Abstract
Agriculture contributes to 22 % of global anthropogenic greenhouse gas emissions, of which fertilizer represents 10.6 % of agricultural greenhouse gas emissions. While there is increasing concern about the impact of chemical fertilizers on climate change, the impact of biofertilizers, especially their manufacturing, has not been addressed extensively. This study quantifies the upstream emissions of a biofertilizer manufacturing plant in Malaysia using the Life Cycle Assessment (LCA) methodology, where electricity consumption (64.2 %) is the biggest source of carbon emissions. The emissions are compared with other fertilizers to determine the environmental advantages of biofertilizers. Compared to other chemical fertilizers, biofertilizer manufacturing emits 23.2 times less carbon emissions than nitrogen fertilizer manufacturing. Chemical fertilizer manufacturing emissions come from various factors, especially energy-intensive processes and direct carbon emissions from material reactions (e.g., carbonate dissolution and material decomposition). Organic fertilizers, such as manure, digestates, and compost, emit up to 10,666 times more carbon emissions due to organic decomposition, which releases carbon dioxide and methane.
