Africa is rich in both natural and human resources, yet nearly 200 million of its people are undernourished because of inadequate food supplies. Comprehensive strategies are needed across the continent to harness the power of science and technology (S&T) in ways that boost agricultural productivity, profitability, and sustainability -- ultimately ensuring that all Africans have access to enough safe and nutritious food to meet their dietary needs. This report addresses the question of how science and technology can be mobilized to make that promise a reality.
The availability of technology options and the experience with their application in some African farming systems is encouraging. There are ample opportunities to bridge yield gaps, thereby increasing productivity and halt the unsustainability spiral. To do this requires systematic fine-tuning of the technology options to improve adoption. There are many examples of successful productivity-enhancing innovations that have been documented. The challenge is to scale them up and develop new options for the future. The production ecological approach can effectively support the search for location specific solutions through its ability to unravel constraints, opportunities and synergies.
There have been many success stories of productivity increases in irrigated and commercial systems practicing sole cropping in Africa. These findings are in line with the global experience of increased specialization, implying to some that the transition from diversified systems to sole cropping is a promising development pathway to enhance productivity. Diversified farming systems on the other hand have good potential to ensure food security, both in terms of increased production and productivity and in terms of income generation. Up to 90 percent of African farmers are engaged in smallholder diversified farming systems in order to ensure their livelihoods in poorly endowed biophysical and socio-economic environments.
Smallholder farmers diversify their systems for various reasons, including spreading climate and market risks; smoothing seasonal labour peaks; exploiting crop synergies (e.g., legumes and cereals, beneficial pest and diseases) and increasing land productivity. Hence market-led productivity improvement can impact on many commodities in smallholder farming systems and not require a conscious and deliberate move from mixtures to single commodities in order for them to adopt and benefit from new technology options. Indeed mixed systems should not be equated with subsistence orientation. Many mixed smallholders in Africa have some marketable surpluses of the various commodities they grow. Complete specialization is not required to have market-led productivity improvements. To the extent potential or attainable productivity improvement in particular commodities in mixed systems outdoes others, so one might expect more specialization in those commodities to occur over time (i.e., they might represent a larger proportion of cropland). However, for the reasons mentioned above, there will remain incentives to have a mixed farm orientation, even including intercropping the species whose productivity has improved the most compared to others, where synergies are possible. It is not a foregone conclusion that such increased specialization will imply a move to more sole cropping at the expense of intercropping.
The transformation of smallholder diversified systems into more specialized systems may not be expected to occur within one generation; an evolutionary increase in productivity for the majority of the farmers is more likely, with many 'rainbow evolutions' across the many farming systems rather than one Green Revolution, as in Asia. This development pathway can meet local food and income needs while fulfilling social and cultural desires. In addition, diversified systems offer favourable options for minimizing adverse environmental consequences.
The review of mixed systems suggests promising options for productivity increases. Generally much is known about the management of soil- and rain-water in mixed systems. Fair knowledge is available on the utilization of nutrients by crop combinations. There is also general consensus that pest and disease pressures are likely to be less severe. However, there is a lack of systematic insight of all the facets of crop and animal production in complex diversified systems. The review shows that specific genetic characteristics may be required for mixtures. Little emphasis has been given in breeding programs to these issues. The insights on water and nutrient management from agronomic research are not yet fully exploited. Interesting synergies may arise when looking for interactions with other measures such as crop characteristics. Scant attention has been given to pest and disease ecology. A recent model analysis by Skelsey and colleagues (in preparation) of the impact of crop combinations on disease dissemination shows promising options and will improve the systematic search for crop combinations that minimize disease infestations. Also little emphasis has been given to the development of machines equipped to handle mixed cropping systems. Lacking the option to introduce appropriate mechanization options into diversified farming systems will limit the increases in land and labour productivity to much lower levels than what might be technically feasible. Failing to address the increase in labour productivity has been shown to hamper adoption of technologies (e.g. Brader 2002). Labour productivity over the past four decades has not increased or even decreased in diversified systems. Enhancing labour productivity therefore requires special attention.
A closer look at current diversified systems and attempts to improve their productivity through low external input use reveals that this approach has limitations. However, incorporation of advanced technological solutions into participatory technology development with indigenous technology options can lead to co-innovations that hold large potentials and benefits for all parties.
These systems ensure the livelihoods of hundreds of millions of African farmers, although their produce rarely finds its way to world markets. To ensure the future international competitiveness of African smallholders, investments must be made in public goods, including science and technology that will help African farmers to compete effectively. In this process, objectives other than economic prosperity, such as enhancing social cohesion and ensuring livelihoods for the poorest farmers, should also be valued.
This review of agricultural production systems in Africa provides an overview of constraints to and opportunities for enhancing productivity. While currently available technology options can enhance productivity with or without specific adaptation for more specialized commercial systems, additional strategic, applied and adaptive research is urgently needed to advance the productivity of the more complex diversified smallholder farming systems. Six major programs are needed to ensure development and adaptation of technology options to the great variety of production systems in Africa in general, and to the identified four priority continental farming systems more specifically:
These programs need to be both generic and specific: generic when concepts, methodologies and approaches are discussed and implemented; specific when the farming systems are considered in more detail.