@misc{10481/70492,
year = {2021},
month = {8},
url = {http://hdl.handle.net/10481/70492},
abstract = {Synthetic nitrogen (N) fertilization has helped boost agricultural yields, but it is also responsible
for direct and indirect greenhouse gas (GHG) emissions. Fertilizer-related emissions are also
promoted by irrigation and manure application, which has increased with livestock
industrialization. Spanish agriculture provides a paradigmatic example of high industrialization
under two different climates (temperate and Mediterranean) and two contrasting water
management regimes (rainfed and irrigated). In this study, we estimated the historical evolution of
the C footprint of N fertilization (including all the life cycle GHG emissions related to N
fertilization) in Spanish agriculture from 1860 to 2018 at the province level (50 provinces) for 122
crops, using climate-specific N2O emission factors (EFs) adjusted to the type of water management
and the N source (synthetic fertilizer, animal manure, crop residues and soil N mineralization) and
considering changes in the industrial efficiency of N fertilizer production. Overall, N-related GHG
emissions increased ∼12-fold, up to 10–14 Tg CO2e yr−1 in the 2010s, with much higher growth in
Mediterranean than in temperate areas. Direct N2O EFs of N fertilizers doubled due to the
expansion of irrigation, synthetic fertilizers and liquid manure, associated with livestock
industrialization. Synthetic N production dominated the emissions balance (55%–60% of GHGe
in the 21st century). Large energy efficiency gains of industrial fertilizer production were largely
offset by the changes in the fertilizer mix. Downstream N2O emissions associated with NH3
volatilization and NO3
− leaching increased tenfold. The yield-scaled carbon footprint of
N use in Spanish agriculture increased fourfold, from 4 and 5 Mg CO2e Mg N−1 to
16–18 Mg CO2e Mg N−1. Therefore, the results reported herein indicate that increased
productivity could not offset the growth in manufacture and soil emissions related to N use,
suggesting that mitigation efforts should not only aim to increase N use efficiency but also consider
water management, fertilizer type and fertilizer manufacture as key drivers of emissions.},
organization = {Spanish Ministry of Economy and Competitiveness	PID2019-107972RB-I00},
organization = {Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria of Spain	MACSUR02-APCIN2016-0005-00-00},
organization = {Comunidad de Madrid	AGRISOST-CM S2018/BAA-4330},
organization = {Juan de la Cierva research contract from the Spanish Ministry of Economy and Competitiveness	IJC2019-040699-I	
FJCI-2017-34077},
organization = {Spanish Ministry of Economy and Competitiveness (MINECO)},
organization = {European Commission ERDF Ramon y Cajal Grant	RYC-2016-20269},
organization = {Programa Propio from UPM},
organization = {Comunidad de Madrid		
European Commission},
organization = {Autonomous Community of Madrid		
UPM	APOYOJOVENESNFW8ZQ-42-XE8B5K},
publisher = {Institute of Physics Publishing},
keywords = {Greenhouse gas emissions},
keywords = {Nitrous oxide},
keywords = {Environmental History},
keywords = {Mediterranean climate},
keywords = {Nitrogen},
title = {Long-term trajectories of the C footprint of N fertilization in Mediterranean agriculture (Spain, 1860–2018)},
doi = {10.1088/1748-9326/ac17b7},
author = {Aguilera, Eduardo and Infante Amate, Juan},
}