EUBCE 2024 - Roozbeh FEIZ - System Conditions for Resource-Efficient Biofertilizers

System Conditions for Resource-Efficient Biofertilizers

Short Introductive summary

A sustainable food production requires a more efficient recycling of nutrients. Using organic waste for biogas production also results in a renewable source of nutrients in the digestate. Such biofertilizers can be resource-efficient alternatives to current synthetic fertilizers, but it is imperative to identify under what conditions. Here, we aim at quantitatively assessing some critical system conditions required for digestate or digestate-based products to serve as viable alternatives to synthetic fertilizers. We use scenario analysis with variables such as transport distance, emissions of methane, ammonia and nitrous oxide during storage and spreading, soil C accretion, and impact allocation between N and P. Emissions from storage and the potential contribution of digestate to soil-C accretion outweigh the transport distance effect on the climate impact of biofertilizers. When allocating primary energy (PE) use to N and P based on their respective price, biofertilizer-P emerges as less fossil-free than synthetic-P. Our results provide a basis to discuss the most appropriate allocation factors.

K. Tonderski, Linköping University, SWEDEN
G. Carraro, Linköping University, SWEDEN
S. Waern, Biototal, SWEDEN
R. Feiz, Linköping University, SWEDEN