An Integrated Approach to a Nitrogen Use Efficiency (NUE) Indicator for the Food Production–Consumption Chain
- A literature review of existing indicators for full-chain NUE in the food production—consumption chain at the national and/or regional scales in European countries;
- A proposal for one indicator or a coherent set of indicators for NUE in the food system in Europe at the national or regional levels, which is ‘linked’ to the general concept agreed upon during the first meeting of the panel (EU Nitrogen Expert Panel, 2014), and which can be used by policymakers and practitioners in Europe (industry, consumers, NGOs, policy, research); and
- A demonstration of the use of the proposed indicator using European national data sets and a discussion of its usability.
2. Literature Review: Approaches to Estimating NUE
- Life Cycle Analysis (LCA): A technique to assess the potential environmental and human health impacts associated with a product, process, or service by: (1) compiling an inventory of relevant energy and material inputs and environmental releases and (2) evaluating the potential environmental impacts associated with the identified inputs and releases (e.g., [9,10,11,12,13,14,15,16,17,18] (See Appendix B, Table A1).
- Nitrogen Budget: The inputs and outputs of nitrogen across the boundaries of a system. Can contain information about internal nitrogen fluxes within the system (e.g., [1,26,27,28,29,30,31,32,33,34,35,36,37]). The farm-gate nitrogen budget is a common indicator for assessing the total inputs and outputs across a farm’s boundaries. The nitrogen balance indicator measures the difference between the nitrogen available to an agricultural system and the nitrogen harvested and exported from the system in agricultural products. The food system waste/loss indicator: this category has received special attention by studies that estimate the loss of N through waste [38,39,40] (See Appendix B, Table A3).
- Environmental Impact Assessment: A process of evaluating the likely environmental impacts of a proposed project or development, taking into account inter-related socio-economic, cultural, and human health impacts both beneficial and adverse (e.g., [41,42,43] (See Appendix B, Table A4).
3. Literature Values
4. Selection of Approach
5. Definition of a Full-Chain NUE (NUEFC)
6. Application of the Country Approach
7. NUE in the Netherlands Based on FAOSTAT Data Compared to National Statistics
8. Country Level NUEFC in the EU Based on FAOSTAT
9. Country Level NUEFC in the EU between 1980 and 2011
10. Factors Determining NUEFC
11. Use of the Indicator
12. Next Steps
Conflicts of Interest
Appendix A.1. Life Cycle Analysis (LCA)
- Ahlgren et al. : Sweden (straw).
- Brentrup et al. . Germany (sugar beets).
- Brentrup et al. . Europe (no crop specified—general background/challenges associated with farm level LCA).
- Brentrup et al. . United Kingdom (winter wheat).
- Caffrey et al. : United States (LCA challenges/perspectives).
- Cederberg et al. : Sweden (milk).
- Gallejones et al. : Spain (biofuel).
- Grizzetti et al. : LCA of food waste across the food system.
- Harris and Narayanaswamy. : Australia (reviews cases).
- Liao et al. : Model of nitrogen releases in LCA of crop production.
- Pelletier & Leip : Nitrogen characterization factors that can be used to aggregate nitrogen flows in LCA. Tested using average EU-27 consumption.
- Thomassen et al. . The Netherlands (conventional/organic milk).
Appendix A.2. Nitrogen Footprint
- Chatzimpiros and Barles. : France (beef, pork, and milk).
- Leach et al. : the Netherlands and the United States (broccoli, lettuce, tomato, spinach, potatoes, beans, corn, broiler chicken, pork, beef, fish, milk).
- Leip et al. : European Union (vegetable and animal products).
- Oita et al. : Global (The nitrogen footprint of nations).
- Pierer et al. : Austria (poultry, pork, beef, milk, vegetables and fruit, potatoes, legumes, cereals).
- Stevens et al. : United Kingdom (poultry meat, pigmeat, beef, milk, fish and seafood, cereals, pulses, starchy roots, vegetables).
Appendix A.3. Nitrogen Budget
- Bleken and Bakken : Nitrogen efficiency of food production in Norway.
- Dalgaard et al. : Poland, the Netherlands, France, Italy, Scotland, and Denmark (poultry, sheep, beef and dairy cattle, pigs, maize, forage, oilseed rape, “horticultural crops”, silage maize, winter wheat, “leguminous plants”, water buffalo—dairy, alfalfa, “vegetables”, grass/clover, peas, oats, fava bean, rye, barley, triticale, and wheat) Cover inputs/exports: beet pulp, cereals, eggs, feed milk, fresh milk, alfalfa, grass, grass/clover, hay, various concentrates, meat, rape cake, soybeans, soybean oil cake, straw, sugar beets, whey, and silage—alfalfa, beet pulp, clover grass, grass, maize, whole crop.
- Galloway and Cowling : Global nitrogen efficiency of plant and animal production.
- Grizzetti et al. : quantifies the nitrogen loss to the environment related to food waste at consumption at the global and European scale and analyses its relative impact on the environment. Examined: cereals, roots and tubers, oilseed and pulses, fruit and vegetables, meat, fish and seafood, and milk (Global).
- Gustavsson et al. : Uses mass flows model to account for losses and waste incurred during each step of the commodity’s food supply chain. Examined: cereals, roots and tubers, oilseeds and pulses, fruits, vegetables, meat, fish and seafood and dairy products. A variety of countries were considered, referred to in paper as industrialized (medium/high income) countries and developing (low income) countries.
- Howarth et al. : USA nitrogen budget, including food and energy production and consumption.
- Isermann and Isermann : Germany nitrogen balance for food and feed production and consumption.
- Lassaletta et al. : Analyzes importance of international trade of food and feed in the alteration of the N cycle at the global scale. Considered 12 regions, with 210 countries (incl. Africa, Europe, India, N. America, etc.) Examined 407 vegetable and 128 animal products.
- Leip et al. : Regionalized focus for Europe (cereals, oilseeds, pulses, fodder maize, fodder beet, grass, beef, pork, poultry meat, cow milk, eggs).
- Ma et al. : NUFER model (Nutrient flows in Food chains, Environment and Resources use) is an integrated assessment model for analysing N and P flows in the food chain from both production and consumption.
- Godinot et al. : Proposes new farm nitrogen budget indicators.
- Oita et al. : Multi-Regional Input-Output analysis that assesses trade-related impacts from a consumption perspective. Applied at a global scale to quantify nations’ footprints. Examined 15,000 industry sectors and 189 countries.
- Parfitt et al. : Review of global food waste literature throughout the supply chain.
- Shindo et al. : Reports the nitrogen load for East Asian countries.
- Westhoek et al. : Assesses environmental impacts and health effects of diets with reduced meat and dairy in Europe.
Appendix A.4. Environmental Impact Assessment
- OECD : The guide is not intended to target one specific country, but the following are member countries of the Organization for Economic Co-operation and Development: Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Korea, Luxembourg, Mexico, the Netherlands, New Zealand, Norway, Poland, Portugal, Slovak Republic, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. No specific food types are targeted in this analysis.
- Payraudeau and van der Werf  has been applied to the following countries and products/foods:
- Environmental risk mapping: Ecuador (soil nutrient balance), Italy (impacts on water quality).
- LCA: Europe (energy crops), Germany (complete conversion from conventional to organic farming).
- Environmental impact assessment: Brazil (ag. technology).
- Multi-agent system: France (groundwater evaluation). Thailand (catchment irrigation).
- Linear programming: Germany (farm level—crops not specified), Mali (crops unspecified).
- Agro-environmental indicators: Europe, Bangladesh.
- Van der Werf and Petit : The guide reviews 12 indicator-based methods spanning a variety of countries and agricultural topics. The relevant studies are as follows: Malaysia (cabbage), four undisclosed locations in Europe (energy crops), Philippines (rice), France (integrative farming animal/crop diversity), and Switzerland (farm pollution sources).
- There is inconsistency in accounting for exports as a portion of national production.
- When performing an N-footprint, some studies chose to include atmospheric emissions and others did not. This can drastically change a food product’s environmental footprint.If including atmospheric emissions, estimating emissions can often be difficult since emission factors (EF) can vary drastically depending on a variety of variables (i.e., soil type, amount of precipitation, amount of N fertilizer applied, etc.)
- ∘Additionally, emission factors must be included from the extraction of raw materials to make fertilizer, from all farm equipment on a farm site, as well as emissions from manure.
- Variability in accounting for biological N fixation.
- Not many studies differentiate between new (e.g., synthetic fertilizer) vs. recycled (e.g., manure) N inputs.
- Difficulty with and a relatively high amount of inconsistency in approaching crop rotations, which, most articles agree, is a limitation in calculating an accurate N footprint.
- Animal product allocation at farm gate. There are a variety of methods for determining how much of the N-footprint should be allocated toward multiple products resulting from one animal (for example: butter, milk, meat, etc.), and it is difficult to choose the appropriate methodology.
- Weight, economic value, system expansion, by-product displacement, etc.
- Accurately assessing nitrogen leaching. This usually needs to use a model, and in order to estimate leaching, most studies suggested examining farm dynamics on a relatively small scale.
- Main limitation: Connecting the results of the N-footprint, LCA, etc. to actual environmental impacts. This is the number one limitation in all of the studies.
|Reference||Study Domain||Methodological Scope||Key Features||NUE Value||N Input Values||N Output Values|
|Ahlgren et al., 2012||National (Sweden)||Land use, energy use and greenhouse gas emissions from the production of ammonium nitrate based on biomass. Cradle-to-gate.||1. Describes how N flows change in response to a possible decision and includes effects both inside and outside the life cycle of the system. 2. Identify short and long-term marginal target changes to determine fluctuations in system. 3. Accounts for recycling of nitrogen fertilizers.||n/a||n/a||n/a|
|Brentrup et al., 2001||National (Germany)||Determine Eco-indicator values & evaluate the impact of three different nitrogen fertilizers on the entire environmental burden associated with a sugar beet production system.||1. Life Cycle Impact Assessment—aggregate inventory data to produce one index representing environmental burden. Particularly weighting factors using the “distance-to-target principle”: ratio b/w current level and a target level of an effect. 2. Key issues missing in the Eco-indicator 95 method: the use of resources and land. 3. Comparative analysis related to global warming, acidification, eutrophication and summer smog. 4. Impact assessment cannot be performed site-specific.||n/a||N minimum in soil in spring, fertilizer N, atmospheric N deposition (15 kg/ha), net N mineralization during vegetation (15 kg/ha/day).||Ammonia volatilization (1–20% applied), nitrous oxide emissions, N removal with beets (1.8 kg/t sugar beet), N content of leaves (4 kg/t leaves), N uptake of winter wheat in autumn (5–10% of total N uptake, 210 kg/ha).|
|Brentrup et al., 2004||Regional (Europe)||Evaluates impact of emissions and resource consumption associated with crop production on the following environmental effects: depletion of abiotic resources, land use, climate change, toxicity, acidification, and eutrophication.||New characterization method for abiotic resources and land use; particularly new aggregation, normalization and weighting. Foundation of weighting factors used the ‘distance-to-target principle’.||n/a||n/a||n/a|
|Brentrup et al., 2004||National (United Kingdom)||Environmental impact of different N fertilizer rates in winter wheat production.||Assess resource depletion and environmental impacts. Impact categories: land use, climate change, toxicity, acidification, eutrophication.||n/a||Extraction of raw materials, production and transportation of inputs, all ag operations in field, application of fertilizer (0–288 kg N/ha).||Nutrient removal in grain and straw (30–212 kg N/ha), emissions due to energy consumption, volatilization, leaching.|
|Caffrey and Veal 2013||Literature Review||Review inconsistent methodologies associated with co-products, regional and crop specific management techniques, temporal variations, spatial variations, and nonpoint emission sources.||1. Land use change—examines direct and indirect implications regionally and globally. Discusses leachate and volatilization models, the consequences and processes of livestock production that should be considered. 2. Enteric fermentation and manure handling. 3. Considerations when including aquaculture. 4. Recommends the consideration of economics when comparing systems to determine the best mitigation strategies.||n/a||n/a||n/a|
|Cederberg et al., 2000||National (Sweden)||LCA comparing organic and conventional milk production in Sweden in terms of environmental impacts and land requirements.||Conventional milk production was found to have a larger nitrogen surplus than organic per unit area, but organic has a greater N surplus per unit milk.||n/a||n/a||n/a|
|Gallejones et al., 2014||National (Spain)||1. Evaluates the variability due to site-specific conditions of climate and fertilizer management of the LCA of two different products: biodiesel from rapeseed and bioethanol from wheat. 2. Improves the estimates of the LCA impacts due to N losses normally estimated with unspecific emission factors, that contribute to the impact categories analysed in the LCA of biofuels at local scale.||1. Integrated model simulations into a LCA assessment of biofuels; model accounted for local factors in the estimation of yield and N losses. 2. Crop production was the most influencing stage to every impact category. 3. Nitrous oxide subject to large variability in the LCA. 4. Coproducts addressed with system expansion.||n/a||Soil inorganic N flux (mineralized N from SOM, plant debris and organic amendments to soil), fertilizer N, mineralization.||Roots N, shoot N, grain N, volatilization, denitrification/nitrification/leaching losses, handling and storage, production of biofuel.|
|Harris and Narayanaswamy 2009||Literature Review||Focuses on LCA agricultural literature relevant to the pork, poultry, cotton, sugar, red meat and livestock sectors.||1. Goals: generally compared the environmental impact of farming practices or types of fed. 2. Allocation of co-products: economic allocation used in the past, but studies of beef and dairy have shown this to increase uncertainty. Preference—system expansion, physical relationships/causality, composition and economic value. 3. Merits of foreground (input processes, farm processes and production processes) and background (mining and extraction, grain production, transport) data sources. 4. Argues for uncertainty calculations to be incorporated into LCA results.||n/a||Varies by study: fertilizer N, soil organic and inorganic N, mineralization, manure, green manure.||Varies by study: root N, grain N, residue N, manure, coproducts, leaching, denitrification, nitrification, storage, food system processing.|
|Liao et al., 2014||Varies||Study provides an overview of aspects that need to be taken into account for improved modelling of Nr releases in the LCA of crop production.||1. On-site crop production must include the harvested portion of the crop and the soil with a changing depth down to the water table. 2. Nitrate, nitrous oxide and ammonia should be distinguished within the crop product system and b/w the crop product system and the ecosphere. 3. Stand-alone LCA studies of crop production and those coupled with process-based models should be based on a consistent spatial scale. 4. Fate of Nr losses in the ecosphere should be explicitly modelled in the life cycle impact assessment phase of the LCA of crop production.||n/a||1. PRODUCTS & PROCESSES TO CONSIDER (multiple inputs & outputs). 2. Extraction of natural resources, fertilisers, pesticides, machinery, infrastructure, energy, allocation of crops and crop functions, crop residues, soil N processes (volatilization, nitrification, denitrification, runoff, leaching, fixation, etc.).|
|Pelletier & Leip 2014||Regional (Europe)||Provide set of over 2000 N characterization factors for use in aggregating N flows in LCA. Used life cycle data and N characterization factors to estimate aggregated fixed N losses for an average EU-27 consumer.||1. Provided a set of over 2000 nitrogen characterization factors, which can be used to convert N species into weight of total N for aggregation. 2. The N characterization factors can be used in LCA and other approaches to estimate total N. 3. Applying the N characterization factors for an average EU-27 consumer using an LCA approach generated findings comparable to other studies, which confirms the use of the N characterization factors.||n/a||Inputs for LCA not explicitly described. Sectors considered in LCA were nutrition/food, shelter, consumer goods, and mobility.||Outputs/emissions for LCA not explicitly described. Sectors considered in LCA were nutrition/food, shelter, consumer goods, and mobility.|
|Thomassen et al., 2008||National (Netherlands)||1. Two Dutch milk production systems (organic—11 farms, and conventional—10 farms) were examined from cradle-to-farm-gate. 2. Animal manure, animals, milk, roughage/bedding material were outside of system boundary. 3. Excluded medicines, seeds, machinery, buildings, transport or processing of raw milk.||1. Integral environmental impact (land use, energy use, climate change, acidification, and eutrophication) and hotspots were identified. 2. Conventional: purchased concentrates were found to be the hotspot in off farm and total impact for all categories. 3. Organic: purchased concentrates and roughage were found to the hotspots in off farm impact. 4. Allocation of multifunctional processes was done on the basis of economic allocation.||n/a||Concentrate N content, electricity, diesel, methane emission (enteric fermentation & manure management).||Leaching of nitrate and phosphate (farm-gate balance approach), ammonia volatilization (manure in stable, manure storage, grazing, application of manure & fertilizers), nitrous oxide emission.|
|Reference||Study Domain||Methodological Scope||Key Features||NUE Value||N input Values||N output Values|
|Chatzimpiros & Barles 2013||Local (France)||Livestock system for consumption of dietary N in the form of beef, pork and fresh milk in France.||1. N Food-print: N loss associated with its agricultural production. 2. Uses the N Food-print to connect N flows and losses in livestock systems to the consumption of dietary N in the form of beef, pork and fresh milk. 3. Weight the amount of consumption proportionally to French administrative regions’ share in the national gross meat and milk production; foreign countries: proportionally to their share in national trade balances.||1. Feed crop cultivation on the livestock farms: Beef (76%) Milk (76%) Pork (62%). 2. Rapeseed Farms: Milk (40%) Cereal Farms: Pork (63%), Soybean Farms: Beef (50%). 3. Overall NUE in ration production: Beef (72%) Milk (56%) Pork (53%) 4. Overall NUE per livestock system: Beef (7.2%) Milk (13.4%) Pork (12.7%).||1. Feed N—roughages (grasses and legumes), annual fodder (maize, beetroots, cereals and protein meals from soybeans/rapeseed crops). 2. N return in manure to fodder crops. 3. N losses from livestock farms (fodder land on the livestock farms).||1. N in animal product and by-products (slaughter waste, as well). 2. N manure to crop agriculture.|
|Leach et al., 2012||National (United States, Netherlands)||Per capita nitrogen footprint including housing energy, transport, food consumption & production, and goods and services.||1. The food sector is the largest contributor to personal nitrogen footprints, especially food production. 2. Dietary choices influence the food nitrogen footprint; meat and dairy products have a larger nitrogen footprint than vegetable protein sources.||Farm-level data reported as virtual N factors, which describe the N losses during food production by food category.||Fertilizer, manure and BNF inputs, feed for livestock.||Food produced, losses to the environment at each stage of food production.|
|Leip et al., 2014||Regional (European Union)||1. Two different models (CAPRI & MITERRA) were used to quantify the N flows in agriculture in the European Union, at country-level and for EU agriculture as a whole, differentiated into 12 main food categories. 2. Did not include wastage that occurs during further processing, retail or preparation of food products.||1. N footprint, defined as total N losses to the environment per unit of product, varies widely b/w different food categories with substantially higher values for livestock products (c. 500 g N/kg beef) as compared to vegetable products (c. 2 g N/kg product for sugar beet, fruits and vegetables, and potatoes). 2. Did not consider fish and seafood products. 3. Agricultural sub-pools considered: livestock production systems, manure management systems, soil cultivations systems, and links to human society (consumption, trade) and environment.||N footprint: Vegetables: 4.5–6.3; Livestock Products: 63.5–64.7; Food products: 31.5–33.1.||Crop residues; fertilizer; atmospheric deposition, biological N-fixation.||Losses dominated by N leaching and run-off, and ammonia volatilization. N outputs: product for which N footprint was calculated; ‘waste’ streams that are recycled; slaughter house waste; manure.|
|Oita et al., 2016||Global||N emission flows embodied in international trade using a high-resolution global Multi-Region Input-Output (MRIO) database for 189 countries||1. Connect the IPCC’s model for the global N cycle with data on emissions of all forms of Nr to generate a complete account of emissions for 189 countries & 15,000 industry sectors. 2. Of the 117,000 Gg of N emitted worldwide, 25% of the total became embodied in international trade. 3. Traded N amounts vary significantly across countries. 4. Main net exporters are often developing countries and net importers are almost exclusively developed countries.||117,000 Gg of N emitted worldwide per year.||Crop production, livestock manure, fertilizers, harvest area (161 crops, 215 countries); deposition; crop residues.||Emission to water and air: manure management, emissions to soil, surface water and underground water; Mineralization, leaching, denitrification.|
|Pierer et al., 2014||National (Austria)||1. Footprints describe Nr losses, but do not link to effects. 2. Food production virtual N: real losses of Nr along the entire production and consumption chain (fertilizer application to final consumption). 3. Food production energy N: N loss associated with processes such as packaging and transportation; combustion-related emissions of NOx. 4. Food consumption N: all N consumed as food is excreted.||1. Total N footprint dominated by food production & consumption (85%). 2. Avg. N Footprint: 19.8 kg N/yr per Austrian inhabitant. 3. Do not account for co-production; no allocation. 4. Compared N footprints to simple mass of food and protein content. Ex: vegetables & fruits as well as potatoes have very low N footprints per mass, but relatively high footprints per amount of protein. 5. Do not include fish or seafood.||Poultry: 24% Pork: 18% Beef: 11% Milk: 16% Cereals: 45% Vegetables & fruits: 19% Potatoes: 33% Legumes: 72%.||Applied N, N in harvested crop, N in the product after first raw processing, N in the product after second processing and packaging, N in meat product, N in milk product, N available as feed for animals, N in live animal, N in slaughtered animal.||N not taken up by crop, crop processing waste, handling & storage, processing waste, retail food waste, consumer food waste, food preparation waste, N excreted, slaughter waste.|
|Stevens et al., 2014||National (United Kingdom)||1. Food N Footprint: sum of the food consumption and food production N footprint. N parameters: available N, % of previous N available, N waste produced, % N recycled, N recycled, and N loss. 2. Energy N Footprint: housing and transport energy consumption, NOx emission factors, Environmental Extended Input Output analysis for food, housing, transport, goods and services.||UK N-Calculator used to test scenarios that would be affected by changes in consumption patterns: (1) Recommended protein; (2) Vegetarian diet; (3) 50% food waste; (4) Sustainable food; (5) Advanced wastewater treatment plant; (6) renewable energy; (7) Public transit, (8) Combination (#1-7).||N Footprint: 27.1 kg N per capita per year.||Applied N, N in harvested crop, N in product after processing, packaging, N in meat production, N in animal by-products, N in live animal, N in slaughtered animals.||N not taken up by crop, crop processing waste, handling & storage, processing waste, retail food waste, consumer food waste, food preparation waste, N excreted, slaughter waste.|
|Reference||Study Domain||Methodological Scope||Key Features||NUE Value||N input Values||N output Values|
|Bleken and Bakken 1997||National (Norway)||Estimation of the N efficiency of the food producing sector in Norway, including the overall production system as well as specific products.||1. The food producing sector is the largest N-flow sector in Norway. 2. N-cost is defined as the ratio between fertilizer N-input and the N in products. 3. Recycling of wastes and dietary changes are key mitigation efforts.||Norway NUE = 10%||Synthetic fertilizer, biological fixation, atmospheric deposition, feed.||Wholesale food supply, food waste, sewage, trade export.|
|Dalgaard et al., 2012||National/Regional (Poland, the Netherlands, France, Italy, Scotland, Denmark)||1. Analyses farm N-losses and the complex interactions within farming systems by developing efficient methods for identifying emissions hotspots and evaluating mitigation measures at the farm and landscape scale. 2. Farm N balance defined as from the farm gate, including N inputs to the farm, and N outputs from the farm.||1. Developed a common method to undertake farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11,440 ha of farmland. 2. Results showed farm N surpluses may be used as an independent dataset for validation of measured and modelled N emissions in agricultural landscapes.||n/a||Fodder: N in imported fodder and seed, minus N in cash crops sold, fertilizer: N imported in synthetic fertilizer and animal manure, deposition: atmospheric deposition and biological N fixation.||Milk and other animal produce (incl. meat, live animals, eggs and wool).|
|Galloway and Cowling 2002||Global||Overall N efficiency of plant and animal production, starting with the input of N to a crop field and ending with the final food product.||1. Global average NUE is 14% for plant products and 4% for animal products. 2. Most of N used in food production is lost to the environment.||Global NUE = 14% for plant products and 4% for animal products.||N fertilizer or other input applied to a crop field, feed.||Food product, N loss at each stage of production.|
|Grizzetti et al., 2013||Global and regional (Europe)||1. Quantifies N losses to the environment related to food waste at consumption at the global and European scale. 2. Analyses its relative impact on the environment.||1. 7 regions: (1) Europe (2) USA, Canada & Oceania (3) Industrialized Asia (4) Sub-Saharan Africa (5) North Africa, West and Central Asia (6) South & South-East Asia (7) Latin America. 2. Food Groups: (1) Cereals (2) roots and tubers (3) oilseed & Pulses (4) fruit and vegetables (5) meat (6) fish and seafood (7) milk. 3. Applied virtual N and N footprint concept to quantify the amount of N delivered to the environment that is related to the production of food then wasted.||n/a 9% of the total nitrogen food supply is lost to environment; 2% of the global annual input of synthetic N fertilizer.||Total N in food at consumption.||Amount of N lost or wasted at consumption.|
|Gustavsson et al., 2011||Global||1. Losses occurring along the entire food system (food intended for human consumption). 2. Assesses magnitude of food loss, mass flows. 3. Identifies causes & prevention methods.||1. Roughly 1/3 of food produced for human consumption is lost or wasted globally (1.3 billion tons). 2. On a per-capita basis, more food is wasted in the industrialized world than in developing countries: Developing countries have greater food losses in the first steps of the FSC. Developed countries have greater food losses at the retail and consumption levels. 3. Study revealed major data gaps in the knowledge of global food loss and waste.||n/a||1. N LOSSES: Vegetable Commodities & Products. 2. Agricultural production: losses due to mechanical damage and/or spillage during harvest operation, crops sorted postharvest, etc. 3. Postharvest handling & storage: losses due to spillage, degradation during handling, storage and transportation b/w farm and distribution. 4. Processing: losses due to spillage during industrial or domestic processing. 5. Distribution: losses and waste in the market system. 6. Consumption: losses and waste during consumption at the household level.||1. N LOSSES: Animal Commodities & Products. 2. Agricultural Production: animal death during breeding, discards during fishing, decreased production due to animal sickness. 3. Postharvest handling & storage: death during transport to slaughter and condemnation at slaughterhouse. Spillage and degradation during packaging, storage and transportation. 4. Processing: trimming spillage during slaughtering and losses during industrial processing. 5. Distribution: losses and waste in the market system. 6. Consumption: losses and waste during consumption at the household level.|
|Howarth et al., 2002||National (USA)||Anthropogenic nitrogen budget for the United States, including food and energy production and consumption.||1. About 50% of new reactive N inputs to agricultural fields are removed as harvested crops. Most of these crops go towards livestock feed. 2. 15% of crop harvest N is consumed directly by humans, and about 70% goes towards livestock feed. 3. About 5% of the new reactive N inputs to agricultural feeds for animal protein production is consumed by humans.||USA NUE = 15% for plant protein and 5% for animal protein.||Inorganic N fertilizer, N fixation in agricultural systems, NOx emissions from fossil fuel combustion.||Export in rivers, food and feed export, atmospheric advection to oceans, denitrification and storage.|
|Isermann and Isermann 1998||National (Germany)||Country-level N balance for food and feed production and consumption.||1. The production and consumption of food and feed in Germany is 50% higher than what is needed for basic nutrition needs. 2. Inefficiency leads to N losses to the hydrosphere and atmosphere that were 2–8 times too high. 3. Propose a need-oriented production food production/consumption system.||Germany NUE = 10%||Atmospheric deposition, biological fixation, sewage sludge, biocomposts, imported feeds, net mineralization, mineral fertilizer, manure.||Removal by biomass; surplus to the pedosphere, atmosphere, and hydrosphere; leaching; volatilization.|
|Lassaletta et al., 2014||Global||1. Analyses the importance of international trade of food and feed in the alteration of the N cycle at the global scale. 2. Assigned N content to every product (407 vegetables, 128 animal products) with data from different literature sources. 3. Calculated total net importer and exporter values for all 210 countries.||1. Used information on food and feed trade, and assumed that N constitutes 16% of proteins to quantify the N traded annually during 1961–2010. 2. Amount of N traded between countries increased eightfold, now concerns 1/3 of the total N in world crop production. 3. Divided world in 12 regions and studied N transfer in 2 reference years: 1986 & 2009. 4. A small number of countries, with regard to proteins, are feeding the rest of the world. 5. Globally, system is becoming less efficient—disconnect b/w crop and livestock production across regions||n/a Net importer and exporter status varies by country.||N contained in imported products.||N contained in exported products.|
|Leip et al., 2011||Regional (Europe, EU27 countries)||Farm, land and soil N-budgets for countries in Europe and the EU27 using agro-economic model CAPRI.||1. CAPRI: global economic model for agriculture with a regionalized focus for Europe. 2. Farm N budget is constructed by a combination of the market and animal balances. 3. Market Balances: captures market appearances from domestic production and imports, and their distribution to various domestic uses and exports. 4. Animal Balance: calculates inputs of N by feed and the output in animal products.||Farm N budget NUE: 31% (varies from 15% Ireland—50% Romania) Land N budget NUE: 60% Soil N budget NUE: 63%.||Manure (application): accounts for losses from housing & management; N content of crops; N intake of crude protein; Feed (concentrates); Crop residues returned; Biological N fixation; Atmospheric deposition; Mineral fertilizer.||Manure (excretion): includes leaching, runoff & gaseous emissions; Product output (milk or meat); Sold crop products; Fodder; Crop residues; Soil N-stock changes; Leaching, runoff, and gaseous emissions before manure.|
|Ma et al., 2010||National (China)||Nutrient flows (nitrogen and phosphorus) along the entire food system.||1. The NUFER model (NUtrient flows in Food systems, Environment and Resources use) tracks N and P efficiencies and losses at a national scale. 2. Links to species of N lost to the environment (ammonia, nitrous oxide, dinitrogen, and nitrogen oxides). 3. N and P efficiency can be improved with increased production, balanced fertilization, and improved manure management.||China N use efficiency for crop production (26%), animal production (11%), and the whole food chain (9%).||Fertilizer inputs, crop yields and areas, number of animals, consumer diets, harvested crop and animal product nutrient content, rate and content of animal excretion.||Regional N and P flows, use efficiencies, and emissions by type.|
|Godinot et al., 2016||Regional (Europe)||Applies three new proposed farm nitrogen indicators at the European scale: system N efficiency (SyNE), relative N efficiency (RNE), and system N balance (SyNB).||1. The farm NUE and FGB do not adequately account for all nitrogen flows in systems. 2. Proposed indicators (SyNE and SyNB) better account for indirect N losses. 3. RNE compares the actual N efficiency to an attainable N efficiency, which can identify how much N efficiency can be improved on a given farm.||European NUE is 0.35 and Farm-Gate Balance (FGB) is 86 kg N/ha, whereas the SyNE is 0.23 and SyNB is 113 kg N/ha. Mean RNE is 0.43.||1. NUE and FGB: Inorganic fertilizers, manure, fixation, atmospheric deposition, crops, animals, energy. 2. SyNE and SynB: Inorganic fertilizers, manure, fixation, atmospheric deposition, crops, animals, energy, indirect losses. 3. RNE: SyNE divided by an attainable efficiency.||1. NUE and FGB: Crops, animal products, manure. 2. SyNE and SyNB: Crops, animal products, manure. 3. RNE: SyNE divided by an attainable efficiency.|
|Oenema 2003||Varies||1. Explores nutrient budgeting approaches and summarizes sources of uncertainty associated with these approaches. 2. Implications of uncertainties are discussed.||1. Three types of nutrient budgets: (1) farm-gate: most integrative measure of environmental pressure; (2) Soil surface: estimating net loading of the soil with nutrients and (3) soil systems budgets: nutrient inputs and outputs, recycling of nutrients within the system, nutrient loss pathways and changes in soil nutrient pools. 2. Considerable uncertainty in budget: personal bias, sampling bias, measurement bias, data manipulation bias, sampling and measurement errors, partitioning of nutrient losses. 3. Note: N losses from silage conservation, livestock buildings and manure storage systems, and changes in the N stocks of livestock, animal manure and animal feed are not addressed in any of the budgets.||n/a||1. Farm-gate budget: fertilizer, feed, manure, cattle, bedding material, Biological N fixation, atmospheric deposition. 2. Soil surface budget: fertilizer, urine and dung deposition, manure, forage losses, BNF, atmospheric deposition. 3. Soil system budget: fertilizer, urine and dung depositions, manure, forage losses, BNF, atmospheric deposition.||1. Farm-gate budget: milk, cattle, animal manure, animal feed. 2. Soil surface budget: harvested grass by grazing animals, harvest silage maize & grass. 3. Soil system budget: harvested grass, harvest silage maize & grass, ammonia volatilization from dung & urine, manure, and forages, denitrification, leaching and runoff, net immobilization.|
|Oenema 2006||Varies||Reviews N input-output budgets and N losses in livestock farming systems.||1. Generally, N inputs and losses increase in the order grazing systems < mixed systems < land-less systems. 2. Difficulties of establishing N budgets arise from the tendency of N to dissipate into the wider environment in a variety of species, including gaseous N species. 3. Standardization of methodologies is required to allow comparison of budgets. 4. Improve utilization of animal manure as fertilizer and manure management in general.||n/a||Feed, fertilizer, deposition, biological fixation.||Milk, meat, manure export, ammonia loss, denitrification, leaching.|
|Parfitt et al., 2010||Global||Review of literature on food waste throughout the supply chain in developing, transitional, and developed countries.||Food waste is highest at the immediate post-harvest level in developing countries and the post-consumer level in developed countries.||n/a||n/a||n/a|
|Shindo et al., 2003; 2006||Regional (East Asia)||Report the N load for East Asian countries using a budget approach, including N from biological fixation, energy production, human waste, and farmland.||1. Food production contributed more than 90% of the nitrogen load in East Asia. Fossil fuel N was only significant in Japan and South Korea. 2. N load was reported by sector as the difference between N input and N uptake.||East Asia NUE has a large range.||Fertilizer consumption, food balance sheets.||Food production and consumption, NOx emissions by region, N losses to waterways, denitrification, organic matter accumulation.|
|Westhoek et al., 2014||Regional (Europe)||The environmental impacts (nitrogen emissions, greenhouse gas emissions, and cropland) and health effects of 6 alternative diets with reduced meat & dairy were reviewed.||1. Nitrogen emissions could be reduced by 40% from reductions in meat and dairy intake. 2. A variety of data sets and models were used to assess nitrogen inputs and emissions across the US. Resources include FAO for dietary data and the GAINS model for livestock excretion rates and N emissions.||Current Europe NUE = 18%. NUE would increase to 41–47% with meat and dairy reduction scenarios.||Feed imports, fertilizer, N fixation, N deposition.||Food produced, food exported, emissions to air, emissions to groundwater and surface waters.|
|Reference||Study Domain||Methodological Scope||Key Features||NUE Value||N input values||N output Values|
|OECD 2001||Global||Reviews existing agricultural environmental indicators and their results over the last several decades.||1. A nitrogen-specific indicator for the environmental impacts of nitrogen does not yet exist. 2. Existing environmental impact indicators for agriculture assess soil quality, water quality, land conservation, greenhouse gases, biodiversity, wildlife habitats, and landscape.||n/a||n/a||n/a|
|Payraudeau and van der Werf 2005||Global||Review of six methods for environmental impact assessment: Environmental Risk Mapping (ERM), life cycle assessment (LCA), environmental impact assessment (EIA), multi-agent system (MIA), linear programming (LP), agro-environmental indicators (AEI).||1. The methods presented all link to environmental impacts; the authors state that indicators that link to environmental effects are preferable over those based on specific farming practices. 2. Two important metrics are impact per kg of product and impact per unit of land area.||n/a||n/a||n/a|
|Van der Werf & Petit 2001||Varies||Reviewed 12 methods that use a set of indicators to evaluate the environmental impact of agriculture at the farm level.||1. Taylor et al., (1993) use a Farmer Sustainability Index (FSI)—farmer production practices yield a positive or negative score, which are summed. 2. Ecopoints: assign scores to farmer production practices and landscape maintenance (used to establish payment incentives). 3. Agro-ecological Indicators (AEI): reflect the impact of one production practice on ALL environmental components. 4. Multi-objective parameters: accounts for a set of ecological, economic and social objectives chosen to solve problems in the current system. 5. Environmental management for agriculture (EMA): computer based systems produces eco-ratings reflecting environmental performance by comparing actual farmer production practices and site-specific details. 6. Solagro diagnosis: performance levels for criteria, the number of production systems w/in the farm, diversity of crops grown, management of inputs and management of space. 7. LCA for farm management: identifies the main pollution sources and evaluates possible modifications of the farms or farming methods. 8. Indicators of farm sustainability: assigns scores to production practices and behaviours.||n/a||Use of non-renewable energy & other non-renewable resources, land use, water use, nitrogen fertilizer use, pesticide use, waste utilization.||Emission of: greenhouse gases, ozone depleting gases, acidifying gases, nutritious substances, pesticides, terrestrial ecotoxicity, aquatic ecotoxicity, human toxicity, waste production.|
- Inconsistency in accounting for exports as a portion of national production.
- Variability in accounting for biological nitrogen fixation (BNF), total soil nitrogen, nitrogen sources, and nitrogen sinks.
- Limited differentiation between new (e.g., synthetic fertilizer) versus recycled (e.g., manure) N inputs.
- Inconsistency in approaches that address crop rotations, which in most cases is a limitation in calculating crop specific N use.
- Animal and plant product allocation to different final products at the farm gate. There are a variety of methods for determining how much of the N use should be allocated toward multiple products.
- For the approaches based on losses, some studies chose to include gaseous emissions to the atmosphere and others did not. Atmospheric nitrogen deposition is often lacking as well as denitrification. In these studies, N leaching estimation is uncertain and therewith the N outputs.
- There are limited connections between the N use results and actual environmental impacts.
- Sutton, M.A.; Howard, C.M.; Erisman, J.W.; Erisman, J.W.; Billen, G.; Bleeker, A.; Grennfelt, P.; van Grinsven, H.; Grizzetti, B. The European Nitrogen Assessment; Cambridge University Press: Cambridge, UK, 2011. [Google Scholar]
- Oenema, O. Nitrogen budgets and losses in livestock systems. Int. Congr. Ser. 2006, 1293, 262–271. [Google Scholar] [CrossRef]
- Galloway, J.N.; Townsend, A.R.; Erisman, J.W.; Bekunda, M.; Cai, Z.; Freney, J.R.; Martinelli, L.A.; Seitzinger, S.P.; Sutton, M.A. Transformation of the nitrogen cycle: Recent trends, questions, and potential solutions. Science 2008, 320, 889–892. [Google Scholar] [CrossRef] [PubMed]
- Fowler, D.; Coyle, M.; Skiba, U.; Sutton, M.A.; Cape, J.N.; Reis, S.; Sheppard, L.J.; Jenkins, A.; Grizzetti, B.; Galloway, J.N.; et al. The global nitrogen cycle in the twenty-first century. Philos. Trans. R. Soc. Lond. B Boil. Sci. 2013, 368, 20130164. [Google Scholar] [CrossRef] [PubMed][Green Version]
- Galloway, J.N.; Aber, J.D.; Erisman, J.W.; Seitzinger, S.P.; Howarth, R.W.; Cowling, E.B.; Cosby, B.J. The nitrogen Cascade. BioScience 2003, 53, 341–356. [Google Scholar] [CrossRef]
- Erisman, J.W.; Galloway, J.N.; Seitzinger, S.; Bleeker, A.; Dise, N.B.; Petrescu, R.; Leach, A.M.; de Vries, W. Consequences of human modification of the global nitrogen cycle. Philos. Trans. R. Soc. Lond. B Boil. Sci. 2013, 368, 20130116. [Google Scholar] [CrossRef] [PubMed]
- Sutton, M.A.; Bleeker, A.; Howard, C.M.; Bekunda, M.; Grizzeetti, B.; de Vries, W.; van Grinsven, H.J.M.; Abrol, Y.P.; Adhya, T.K.; Billen, G.E.A.; et al. Our Nutrient World: The Challenge to Produce More Food and Energy with Less Pollution; Centre for Ecology and Hydrology: Edinburgh, UK, 2013; 128p. [Google Scholar]
- EU Nitrogen Expert Panel. Nitrogen Use Efficiency (NUE)—Guidance Document for Assessing NUE at Farm Level; Wageningen University: Wageningen, The Netherlands, 2016. [Google Scholar]
- Ahlgren, S.; Baky, A.; Bernesson, S.; Nordberg, Å.; Norén, O.; Hansson, P.A. Consequential Life Cycle Assessment of Nitrogen Fertilisers Based on Biomass—A Swedish Perspective. Insci. J. 2012, 2, 80–101. [Google Scholar] [CrossRef]
- Brentrup, F.; Kusters, J.; Kuhlmann, H.; Lammel, J. Application of the life cycle assessment methodology to agricultural production: An example of sugar beet production with different forms of Nitrogen Fertilisers. Eur. J. Agron. 2001, 14, 221–233. [Google Scholar] [CrossRef]
- Brentrup, F.; Küsters, J.; Lammel, J.; Barraclough, P.; Kuhlmann, H. Environmental impact assessment of agricultural production systems using the Life Cycle Assessment (LCA) methodology II. The application to n fertilizer use in winter wheat production systems. Eur. J. Agron. 2004, 20, 265–279. [Google Scholar] [CrossRef]
- Caffrey, K.R.; Veal, M.W. Conducting an Agricultural Life Cycle Assessment: Challenges and Perspectives. Sci. World J. 2013, 2013. [Google Scholar] [CrossRef] [PubMed]
- Cederberg, C.; Mattson, B. Life cycle assessment of milk production: A comparison of conventional and organic farming. J. Clean. Prod. 1999, 8, 49–60. [Google Scholar] [CrossRef]
- Gallejones, P.; Pardo, G.; Aizpurua, A.; del Prado, A. Life cycle assessment of first-generation biofuels using a nitrogen crop model. Sci. Total Environ. 2014, 505, 1191–1201. [Google Scholar] [CrossRef] [PubMed]
- Harris, S.; Narayanaswamy, V. A Literature Review of Life Cycle Assessment in Agriculture; Rural Industries Research and Development Corporation: Barton, Australia, 2009; p. 45. [Google Scholar]
- Liao, W.; van der Werf, H.M.G.; Salmon-Monviola, J. Improved environmental life cycle assessment of crop production at the catchment scale via a process-based nitrogen simulation model. Environ. Sci. Technol. 2015, 49, 10790–10796. [Google Scholar] [CrossRef] [PubMed]
- Pelletier, N.; Leip, A. Quantifying anthropogenic mobilization, flows (in product systems) and emissions of fixed nitrogen in process-based environmental life cycle assessment: Rationale, methods and application to a life cycle inventory. Int. J. Life Cycle Assess. 2014, 19, 166–173. [Google Scholar] [CrossRef]
- Thomassen, M.A.; Van Calker, K.J.; Smits, M.C.J.; Iepema, G.L.; De Boer, I.J.M. Life cycle assessment of conventional and organic milk production in The Netherlands. Agric. Syst. 2008, 96, 95–107. [Google Scholar] [CrossRef]
- Chatzimpiros, P.; Barles, S. Nitrogen food-print: N use related to meat and dairy consumption in France. Biogeosciences 2013, 10, 471–481. [Google Scholar] [CrossRef]
- Leach, A.M.; Galloway, J.N.; Bleeker, A.; Erisman, J.W.; Kohn, R.; Kitzes, J. A nitrogen footprint model to help consumers understand their role in nitrogen losses to the environment. Environ. Dev. 2012, 1, 40–66. [Google Scholar] [CrossRef]
- Stevens, C.J.; Leach, A.J.; Dale, S.; Galloway, J.N. Personal nitrogen footprint tool for the United Kingdom. Environ. Sci. Process. Impacts 2014, 16, 1563–1569. [Google Scholar] [CrossRef] [PubMed][Green Version]
- Pierer, M.; Winiwarter, W.; Leach, A.M.; Galloway, J.N. The nitrogen footprint of food products and general consumption patterns in Austria. Food Policy 2014, 49, 128–136. [Google Scholar] [CrossRef]
- Shibata, H.; Cattaneo, L.R.; Leach, A.M.; Galloway, J.N. First approach to the Japanese nitrogen footprint model to predict the loss of nitrogen to the environment. Environ. Res. Lett. 2014, 9, 11503. [Google Scholar] [CrossRef]
- Shibata, H.; Galloway, J.N.; Leach, A.M.; Noll, C.; Erisman, J.W.; Erisman, J.W.; Gu, B.; Liang, X.; Hayashi, K.; Ma, L.; et al. Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment. Ambio 2017, 46, 129–142. [Google Scholar] [CrossRef] [PubMed]
- Galloway, J.N.; Winiwarter, W.; Leip, A.; Leach, A.M.; Bleeker, A.; Erisman, J.W. Nitrogen footprints: Past, present and future. Environ. Res. Lett. 2014, 9, 115003. [Google Scholar] [CrossRef]
- Bleken, M.A.; Bakken, L.R. The nitrogen cost of food production: Norwegian society. Ambio 1997, 26, 130–135. [Google Scholar]
- Dalgaard, T.; Bienkowski, J.F.; Bleeker, A.; Dragosits, U.; Drouet, J.L.; Durand, P.; Frumau, A.; Hutchings, N.J.; Kedziora, A.; Magliulo, V.; et al. Farm Nitrogen Balances in Six European Landscapes as an Indicator for Nitrogen Losses and Basis for Improved Management. Biogeosciences 2012, 9, 5303–5321. [Google Scholar] [CrossRef][Green Version]
- Galloway, J.N.; Cowling, E.B. Reactive nitrogen and the world: 200 years of change. Ambio 2002, 31, 64–71. [Google Scholar] [CrossRef] [PubMed]
- Howarth, R.W.; Boyer, E.W.; Pabich, W.J.; Galloway, J.N. Nitrogen use in the United State from 1961–2000 and potential future trends. Ambio 2002, 31, 88–96. [Google Scholar] [CrossRef] [PubMed]
- Isermann, K.; Isermann, R. Policy scenarios: Impacts of EU and national legislation on nutrient dynamics in river basins and oceans. In Plant Nutrition for Food Security, Human Health and Environmental Protection; Li, C.J., Zhang, F.S., Dobermann, A., Hinsinger, P., Lambers, H., Li, X.L., Marschner, P., Maene, L., McGrath, S., Oenema, O., Eds.; Tsinghua University Press: Beijing, China, 2005; pp. 1150–1151. [Google Scholar]
- Lassaletta, L.; Billen, G.; Grizzetti, B.; Anglade, J.; Garnier, J. 50 year trends in nitrogen use efficiency of world cropping systems: The relationship between yield and nitrogen input to cropland. Environ. Res. Lett. 2014, 9, 105011. [Google Scholar] [CrossRef]
- Leip, A.; Britz, W.; Weiss, F.; De Vries, W. Farm, land, and soil nitrogen budgets for agriculture in Europe calculated with CAPRI. Environ. Pollut. 2011, 159, 3243–3253. [Google Scholar] [CrossRef] [PubMed]
- Ma, L.; Ma, W.Q.; Velthof, G.L.; Wang, F.H.; Qin, W.; Zhang, F.S.; Oenema, O. Modeling nutrient flows in the food chain of China. J. Environ. Qual. 2012, 39, 1279–1289. [Google Scholar] [CrossRef]
- Godinot, O.; Leterme, P.; Vertès, F.; Carof, M. Indicators to evaluate agricultural nitrogen efficiency of the 27 member states of the European Union. Ecol. Indic. 2016, 66, 612–622. [Google Scholar] [CrossRef]
- Oenema, O.; Kros, H.; De Vries, W. Approaches and Uncertainties in Nutrient Budgets: Implications for Nutrient Management and Environmental Policies. Eur. J. Agron. 2003, 20, 3–16. [Google Scholar] [CrossRef]
- Shindo, J.; Okamoto, K.; Kawashim, H. A model-based estimation of nitrogen flow in the food production–supply system and its environmental effects in East Asia. Ecol. Model. 2003, 169, 197–212. [Google Scholar] [CrossRef]
- Shindo, J.; Okamoto, K.; Kawashima, H. Prediction of the environmental effects of excess nitrogen caused by in- creasing food demand with rapid economic growth in eastern Asian countries, 1961–2020. Ecol. Model. 2006, 193, 703–720. [Google Scholar] [CrossRef]
- Grizzetti, B.; Bouraoui, F.; Aloe, A. Changes of nitrogen and phosphorus loads to European seas. Glob. Chang. Biol. 2012, 18, 769–782. [Google Scholar] [CrossRef]
- Gustavsson, J.; Cederberg, C.; Sonesson, U.; van Otterdijk, R.; Meybeck, A. Global Food Losses and Food Waste; Food and Agriculture Organization of the United Nations: Rome, Italy, 2011; Available online: http://www.fao.org/fleadmin/user_ upload/ags/publications/ GFL_web.pdf (accessed on 6 November 2013).
- Parfitt, J.; Barthel, M.; Macnaughton, S. Food waste within food supply chains: Quantification and potential for change to 2050. Philos. Trans. R. Soc. B 2010, 365, 3065–3081. [Google Scholar] [CrossRef] [PubMed]
- Organisation for Economic Co-operation and Development (OECD). Environmental Indicators for Agriculture; Organisation for Economic Co-operation and Development: Paris, France, 2001. [Google Scholar]
- Payraudeau, S.; van der Werf, H.M.G. Environmental Impact Assessment for a Farming Region: A Review of Methods. Agric. Ecosyst. Environ. 2005, 107, 1–19. [Google Scholar] [CrossRef]
- Petit, O.; Corcos, B.; O’Connor, M. Appropriation Sociale du Problème de Gestion Durable de la Nappe de Beauce. Programme Inter-Institutionnel de Recherches et d'Études en Économie de l'Environnement (PIREE); Universite ́ de Versailles-Saint Quentin en Yvelines: Guyancourt, France, 2001; p. 90. [Google Scholar]
- Isermann, K.; Isermann, R. Food production and consumption in Germany: N flows and N emissions. Nutr. Cycl. Agroecosyst. 1998, 52, 289–301. [Google Scholar] [CrossRef]
- Westhoek, H.; Lesschen, J.P.; Leip, A.; Rood, T.; Wagner, S.; De Marco, A.; Murphy-Bokern, D.; Pallière, C.; Howard, C.M.; Oenema, O.; et al. Nitrogen on the Table: The Influence of Food Choices on Nitrogen Emissions and the European Environment; European Nitrogen Assessment Special Report on Nitrogen and Food; Centre for Ecology & Hydrology: Edinburgh, UK, 2015. [Google Scholar]
- Bouwman, A.F.; Boumans, L.J.M.; Batjes, N.H. Modeling global annual N2O and NO emissions from fertilized fields. Glob. Biogeochem. Cycles 2002, 16, 28-1–28-9. [Google Scholar] [CrossRef]
- Simpson, D.; Aas, W.; Bartnicki, J.; Berge, H.; Bleeker, A.; Cornelis, C.; Franciscus, D.; Tony, D.; Erisman, J.W.; Fagerli, H.; et al. Atmospheric transport and deposition of nitrogen in Europe. In The European Nitrogen Assessment; Sutton, M.A., Howard, C.M., Erisman, J.W., Billen, G., Bleeker, A., Grennfelt, P., van Grinsven, H., Grizzetti, B., Eds.; Cambridge University Press: Cambridge, UK, 2011. [Google Scholar]
- Röell, C.; Erisman, J.W. Kwantificeren van de stikstofstromen in Nederland. Milieu 2011, 17, 23–26. [Google Scholar]
- World Health Organization (WHO). Protein and Amino Acid Requirements in Human Nutrition: Report of a Joint FAO/WHO/UNU Expert Consultation (WHO Technical Report Series 935); WHO: Geneva, Switzerland, 2007. [Google Scholar]
- Oita, A.; Malik, A.; Kanemoto, K.; Geschke, A.; Nishijima, S.; Lenzen, M. Substantial nitrogen pollution embedded in international trade. Nat. Geosci. 2016, 9, 111–115. [Google Scholar] [CrossRef]
- Van Der Werf, H.M.G.; Petit, J. Evaluation of the environmental impact of agriculture at the farm level: A comparison and analysis of 12 indicator-based models. Agric. Ecosyst. Environ. 2001, 93, 131–145. [Google Scholar] [CrossRef]
|Links to Environmental Impacts||Can Account for Trade||Flexible System Boundaries 1||Models Internal N Fluxes||Socio-Economic, Cultural, and Health Impacts 2||Can Account for Recycled and New N||Mass Flow Model 3||Data Intensive||Inconsistent Allocation Methods||Difficult to Compare Impacts 4||Regional Level and Above||Site-Specific||Indeterminable Fate of System Outputs 5|
|Life Cycle Analysis||X||X||X||X||X||X||X|
|Environmental Impact Assessment||X||X||X||X||X||X||X|
|Part of NUE||Specific Flow/Part of NUE||Country Level Data Source|
|New N||Fertilizer||Fertilizer application per crop, IFA; FAOSTAT|
|Biological N fixation|||
|Atmospheric deposition to agricultural areas||European Monitoring and Evaluation Programme (EMEP)|
|Import–export||Country matrix,  based on FAOSTAT|
|Stock change||FAOSTAT food balance|
|Agricultural systems NUE (see EU Nitrogen Expert Panel (2016)||N-budget on the country scale|
|Food processing||FAOSTAT Food balance|
|Food N food availability for consumption||FAOSTAT, note this is the food availability for consumption|
|N content of food products|||
|This Study||Roell and Erisman |
|Kton N/yr||Kton N/yr|
|Manure export (national data)||15||77|
|Net annual change||Annual changes in stock||18|
|NUE (incl. manure export)||26||22|
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Erisman, J.W.; Leach, A.; Bleeker, A.; Atwell, B.; Cattaneo, L.; Galloway, J. An Integrated Approach to a Nitrogen Use Efficiency (NUE) Indicator for the Food Production–Consumption Chain. Sustainability 2018, 10, 925. https://doi.org/10.3390/su10040925
Erisman JW, Leach A, Bleeker A, Atwell B, Cattaneo L, Galloway J. An Integrated Approach to a Nitrogen Use Efficiency (NUE) Indicator for the Food Production–Consumption Chain. Sustainability. 2018; 10(4):925. https://doi.org/10.3390/su10040925Chicago/Turabian Style
Erisman, Jan Willem, Allison Leach, Albert Bleeker, Brooke Atwell, Lia Cattaneo, and James Galloway. 2018. "An Integrated Approach to a Nitrogen Use Efficiency (NUE) Indicator for the Food Production–Consumption Chain" Sustainability 10, no. 4: 925. https://doi.org/10.3390/su10040925