**3. Characteristics of farming systems**

Any farm as a unit could be a factory for decision making, it can be a production unit for either crops or livestock or a mixture from both of them. The farmer and other human elements of the farm, the physical and biological environment are the boundaries where this farm as a system operate, and it may change, so it is dynamic. So as pointed out by Dixon *et al.*[16] farming system approach considers both biophysical dimensions and socio-economic aspects at the level of the farm, where most of the agricultural production and consumption decisions are taken. The power of this approach lies in its ability to integrate multidisciplinary analysis of production and its relationships to the key biophysical and socioeconomic determinants [16]. Between the constituents of any farming system, the human, the physical and biological parts, there is complicated interactions between so many detailed components. For example, the human element may be a set of household members including family labour, which in addition to hired labour constitute the multi-nature of each constituent. Also the soil is not only such particles where the plant grow, but a series of physical and chemical characteristics

Generally in the literature, there are so many definitions to farm or farming system, each one of them was trying to define the term from different perspective: Okigbo [17] defined a farming system as an enterprise or business in which sets of inputs or resources are uniquely orches‐ trated by the farmer in such a way as to satisfy needs and to achieve desired objectives in a given environmental setting. It could also be defined as a decision making unit as it transforms land, capital, and knowledge into useful products that can be consumed and sold [18]. According to McConnell and Dillon, [15], the term farming system refers to the cultivation patterns used in a plot conceptualized in relation to the farm, other agricultural entities, the socioeconomic and ecological context and the technology available that determine its character [15]. This implies that a farming system is a part of a larger ecological, social, political, economic, cultural environment that is affecting its characteristics. Hence, it is clear from the definitions that farming systems or agro-ecosystems are comprised of many components and agents. The components could be biophysical, socio-economical, and cultural and the agents could be species, ecosystems, households, social communities, scientists, policy makers. Those components and agents are operating on different scales (e.g. local, national, global) while

Rosen [19] defined life as an open process of autopoiesis distinct from the type of external driven organization typical of machines. So building on this definition, Gomeiro et al, [1] mentioned that agriculture implying dealing with life and agricultural systems are also agroecosystems, and agricultural science can be referred to as agro-ecology. Furthermore, Altieri, [20] defined agro-ecosystems as communities of plants and animals interacting with their chemical and physical environments that have been modified by people to produce food, fiber, fuel, and other products for human consumption and processing [20]. In this regard, and as pointed out by Kerr, [21] farms can be considered as ecosystems managed by farmers; thus

and reactions, all of which are very important for the plant life cycle.

pursuing different objectives.

4 Agroecology

agriculture is concerned with farmer-managed ecosystems.

Agricultural systems, even the most traditional ones, are not static systems; in fact they are dynamic [7].

Spedding [23] emphasized that the classification of agricultural systems has a long history, but there is no generic system that is truly comprehensive and can serve all purposes [23]. They exhibit great diversity and have been classified in various ways including an ecologically based classification [24], [25]. According to Fresco and Westphal [25] there are basically two ways to classify farm systems. First the farm systems of the world can be grouped together in broad classes that reflect fundamental structural differences, for example, plantation systems, tillage system (with and without livestock), alternating systems and grassland systems [26]. The second approach is that used by Grigg [27] who makes explicit reference to geographical units. These classifications and others have in common that they combine economic and biological factors. The main usefulness of this type of broad classification lies in its indication of the relative importance of different classes of farm system and their relevance to the setting of priorities in international agricultural research. The weakness of these past attempts is that they provide little systematic insight into the way the classification relates to the development of agricultural technology. Furthermore, all these approaches classify elements of farm systems (livestock, crop, capital use) but do not do justice to the interaction of the elements which make up the system [25].

Existing classification are based on a wide variety of factors and differ markedly in their utility, comprehensiveness, and ability to be mapped [28]. A summary of comparison between the existing global classification systems is illustrated in the table 1.


**Table 1.** Comparison between existing Global Livestock Classification Systems

A system is characterized by its elements, their inter-relationships and by definition of the boundary of the system. It could also be open, in a sense that external relationships are also included. However, systems at each level are inter-linked and even with sub-systems [29].

Around the world, agricultural ecosystems show tremendous variation in structure and functions, because they were designed by diverse cultures and diverse socioeconomic conditions in diverse climatic conditions [30]. According to John Dixon et al, [16] the following is the key biophysical and socioeconomic determinants of a farming system:


These categories represent the major areas in which farming system characteristics, perform‐ ance and evolution are likely to be significantly affected over the next thirty years. Some of these factors are internal to, or part of the farming system, whereas others are external. Policies, institutions, public goods, markets and information are external and they influence the development of the farming system. Technologies which determine the nature of production and processing, and natural resources, are largely endogenous (internal) factors. In general terms, the biophysical factors tend to define the set of possible farming system, whilst the socioeconomic factors determine the actual farming system which can be observed at a given time [16]. In the African context, for example, Guyer and Peters [31] mentioned that there is an extensive literature on African agrarian systems that highlight how social and cultural relations shape agricultural production and investment, the type of technologies adopted, and the operation of agricultural markets.

Each individual farm or farm system has its own specific characteristics arising from variations in resource endowments and family circumstances within the context of local institutions and policies. These are translated into productive activities, and household consumption and decision making activities. In the context of sustainability, Koohafkan, *et al.* [7] had suggested, based on extensive literature review, a series of attributes that any agricultural system should exhibit in order to be considered sustainable, the following are these basic attributes:


**Classification Crops status Livestock status Categories no. Pros and cons**

permanence

permanence

permanence

Degree of movement/

Degree of movement/

Degree of movement/

Not dealt with though

Cluster spatial units based on

A system is characterized by its elements, their inter-relationships and by definition of the boundary of the system. It could also be open, in a sense that external relationships are also included. However, systems at each level are inter-linked and even with sub-systems [29]. Around the world, agricultural ecosystems show tremendous variation in structure and functions, because they were designed by diverse cultures and diverse socioeconomic conditions in diverse climatic conditions [30]. According to John Dixon et al, [16] the following

is the key biophysical and socioeconomic determinants of a farming system:


probably could be included As required

livestock densities As required

8 major Categories too broad

9 major System incomplete and

8 major 72 globally by region

and incomplete

somewhat selective

Derivation not explicit, difficult to map using existing global data set

Livestock based, so no categorization of crop systems, can be mapped using appropriate proxies

Easily mapped, assesses what may be, rather than what actually is

Easily mapped, arbitrary, data sensitive, and nonreplicable




Match land suitability to crop requirements for given inputs and technology

Cluster spatial units based on crop densities,

**Table 1.** Comparison between existing Global Livestock Classification Systems

intensities

Source: adapted from Robinson et al., [28]

**1.** Natural resources and climate

**5.** Information and human capital

**3.** Trade liberalization and market development

**4.** Policies, institutions and public goods

**2.** Science and technology

grass - crop type



Ruthenberg 1980

6 Agroecology

Grigg 1972

Dixon et al 2001

Sere and Steinfeld

Explicit AEZ method, e.g. Fischer

et al. 2002

Statistical classification, e.g. Wint et al. 1997

1996


The design of agro-ecosystems that exhibit many of the attributes of sustainability has become a leading objective of scientific research and policy agendas [7].
