Sustainable farming systems

The term sustainability relates to the ability of a characteristic to maintain itself, i.e. not to decline with the passage of time. An unsustainable characteristic or variable may decline in varied ways or for various reasons. The decline may be from endogenous reasons, such as a regular decline in soil fertility because of nutrient mining. Conversely, this decline may depend on exogenous factors, such a drought (Tisdell, 1996).

According to Batie, agricultural economists can help clarify the concept of sustainable development by "operationalizing" it, by assisting in designing institutions that incorporate sustainable development goals, or by analysing interrelationships between economic and ecological systems (Batie, 1989). The delineation of sustainable development has resulted in many definitions for sustainable agriculture and sustainable farming systems. In the following pages, several attempts to define sustainable farming systems are reviewed.

One of the first attempts to analyse agroecosystems in terms of sustainability was made by Conway (Conway, 1987). He compiled a hierarchy of agroecosystems, starting from the individual plant or animal, proceeding on a higher level through a crop or a herd, which in turn are organized in a field or a paddock. These are then organized into a higher cropping system or a livestock system, which then form a farming system according to Figure 1.

Conway notes that while welfare economics provides a good theoretical basis for defining social value, the concepts involved are of limited practical value. He, therefore, proposes four properties whereby an agroecosystem’s performance can be realized with respect to the goal it has to fulfil. These properties are productivity, stability, equitability and sustainability. Productivity is defined as the output of valued product per unit of resource input (yield, income per hectare, total production per household or region, etc.). Stability is defined as the constancy of productivity in the face of disturbing forces that arise from normal fluctuations and cycles in the environment. Stability can be measured, for example, by the coefficient of variation in productivity, which is determined from a time series of productivity measurements. The third property, equitability, is defined as the evenness of distribution of the productivity of the agroecosystem among the human beneficiaries.

The fourth of these properties, sustainability, is defined as the ability of an agroecosystem to maintain productivity when subject to stress or shock. In this case, stress is defined as a frequent (sometimes continuous), relatively small and predictable disturbing force that has a large cumulative effect. Examples of stress are salinity, toxicity, erosion, indebtedness and declining market demand. Alternatively, the disturbance can be caused by a shock, which is defined as an infrequent, relatively large and unpredictable force that has an immediate effect. Examples of a shock are a rare drought or flood, a new pest or a sudden rise in input price. Following stress or shock, the agroecosystem may be (a) unaffected, (b) may fall and then return to the previous level, (c) settle on a lower level or sometimes (4) may disappear altogether. Various measures of sustainability are available: inertia (resistance), elasticity, amplitude and malleability. Sustainability, in Conway’s view, determines the persistence or durability of an agroecosystem's productivity under known or possible conditions. An ubiquitous input is a subsidy, often in the form of a fertilizer application, intended to counter stress of repeated harvesting, or a control agent, like a pesticide, to counter pest or disease attack.

Sustainable agriculture is characterized by a non-negative trend in measured output per area. A stress is a relatively small disturbance in the system, while a shock is a bigger disruption of the production system. Conway emphasizes stability in the sense that an agroecosystem should be resilient. The term resilience is understood as an ability to withstand shocks and stresses.

Lynam and Herdt draw upon Conway’s work in an attempt to specify criteria for the incorporation of sustainability issues in agricultural research (Lynam and Herdt, 1989). They note that sustainability essentially consists of a set of concerns, and use as a starting point the definition of sustainability as the ability of an agroecosystem to maintain productivity when subject to stress or shock. In the course of their work they give sustainability a more operational formula. According to the new formula, sustainability is the capacity of a system to maintain output at a level approximately equal to or greater than its historical average, with the approximation determined by its historical level of variability. Hence, a sustainable system is one with a non-negative trend in measured output. For example, technology adds to system sustainability if it increases the slope of the trend line. Starting from this definition they make the following seven propositions:

    1. Sustainability is a relevant criterion for evaluating agricultural technologies only when a system using a technology has been well specified, and therefore in most cases the criterion cannot be empirically applied above the farming systems level.


      2. Lynam and Herdt argue that the concept of sustainability is problematic during its "operationalization" because of the specification of boundary levels. The problem of boundaries arises from choosing the system level at which sustainability becomes a relevant characteristic. According to the authors, confusion originates from the mixing of different levels.
       

    2. In order to determine sustainability at the crop, cropping or farming system levels, the appropriate measure of output is total factor productivity, which is defined as the total value of all outputs used by the system during one cycle divided by the total value of all inputs used by the system during one cycle of the system. A sustainable system has a non-negative trend in total factor productivity over the period concerned.


      3. Given that sustainability is a characteristic of a system's productive performance over time, it follows that output is a central part of sustainability. Output is modified by technology, which affects input use. Output will depend on the system level. At the crop variety level, output is the yield per plant or per hectare, at the crop level and cropping system levels, output is total factor productivity. At the farming system level, output is income, whereas at the market level output is commodity supply. According to the authors, the time period concerned is greater than 3-5 years and perhaps greater than 10-20 years in nearly every case.

      One may argue that this definition by Lynam and Herdt may not pay enough attention to what happens to the environment, on which output does not depend. Therefore, one can argue, the definition measures economic sustainability but not environmental sustainability, at least not if one applies strong conditions for sustainability as a starting point. Therefore, it may be necessary to measure environmental sustainability with other indicators.
       

    3. The sustainability of a system cannot be measured feasibly without a prior determination of the factors likely to make that system unsustainable.


      4. One needs to know something about the factors that make the system unsustainable. If one has no perception of how the factors make a system unsustainable, how can one measure those factors?
       

    4. Whether sustainability should be a criterion of research programs depends on their target area. Unsustainability is often locally or regionally defined and depends on such factors as the rate of increase in exogenous demand on the system, the agroclimatic environment, and the relative intensity (generally in land use) of existing systems.


      5. Designing sustainable framing systems requires an understanding of the process by which farmers adjust to a changing external environment. The targeting of the area thus becomes a key issue.
       

    5. The sustainability of common-resource systems necessarily incorporates a value judgement on multiple criteria and regarding how the community wishes to utilize the resource. Moreover, the sustainability of the system will require spending more on social institutions controlling access and use than on production technologies.


      6. Situations in which common resource systems (like water resources, grazing areas, forest areas or fishing areas) have been overexploited or which are suffering from pollution are not uncommon. However, it is difficult to apply the definition of sustainability while taking total factor productivity or output as a starting point. What is the output of a common resource? Therefore, some kind of overall value judgement is needed to incorporate value judgements regarding how the community would like to treat the externalities deriving from the current production technology.
       

    6. Dividing research solutions to the sustainability problem into two distinct and competing strategies is counterproductive; to be successful the biological research agenda must complement the continued use of inputs in the intensification of farming systems in the tropics.


      7. By this proposition the authors want to emphasize that it is not productive to divide research into low-input research versus high input research, or ecological research versus chemical input research. In other words, Lynam and Herdt are not in favor of labeling agricultural research with two categories: conventional and ecological.

      Finally the authors make what they consider is a perhaps unsettling seventh proposition:
       

    7. Sustainability is first defined at the highest system level and then proceeds downward; and as a corollary, the sustainability of a system is not necessarily dependent on the sustainability of the sub-systems.
For instance, if famine, market development or increased social organization are keys to solving the problem of the resource use of common resources, these sustainability issues have to be defined first and before specification at lower levels (like the farming systems level) is made.

As a conclusion, it may be noted that Lynam and Herdt follow a rather weak definition of sustainability, i.e. a non-negative trend in output would suffice to make a system sustainable. Clearly, this definition incorporates a weakness because it does not account for the degradation of agricultural land and natural resources since these do not affect production. But their proposition is quite practical from an operational point of view and may offer possibilities for the quantitative measurement of the sustainability of farming systems in the CEECs. A good way to advance is to accept the definitions and propositions by Conway, Lynam and Herdt and to complement them with some environmental indicators, e.g. some of those developed by the OECD. In other words, additional indicators can be included to the framework in order to ensure that the environmental and social dimensions are included.

For the sake of comparison one may compare the definition above to the definition made by Smit and Brklacich who define sustainable agriculture as a "food production system which simultaneously maintains environmental quality, provides acceptable economic and social rewards to producers and ensures an adequate food supply". (Smit and Brklacich, 1989, 411) Clearly, this definition better incorporates the preservation of the natural resource base for future generations. It accounts also for factors other than a non-negative trend.

Agricultural production technology should not irreversibly spoil natural resource capital (like fresh water resources, sea ecosystems, air and soil) or reduce genetic diversity by destroying natural habitats. "Operationalizing" this aspect may be more difficult to achieve. My own view is that the natural resource base is a local or a regional issue in most cases, and that "operationalizing" methods are difficult to describe in very general terms.

What are the relations between low-input sustainable agriculture (LISA) and low-input agriculture, and their relation to sustainable agriculture? Sometimes it is claimed that sustainable agriculture is characterized by (a) sparse use of scarce raw materials and (b) no irreversible damage on the natural resource base. Low-input agriculture is claimed to be sustainable agriculture. Buttel et al. launched the term reduced-input agricultural systems in order to describe systems whose use of chemical fertilizers and pesticides is modest but significantly reduced in comparison to conventional systems (Buttel et al., 1986). The arguments are that inputs, like fertilizers and pesticides, may contribute to the pollution of surface and ground water. Therefore, sustainable agriculture could be considered an agriculture of reduced inputs, which substitutes knowledge and management for polluting inputs.

However, one may question whether low-input agriculture is always sustainable. For instance Ruttan has warned against this assumption (Ruttan, 1988). He claims that it would be premature to attempt to specify the technology and practices that meet the criteria of sustaining productivity. Setting an equality sign between low-input agriculture and sustainability must be verified case by case regarding technology. In the case of the CEECs, where depletion of soil nutrients is common, one could claim justifiably that this type of low-input agriculture is unsustainable.

Graham-Tomasi claims that in order to measure sustainability by practical, empirical procedures two types of theoretical sustainability measures are needed: one that measures the depletion of natural capital and a second that measures environmental pollution and the damages caused by it (Graham-Tomasi, 1991). It is useful to recall the so-called High Natural-Value (HNV) farming systems. In a certain sense, HNV farming systems are related to the issue of sustainable farming systems. It is possible to identify broad types of agriculture that could be expected to be of nature-conservation importance. These types usually include those with a low usage of inputs and a continuation of traditional, integrated, management practices. The biodiversity of these semi-natural habitats is usually higher than in modern farming (Baldock and Beaufoy, 1993). Such HNV-farming systems, which exist in various parts of the EU, are also likely to exist in many places in the CEECs. Examples from Greece and Spain have shown that severely reduced profitability has led to the abandonment of HNV-farming systems. The fundamental reason for this abandonment is low profitability and imperfect markets for public goods. (Pulido and Escribano 1995, Baldock et al., 1996, Tikof, 1997)

Since Conway made his definition, which Lynam and Herdt then followed up, the concept sustainable farming systems has gained emphasis. Especially in the FAO farm systems management series this development is clear. The farming-systems approach, as interpreted by de Haen (FAO, 1993), considers the farm-household the basic unit of decision-making and analysis in most agricultural development situations. The physical, socio-cultural and economic environments have an important influence on farm household decisions and upon their outcomes. The environment is affected by the farm household and vice-versa. According to Ariyaratne, the interdependence of the farm and the physical, socio-cultural, institutional and economic environment is recognized in the sustainable farming-systems approach (Ariyaratne, 1998). Furthermore, in order for farming systems to be sustainable and maintained at a level of defined output without damaging the environment, there needs to be a dynamic institutional arrangement. This could be achieved through the participation of officials at different levels and the farming population. The farming population could also participate through the formation of their own organizations. Ariyaratne claims that these institutional arrangements are essential to ensuring that the benefits of farming systems research are transferred to the farming population. This is one way to try to accomplish social sustainability or equitability.

So far, only social sustainability has been mentioned. Experience from development work in many parts of the world clearly shows that inadequate attention has been given to smallholders and their needs. This may lead to a polarization like the kind that seems to be taking place in some CEECs currently. Reasons for this, according to the FAO, are the following (FAO, 1990):

As a conclusion of this brief review of sustainable farming systems, one may identify at least seven conceptualizations of sustainable agriculture and farming systems:
    1. A sustainable farming system is a system in which natural resources are managed so that crop yields do not decline over time.
    2. A sustainable farming system is a system in which natural resources are managed so that the stock of natural resources do not decline over time.
    3. A sustainable farming system is one that satisfies minimum conditions of ecosystem stability and resilience over time.
    4. A concept related to sustainable farming systems is HNV farming systems, which are likely to be of importance from a nature-conservation point of view.
    5. Sustainable agriculture is organized so that the necessary support services (credit, extension, and input supply) are guaranteed.
    6. Sustainable agriculture is a system guaranteeing equality, i.e. distributional and welfare aspects are given due attention through institutions that make farmer participation possible, that are concerned about the poor and that are administered with a bottom-up approach.
    7. A sustainable farming system is not unduly constrained by the socio-cultural environment or the policy-institutional environment.
While the definition of Conway is useful, it may be broadened to account for the economic and social aspects more appropriately. The definition has been followed and expanded by McConnell and Dillon (FAO, 1997). They have listed eight properties that need to be addressed when analysing farming systems. All of them, as follows, are given quantifiable measures:
    1. Productivity
    2. Profitability
    3. Stability
    4. Diversity
    5. Flexibility
    6. Time-dispersion
    7. Sustainability
    8. Complementarity and environmental compatibility
It is worth noting that all of these measures can be quantified, at least conceptually. All of them are "desirable" or at least neutral in the sense that an individual farm that ranks high on one property represents a system superior to that of a farm which ranks low. All properties are relevant to evaluation and planning both at the farm level and at a broader social level. The social dimension is important to take into account if the farming system is to be fully sustainable. Equitability could still be added as a ninth criterion on the social level. It is worth noting that some of the properties, such as productivity, stability and sustainability, might be well more important from a social than from a private-household point of view. As McConnell and Dillon wrote, "to plan new farms which are profitable is one thing; to plan profitable farms which also make optimal sustainable use of what are finally social resources is yet another. Even more difficult and increasingly important is to develop new or restructured farm systems that have all these desirable properties and, in addition, are compatible with the social environment and not destructive of the physical environment. Also, as evidenced by increasing interest in gender analysis, equity within farm-household systems may also be important from a societal view." (FAO, 1997).

While Conway’s definition of productivity, stability, sustainability and equitability have been explained previously in this section, some explanations of the remaining five properties defined by McConnell and Dillon shall be given.

    1. Profitability can be measured by gross margins for activities or enterprises. Gross margins may be less relevant on subsistence farms. On the whole-farm level various financial measures of profitability are possible, although it is typically measured as gross financial revenue minus total financial costs. Financial profit as a criterion for measuring performance of the farm-household system can be unreliable if profits have been acquired through unsustainable resource-use (e.g. soil degradation) or by exposing the farm to a high liquidity risk. Nevertheless, financial profit is often used in farm economic surveys to measure performance. Profitability over time can be measured through various discounting measures.
Diversity is a traditional way of reducing the overall risk of the farm. If the number of activities is high, the farm may be less dependent on price risk or yield risk caused by natural calamities. There may be a better utilization of resources. However, diversity may be achieved at the expense of a reduction in profit. Diversity is commonly measured through Simpson’s diversity index.

Flexibility refers to the availability of alternative ways of product disposal. There are four main ways to dispose of produce: consume/use, sell/barter, store or process.

Time-dispersion implies how production or incomes are dispersed over time, for instance over a year.

Finally, complementarity and environmental compatibility define the system’s capability to manage the environment and natural resources in terms of management practices, resources and technologies used and the disposal of products and side products. Typically these effects are measured through environmental indicators.

In the next section a measure of these properties will be presented.


 
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