摘要

Anaerobic digestion slurry (ADS) is typically applied as a liquid fertilizer and soil amendment because it contains high concentrations of plant nutrients. For many years, macronutrients such as nitrogen and phosphorus in ADS has been widely studied, whereas little attention has been paid to plant hormones. Lab-scale batch experiments were conducted to evaluate the effect of anaerobic digestion (AD) on plant hormones (gibberellic acid (GA(3)), indoleacetic acid (IAA), abscisic acid (ABA)) in three typical animal manures (chicken, dairy, and pig). Results from the lab-scale batch experiments revealed that ADS contained higher concentrations of plant hormones than the original animal manures. Subsequently, quantitative analysis of samples from large-scale continuously fed biogas plants verified the high contents of plant hormones in ADS. However, the storage experiment demonstrated a significant loss of plant hormones in ADS prior to land application because of decomposition and transformation. Specifically, the results showed that the patterns of GA3, IAA, and ABA variations depended on the storage temperature, showing increased losses at increased storage temperatures. Consequently, it is important to assess plant hormones availability in ADS prior to indiscriminate application for efficient utilization.