For instance, in 1960, one hectare of land was available for the production of food for two people. By 2050, the same amount of land will need to feed more than six people. Environmental stresses such as limited water availability, climate change and variability, as well as legacies from the unsustainable management of natural resources and poor agricultural practices (soil erosion and depletion of minerals), make feeding the population a complex and challenging target.
In Africa, the issue of food security is even more acute and is affected by a combination of factors. Across the continent millions of people still live in poverty. Some areas are prone to drought and many people have no access to clean drinking water. A recent report revealed that sub-Saharan Africa has ‘the lowest drinking water coverage of any region’ in the world. Additionally, as is the case throughout the world, most of the population increase in Africa will be via the growth of urban populations. A major revitalisation of agriculture in Africa is needed to underpin development ahead of the drivers of population increase, demographic change and climate change.
Supporting the development of research in the chemical sciences and strengthening its links with other complementary disciplines across Africa and beyond needs to be a key part of a long-term plan to ensure the future food security of the continent.
African economies rely heavily on agriculture. It is estimated that the contribution of agriculture to the gross domestic product (GDP) is as high as 75% in some sub-Saharan countries.4 Many of the crops grown in Africa, such as sorghum and millet, are not commonly consumed as food outside of the region, which means that strategies to increase productivity for these crops need to be led by researchers in Africa.
Models used to predict alterations in agricultural productivity in relation to climate change show a likely future improvement in many regions in the northern hemisphere (eg Europe), but predict that productivity will not improve or decline in Africa.5 Climate change and variability can have significant effects in a number of ways. Factors such as rainfall and average temperature directly affect the growth of crops, but it is often indirect effects, such as species adaptation to climate variability and change, that produce the most significant problems for agriculture. The problem is complex because the status of a species cannot be considered in isolation; other species with which they interact must also be taken into account. The predicted effects of climate change and variability will influence crop yields in different ways, with crops such as sorghum potentially being worse affected than wheat or rice by increases in atmospheric carbon dioxide.
The nature of the farming system in Africa needs to be taken into account when considering ways in which productivity can be increased. New technologies for sustainably increasing crop yields are essential, and chemical scientists, working together with scientists from other disciplines, will be critical in delivering these.
A holistic approach that examines agriculture and its impacts on the environment is needed to achieve sustainable intensification. One way is to take the agroecosystem as a whole and examine the production of food in relation to the surrounding environment, taking into account all species interactions, and not only those relating to crop production. Chemistry can help us to understand agroecosystem function, in particular, nutrient cycles and the interactions within and between species via biosignalling.
While new technologies have a key role to play in increasing agricultural productivity, any strategy must also consider the socioeconomic conditions of the continent. The large majority of farming in Africa is carried out by smallholders, so solutions must be scalable, affordable and able to reach those who need them the most if they are to have a significant impact.
A Guest Editorial