Biochar Effects on Microbial Community Profiling of a Tropical Sandy Loam.

Corn cob biochar pyrolysed at 550^OC was applied to a tropical sandy loam at application rates of 15 t/ha, 30 t/ha and 30 t/ha + P (Tripple Super Phosphate) to elucidate its effects on microbial community. Microbial community structure was determined by Phopholipid Fatty Acids (PLFA) analysis method. Application of biochar increased soil microbial biomass and respiratory quotient in the plots that were treated with 30 t ha^-1 of biochar. A significant increase in specific maintenance respiration (qCO2) rate was also observed in the BC-30 and BC-30+P amended soils, implying a less stressed ecosystem and improved microbial C efficiency in these treated soils, relative to the control. Application of corn cob biochar also increased urease and dehydrogenase enzyme activities, and this effect was pronounced in the 30 t ha^-1 amended soils. The biochar amended soils recorded a significant increase in total PLFA in the treated soils due to increased soil carbon and nitrogen contents which serve as a source of energy for soil microbial growth. In this study, corn cob biochar application resulted in a significant increase in Fungal: Bacteria ratio, which implies an enhanced C storage and sequestration potential in threated soils. Thus, corn cob biochar applied to a tropical sandy loam could potentially increase enzyme activities and improve microbial community structure to improve soil ecosystem functions and activities for improved soil quality.