Greenhouse gas emissions associated with four types of fertilization for corn crops in a Mediterranean basin

The environmental impacts associated with the intensification of agricultural practices have become an emerging issue, and new techniques are being developed to satisfy public demands. The application of fertilizers is a crucial step for agriculture practices. Building upon previous studies at a Mediterranean basin, the objective of the research presented herein was to quantify the greenhouse gas emissions associated with four different types of fertilization in the production of corn: traditional (NPK 8-15-15 and urea), controlled-release (NPK 8-15-15, and a combination of urea and encapsulated urea), and two types of fertilization with pig slurry (NPK 8-15-15, pig slurry and different amounts of urea). The Life Cycle Assessment methodology was employed, with the Ecoinvent database and the IPCC 2013 GWP 100y impact assessment method. The results revealed that traditional fertilization emitted 3251 kg CO2-eq/ha center dot year, against 2191 kg CO2-eq/ha center dot year for controlled-release fertilization. Pig slurry fertilization emitted 2160 kg CO2-eq/ha center dot year, and its alternative with less urea, only 1030 kg CO2-eq/ha center dot year. The utilization of pig slurry solves the issue of its disposal and entails lower costs (commercial fertilizer prices follow the prices of oil and gas). The results demonstrated the potential of controlled-release fertilization and pig slurry to contribute to climate change mitigation.