THE EFFECT OF BIOGAS FERTILIZER APPLICATION ON THE YIELD, QUALITY, AND ENVIRONMENTAL RISK OF CHERRY TOMATO

The number of biogas stations in China has increased dramatically in recent years. As a result, recycling anaerobic digestate has become an urgent task to avoid the risk of environmental pollution. A field experiment was conducted to study the effect of biogas fertilizer on the yield, quality, and environmental risk of organic cherry tomato, which uses biogas residua as base fertilizer and slurry as topdressing in a greenhouse in Beijing. The tomato received a total of six treatments, with fertilizer input rate N increasing from 0 kg N hm-2 to 470 kg N hm-2. The results show that the tomato yield has a significant linear-plateau relationship with N. The tomato yield stopped increasing after the inflect point (273 kg N ha-1) was reached, with a maximum yield at 59 t ha-1. However, soil residua Nmin after tomato harvest always increase when the applied N rate is raised. By contrast, nitrogen use efficiency and tomato fruit quality (vitamin C and nitrate contents) decrease continuously as N fertilizer input increases.