Higher biochar rate strongly reduced decomposition of soil organic matter to enhance C and N sequestration in nutrient-poor alkaline calcareous soil

Biochar Application Improves Soil Respiration and Nitrogen Mineralization in Alkaline Calcareous Soil under Two Cropping Systems

“…This implies the availability of labile C in native organic matter and added biochar for microorganisms initially during organic matter decomposition and vanished soon during early days of incubation. Similar pattern in C mineralization and CO 2 efflux has been reported earlier by other researchers such as Fatima et al (2020) and several others such as Kuzyakov (2011), Zimmerman et al (2011 and Mason-Jones and Kuzyakov (2017). The results of this study suggest that biochar amendment enhanced CO 2 evolution during short-term incubation period (i.e., 16 days).…”

“…As in this study, Deng et al (2017) further showed a decreasing trend in CO 2 evolution over time. Fatima et al (2020) on the other hand found that the biochar-only treatments produced lower or similar CO 2 efflux compared with the control treatment and observed inverse relationship to the biochar rates. The biochar and control treatments exhibited similar rate of C mineralization.…”

“…The biochar used in this study was prepared at low pyrolysis temperature and would contain greater amount of labile fraction of C which could be responsible for greater CO 2 evolution than the control. The same was the case with Fatima et al (2020). It is now clear that biochar which is prepared at temperature contain higher amount of labile C. When such biochar is added to soil, it quickly promotes microbial activity resulting in higher organic matter decomposition (for example, Guo et al, 2020).…”

Evaluating the Effects of Biochar with Farmyard Manure under Optimal Mineral Fertilizing on Tomato Growth, Soil Organic C and Biochemical Quality in a Low Fertility Soil

“…The soil C mineralization, measured as soil basal respiration, increased with biochars, and was the highest under the corncob biochar along FYM. This could be due to higher labile C contents in corncob biochar resulting in higher microbial activity and C mineralization [85,86]. However, the lower soil basal respiration for the cotton stick and rice straw biochars without notable influence of FYM might suggest the presence of less labile than recalcitrant C and varying degree of microbial co-metabolism for C substrate from soil, biochar and FYM [87].…”

“…The higher MBC in the combined biochar and FYM treatments suggested higher microbial accessibility of WEOC which could have resulted from desorption and degradation of biological matter and C substrate from biochar. However, the differences in MBC contents between biochars were probably due to variations in microbial ability to access soluble C that influence MBC and net C mineralization [85,86]. The contrasting effects of biochars on soil basal respiration and MBC might be due to the potential of biochar to adsorb soil native and added C (FYM) which increased the MBC but had little effects on soil basal respiration [90].…”