses, which were carried out using microbial quantification, enzyme stoichiometry and enzymatic vector calculations, demonstrated that the microbiome of these plants is active and well-structured in terms of nutritional acquisition. It was observed that the Agave fields microbiome is very similar to that of the native vegetation. This finding suggests that the soil and rhizosphere microbiota are healthy and stable in the Agave fields evaluated, even with the implementation of agronomic exploitation models, as the chemical analysis of the soil reveals that all measured parameters are consistent with those of soils suitable for crop production. These observations persist even in long-established Agave plantations of varying ages that have never received any type of implement or soil correction. Thus, the integration of the chemical and biological data through PCA, RDA and PERMANOVA enabled the differentiation of the soil among the three Agave species, which shows the influence of the plant genotype on its microbiota.