Agriculture Reference
In-Depth Information
drought sensitive, nutrient-poor Lixisol or Arenosol. The same is true for, for example,
poorly drained versus well-drained soils. When discussing existing and potential soil
conditions for smallholder agriculture and the associated ecosystem services, atten-
tion will therefore be focused on the soil types that occur that may allow extrapolation
of results to other sites where the same soils occur. This represents the traditional
procedure of soil survey interpretation and land evaluation, where soil types are used
as “carriers of information” functioning as class-pedotransfer functions (e.g., Bouma
1989; Bouma et al. 2012). However, a focus on soil type alone is not enough as it is
based on permanent properties of soils formed by the soil-forming factors over peri-
ods of thousands of years or longer. However, for practical applications, emphasis
should also be on soil behavior in terms of the effects of different forms of soil man-
agement on the functioning of a given soil type, resulting in a series of characteristic
phenoforms. Genoforms are genetic soil types, as distinguished in soil classification
systems based on pedogenetic principles that are represented on soil maps, while
phenoforms describe different properties as a function of different types of manage-
ment applied to that particular soil type. A series of phenoforms of a given geno-
form defines its functionality, not only reflecting its potential but also its limitations
and resilience. Each soil type (genoform) has a characteristic range of phenoforms,
and extrapolation of data obtained for specific phenoforms is particularly relevant for
land evaluation. The phenoform analysis has been made for two major soil series in
the Netherlands (Droogers and Bouma 1997; Pulleman et al. 2000; Sonneveld et al.
2002). Thus far, standard soil survey procedures do not include a phenoform analysis
but soil surveyors are advised to do so in the future expressing the specific effects of
soil management rather than only a focus on static, inherent soil properties.
2.2.2
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2.2.2.1 Introduction
The benefits people obtain from ecosystems are described in terms of ecosystem ser-
vices, a concept that has proved to be effective as a communication tool (MA 2005).
Sixteen services are defined for four categories: supporting, provisioning, regulating,
and cultural services. Of these, all have a clear connection with soils. To avoid overly
complicated schemes with partly overlapping subcategories, a link can be proposed
between ecosystem services and soil functions, as defined by the European Union
(EU) Soil Protection Strategy of 2006 (Commission of the European Community
[CEC] 2006). Each of these functions represents a soil-provided ecosystem service
in terms of producing (i) food and fiber (a provisioning service); (ii) fresh water by its
filtering action (a provisioning and regulating service); (iii) biodiversity (a supporting
service); (iv) a physical and cultural environment for human activities (a cultural ser-
vice); (v) raw materials (a provisioning service); (vi) a pool for carbon (a regulating
service); and (vii) an archive, expressing our common geological and archeological
heritage (a cultural service). In turn, these seven ecosystem services are reflected in
the soil security concept because when they are considered to be adequate now and
in the future, maintenance and improvement of the soil resource is assured, provid-
ing the desired security. Of course, the question as to what is “adequate” has to be
