Agriculture: nitrogen balance
Agricultural nitrogen surpluses (the difference between all nutrient inputs and outputs on agricultural land) show a declining trend, thereby potentially reducing environmental pressures on soil, water and air. Many countries, however, still maintain a large surplus.
Is the nitrogen surplus from agriculture being reduced?
Nitrogen input on agricultural land in Organisation for Economic Co-operation and Development (OECD) countries
Note: How to read the graph: between 1995 and 2004, total nitrogen input on agricultural land in Germany decreased from about 5 to about 4 million tonnes
Based on OECD, 2008.
Nitrogen balance per hectare of agricultural land
Note: How to read the graph: in 20 years, nitrogen balance per ha was reduced from 240 to 173 kg/ha in Belgium.
Based on OECD, 2008.
A nutrient balance describes the difference between all nutrient inputs and outputs on agricultural land. A positive balance or surplus reflects inputs that are in excess of crop and forage needs. It can result in diffuse pollution through the loss of nutrients to water bodies, decreasing water quality while promoting eutrophication. Surplus nitrogen can also be lost to air as ammonia and other greenhouse gases.
All European countries exhibit a nitrogen surplus. Overall however, these surpluses have declined since the mid-1980s, reducing the environmental pressures on soil, water and air. The adoption of nutrient management plans and environmental farm plans has had a key role in this reduction.
It is, however, important not only to consider rates of surplus decline but also their absolute values. Belgium and the Netherlands, for example, show significant decreases although nutrient surpluses in these two countries currently remain much higher than the average across all countries, indicating high productivity and pressure on biodiversity.
Conversely, some countries show an increase but still remain below the average.
In most countries, national nutrient balances typically mask considerable regional variation due to variation in the type and intensity of farming.
Although gross nitrogen balance can show areas where ground and surface waters may be at risk from nitrogen leaching, it should not be interpreted as data on actual losses to the environment. In order to assess the environmental impact of excess nitrogen, more information is needed on farm nitrogen management, soil type, and climate conditions, all of which play a role in the fate of nitrogen in the environment. 'Gross nitrogen balance' is also an agri-environmental indicator and part of the compulsory indicators of the Common Monitoring and Evaluation Framework (CMEF) for rural development. Work is ongoing on streamlining similar indicators used in different processes.
Indicator specification and metadata
'Gross nitrogen balance' estimates the potential surplus of nitrogen on agricultural land. This is done by calculating the balance between nitrogen added to an agricultural system (nitrogen input can be taken as a proxy indicator for the general intensity of agricultural management) and nitrogen removed from the system per hectare of agricultural land. The indicator accounts for all inputs to and outputs from the farm, and therefore includes nitrogen input.
The units used in this indicator are:
kilogrammes per hectare
Policy context and targets
High nitrogen inputs and losses generally coincide with high phosphorous, and pesticide inputs and losses. The nitrogen balance is related to nutrient leaching risks: high nitrogen inputs and imbalances normally lead to high pressure on biodiversity within and outside the farmed environment.
Agriculture is intensifying in many places, causing increasing pressure on biodiversity. Increasing nitrogen availability favours a few nitrophilous species and suppresses many other, rarer species. The 'nitrogen balance' includes nitrogen input (fertilising, nitrogen fixation and nitrogen deposition among other things) and nitrogen output (denitrification and the emission of ammonia among other things) and thus reflects a major part of the nitrogen cycle and the impact of farm management on the hydrosphere and atmosphere. Nitrogen input (fertilising and nitrogen fixation) more directly affects the level of biodiversity in fields and grasslands.
Relation of the indicator to the focal area
The sustainable management of agricultural ecosystems would minimise the negative effects from excess nitrogen through management of the nitrogen-balance.
2020 EU Biodiversity Targets: target 3
Related policy documents
EU 2020 Biodiversity Strategy
in the Communication: Our life insurance, our natural capital: an EU biodiversity strategy to 2020 (COM(2011) 244) the European Commission has adopted a new strategy to halt the loss of biodiversity and ecosystem services in the EU by 2020. There are six main targets, and 20 actions to help Europe reach its goal. The six targets cover: - Full implementation of EU nature legislation to protect biodiversity - Better protection for ecosystems, and more use of green infrastructure - More sustainable agriculture and forestry - Better management of fish stocks - Tighter controls on invasive alien species - A bigger EU contribution to averting global biodiversity loss
Methodology for indicator calculation
Calculation of the indicator per country: see the OECD/Eurostat gross nutrient balance handbook.
Total Nitrogen input:
- Total fertilisers;
- Inorganic fertilisers (simple mineral fertilisers, complex mineral fertilisers, mineral-organic compounds);
- Organic fertilisers (urban compost, sewage sludge spread on agricultural land);
- Livestock manure production;
- Manure stocks (stock levels, imports and exports of livestock manure);
- Biological nitrogen fixation (nitrogen fixed in the soil);
- Atmospheric deposition of nitrogen compounds; and
- Other inputs (seeds and planting material, ...).
Total nitrogen outputs from farm unit: total harvested crops and forage.
Subtracting the sum of the total nitrogen output from the total nitrogen input results in the gross nutrient balance for nitrogen.
Methodology for gap filling
No methodology references available.
No uncertainty has been specified
Data sets uncertainty
No uncertainty has been specified
MAIN DISADVANTAGES OF THE INDICATOR
- The data is available at national level. National nitrogen balances can hide great regional variation and thus lead to regional problems being overlooked. This is a particular issue for larger countries with different areas under different (intensive or extensive) agricultural regimes.
- Input and balance of nutrients is only one of the factors that determines agricultural intensity and is relevant to biodiversity. Pesticide use and crop diversity, for example, are also important.
ANALYSIS OF OPTIONS
There are various possible indicators for this process: nitrogen balance, phosphorous balance, pesticide inputs, crop and dairy yields, livestock density, diversity of crop rotation etc. The 'nitrogen balance' indicator was selected because it is relatively well documented, it relates well to the majority of farming systems and eutrophication is an important environmental problem adversely affecting biodiversity.
It is closely related to other nitrogen-related indicators:
- Mineral fertiliser consumption (IRENA 08, Environmental Risk Assessment for European Agriculture -- ENRISK).
- Nitrogen excretion from livestock manure (ENRISK).
- Share of agriculture in total nitrogen load in rivers (ENRISK).
- Share of agriculture in nitrate contamination (IRENA 34.2).
- Several OECD agri-environment indicators.
Gross Nutrient Balance
provided by Statistical Office of the European Union (Eurostat)
Biodiversity (Primary topic)
Typology: Efficiency indicator (Type C - Are we improving?)
- SEBI 019
Contacts and ownership
EEA Contact InfoKatarzyna Biala
EEA Management Plan2010 1.2.2 (note: EEA internal system)
Frequency of updates
For references, please go to http://www.eea.europa.eu/data-and-maps/indicators/agriculture-nitrogen-balance/agriculture-nitrogen-balance-assessment-published or scan the QR code.
PDF generated on 04 Dec 2016, 07:16 AM