Mixed farming is an agricultural system in which a farmer conducts different agricultural practice together, such as cash crops and livestock. The aim is to increase income through different sources and to complement land and labour demands across the year.
Mixed farming systems can be classified in many ways. They can be based on land size, type of crops and animals, geographical distribution, market orientation, and so on. Three major categories are distinguished here (FAO, 2001).
- 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 enables the recycling of resources generated on a single farm. Between-farm mixing can be used to resolve waste disposal problems where by crop farmers use dung from animal farms for fertiliser.
- Mixing within Crops and/or Animal Systems
This practice involves multiple cropping or keeping different types of animals together. For example, grain-legume association can provide grain with nitrogen. With plant inter-cropping farmers can make the most of the space available to them by selecting plants and cropping formations that maximise the advantage of light, moisture and soil nutrients. Examples of mixed animal systems include chicken-fish production where chicken dung serves as fish fodder.
- Diversified versus Integrated Systems
In a diversified system some components exist as independent units. In an integrated system, maximum use is made of resources, making the system highly interdependent.
Mixed farming technology contributes to adaptation to climatic change because the diversification of crops and livestock allows farmers to have a greater number of options to face the uncertain weather conditions associated with the increased climate variability. Mixed farming can also give a more stable production because if one crop or variety fails, another may compensate. Livestock represents a means by which families can save and invest in the future. Livestock is a walking bank of assets that can be sold during periods of need such as if crops fail due to drought or flooding.
This technology also allows greater food security and improved household nutrition levels. In addition, farmers can generate a surplus of some products that can be sold at market. Among other benefits, this technology also allows farmers to grow fodder for livestock and poultry. An additional benefit of mixed rice–fish culture systems is that the fish may help reduce populations of existing and emerging disease vectors such as mosquitoes.
In many areas the hungry season on farms comes in the months just after the rains start when producers need to invest labour in the planting and management of crops, but before they start to produce. Conversely grass production starts immediately with the rains, and livestock quickly gain weight and increase milk production. The high milk production in the rains can greatly help support the nutrition of farmers while they are tending their crops and waiting for harvest. The advantages of mixed farming systems for the environment are shown in Box 1 below.
Box 1: Advantages of mixed farming systems for the environment
Mixed farming systems maintain soil fertility by recycling soil nutrients and allowing the introduction and use of rotations between various crops and forage legumes and trees, or for land to remain fallow and grasses and shrubs to become re-established;
Mixed farming systems maintain soil biodiversity, minimise soil erosion, help to conserve water and provide suitable habitats for birds;
Mixed farming systems make the best use of crop residues. When they are not used as feed, stalks may be incorporated directly into the soil, where, for some time, they act as a nitrogen trap, exacerbating deficiencies. Burning the crop residues, the other alternative, increases carbon dioxide emissions; and
Mixed farming systems allow intensified farming, with less dependence on natural resources and preserving more biodiversity than would be the case if food demands were to be met by crop and livestock activities undertaken in isolation.
Source: FAO, 1996
One limitation is that production levels in mixed systems (tons per hectare, milk per animal daily, increase and reproduction rates), can be lower than in specialised systems (monoculture) (FAO, 1999). Another disadvantage is that where farmers depend on wild animal stock rather than domesticated species, they may face increased vulnerability in instances where animal population levels are affected due to climate change (for example, where livestock populations need to be trimmed).
Partly because of overgrazing, some mixed farming systems of the tropical highlands of Asia and Central Africa are among the most eroded and degraded systems of the world (FAO, 1996). Integrating crops and livestock can help improve soil neutirent and reduce the stress on farming land.
As for most cases, to estimate the costs of implementing this technology the cost of wages, agricultural tools, and inputs (such as seeds and fertilisers) must be considered. Infrastructure for supporting livestock will be an added cost in crop-animal systems. The main financial needs are associated with credits for the acquisition of inputs, investment in training and in the dissemination of this technology. Investment is needed also to obtain the necessary qualitative and quantitative micro-climate information for managing the synchronisation of mixed crop cycles (phenologies).
Knowledge about the phenology and lifecycles of different crops to be cultivated simultaneously (or with some time lag between them), as well as knowledge about the soil nutrients required by each of them (so they can complement each other, is required to use this technology. For example, some crops require higher levels of nitrogen, while others require more potassium. Knowledge is also required about the season in which each of the crops involved should be sown and which crop species and varieties can be grown together because of the inter-species competition.
The organisations promoting this technology need to have qualified technicians both in agronomy and livestock production. These organisations must identify the farmers that are familiar with the technique of multiple crops in the area and develop positive relationships with them.
The main obstacle for the implementation of this technology is farmers’ reluctance since mixed farming is considered to have low productivity in comparison with monocultures which have a high yield in terms of tons per hectare (t/ha). The best way to overcome these barriers is to demonstrate mixed farming systems with better productivity levels; to disseminate the benefits of this technology, and to provide training.
The main opportunity for implementing mixed farming is that it improves and guarantees the range of products a farmer has available to sell at market. One option to increase productivity while maintaining economic and environmental benefits of mixed farming is specialisation. Partnerships with specialised farms are formed to facilitate the exchange of crops and waste products from manure. For example, the traditional association between nomads and farmers reaping where nomadic cattle converts crop residues into manure for cultivation. More recent developments include partnerships between dairy farmers and vegetable growers. Similarly, in organic farming in Europe between specialised organic farms there is an exchange of secondary products and crop residues for manure (FAO, 1999).
FAO (1996) Livestock & the environment: Finding a balance, FAO, Rome.
FAO (1999) Manual on Livestock Disease Surveillance and Information Systems, FAO, Rome.
FAO (2001) Animal Production and Health. FAO. Rome.