Differential ability of pyrolysed biomass derived from diverse feedstocks in alleviating salinity stress

Abstract

Effectiveness of application of pyrolysed biomass (biochar) derived from different feedstocks in mitigating adverse response in the saline environments needs further insight. Therefore, ability of three different biochars [maize stover biochar (MB), poultry manure biochar (PB), rice straw biochar (RB)] in ameliorating saline soils varying in electrical conductivity (EC2, EC8, EC16 dS m−1) was investigated by conducting an incubation experiment for 8 weeks. Increasing salinity reduced (28–45%) soil microbial activity in the unamended soils. However, greater C mineralization and microbial biomass C (MBC) were noticed in soils amended with PB followed by RB or MB. Likewise, the percentage of net C mineralized was greater in the PB-amended (15–23%) compared to RB (11–19%)- or MB (9–17%)-amended soils at given salinity levels. Furthermore, greater available N and P in soils amended with PB than RB or MB could be related to its lower C to N ratio and better ash content. Instead, significantly higher soil organic C (SOC) concentration observed in the saline soils amended with RB (41–67%) than PB (17–44%) was most likely due to its higher C content and greater stability. Additionally, RB with its greater reserve of potassium can serve as a good source of available K in the saline soils. The study showed the potential of biochar derived from different feedstocks in ameliorating saline soils. Greater ability of poultry manure biochar in improving resilience of soil microbial biomass to survive under salinity was a noticeable evidence of feedstock’s type in influencing biochar behavior in stressed environments.