摘要
Purpose The aim of the study was to examine the remediation effect of biochar derived from three feedstocks on soil acidification. Materials and methods The effects of biochar derived from peanut hull, rice straw and rape straw on soil acidity, chemical and microbial properties, nutrients absorption, and growth of orange seedlings planted in an acidic soil were studied in a greenhouse experiment. Results and discussion Soil pH was increased 0.70, 0.92, and 0.63 by peanut hull, rice straw, and rape straw biochars. However, only peanut hull biochar significantly increased plant growth and the biomass of trifoliate orange seedlings. Soil microbial biomass C and basal respiration were increased by peanut hull and rice straw biochar, and the geometric mean of enzyme activities (GMea) were increased by the three biochars, peanut hull biochar result in the highest increase. Rice straw and rape straw biochars had more abundant mineral nutrient, led to greater influence on soil and plant nutrient contents than peanut hull biochar. However, peanut hull biochar resulted in higher plant nutrients accumulation due to the improvement of plant biomass. Conclusions Although the three biochars effectively neutralized soil acidity, only peanut hull biochar raised plant growth and the biomass of orange seedlings significantly, and the increase of soil microbial properties and enzyme activity would be the key factors for the improvement of plant growth.