Crop diversification and new varieties

Opportunities enabled

The introduction of new cultivated species and improved varieties of crop is a technology aimed at enhancing plant productivity, quality, health and nutritional value and/or building crop resilience to diseases, pest organisms and environmental stresses. Crop diversification refers to the addition of new crops or cropping systems to agricultural production on a particular farm taking into account the different returns from value-added crops with complementary marketing opportunities. Major driving forces for crop diversification include:

  • Increasing income on small farm holdings
  • Withstanding price fluctuation
  • Mitigating effects of increasing climate variability
  • Balancing food demand
  • Improving fodder for livestock animals
  • Conservation of natural resources
  • Minimising environmental pollution
  • Reducing dependence on off-farm inputs
  • Depending on crop rotation, decreasing insect pests, diseases and weed problems
  • Increasing community food security.


New and improved crop species can be introduced though two different processes:

  1. Farmer experimentation with new varieties. Farmers have introduced new and improved species over centuries, mainly in regions that constitute world centres of cultivated crop diversification, such as Meso-America, the Andes, Africa and parts of Asia, in response to environmental stress conditions. There are many thousands of existing varieties of all of the important crops, with wide variation in their abilities to adapt to climatic conditions. Agricultural researchers and extension agents can help farmers identify new varieties that may be better adapted to changing climatic conditions, and facilitate farmers to compare these new varieties with those they already produce. In some cases farmers may participate in crossing select seeds from plant varieties that demonstrate the qualities they seek to propagate to develop new varieties with the characteristics they desire.
  2. The introduction of new crop species to diversify the crop production systems needs to take into account the following inter-related categories:
    • Availability and quality of resources including irrigation, rainfall and soil fertility.
    • Access to technologies such as seed, fertiliser, water, marketing, storage and processing.
    • Household related factors covering food and fodder self-sufficiency requirement as well as investment capacity.
    • Price and market related factors including output and input prices as well as trade policies and other economic policies that affect these prices either directly or indirectly.
    • Institutional and infrastructure related factors covering farm size and tenancy arrangements, research, extension and marketing systems and government regulatory policies.

How this Technology Contributes to Climate Change Adaptation

Breeding new and improved crop varieties enhances the resistance of plants to a variety of stresses that could result from climate change. These potential stresses include water and heat stress, water salinity, water stress and the emergence of new pests. Varieties that are developed to resist these conditions will help to ensure that agricultural production can continue and even improve despite uncertainties about future impacts of climate change. Varieties with improved nutritional content can provide benefits for animals and humans alike, reducing vulnerability to illness and improving overall health.

The aim of crop diversification is to increase crop portfolio so that farmers are not dependent on a single crop to generate their income. When farmers only cultivate one crop type they are exposed to high risks in the event of unforeseen climate events that could severely impact agricultural production, such as emergence of pests and the sudden onset of frost or drought. Introducing a greater range of varieties also leads to diversification of agricultural production which can increase natural biodiversity, strengthening the ability of the agro-ecosystem to respond to these stresses, reducing the risk of total crop failure and also providing producers with alternative means of generating income. With a diversified plot, the farmer increases his/her chances of dealing with the uncertainty and/or the changes created by climate change. This is because crops will respond to climate scenarios in different ways. Whereas the cold may affect one crop negatively, production in an alternative crop may increase.

Advantages of the technology

The process of farmer experimentation and the subsequent introduction of adapted and accepted varieties can potentially strengthen farmers’ cropping systems by increasing yields, improving drought resilience, boosting resistance to pests and diseases and also by capturing new market opportunities. To make the products of the research process more relevant to the needs of smallholder farmers, research organisations are increasingly engaged in participatory research in recognition of its potential contribution to marginal areas with low agricultural potential. There is a need to identify crops and varieties that are suited to a multitude of environments and farmer preferences. Participatory approaches increase the validity, accuracy and particularly the efficiency of the research process and its outputs. Researchers are better informed and can better inform about the traits that should be incorporated in improved varieties. Participatory processes also enhance farmers’ capacity to seek information, strengthen social organisation, and experiment with different crop varieties and management practices.

Crop diversification provides better conditions for food security and enables farmers to grow surplus products for sale at market and thus obtain increased income to meet other needs related to household well-being. Crop diversification can enable farmers to gain access to national and international markets with new products, food and medicinal plants. Diversifying from the monoculture of traditional staples can have important nutritional benefits for farmers in developing countries and can support a country to becoming more self-reliant in terms of food production. Diversification can also manage price risk, on the assumption that not all products will suffer low market prices at the same time. Compared to producing monocultures, management techniques for diversified crops generally consist of more sustainable natural resource practices.

Disadvantages of the technology

Farmer experimentation using only native varieties can limit the range of benefits and responses that may be found amongst the materials being tested, although local adaptation and acceptance are ensured. At the same time, problems can with the introduction of exotic species (from other origin centres) that after being introduced turning into pests. There are several examples of introduced species that have escaped control becoming pests or agricultural weeds (Ojasti, 2001; Hall, 2003).

A limitation of crop diversification is that it may be difficult for farmers to achieve a high yield in terms of tons per hectare given that they have a greater range of crops to manage. In terms of commercial farming, access to national and international markets may be limited by a range of factors including government policy including subsidies, the price and supply of inputs, infrastructure for storage and transportation, amongst others. Farmers also face risk from poor economic returns if crops are not selected based on a market assessment. For example, drought tolerant crop varieties may fetch a low market price if there is not sufficient demand.

Financial requirements and costs

Costs of farmer experimentation are generally low, but results may only have local applicability. Capital investment will relate to the purchase of new seed varieties (if not available ‘wild’ locally) and labour time. Where farmers are implementing a project initiated by an external agency, capital costs for training, technical experts and field staff, on farm trial equipment (an experimental plot may be established), and site visits may also be required. In a project in Mexico, estimated total costs of a five-year project involving around 1,000 farmers came to around $300,000 (Smale et al, 2003).

Financial requirements of diversification revolve around the costs involved in researching the species to be planted and training in the management of diversified systems. Preliminary feasibility and market research need also to be considered in the financial requirements. Infrastructure (such as transport and storage) and marketing costs should also be considered.

Knowledge and Monitoring Requirements

Plant breeding requires know-how and investment in terms of human and financial resources as well as time. It may take a number of years to create a new variety with improved features and an additional number of years for it to be introduced into the market and taken up by farmers.

Before contemplating any introduction, a rigorous security assessment should be conducted. This involves compiling an inventory of varieties by crop, including varieties currently used by farmers, as well as new varieties not yet available to farmers for testing. It is important to get an overview of the strengths and weaknesses of current agricultural and seed systems and an in-depth understanding of the root causes of any current and potential stresses. Fundamentally, a decision to introduce new varieties needs to be founded on sufficient evidence that new varieties offer promising opportunities, and, equally, that their introduction will not expose farmers further to increased risk.

It is important to monitor and evaluate (with farmer participation) the performance of new varieties, report results and recommend next steps and changes to improve processes. It is also important to provide detailed information on yields and production conditions.

In making decisions about diversification, farmers need to consider whether income generated by new farm enterprises will be greater than the existing activities, with similar or less risk. While growing new crops or raising animals may be technically possible, these may not be suitable for many farmers in terms of their land, labour and capital resources. Moreover, markets for the products may be lacking. Therefore preliminary feasibility and market studies are recommended before crop diversification selection is implemented.

Institutional and organisational requirements

In order to support farmer innovation, communities have to be linked to research programmes and should have access to research products. These links might be direct or through intermediary organisations such as NGOs and development organisations. In all cases, these links have to be made explicit and institutionalised. Support for the decentralised selection by farmers of preferred varieties (as well as their production and marketing) should be seen as part of a wider set of interventions to decentralise service delivery to farmers.

Institutional recommendations include establishing farmers’ committees in order to synchronise diversification on neighbouring farms or plots that share common ecosystems. The committee exercises some authority by establishing the most appropriate crop portfolio and can provide a body that supports local farmers to access financing and technical support. Production can also be coordinated in relation to market demand, either staggering to provide a stable supply or coinciding to make a bulk sale. Government policy supporting diversification is key to facilitating access to inputs and technical skills and building national markets and developing links to external markets.

Barriers to implementation

The main barrier to introducing new and improved crop varieties through farmer experimentation is the misconception that local species have low productivity. In the same vein, several communities in developing countries have lost ancient knowledge about resistant species.

The main barrier to diversification is market demand which can lead farmers to produce fewer crops or monocultures and to rely on chemical inputs. In turn, this can increase vulnerability of both the agricultural system itself to external factors such as climate change, and also the farmer to price fluctuations.

Opportunities for implementation

Opportunities for new and improved crop varieties arise where attractive native species can be developed for sale on national and international markets. By implementing market development strategies and integrating various actors across and within the input-supply, production, sale/storage, and marketing stages of the value chain the production, profitability and competitiveness of crops can be increased. Opportunities may also arise for innovative partnerships between producers, research institutes and the private sector.

Real Examples of Application

Farmer experimentation on improved varieties of beans in Honduras have reduced the spread of diseases and therefore avoided drops in crop productivity. Participative development processes have increased access to and adoption of improved varieties for small farmers (Rosas 2001). In Central America, there are already other experiences of participative improvement of beans and maize, and there is an increasing interest from farmers, organisations and donors (Rosas 2001).


  • Hall, J. (2003) Environment: Aliens plant species invade Southern Africa. Global Information Network. June 27: 1-2. 2003
  • Ojasti, J. (2001) Especies exóticas invasoras. Estrategia regional de biodiversidad para los países del trópico andino. Convenio de Cooperación Técnica ATN/JF-5887-RG CAN-BID. Venezuela.2001
  • Rosas, J. C. (2001) “Aplicación de metodologías participativas para el mejoramiento genético del frijol en Honduras” in Agronomía Mesoamericana 12 (2): 219 -228. 2001. Universidad de Costa Rica, Alajuela
  • Smale, M., M.R. Bellon , J.A. Aguirre, I. Manuel Rosas, J. Mendoza, A.M. Solano, R. Martínez, A. Ramírez, J. Berthaud, (2003) “The economic costs and benefits of a participatory project to conserve maize landraces on farms in Oaxaca, Mexico”, in Agricultural Economics 29 (2003) 265–275