Most of sub-Saharan Africa’s economies are dominated by the agriculture sector. On average, agriculture accounts for 32% of gross domestic product and employs 65% of the labour force. In some countries, it contributes over 80% of trade in value and more than 50% of raw materials to industries.

But despite being a crucial sector in many economies, agricultural productivity on the continent is very low. Yields of maize and other staple cereals have typically remained at about one tonne per hectare – about 1/3 of the average achieved in Asia and Latin America. During the past 30 years, the competitiveness of many sub-Saharan Africa export crops has declined and the region’s dependence on imported food crops has increased. In the years ahead, global warming is expected to intensify the current constraints on food production.

Is the lack of mechanisation the Achilles heel of African agriculture?

The greatest source of power for land preparation in sub-Saharan Africa remains human muscle power. In Central Africa an estimated 80% of cultivated land is worked manually while in Eastern and Southern Africa, that figure is about 50%. On average, less than 20% of mechanisation services are provided by engine power in sub-Saharan Africa.

Furthermore, sub-Saharan Africa is the only developing region where the number of agricultural workers per hectare is no more than half of the average for all developing regions. Not only does sub-Saharan Africa have an acute lack of human resources available for agricultural production, it also has very few tractors available as an alternative source of power. Taking the number of four-wheel tractors as an indicator of advancement in mechanisation, FAO reports the following trends over the past 40 years.

• In Asia, the tractor numbers increased five times between 1961 and 1970, from 120,000 to 600,000 units. Thereafter the number increased by 10 times to six million units by 2000. Since then, numbers have continued to increase, especially in India, which had 2.6 million tractors in 2010, and China which reached over two million units by 2008.
• In the Latin America and Caribbean region, tractor numbers increased 1.7 times between 1961 and 1970, from 383,000 to 637,000 units and thereafter tripled to 1.8 million units by 2000.
• In sub-Saharan Africa, the trend has been rather different. In 1961, the number of tractors in use was more than in both Asia and the Near East (at 172,000). After that the number increased slowly to peak at 275,000 by 1990 before declining to 221,000 by 2000.

Experiences in other continents and especially in the developing economies of Asia and Latin America show that agriculture has been transformed in recent years into a progressive, more productive industry. Investments in irrigation, fertiliser and high-yielding varieties went hand in hand with increasing power inputs, mainly in the form of tractors for land preparation and diesel engines for irrigation. This has enabled farmers to intensify production and improve their quality of life as well as contribute to national and local prosperity.

Meanwhile, in most of sub-Saharan Africa, where farming systems were more complex across variable agro-ecological zones, quality seed and fertiliser were not backed by irrigation support or mechanisation inputs. Sub-Saharan Africa was therefore largely bypassed by the Green Revolution that helped transform agriculture and reduce poverty in Asia and Latin America.

The evidence is incontrovertible: Higher levels of mechanisation are linked to economic growth, improved farm productivity, higher incomes and greater food security.

But mechanisation is no panacea: If not done right, it can potentially burden small farmers with machines they can’t afford or maintain and tools that eliminate jobs and disempower wage earners. It can also harm the environment by increasing pressure on fragile natural resources, driving soil erosion and compaction, prompting overuse of chemical inputs and encouraging farmers to farm lands that currently serve as valuable forest and rangelands. So any sort of move towards mechanisation will have to be done in a careful, considered way to ensure that it brings positive, rather than negative, outcomes.

Nonetheless, it is clear that sub-Saharan Africa can no longer rely on human muscle power to feed its growing population. It is essential for decision-makers and the development community to take a new look at the opportunities available for mechanising agriculture in sub-Saharan Africa. ‘Hello Tractor’, a Nigerian social enterprise that allows farmers to request affordable tractor services via text message is one promising and innovative approach. Indeed, there is much that can be done to make sub-Saharan Africa’s agricultural development and food security policies, strategies and programmes “mechanisation-smart” and promote interventions to support efficient, lean and environmentally-sound mechanisation.

Ethel Sennhauser is director of the Agriculture Global Practice at the World Bank. Chakib Jenane works with the World Bank’s Global Food and Agriculture Practice (GFADR). This article was first published on the World Bank’s blog network.