Biochar inoculated with Pseudomonas putida improves grape (Vitis vinifera L.) fruit quality and alters bacterial diversity

Abstract

Soil degradation is the major factor restricting agricultural and fruit industry development in Xinjiang. In the current study, biochar inoculated Pseudomonas putida Rs-198 were applied to soil to improve grape (Vitis vinifera L.) quality, soil quality and microbial community. Field experiments showed that the fruit weight, length and width in the inoculated biochar treatment increased by 7.6%, 3.8% and 3.8% when compared to that of control, respectively (P < 0.05). The soluble protein and hardness of grape treated with the inoculated biochar were increased by 28.6% and 10.8%, while the total acid was reduced by 15.8%. Physicochemical and biological properties such as electrical conductivity, alkali-hydrolyzed nitrogen, available phosphorus, available potassium, organic matter, urease activity, sucrase activity of soil which the inoculated biochar was added increased by 87.3%, 24.28%, 73.2%, 78.17%, 71.6%, 17.50%, and 82.11%, respectively. 16S rRNA sequencing results indicated that inoculated biochar application causes increased (P < 0.05) Gemmatimonadetes, Actinobacteria, Bacteroidetes and Planctomycetes, while Acidobacteria, Chloroflexi, Rokubacteria, Nitrospirae were reduced (P < 0.05). Redundancy analysis suggested that the inoculated biochar amendment significantly affected soil microbial community structure, critical environmental factors consisted of alkali-hydrolyzed nitrogen, available phosphorus, available potassium, urease activity, sucrase activity. In conclusion, the inoculated biochar has the ability to improve the quality of grape fruit, increase the nutrient content of the soil, and affect the bacterial community as a potential soil amendment agent.