Effect of indigenous bio-inoculants and commercial biological inputs on soil microbial population, soil health dynamics and pepper (capsicum annum L.) production

Overusage of chemical fertilizers by farmers had adversely impacted soil fertility and agricultural ecosystem sustainability. To explore safer alternatives, six bio-treatments based on two Bacillus spp. consortium and three biological inputs were investigated. Assessments, carried out over two consecutive cropping years, were focused on their effects on soil microbial traits, pepper production and health status as measured by fungal and nematode infection levels. Rhizosphere microbial populations were more abundant at the second cropping year than at the first one, thus indicating their cumulative effects. The two Bacillus spp. strains applied individually, and Acadian input had induced significant increments in pepper production by 22-25% over control. No significant differences were recorded between two Bacillus spp. and their consortium on the severity of pepper-associated soil-borne diseases. B. amyloliquefaciens subsp. plantarum SV65 performed 39.7 and 59.6% better than Acadian and Trianum-P-& REG; in reducing nematode galling index and foliar severity index, respectively. Interestingly, single treatment using B. amyloliquefaciens subsp. plantarum SV65 performed better than the three biological inputs based on the majority of tested parameters. Thus, this strain used individually or in combination with B. subtilis SV41 is a promising eco-friendly alternative for the enhancement of pepper health and production.