Nutrient-balance
of the soil (nutrient input/output)
RD-4
Resource
Depletion
Pressure
1 Indicator
definition and unit of measurement
The
average balance of input and output of phosphorus and nitrogen per hectare of
agricultural area per year, expressed in eutrophication equivalents per hectare
per year.
2 Placement
in the framework
5EAP:
Partly
deals with natural resources in Chapter 5: The themes and targets of the
programme, section 5.3: Protection of nature and biodiversity, table 10 and
section 5.4: Management of water resources, table 11. See also Chapter 4:
Selected target sectors, section 4.4: The agriculture sector, table 4.
Agenda
21:
Agenda
21 in many of its chapters calls for policies and actions in various areas,
that take into account the vulnerability and availability of natural resources,
and for an increased efficiency in the use of these resources. Chapter 14:
Promoting sustainable agriculture and rural development, calls for an improved
nutrient efficiency, a transition towards organic fertilisers and less use of
external production means (among others, artificial fertilisers).
International
conventions and agreements:
Article
130 of the Treaty on the European Union (Maastricht, 1992) calls for prudent
and rational utilisation of natural resources. The Protocol of Chambery (1994)
calls for the sustainable development of mountain agriculture.
Ranking:
Core
ranking:
4
(38%)
Policy
Relevance:
10
(2.8)
Analytical
Soundness:
10
(2.9)
Responsiveness:
15
(2.2)
Most
appropriate related state indicator:
The
average concentration of phosphorus and nitrogen in the upper ground water
level in relation to the eutrophication sensitivity of the average soil.
3 Significance
Purpose:
The
indicator represents the overall pressure on the main quality aspect of the
soil, the eutrophication of the upper soil and ground water levels.
Relevance:
Eutrophication
by excessive use of manure and chemical fertilisers by agriculture is
considered to be one of the most important threats for soil quality.
Eutrophication affects the capability of the soil to support biodiversity and
affects the possibilities to use ground water for drinking water production.
Linkages
to other pressure indicators:
There
is a linkage with the indicator depicting ground water abstraction for drinking
water purposes (RD-1).
Targets:
Reference
levels for this indicator can be derived from existing policy targets in the
field of fertiliser use. Sustainability levels can be derived from figures on
soil type and climate on the basis of equilibrium fertilisation.
4 Methodological
description and underlying definitions
Underlying
definitions and concepts:
The
amounts of phosphorus and nitrogen are weighed on the basis of their
eutrophication potential and added. The difference between input and output
gives the figure for the indicator. The input includes organic and artificial
fertilisers while the output includes all nutrients removed from the soil by
harvesting and grazing. Only phosphorus and nitrogen are considered.
Eutrophication can also be caused by potassium, however it is generally assumed
that this is of minor importance.
Measurement
methods:
The
indicator is measured in eutrophication equivalents which enables to add
phosphorus and nitrogen.
Limitations
of the indicator:
The
reference level of the indicator is affected by climatological conditions and
types of soil. Another factor influencing the target level is the farming
efficiency. Therefore the analytical soundness and the responsiveness are not
very good, which has an impact for the interpretation of the indicator value.
Alternative
definitions:
The
indicator could be improved by also taking into account the sensitivity of the
soil for eutrophication, however, experience has shown that this will make the
indicator very complex.
