Longread Africa needs more productive agriculture and lower fertility rates (1)

Africa is the continent with the highest level of food insecurity. After 2000 the prevalence of undernourishment declined from 26% to 17% in 2013, but since then it rose again to 22%. This challenge is not easily solved as Africa also has the fastest growing population of all continents. The population has grown more rapidly than did food production.

There has been much debate on the multiple risks of rapid population growth. Roughly speaking there are two main opposite schools:

1. Some warn rapid population growth is a time bomb that will increase hunger, mass unemployment, social unrest, civil wars and mass emigration.
   This opinion corresponds with Malthus’ pessimistic theory that natural resources will sooner or later limit population growth.


2. By contrast, others expect a “demographic dividend” because the upcoming young generation will provide a growing labour force that will enhance production and economic growth. Such a dividend can be realized if the ratio of working-age people to dependent people (children and elderly) increases. This opinion corresponds with the optimistic theories of anthropologist Ester Boserup and economist Julian Simon, saying that population growth is a key driver of economic growth.

In this article, we explore which of these theories will apply when and where in Sub-Saharan Africa (SSA). We focus on one resource: food production, which still is a key economic sector in many countries in SSA¹. Within food production, we further focus on cereals².

We will argue that each of these theories may apply in Sub-Saharan African countries depending on their agricultural and demographic development:

• If and where food production increases less rapidly than the population (or not at all), food security may decline and crises can hardly be avoided, unless the country can afford increasing its food imports. This is in line with the pessimistic theory. If production growth matches population growth but yields per hectare do not, this will not contribute to economic growth.
• By contrast, if and where agricultural production increases faster than the population, food security will improve. And if productivity – yields per hectare – also grow faster than the population, this will also boost economic growth, which is in line with the optimistic theory.

This means that if a country aims to avoid or reduce hunger and simultaneously boost the economy, two strategies are available: increasing yields and mitigating population growth. Combining these strategies will accelerate progress.

Importing more food is a third option, but that will increase dependency on the world market, with its price and supply risks, which became obvious after the COVID-outbreak and the Russian invasion into Ukraine. The African Union seeks to reduce these risks by making Africa more self-sufficient in food. Imports can also become a burden on the trade balance and the economy.

Why is yield growth more effective than area expansion? Because some countries don’t have much land, let alone fertile land, left for farmland expansion. In addition, such expansion cannot contribute much to economic growth as it typically does not reduce production costs. Yield growth can do that.
Reducing fertility rates can accelerate attaining both food security and economic growth. In addition, it can help bring a country closer to a so-called “demographic dividend”. This is explained in Box 1.


Growth of population and food production
As mentioned, the population of Africa is still growing rapidly. From 2010 to 2023, it grew from 1.072 to 1.481 million (+38%), although the annual growth rate declined from 2.61% to 2.34%. The median age increased from 17.9 to 19 years⁶.

In the same period, cereal production increased by 29%. This was somewhat more due to cereal area expansion (+15%) than to yield growth (+12%).
These developments combined have been visualized in one graph taken from Our World in Data⁷.


Overall, this pattern is not encouraging, as cereal production growth is lagging behind population growth since 2016.

However, developments in Sub-Saharan Africa alone have been somewhat more encouraging. Van Ittersum et al. (2025)⁸ recently found that cereal self-sufficiency increased from 84% in 2010 to 92% in 2020, despite a population increase by 29%. The production growth was attained by three developments: yield growth (44%), expansion of the cultivated area (34%) and replacement of millet by the higher-yielding crop maize (22%). These figures are more beneficial for food security and the economy than those presented above in the graph for the whole African continent.

Major differences between countries
Figures vary greatly between countries. We mention four contrasting cases in the period 2017-2023:⁹

• Gabon: cereal production grew by 4% only, lagging far behind population growth (15%), and entirely through area expansion (4%), with zero yield growth. This pattern is detrimental to food security and the economy. Area expansion also affects natural habitats and thereby the climate.


• Nigeria: cereal production grew by 4% only, lagging far behind population growth (14%), with yields growing only 3% and cereal area 1%. This undermines food security and the economy, although it is somewhat less detrimental to nature and the climate.


• Senegal: cereal production grew by 69%, much faster than the population (17%), and through yield growth (48.5%) rather than area expansion (14%). This is positive for food security. Yields even grew nearly 3x as fast as the population, an outstanding performance in Sub-Saharan Africa, positive for the economy. Yet the area expansion was detrimental to nature and the climate.


• Angola (see graph): cereal production grew much faster (34%) than the population (22%) and almost entirely through yield growth (32%), area growing 3% only. Such a pattern benefits food security and the economy and is much less detrimental to nature and the climate. However, the annual growth rate of the population is still high: 3% compared to 2.5% in Sub-Saharan Africa at large. This makes it hard to achieve a demographic dividend in the next decades.

So far about actual figures. What about the potential figures? How much cereals can Sub-Saharan Africa produce in the future?

Potential production
The potential production of a crop depends on the potential area that can be cultivated and the potential yield per hectare.

As for area, there are still large areas of savannas and forests in many countries that could be reclaimed for arable farming. But as said, some countries don't have much suitable area left. In addition, farmland expansion has detrimental impacts on nature (savannas, forests and wetlands) and the climate.

A key variable for yield growth is the “yield gap”: the difference between the actual yield and the biophysically potential yield. This gap varies between countries, climate zones and soil types. For many countries in Sub-Saharan Africa, such figures can be found in the Global Yield Gap Atlas.¹⁰
In most Sub-Saharan African countries, the remaining yield gaps of cereals are still large. Take maize in Nigeria: the average actual yield (rain-fed) in 2000-2019 was 2 s/ha. The remaining yield gap of (8.7-2 =) 6.7 tons/ha is called the “exploitable yield gap”. The actual yield can grow by a factor of (8.7/2 =) 4.35 tons/ha.

If we assume that yields can grow at the same rate as during the Green Revolution in Asia, i.e. by about 50 kg per hectare per year, then growing from 2 to 8.7 tons per ha would take as much as 134 years.¹¹ Projections at such a long time frame make little sense in view of the many uncertainties in the context, in climate alone. It is more realistic to assume that by 205025x50=1.250 kg/ha yield growth can be attained. That is 25% more than the actual yield, yet just 14% of the so-called exploitable yield gap.

However, a few countries, including Ghana, have recently shown growth rates of more than 100 kg/ha/year (see next article). If that rate can be persevered unto 2050, the exploitable yield gap can get closed by 28%. Of course, such a growth is no longer possible for those few countries that have already approached their attainable yield, such as Senegal in the case of rice.

Why accelerate yield growth?
Yield growth is a key factor in most Sub-Saharan African countries to attain food security.
If the growth rate is higher than the population growth rate, a wider range of advantages can be achieved:

• Higher farmers’ incomes, leaving money for other expenditures.
• These expenditures may benefit the wider economy.
• Less food imports are needed, leaving more money for other expenditures.
• Lower production costs, followed by lower food prices.
• This may mitigate wages and labour costs, creating better opportunities for developing competitive industries (e.g. food, textiles) and services, with associated jobs.
• This in turn may help harnessing a potential demographic dividend.
• Higher incomes often reduce fertility rates. In the case of farmers this may help to end or even reverse farm fragmentation and create better opportunities for viable farms large enough to buy inputs, increase yield, reduce production costs and sell more food on the market.

Summarizing, yield growth can generate a virtuous socio-economic cycle. In addition, it can help reduce farmland expansion and pressure on natural habitats and the climate.
However, in the short term, yield growth rates that outpace population growth will be a challenge in most countries. Between 2017 and 2023, such a rate was attained only in 4 Sub-Saharan African countries: Senegal, Ghana, Angola and Kenya.

It may also take decades to arrive at a potential demographic dividend. To shorten that period, countries can mitigate fertility rates, particularly those countries where this rate is still too high to attain an advantageous dependency ratio any time soon.

This raises two questions:

1. How can yield growth be accelerated?


2. How can fertility rates be mitigated?

How to accelerate yield growth?
Attaining high growth rates is not simply a matter of applying extra fertilizer. It requires a consistent holistic agricultural policy which creates an enabling environment for farmers to increase productivity. A wide range of options are available:¹²

• Technical options: more use of soil amendments (manure, compost, lime¹³), higher-yielding seeds and crop protection means, better access to education, extension services, and capital. Also key: better transport, storage and cooling facilities. Expansion of irrigation can contribute as well, though much less than can soil improvement and intensification in the much vaster area of rain-fed farmland.¹⁴
• Policy options: create better access to markets of inputs and produce, support investments in transport infrastructure and processing industries, and sustain and stabilize prices for farmers. More stable prices can be achieved by reducing internal trade barriers in the African Union, while simultaneously raising tariffs on cheap staples (not fertilizers!) from the world market, which would also help reduce import dependency.¹⁵ Import tariffs are justified even from a liberal economic point of view, as the US, the EU as well as major exporting countries in Asia are still subsidizing their agriculture.

We should keep in mind, however, that climate change will be a disruptor. Associated risks can be reduced by soil amendments that help conserve water, and locally by investments in irrigation.

How to mitigate fertility rates?
How can fertility rates be mitigated in an ethical way, i.e. strictly voluntary, avoiding unethical compulsory measures such as China’s former 1-child policy?

This is a sensitive issue, debates about which are often confused by misunderstandings and half-truths.¹⁶
A wide range of options have been put forward, each having its opportunities and limitations:

• Economic development. Higher incomes very often reduce fertility rates. E.g. in Ethiopia, fertility rates were 6.4 birth per woman for a bottom income quintile and only 2.6 for the top quintile.¹⁷ However, in many Sub-Saharan African countries incomes can not easily grow fast as long as yields in agriculture do outpace population growth. Nor as long as the ratio of working-age people to dependent people (children and the elderly) is below 1.7:1.
• Urbanisation is already underway and will reduce fertility rates on average by about two children per woman.¹⁷ In cities such as Accra (Ghana) and Addis Ababa (Ethiopia) fertility levels are already close to replacement levels. However, accelerating urbanisation is problematic as expanding cities often have major sanitary, disease and other health problems. Forward-looking urban planning is required, which may take decades. And of course, urbanisation does not reduce fertility rates in rural areas, where average incomes are lower. A serious problem in African agriculture is the small average farm size. In Sub-Saharan Africa excluding South Africa it is less than 1.6 hectare.¹⁹ And even small farms are sometimes fragmented due to a high number of children. Such farms cannot provide subsistence so farmers are net food consumers rather than producers, which leaves the farm without economic perspective.
• A pension system may reduce parents’ wish to have more children as an “insurance” for their old age. However, such a system may be too expensive for most Sub-Saharan African countries, although Namibia has one.²⁰
• Longer education for girls and young women. This is beneficial in its own right but will also reduce the number of children per woman in two ways: it delays the first pregnancy and school-leavers typically desire less children than those with less school years. However, the effect on fertility rates will be limited if there are not enough jobs to absorb the school-leavers, which may even leave them frustrated. This risk makes job creation even more important.
• Improving health care is also beneficial in its own right, but will also reduce infant mortality, which will mitigate the desire for more children. If parents have doubts about the survival of their baby, they may wish a next pregnancy soon, just to be sure to have “enough” children.
• Strengthening women’s reproductive health and rights is also beneficial anyway but can also reduce fertility. There is a substantial unmet need for modern contraceptives. Approximately 32% of fertile women in Sub-Saharan Africa use modern contraceptives, compared to 66% in Asia and 73% in Europe. Better access can be very effective, as has been demonstrated by Uganda, Malawi, Kenya, Ethiopia and other countries (Cilliers, 2025). However, in many countries there are serious cultural and religious barriers. For example, men on average desire more children than do women. The 2022 Kenya Demographic and Health Survey (KDHS) reported that the average preferred number of children by women aged 15-49 was 3.7, while men in the same age group desired an average of 4.2 children.²¹ A study in Nigeria, a country that still has a high fertility rate, identified a wide range of cultural barriers among men. Most of them wanted a large number of children. For the most part, the reasons given were: to populate the earth, help with farm work, and to provide old-age support, honour and prestige.²² For Ghana, a study among a representative sample of 1.528 couples in monogamous marriages, found the mean desired number of children for husbands to be higher than for their spouses: 5.4 and 4.7, respectively.²³

Cilliers (2025) advocates several of the above-mentioned options while prioritizing the latter one as it has an immediate effect. The Handbook of African Demography states: “Addressing contraceptive needs would be a starting point in furthering fertility decline in countries with low contraceptive prevalence and high fertility.”²⁴ This is most needed in those countries that are still many decades away from a potential demographic dividend. In countries that approach the window for a demographic dividend, emphasis would shift to job creation and education to develop skills needed for those jobs.

Perspectives differ between countries
Of course there are major differences between countries. As for agriculture, some countries, including Angola, Ethiopia and Ghana, have already attained a high yield growth rate, several other countries are lagging far behind. As for fertility rates, two countries (South Africa and Botswana), have approached the replacement rate of 2.1 children per woman.²⁷ Between 2010 and 2019 Uganda, Malawi, Sierra Leone, Ethiopia and Kenya reduced their fertility rates relatively fast. However, in 2023 Somalia, Chad, Niger and DR Congo still had a fertility rate of above six births for every fertile woman (Cilliers, 2025).

Countries rich in mineral and energy resources have more options to harness a future demographic dividend by creating jobs in industries and services. However, South Africa (61%), Botswana (44%), Gabon (36%) and Angola (28%) have very high unemployment rates among youth (ages 15-24 years), way above the Sub-Saharan Africa average of 10%.²⁸ These countries can afford major food imports from the world market, so may not feel an urgent need to increase their domestic food production and yield growth. In that case they risk missing an opportunity to reduce their food dependency, to broaden the basis of their economy and to prevent rural areas from lagging behind.

Summarizing, most countries in Sub-Saharan Africa that wish to realize food security, boost economic growth and harness a demographic dividend in the next decades, will need to accelerate their yield growth, while simultaneously mitigating their fertility rates. In a follow-up article, co-authored by Emelia Atabo from Ghana, I will illustrate and test this view by focusing on her home country.

Thanks are due to Professor Leo van Wissen for his comments and suggestions.