Digestate as Biofertilizer for the Growth of Selected Vegetables and Illumina analysis of Associated Bacterial Community

Abstract

Chemical content of crops above desirable level, high cost, in addition to land and water pollution is a major drawback of applying chemical fertilizers. In this study, Digestate was used as a biofertilizer for the growth of selected vegetables. Furthermore, Illumina platform was employed to unravel the bacteria community of the digestate. Corchorus olitorius, Amaranthus hybridus, Bot-celosia argentia and Talinum triangulare were grown in 16 experimental pots for 35days using cured digestate. Soil treated with chemical fertilizer was used as a positive control while the soil without any fertilizer was used as a negative control. The plant height of Talinum triangulare for soil treated with digestate was 23.5cm and 34cm by days 7 and 35 respectively after plant emergence. Corchorus olitorius had stunted growth under same treatment. Whereas, Bot-celosia argentia and Amaranthus hybridus grew poorly on all treatments. The statistical analysis showed a significant difference (p[≤]0.05) between Talinum triangulare grown in soil treated with digestate (plant height = 23.50, plant number =10 at day 7) compared with those treated with NPK (plant height = 18.50, plant number = 6.50 at day 7). The plant height and number for untreated soil at day 7 were 10.90 and 5.0 respectively). The Illumina sequencing of the digestate revealed the presence of some beneficial soil bacteria including Clostridium, Bacillus, Pseudomonas, Actinobacteria, and Micrococcus. The presence of these bacteria known to be Nitrogen fixers and Phosphate solubilizers confer biofertilizer potential to the digestate.