Characterization of Bioactive Compounds in Blueberry and Their Impact on Soil Properties in Response to Plant Biostimulants

ABSTRACT

Vaccinium corymbosum L. (Ericaceae) is a highly valued fruit crop and the most common type of blueberry grown in Chile. Plant growth and yield crop production are affected by agricultural practices and different soil parameters including chemical and biological properties. We performed a field assay to assess the effect of the inoculation with a mixture of 10 microorganisms and the addition of humic substances on the growth of blueberry, quality of fruit and soil chemical and biological properties. Two years after planting, the microbial consortium was more effective than the addition of humic substances recording a 35% increase in shoot dry weight, 70% increase in root dry weight and 104% on total fruits yield compared to the control plants. Total polyphenols and ferric reducing antioxidant power (FRAP) in fruit were increased on humic substance treatment. The combination of both factors increased by 18% organic matter and 60% cation exchange capacity. Soil respiration, microbial biomass C and enzyme activities (dehydrogenase, phosphatase, β-glucosidase, urease, and protease) to a greater extent than individual application. The combined treatment, involving microbial inoculant and humic substances, had an additive effect on improving the biochemical and microbiological quality of the soil.