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Mixed crop-livestock farming

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Chapter 2

Characterization of mixed farms

Mixed farming is common worldwide, in spite of a tendency in agribusiness, research and teaching towards specialized forms of farming. Obviously, mixing has both advantages and disadvantages. For example, farmers in mixed systems have to divide their attention and resources over several activities, thus leading to reduced economies of scale. Advantages include the possibility of reducing risk, spreading labour and re-utilizing resources. The importance of these advantages and disadvantages differs according to the sociocultural preferences of the farmers and to the biophysical conditions as determined by rainfall, radiation, soil type and disease pressure. This chapter first describes several forms of mixing. Second, it explains how mixing of several parts requires a special approach to make a success of the total mix. What counts is the yield of the total, not of the parts. Trees in and on the edge of a crop field generally reduce the grain yield, but the combination of the trees (for fodder and timber) and crops is valuable, because each of the components produces useful products for the farm (people and animals included).

WHAT IS MIXED FARMING?

Mixed farming exists in many forms depending on external and internal factors. External factors are weather patterns, market prices, political stability, technological developments, etc. Internal factors relate to local soil characteristics, composition of the family and farmers' ingenuity. Farmers can decide to opt for mixed enterprises when they want to save resources by interchanging them on the farm - because these permit wider crop rotations and thus reduce dependence on chemicals, because they consider mixed systems closer to nature, or because they allow diversification for better risk management.

There is wide variation in mixed systems. Even pastoralists practise a form of mixed farming since their livelihood depends on the management of different feed resources and animal species. At a higher level, a region can consist of individual specialized farms and service systems that together act as a mixed system. Other forms of mixed farming include cultivation of different crops on the same field, such as millet and cowpea or millet and sorghum, or several varieties of the same crop with different life cycles, which uses space more efficiently and spreads risks more uniformly (Photos 3 and 4).

BOX 1

IS MIXING AN IMPROVEMENT?

The choice of mixed farming is not always a sign of improvement of the situation in which people may find themselves. Mobile Fulani herdsmen in West Africa engage in crop production only when forced by circumstances, such as drought or animal diseases, leading to severe losses in livestock, making continuation of their former way of life impossible. Mixed farming is for them a poverty-induced option. Resource-poor farmers going into mixed farming have to apply labour- intensive techniques (their only resource) and, because of their low purchasing power, they cannot afford external inputs and have no option but to overexploit the environment.

(Based on Slingerland, 2000.)

The study of a wide variety of mixed systems at different levels is beneficial to understanding the logic of mixed systems in general. Disciplines such as ecology, economics and complex system theory have tools and concepts that can help us to understand better the mixed blessings of mixed systems. One essential point here is that the principle of mixing occurs everywhere, also in society - domestic waste such as glass, bottles or paper is also recycled. Another point is that in mixing the different functions of plants and animals can be observed: a cereal crop produces grain and straw, a legume provides grain, organic matter, fodder and nitrogen. A third point is that it tends to be more important to look for high yield of the combination of the components rather than for the (high) yield of one component. Mixed farms are systems that consist of different parts, which together should act as a whole. They thus need to be studied in their entirety and not as separate parts in order to understand the system and the factors that drive farmers and influence their decisions. That principle is here referred to as the "command ideotype"(Donald, 1981; Schiere et al., 1999). It may be the most important principle to achieve increased production in mixed systems, together with the awareness that crops and animals have multiple functions (Boxes 2 and 3).

FORMS OF MIXED FARMING

Mixed farming systems can be classified in many ways - based on land size, type of crops and animals, geographical distribution, market orientation, etc. Three major categories, in four different modes of farming, are distinguished here. The categories are:

The modes of farming refer to different degrees of availability of land, labour and inputs, ranging from plenty of land to a shortage of land. The modes are characterized by Schiere and De Wit (1995) as expansion agriculture (EXPAGR, plenty of land), LEIA, HEIA and new conservation agriculture (NCA, a form of land use where shortages are overcome by more labour, more inputs and keen management).

PHOTO 3

Mixed cropping: pyrethrum and maize (Kenya)

PHOTO 4

Mixed cropping: maize stover intersown with a legume (Dolichos lablab) to provide fodder after the grain harvest (Honduras)

On-farm versus between-farm mixing

On-farm mixing refers to mixing on the same farm, and between-farm mixing refers to exchanging resources between different farms. On-farm mixing occurs particularly in LEIA where individual farmers will be keen to recycle the resources they have on their own farm. Between-farm mixing occurs increasingly in HEIA systems - in countries such as the Netherlands it is used to mitigate the waste disposal problems of specialized farming. Crop farmers use dung from animal farms, a process that involves transport and negotiation between farmers and even politicians. Between-farm mixing also occurs at the regional level - in the store cattle systems of the United Kingdom and the United States, animals are raised in one area to be fattened in another area where plenty of grain is available. In tropical countries also, manure may be transported from livestock farms to farmers and vegetable cropping areas where manure is in short supply.

 

BOX 2

PIGS IN SWEDISH CROP ROTATIONS

Swedish farmers and researchers incorporated the natural behaviour of pigs in the design of farming systems to improve crop and animal performance. They dealt with the behaviour and performance of outdoor pigs on clover/grassland and with tillage effects resulting from rooting by pigs on winter wheat performance. Environmental loading in an ecological pig production system (EPS) was 64 percent less than in a conventional production system (CPS) but labour requirements were higher in EPS. On-farm production of feed in the EPS reduced purchased inputs for feeds by 48 percent compared with CPS. Levels of tillage caused by rooting pigs and yields of winter wheat grain in the following year were significantly correlated. Grain yields were greater from the areas treated by pigs compared with mechanical tillage, when soil moisture content was high enough. Mean daily weight gain varied between 626 g and 811 g for EPS and CPS, respectively. The increasing live weight indicated a large maintenance requirement for energy, especially in young pigs, probably due to high levels of activity in EPS. Rooting activity increased when soil moisture content increased or supplemental feeding was restricted. Daily allocation of new land stimulated foraging activity and deposition of urine and faeces in the newly allotted land.

(Based on Andreson, 2000.)

 

BOX 3

LIVESTOCK AND CROP PRODUCTION

Agropastoralists in Nigeria use the hoof action of livestock to prepare land for growing small cereals. They concentrate cattle on a small area of cleared land and then broadcast the seed over the broken soil surface the following morning. Similarly, goats in parts of the Near East are sometimes used to weed crops. The goats are allowed to satisfy their initial appetite on natural pasture and are then put into cereal fields where they selectively eat the herbs.

(Based on Reijntjes, Haverkort and Waters-Bayer, 1992.)

Pastoralists from such systems in West Africa and on the Indian subcontinent also exchange cattle and crop products with crop farmers. Cultivators receive manure, labour and, less important, milk in return for cash, grain and water rights traded to pastoralists. Entrustment of livestock from crop farmers to pastoralists follows more or less the same rules. In return for taking care of the herd, herders receive either cash, or cropland, or labour for the cropland or a share of the milk and the offspring.

Mixing between nearby farms is considered here as providing the same advantages as on-farm mixing, but it should be underlined that there are important differences in terms of social organization and transaction costs. For example, in West Africa the exchange between farms leads to tension and accidents as crop farmers start to use land that used to be pastoral only. The amount of grazing land is decreasing and dependence on the grazing of crop residues is increasing. When herders bring in the animals before the field is properly harvested serious incidents and conflicts can arise.

BOX 4

BUFFALOES IN A SMALLHOLDER DAIRY IN THE HINDU KUSH-HIMALAYAS: A CASE OF BETWEEN-FARM MIXING

A farmer buys a milch buffalo from a lowland buffalo trader at a price of between Rs 23 000 and 28 000. The animal is milked for eight months to a year and the gross income amounts to Rs 25 000-30 000. Some farmers sell expectant bakerno buffaloes for Rs 18 000-20 000 after one year of milking and buy an in-milk buffalo laino from the trader at a price of Rs 25 000-30 000 to ensure continued milk production. If the farmer waits for the bakerno buffalo, it takes about eight months before it calves and begins producing milk. The strategy is most suitable for smallholders who manage only one buffalo, but farmers who have more than one buffalo also adopt it. The lactating buffaloes come from the lowland areas where conception is easier.

(Based on Tulachan and Neupane, 1999.)

Mixing within crop and/or animal systems

Mixing within crop and/or within animal systems refers to conditions where multiple cropping is practised, often over time, or where different types of animals are kept together, mostly on-farm. Both these systems occur frequently though they are not always apparent.

Within-crop mixing takes place where crop rotations are practised over and within years. For example, a farmer has a grain-legume rotation to provide the grain with nitrogen or a potato-beet-grain rotation to avoid disease in the potatoes. Plants can also be intercropped to take maximum advantage of light and moisture, to suppress weeds or prevent leaching of nutrients through the use of catch crops. Examples of mixing between animals are found in chicken-fish pond systems where chicken dung fertilizes the fish pond; in beef-pork systems where pigs eat the undigested grains from the beef cattle dung; or in mixed grazing such as cow-sheep mixes to maximize biomass utilization or to suppress disease occurrence (Photos 5 and 6).

PHOTO 5

Cows and sheep grazing together in a pasture in the Netherlands to optimize biomass utilization and to reduce disease pressure

PHOTO 6

A model farm near Durban (South Africa) where the dung from the chickens is used to fertilize the algae growth in the fish pond

Diversified versus integrated systems

The distinction between diversified and integrated systems is perhaps the most relevant one for this report. Diversified systems consist of components such as crops and livestock that co-exist independently from each other. In particular, HEIA farmers can have pigs, dairy and crops as quite independent units. In this case the mixing of crops and livestock primarily serves to minimize risk and not to recycle resources.

Integration is done to recycle resources efficiently. It occurs in mixed ecological farms of temperate countries (here called the mode of new conservation agriculture, NCA), but also in mixed, relatively low input farms of southern and southwestern Australia with grain-legume-sheep mixtures. Integration occurs most often, however, in LEIA farming systems that exist in many tropical countries where products or by-products of one component serve as a resource for the other - dung goes to the crops and straw to the animals. In this case the integration serves to make maximum use of the resources. Unfortunately, these systems tend to become more vulnerable to disturbance because mixing of resource flows makes the system internally more complex and interdependent.

In Asia, the integration of livestock, fish and crops has proved to be a sustainable system through centuries of experience. In China, for example, the integration of fishpond production with ducks, geese, chickens, sheep, cattle or pigs increased fish production by 2 to 3.9 times (Chen, 1996), while there were added ecological and economic benefits of fish utilizing animal wastes. Environmentally sound integration is ensured where livestock droppings and feed waste can be poured directly into the pond to constitute feed for fish and zooplankton. Livestock manure can be used to fertilize grass or other plant growth that can also constitute feed for fish. Vegetables can be irrigated from the fishponds, and their residues and by-products can be used for feeding livestock.

Grazing of livestock under plantation trees such as rubber, oil palm or coconut is a form of crop-livestock integration that is often found in Southeast Asia. Experiments in Malaysia with cattle and goats under oil palm showed better oil palm bunch harvest and comparable results were found where goats fed under rubber trees. In rubber and oil palm plantations in Malaysia, the integration of livestock to utilize the vegetative ground cover under the tree canopy increased overall production and saved up to 40 percent of the cost of weed control. Similarly, sheep helped to control weeds in sugar cane fields in Colombia. This suppressed the costs of herbicides, reduced the cost of weed control by half and provided additional income from meat production (FAO, 1995a). This also occurs where cows graze under coconuts (Photo 7).

BOX 5

MORE MIXING OF LIVESTOCK

By keeping several species, farmers can exploit a wider range of feed resources than if only one species is kept. In pastoral areas, camels can graze up to 50 km away from watering points, whereas cattle are limited to a grazing orbit of 10-15 km. Camels and goats tend to browse more, i.e. to eat the leaves of shrubs and trees; sheep and cattle generally prefer grasses and herbs. Different animal species supply different products; e.g. camels and cattle can provide milk, transport and draught power, whereas goats and sheep tend to be slaughtered more often for meat. Chickens often provide the small change for the household, sheep and goats are sold to cover medium expenditures, while larger cattle are sold to meet major expenditures.

Keeping more than one species of livestock is also a risk-minimizing strategy. An outbreak of disease may affect only one of the species, e.g. the cow, and some species or breeds are better able to survive droughts and thus help carry a family over such difficult periods. Advantage can also be taken of the different reproductive rates of different species to rebuild livestock holdings after a drought. For example, the greater fecundity of sheep and goats permits their numbers to multiply quicker than cattle or camels. The small ruminants can then be exchanged or sold to obtain large ruminants.

(Reijntjes, Haverkort and Waters-Bayer, 1992.)


BOX 6

INTEGRATED FARMING SYSTEMS

An experimental farm in Thailand maintains pigs and chickens, as well as a vegetable garden and a fish pond. Animal wastes are used for fertilizer, fish feed and biogas generation. Crop and human wastes are also added to the biogas unit. Liquid effluent from the biogas generator is used in the fishpond and solid residues on the garden. Periodically the locations of the garden and the pond are reversed, so residues from one serve as nutrients for the other. Little is wasted in such a system.

(Based on BOSTID, 1981.)

The best known type of integrated mixed farming is probably the case of mixed crop-livestock systems. Cropping in this case provides animals with fodder from grass and nitrogen-binding legumes, leys (improved fallow with sown legumes, grasses or trees), weeds and crop residues. Animals graze under trees or on stubble, they provide draught and manure for crops, while they also serve as a savings account (Figure 1). This kind of system using crops and ruminants such as cattle, buffaloes, sheep and goats is the focus of this publication. But even here it is necessary to further distinguish different systems (called "modes") as explained in the following section.

PHOTO 7

Crop and livestock integration: cattle grazing under coconut trees (Sri Lanka)

PHOTO 8

Crop-livestock integration: sheep grazing under tall-stemmed fruit trees (the Netherlands)

MIXED CROP-LIVESTOCK SYSTEMS, DIFFERENT MODES

Even in integrated systems the exchange of resources such as dung, draught and crop residues takes place in degrees that differ among the so-called modes of farming (Schiere and De Wit, 1995), based on the availability of land, labour and capital respectively (Table 1):


FIGURE 1

An outline of different resource flows in mixed crop-livestock systems

Different modes of mixed farming

The EXPAGR mode occurs where land is abundant, i.e. where shortage of land or local fertility are overcome by migration or by expansion into other regions where bush and forest fallow still occur. Typical examples of mixed farming in this mode are found in West Africa and in old Asian and European grazing systems. Animals were sent out to graze and would (occasionally) come home to "pull the plough or fertilize the crop fields". The crop fields themselves could move elsewhere if local soil fertility declined. However, this mode is becoming more rare as land resources are exhausted throughout the world.

Mixed farming in LEIA occurs where the shortage of land can no longer be overcome by migration or use of substantial areas elsewhere for grazing. Lack of access to external inputs such as fuel, chemical fertilizers or pesticides implies that only increased use of labour and skills offers a way out. This also implies the introduction of modified practices, and the need to adjust demand according to resource availability (see, for example, Box 7). Dung is carried around on the farm by using more labour because a lack of soil fertility cannot be compensated by shifting to more land or by employing more livestock to "produce" more dung. In LEIA systems the latter is considered a resource but a waste product in HEIA systems (Photos 2, 9, 10 and 11). If not managed properly and if demand for food and other crops is not adjusted to the carrying capacity of the soil, this can result in mining of soils and/or collapse of the systems. Van der Pol (1992) calculated that the cotton-cereal systems in southern Mali earned 40 percent of their income by mining the soil. However, this cannot go on indefinitely and sooner or later the system will collapse if there are no changes. Some researchers think that animals, when managed correctly, can serve to fill part of the gap that exists between the output and the input of nutrients in the system, together with a proper use of chemical fertilizer.

TABLE 1

Characterization of different modes of mixed crop-livestock farming

Mode of farming

EXPAGR

LEIA

HEIA

NCA

Relative access to production factors1:

       

Land

+

-

-

-

Labour

-

+

-

+/-

Capital

-

-

+

+/-

Characteristics of farming:

       

Source of animal feed

Outfield

Infield2
roadsides

Infield
Import

Infield

Role of animals as savings account

High

Medium

Low

Low

Importance of excreta

       

- Dung

Positive

Positive

Negative

Positive

- Urine

Neglected

Positive

Negative

Positive

Source of energy for labour

Humans/animals

Humans/animals

Fossil fuel

Fossil fuel/animals

Form of mixing

Diversity

Integration

Specialization

Integration

 

Can be between and on-farm

On-farm

May be between farms

Mainly on-farm

Crop residue feeding

Irrelevant

Very relevant

Irrelevant

Relevant

Role of leys

       

- For weed control

NA3

Low/NA

NA

Important

- For nutrient dynamics

NA

Low/NA

NA

Important

- For erosion control

NA

Low/NA

Low/NA

Important

Ratio outfield/infield2

       

- Local level

High

Low

Low

Low

- International level

Low/NA

Low/NA

High

Low/NA

Output of milk or meat per animal

Low

Low

High

Medium

Attention to conservation of the resource base

Low

Medium

Low

High

1 The access to land, labour and capital is to be read within a column, contrary to what has to be done for the comparison of system characteristics between modes (over rows). For example, a "-" for labour in the HEIA column means that labour is relatively scarce compared to capital inputs in that mode; not necessarily as compared with LEIA where it is indicated with a "+".

2 Infield is defined as the crop area that depends on grazing from outfield for its nutrients.

3 NA: not applicable.

Source: Based on Schiere and De Wit (1995).

PHOTO 9

Kenyan farmer holding dung in his hands; dung has become a valuable resource

PHOTO 10

A dung heap at an ecological farm in the Netherlands

PHOTO 11

The spout of a tank for separate urine collection from animals (the Netherlands)

PHOTO 12

Sheepsty on wasteland (the Ginkelse hei) in the Netherlands used to house animals and collect dung

Mixed farming in the HEIA mode is not frequently found because it implies plentiful access to resources such as external feed and fertilizer that make exchange and recycling of resources at farm level not relevant. Exchange of resources between farms only exists, as seen in the section On-farm versus between-farm mixing, after the excessive use of fertilizer forces farmers to recycle the waste. In the HEIA mode the demand for output determines the use of inputs. The use of external resources can reach such high levels that the environment is affected by emissions from the crop and/or animal production systems, ultimately leading to waste disposal problems, thus forcing HEIA into NCA.

NCA is a mode of farming where production goals are matched as closely as possible to the resource base. This approach represents a mix between HEIA and LEIA, i.e. it aims to replace the removed nutrients but it also aims to achieve keen farming and adjusted cropping and consumption patterns to suit local conditions. The use of leys (improved fallows for grazing) is important to regenerate soils, to add nitrogen, to mobilize phosphate and to suppress weeds (i.e. to avoid herbicides).

CONCLUDING COMMENTS

Mixed systems occur in several forms. For example, pastoral systems have experience in the management of mixed herds and of livestock with feed resources. One form of mixing occurs where livestock is kept on grazing lands distant from cropland in the EXPAGR mode where land is abundant. Mixed systems can also occur as a combination of specialized farms that exchange resources among them, particularly in HEIA. This report focuses on the kind of mixing that is found in integrated crop-livestock systems. Diversified systems are a combination of specialized subsystems that aim to reduce risk in conditions of variable but relatively abundant resources. Strong integration is associated with LEIA and NCA conditions where use of resources such as fertilizer and fossil fuel is restricted because of problems with pollution. This gives clues to development workers and policy-makers: cheap resources lead to specialization, restricted use of resources leads to mixing. An important aspect in promoting mixed farming is that the yield of the total enterprise is more important than the yield and/or efficiency of the parts. This is elaborated in the next chapter in which the technologies are presented.

BOX 7

VILLAGE AGROFORESTS IN JAVA

Village agroforests have existed in Java since at least the tenth century and today comprise 15-50 percent of the total cultivated village land. They represent a permanent type of land use, which provides a wide range of products with a high food value (e.g. fruit, vegetables, meat and eggs) and other products, such as firewood, timber and medicines. In their small plots, often less than 0.1 ha, Javanese peasants mix a large number of different plant species. Within one village, up to 250 different species of diverse biological types may be grown: annual herbs, perennial herbaceous plants, climbing vines, creeping plants, shrubs and trees ranging from 10 to 35 m in height. Livestock form an important component of this agroforestry system - particularly poultry, but also sheep grazing freely or fenced in sheds and fed with forage gathered from the vegetation. The animals have an important role in nutrient recycling. Fish ponds are also common and the fish are fed with animal and human wastes. Natural processes of cycling water and organic matter are maintained; dead leaves and twigs are left to decompose, keeping a continual litter layer and humus through which nutrients are recycled. Compost, fishpond mud and green manures are used on cropland. These forms of recycling are sufficient to maintain soil fertility without the use of chemical fertilizers. Villagers regulate or modify the functioning and dynamics of each plant and animal within the system.

(Based on Reijntjes, Haverkort and Waters-Bayer, 1992.)

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