Temporal response of soil bacterial communities to application of organic and inorganic phosphate based fertilisers under of Vicia faba L cultivation

It is important to investigate to which extent and how specifically soil-plant-microbe interactions can be conditioned by different agricultural practices. Legumes such as Vicia faba is one of the essential functional group in intercropping and crop rotations due to its higher N fixing capacity. Hence, it is important to study the living microbial community of this legume. Further, it is also expected that fluctuations in soil microbial diversity and composition could be complemented by plant phenological stages and different fertilizer amendment. Thus, we investigated bacterial community composition in soil treated with phosphate-based inorganic and organic fertilizers, in presence of Vicia faba plants at flowering and fruiting time using NGS 16S rRNA gene amplicon sequencing. Further, evaluation of plant biomass parameters under different fertilizer treatment was also carried out. Our results showed that plant presence was a key dominating factors followed by fertilizers and time in affecting soil bacterial diversity and composition. Organic and inorganic fertilizers with equivalent total nutrient content had comparable effect on soil bacterial community as they shared a common microbiome as well as enriched by specific taxa. Proteobacteria, Actinobacteria and Cyanobacteria were most abundant phyla and Chelatococcus, Cyanobacteria, Sphingomonas and Microvirga were most abundant genus that contributed most in co-occurrence pattern, which suggest that these generalists are adapted to a variety of environments. These finding indicates that plant recruit system - (fertilization and time) specific taxa due to differences in available nutrients and energy sources among different treatments. Further, considering the number and the dry weight of seeds obtained by an organic fertilizer, the values were only 18.8% and 28.3% lower than those by the inorganic treatment. Decrease in plant production could be acceptable as it has given the great importance of preserving soil health and, moreover, it is also in line with recent productivity data in the current research data.