«Measuring Agricultural Sustainability Chapter · September 2010 DOI: 10.1007/978-90-481-9513-8_2 CITATIONS READS 3 authors, including: Zahra Ranjbar ...»
Principles and criteria derived from the function of the agro-ecosystem have been presented in Table 6. With respect to the “environmental pillar”, its function is connected with the management and conservation of natural resources and fluxes within and between these resources. Natural resources provided by ecosystems are water, air, soil, energy and biodiversity (habitat and biotic resources).
Regarding the “economic pillar”, its function in the agro-ecosystem is to provide prosperity to the farming community. In addition, each agro-ecosystem has several social functions, both at the level of farming community and at the level of society. The definition of these functions is based on present-day societal values and concerns. Farming activities should be carried out with respect of the quality of life of the farmer and his family. The agro-ecosystem needs to 86 D. Hayati et al.
be organized in such a way that social conditions are optimal for the people who work on farms. This refers to the physical well-being (labour conditions and health) and the psychological well-being (education, gender equality, access to infrastructure and activities, integration and participation in society both professionally and socially, feeling of independence) of the farm family and its workers.
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7 Agricultural Sustainability Scales at National Level Assessing and implementing sustainability in agriculture can be undertaken by using goal-oriented strategy approaches according to von Wirén-Lehr (2001).
These approaches outlined in Fig. 3 include four fundamental steps, which are:
7.1 Goal Definition Since goal definition represents the basis of strategies, it determines all subsequent steps as well as the whole methodological framework. Corresponding to Fig. 3 Basic features of four-step strategies to assess and implement sustainability in agriculture.
Frames present required data influx (left frames) and expected outcome (right frames) of feature derivation (von Wirén-Lehr 2001) Measuring Agricultural Sustainability 89 the general multidimensional sustainability paradigm, definitions of sustainable agriculture have to include ecological, economic and social aspects with respect to their diverse spatial and temporal scales (Allen et al. 1991; Herdt and Steiner 1995; Christen 1996). Even though this holistic approach integrates all principles of the theoretical term, its applicability is considerably reduced by the high complexity. Hence, a first step must be to condense the holistic sustainability perception, to restrain definitions on single selected principles and to define aims and systems of concern.
Depending on the priorities of participants and target groups, goal definitions may concentrate on one single (one-dimensional goal definition) or various selected dimensions (multidimensional goal definition). In the agricultural sector, the normative focus of sustainability perception is predominantly based on ecological and/or economic aspects (Crews et al. 1991; Dunlap et al. 1992; Neher 1992; Farshad and Zinck 1993).
However, to ensure successful implementation of sustainable systems, management advice has to be strongly adapted to the requirements and abilities not only of target groups but of all groups concerned, for example, also political stakeholders or customers.
They should be included in the conceptual work from the beginning. Consequently, concepts to assess and implement sustainability in agriculture have to enhance cooperation not only between different scientific sections but also between divergent socio-professional groups (Giampietro and Bukkens 1992; Flora 1995). Essential for this interdisciplinary work is a separate survey of normative options, e.g. setting of goals and objective parameters (e.g. agro-technical options) permitting every participant or user to verify the fundamental conditions of the work.
All goal-oriented concepts deduce single indicators or indicator sets to ‘translate’ the defined principles. Indicators represent a powerful tool both to reduce the complexity of system description and to integrate complex system information (Giampietro 1997). Hence, indicators have to be deduced for different systems such as agricultural production systems or other ecosystems, e.g. forests or lakes and at diverse spatio-temporal scales. If the agricultural production system is considered as one compartment of a whole cultured landscape, indicator sets have to provide information not only on imbalances, e.g. releases and deficits of the agricultural production system itself, but also on the external deposition and off-site effects of emissions resulting from agricultural production, e.g. toxic effects in natural aquatic ecosystems due to pesticide residues. Two types of indicators can be distinguished according to their
focus of characterization such as:
• Specific indicators, characterising single parts of the system of concern (Nieberg and Isermeyer 1994; Bockstaller et al. 1997) • Systemic indicators, describing key functions and processes of systems as a whole (Beese 1996; Müller 1998; Xu et al. 1999) 90 D. Hayati et al.
7.3 Evaluation Strategies
Evaluation strategies enable the determination of the sustainability of systems under investigation. They are based on the previously characterised sustainability perception, goal definitions and selected indicators or indicator sets. The evaluation process represents one of the most delicate parts of the concept. First, evaluation ultimately depends on normative options concerning setting of goals, selection of systems of concern and deduction of threshold values or ranges of tolerance (Finnveden 1997). Second, the evaluation of systems based on sets of single indicators ultimately remains inadequate since systemic sustainability represents ‘more than the sum of the parts’.
Two strategies of sustainability evaluation may be distinguished – absolute and relative strategies.
– Absolute evaluation procedures exclusively investigate indicators and corresponding data derived from one single system. Hence, validation is based on a comparison with previously defined margins of tolerance or distinct threshold values for each selected indicator (Mitchell and McDonald 1995). These limits are determined either by estimation, e.g. resulting from expert interviews or referring to socio-political postulates for the reduction of emissions or by scientific deduction, e.g. elaboration of critical loads/levels based on eco-toxicological experiments. Therefore, absolute evaluation assesses distinct datasets e.g. the phosphorus content of the soil compared to the maximum tolerable content. This transparent presentation of results permits end-users to verify the assessment and – if necessary – to adapt the presented data to alternative threshold values.
– Relative evaluation procedures are established on a comparison of different systems among themselves or with selected reference systems. Due to this comparative assessment of systems, there is no need to define distinct margins of tolerance or threshold values. Frequently the results of a relative evaluation are presented as normative point scores.
7.4 Management Advice for Practical Application
The development of management advice for practical application represents the last step for adapting the theoretical outcome of sustainability assessments into implementation of agricultural practice. These recommendations support end-users either in planning new, sustainable production systems or to improve the sustainability of existing systems. The elaboration of management advice considerably varies with respect to the needs and knowledge of the target group, e.g. farmers, political stakeholders or landscape planners.
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total quantity of nitrogen or phosphorus inputs entering the soil and the quantity of nitrogen or phosphorus outputs leaving the soil annually, based on the nitrogen or phosphorus cycle The Profitability coefficient is a ratio obtained when the agricultural surplus is divided by the b sum of the entrepreneur family’s salary requirement and the interest requirement on capital invested Further management advice is provided by lists of critical points indicating parts of systems which diverge from the desired state and consequently should be improved.
However, lists of critical points which result from a separate evaluation of selected indicators represent case- and site-specific information with limited transferability to different agricultural systems. Since they do not provide any information on how to improve the indicated ‘hot spots’, their direct applicability in agricultural practice is considerably restricted. It obligates end-users, e.g. farmers and agronomists to interpret and weigh by themselves the presented set of results to develop a corresponding improvement strategy. ‘One-solution strategies’ resulting from lists of critical points (like strategies exclusively improving nutrient balances) are considered inappropriate to reflect the systemic aspect of sustainability. To enhance successful implementation, case- and site-specific advice should be provided indicating alternative management strategies to optimise the system under investigation.
The most elaborate assistance to the target group is supplied by the formulation of entire improved management strategies. Since the management of agricultural systems is strongly dependent on variable natural conditions, e.g. soil or climate but also on socio-political constraints, e.g. subventions of certain crops or statutory limitations of factor input, final design of these management strategies has to be performed in a caseand site-specific manner in co-operation with end-users (von Wirén-Lehr 2001).
A set of applied indicators for sustainability in different agricultural policy scenarios at the national level is presented by Lehtonen et al. (2005). Their purpose is to provide material for an interactive policy dialogue rather than assemble a comprehensive and conclusive assessment of sustainability of various agricultural policy alternatives (Table 7). They also present what kind of agricultural development each indicator is reflecting and the strategic goal of each specific indicator. It is Measuring Agricultural Sustainability 93 important to realize that not only the numerical values of the calculated indicators but also their relative changes over time are important when evaluating the sustainability of alternative agricultural policies.
8 Agricultural Sustainability Scales at Farm Level The indicators discussed here draw on Taylor et al. (1993). In their paper the index is constructed for a sample of 85 agricultural producers in Malaysia with points scored under the headings of (i) insect control, (ii) disease control, (iii) weed control, (iv) soil fertility maintenance and (v) soil erosion control. Gomez et al. (1996) also construct a farm level index of sustainability where six aspects of sustainability are monitored: (i) yield, (ii) profit, (iii) frequency of crop failure, (iv) soil depth, (v) organic C and (vi) permanent ground cover. The following indicators were then constructed for a sample
of ten farms from the Guba region of the Philippines (Rigby and Caceres 2001):
– Improved farm-level social and economic sustainability • Enhances farmers’ quality of life (US Farm Bill 1990) • Increases farmers’ self-reliance (Pretty 1995) • Sustains the viability/profitability of the farm (Pretty 1995; US Farm Bill 1990; Ikerd 1993) – Improved wider social and economic sustainability • Improves equity (Pretty 1995), ‘socially supportive’ (Ikerd 1993) • Meets society’s needs for food and fiber (US Farm Bill 1990) – Increased yields and reduced losses while • Minimising off-farm inputs (Hodge 1993; Pretty 1995; US Farm Bill 1990) • Minimising inputs from non-renewable sources (Hodge 1993; Ikerd 1993;
Pretty 1995; US Farm Bill 1990) • Maximising use of (knowledge of) natural biological processes (Pretty 1995;
US Farm Bill 1990) • Promoting local biodiversity/‘environmental quality’ (Hodge 1993; Pretty 1995; US Farm Bill 1990).
Senanayake (1991) proposed that agricultural systems have varying degrees of sustainability according to the level of external inputs required to maintain the system that the state of the biotic community within a system operates. His index