Agriculture: nitrogen balance

Assessment versions

Published (reviewed and quality assured)

• Agriculture: nitrogen balance (SEBI 019) - Assessment published May 2010

Justification for indicator selection

MAIN ADVANTAGES OF THE INDICATOR

• Policy relevance: indicates the degree of nutrient pressure from agriculture on biodiversity. Also provides a proxy measure for the intensity of agriculture in general.
• Well developed and established.
• Broad acceptance and understandability.
• Can be updated yearly.

Scientific references:

• No rationale references available

Indicator definition

'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.

Units

No units have been specified

Policy context and targets

Context description

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 nitrogen imbalances normally lead to high pressure on biodiversity within and outside the farmed environment.

Agriculture is intensifying in many places and causes an increasing pressure on biodiversity. Increasing nitrogen availability favours a few nitrophilous species and suppresses many other, rarer species. 'Nitrogen balance' includes nitrogen input (inter alia fertilising, nitrogen fixation, nitrogen deposition) and nitrogen output (inter alia denitrification and the emission of ammonia) and thus reflects a major part of the nitrogen cycle and the impact of farm management to 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

Sustainable management of agricultural ecosystems would manage the nitrogen-balance to minimise the negative effects from excess nitrogen.

Targets

No targets have been specified

Related policy documents

No related policy documents have been specified

Methodology

Methodology for indicator calculation

Calculation of the indicator per country: see the OECD/Eurostat gross nutrient balance handbook. For more details see the specification of EEA core set indicator 025 at
http://themes.eea.europa.eu/IMS/IMS/ISpecs/ISpecification20041007132056/full_
spec.

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.
• 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 for gap filling has been specified. Probably this info has been added together with indicator calculation.

Methodology references

No methodology references available.

Data specifications

EEA data references

• No datasets have been specified here.

Data sources in latest figures

Uncertainties

Methodology uncertainty

No uncertainty has been specified

Data sets uncertainty

No uncertainty has been specified

Rationale uncertainty

MAIN DISADVANTAGES IN THE INDICATOR

• The data are 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 are also important, for example.

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 indicator 'Nitrogen balance' 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.

Work description

SUGGESTIONS FOR IMPROVEMENT If feasible a regionalisation of the indicator would be useful. Relevant work is being developed in cooperation between Eurostat and the EEA in the context of developing regional gross nutrient balances. An alternative approach could be to develop nitrogen balance data on the basis of farm samples. Some relevant information is already available in the FADN survey (farm accountancy data network). Samples should ideally include intensive farmland and  high nature value farmland separately to identify changes on a disaggregated level. Choosing sample locations in line with a stratified sampling framework for monitoring European habitats (see sub-indicator 'High nature value farmland area' of indicator 20), could improve interpretation opportunities. For nitrogen input (and surplus) there are methods under development (i.e. CAPRI (Common Agricultural Policy Regionalized Impact Anaylsis), FATE (Fate of Agrochemicals in Terrestrial Ecosystems in Europe) for deriving their distribution at a finer scale (within 1 to 10 square km cells) and this will allow making some better estimates in the near future. To more fully describe this phenomenon, reference is made to the IRENA set of agri-environment indicators for the EU.

Resource needs

No resource needs have been specified

Status

Not started

Deadline

2099/01/01 00:00:00 GMT+1