Effects of combined bamboo biochar and manure on soil fertility in China

Incubation and column leaching experiments were conducted to evaluate the effects of bamboo biochar (BBC) (0-1.0% wt/wt) combined with manure fertilizer on sandy soil. The results demonstrated that BBC enhanced microbial biomass, enzyme activity, and carbon substrate utilization. Compared to the control, the addition of 1.0% BBC reduced cumulative leaching losses of total organic carbon, total nitrogen, and total phosphorus by 31.88, 43.90, and 57.58%, respectively. Mass balance analysis further indicated that 1.0% BBC retained 1.85, 0.30, and 0.063 mg/g in carbon, nitrogen, and phosphorus, respectively. These findings suggest co-application of BBC and manure fertilizer can improve microbial properties and enhance nutrient retention in sandy soils. Key words: Bamboo biochar, microbial properties, nutrient retention, orchard sandy soil, soil fertility.