Impact of Biochar on Pathogenic Bacteria and Bermuda Grass (Cynodon dactylon) Growth in Soil Treated with Chicken Manure

Abstract

Chicken manure plays an important role in soil amendment by improving soil properties for plant growth. However, the high levels of pathogens can have an adverse effect on humans when used for sports turf. This study was conducted to 1) determine the pathogenic bacteria in chicken manure-amended soil, 2) identify the appropriate decomposition stage of manure associated with reduced number of pathogenic bacteria, 3) assess the effect of different rates of biochar on pathogenic bacteria in the amended soil and 4) determine the effect of biochar on the growth of Bermuda grass. The design used for the laboratory experiment was 3˟3 factorial in Completely Randomised Design (CRD) and it was replicated three times. The factors involved were: decomposition stages of chicken manure (3 levels) and the different rates of biochar (3 levels). The best combination of biochar and chicken manure at the percentages of 0, 5, 10, and 15 were then used together with soil and sand mix at a ratio of 100:00 and 70:30 to plant Bermuda grass. This experiment showed that E. coli was present in chicken manure and that increasing the decomposition period had a significant effect on the E. coli by reducing its load. Also, the addition of biochar to the chicken manure resulted in a significant reduction of E. coli count (p<0.01). The soil amended with the biochar and manure also supported very well the growth of Bermuda grass with the 10% and 15% biochar manure mix in 70 to 30 ratio of topsoil and sand giving the best grass growth in terms of spread, thickness, height, and color. A regression analysis given by the equation Y(coverage)=176.857-23.0402(sprouting) (R2=0.99), indicated that sprouting significantly affected grass coverage such that 99% variation in the grass coverage was attributed to the sprouting. At the end of the study, it was concluded that well-composted chicken manure should be used together with biochar on sports fields to help remediate the problem of E. coli infestation and also improve the growth of grass on fields. Furthermore, biochar with chicken manure-amended soil could be ideal for vegetable garden to help reduce foodborne diseases caused by E. coli infestation.