TY - JOUR
T1 - Nutrient-extended input-output (NutrIO) method for the food nitrogen footprint
AU - Oita, Azusa
AU - Katagiri, Kiwamu
AU - Eguchi, Tetsuya
AU - Morioka, Ryoko
AU - Shindo, Junko
AU - Hayashi, Kentaro
AU - Matsubae, Kazuyo
N1 - Publisher Copyright:
© 2021 The Author(s). Published by IOP Publishing Ltd.
PY - 2021/11
Y1 - 2021/11
N2 - Agro-food systems require nutrient input from several sources to provide food products and food-related services. Many of the nutrients are lost to the environment during supply chains, potentially threatening human and ecosystem health. Countries therefore need to reduce their nutrient/nitrogen footprints. These footprints are importantly affected by links between sectors. However, existing assessments omit the links between sectors, especially between the agriculture, manufacturing, and energy sectors. We propose a novel approach called the nutrient-extended input-output (NutrIO) method to determine the nutrient footprint as a sum of direct and indirect inputs throughout the supply chains from different sources of nutrients. The NutrIO method is based on a nutrient-based material flow analysis linked to economic transactions. Applying this method, we estimated the nitrogen footprint of Japan in 2011 at 21.8 kg-N capita-1yr-1: 9.7 kg-N capita-1 yr-1 sourced from new nitrogen for agriculture and fisheries, 7.0 kg-N capita-1 yr-1 from recycled nitrogen as organic fertilizers, and 5.1 kg-N capita-1 yr-1 from industrial nitrogen for chemical industries other than fertilizers. A further annexed 55.4 kg-N capita-1 yr-1 of unintended nitrogen input was sourced from fossil fuels for energy production. The nitrogen intensity of the wheat and barley cultivation sector, at 1.50 kg-N per thousand Japanese yen (JPY) production, was much higher than that of the 0.12 kg-N per thousand JPY production for the rice cultivation sector. Industrial nitrogen accounted for 2%-7% of the nitrogen footprint of each major food-related sector. The NutrIO nitrogen footprint sourced from new nitrogen for agriculture and fisheries, at 8.6 kg-N capita-1 yr-1 for domestic final products, is comparable to the food nitrogen footprint calculated by other methods, at 8.5-10.5 kg-N capita-1 yr-1. The NutrIO method provides quantitative insights for all stakeholders of food consumption and production to improve the nutrient use efficiencies of agro-food supply chains.
AB - Agro-food systems require nutrient input from several sources to provide food products and food-related services. Many of the nutrients are lost to the environment during supply chains, potentially threatening human and ecosystem health. Countries therefore need to reduce their nutrient/nitrogen footprints. These footprints are importantly affected by links between sectors. However, existing assessments omit the links between sectors, especially between the agriculture, manufacturing, and energy sectors. We propose a novel approach called the nutrient-extended input-output (NutrIO) method to determine the nutrient footprint as a sum of direct and indirect inputs throughout the supply chains from different sources of nutrients. The NutrIO method is based on a nutrient-based material flow analysis linked to economic transactions. Applying this method, we estimated the nitrogen footprint of Japan in 2011 at 21.8 kg-N capita-1yr-1: 9.7 kg-N capita-1 yr-1 sourced from new nitrogen for agriculture and fisheries, 7.0 kg-N capita-1 yr-1 from recycled nitrogen as organic fertilizers, and 5.1 kg-N capita-1 yr-1 from industrial nitrogen for chemical industries other than fertilizers. A further annexed 55.4 kg-N capita-1 yr-1 of unintended nitrogen input was sourced from fossil fuels for energy production. The nitrogen intensity of the wheat and barley cultivation sector, at 1.50 kg-N per thousand Japanese yen (JPY) production, was much higher than that of the 0.12 kg-N per thousand JPY production for the rice cultivation sector. Industrial nitrogen accounted for 2%-7% of the nitrogen footprint of each major food-related sector. The NutrIO nitrogen footprint sourced from new nitrogen for agriculture and fisheries, at 8.6 kg-N capita-1 yr-1 for domestic final products, is comparable to the food nitrogen footprint calculated by other methods, at 8.5-10.5 kg-N capita-1 yr-1. The NutrIO method provides quantitative insights for all stakeholders of food consumption and production to improve the nutrient use efficiencies of agro-food supply chains.
KW - agro-food systems
KW - input-output analysis
KW - material flow analysis
KW - nutrient use efficiency
KW - supply chains
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U2 - 10.1088/1748-9326/ac2c35
DO - 10.1088/1748-9326/ac2c35
M3 - Article
AN - SCOPUS:85118742380
VL - 16
JO - Environmental Research Letters
JF - Environmental Research Letters
SN - 1748-9326
IS - 11
M1 - 115010
ER -