Impact of Application of Sulfur Modified Biochar on Some Biochemical and Microbiological Attributes of Soil

Biochar application to soil improve organic carbon and soil quality. The objective of this study was to investigate the effect of biochar and sulfur modified biochar (prepared from sugarcane bagasse and corn residue) on changes in organic carbon and biochemical and microbiological characteristics of a calcareous soil under corn cultivation. This study was conducted in a completely randomized design with five treatments and four replications. Corn residue and sugarcane bagasse biochar and their modified biochar were mixed at 1% (w/w) with the soil sample, and corn was grown in 5 kg pots. The results indicated that the application of biochar and biochar modified with sulfur caused a significant increase in total (56.7-115.4%) and dissolved organic carbon (24.3-60.9%) of the soil, microbial basal respiration (43.8-85.8%), substrate-induced respiration (44.5-98.9%), microbial biomass carbon (54.8-93.4%), dehydrogenase (108.0-114.7) and catalase (105.4-151.6%) activity. Comparison between the two feedstock has revealed that corn residue biochar was more effective in improving total and dissolved organic carbon and soil biochemical attributes than sugarcane bagasse biochar. The positive impact of sulfur-modified biochar on dissolved organic carbon, microbial biomass carbon and catalase activity was significantly greater than the raw biochar. The greatest value of dissolved organic carbon, microbial basal respiration, and substrate induced respiration as well as dehydrogenase, and catalase activity, were related to the biochar treatment of modified corn residue. In general, the results of this study demonstrated that biochar derived from corn residue and sugarcane bagasse could be a suitable organic amendment to improve soil organic matter and soil biochemical properties. In addition, modification of biochar with sulfur and production of acidic biochar can increase its efficiency in improving soil microbial activity.