Challenges and opportunities for reducing food and nutrition insecurity in Africa through integrated soil fertility management
By Dr. Ismahane Elouafi, Director General, International Center for Biosaline Agriculture (ICBA)
Agriculture is the backbone of Africa’s economy. It accounts for around 20% of the continent’s GDP, some 60% of its labor force, and roughly 20% of its total exports. Most of the rural Africans depend on farming for their livelihood. The majority are smallholders.
Feeding a growing population
There are around 33 million smallholder farms in sub-Saharan Africa, representing 80% of all farms in the region. They produce up to 90% of food in some of the countries.
However, per capita food production in the region is the lowest in the world. It has remained nearly stagnant over the past several decades.
One of the main reasons is low agricultural productivity due to such factors as soil degradation. According to the Food and Agriculture Organization of the United Nations, as much as 40% of Africa’s soils suffer from moderate to severe degradation as a result of soil erosion, nutrient depletion, organic matter decline and biodiversity loss. Soil erosion in sub-Saharan Africa is considered one of the root causes of stagnating or declining agricultural productivity.
On the one hand, soil fertility on smallholder farms has considerably gone down due to more nutrients being removed from the soil than replenished. This has caused a very high average annual depletion rate – 22 kg of nitrogen (N), 2.5 kg of phosphorus (P), and 15 kg of potassium (K) per hectare of cultivated land in 37 African countries. The annual fertilizer loss is estimated to be 4 billion USD.
On the other hand, fertilizer use in Africa has changed little over the years. In 2014, the average rate was only 11 kg per hectare, whereas the world average is 110 kg per hectare.
No wonder then that the continent’s dependency on food imports has increased over the decades. Africa became a net importer of agricultural products in the 1970s and a net importer of food in the 1980s.
Per capita food consumption in Africa has been rising 10 times faster than per capita food production, leading to an increase in food imports. Over the next decades, population growth and climate change are expected to make the situation worse.
“Per capita food consumption in Africa has been rising 10 times faster than per capita food production, leading to an increase in food imports. Over the next decades, population growth and climate change are expected to make the situation worse.”
Today Africa’s annual food imports are worth around USD 35 billion and are estimated to reach USD 110 billion by 2025, weakening its economies, damaging its agriculture and exporting jobs from the continent.
This is alarming as the continent is the most food-insecure, has the highest concentration of extreme poverty and is forecast to have the fastest population growth rate over the coming decades.
Hunger has been on the rise in almost all African subregions, making Africa the region with the highest prevalence of undernourishment, at almost 20%. According to The State of Food Security and Nutrition in the World 2019 of the Food and Agriculture Organization of the United Nations, the prevalence of undernourishment reaches 22.8% in sub-Saharan Africa, 26.5 in Middle Africa and 30.8 in Eastern Africa.
Unlike other regions of the world, sub-Saharan Africa is witnessing an increase in extreme poverty. There were 413 million extremely poor people in 2015 in the region, up from 278 million in 1990. The region is home to 27 of the world’s 28 poorest countries and has more extremely poor people than the rest of the world combined. The average poverty rate stood at about 41% in the region in 2015. The World Bank estimates that by 2030, nearly 9 of every 10 people in extreme poverty will be living in sub-Saharan Africa.
Africa also continues to experience high rates of population growth. According to the United Nations Department of Economic and Social Affairs, the population of sub-Saharan Africa is projected to double by 2050. Sub-Saharan Africa will account for most of the growth of the world’s population over the coming decades.
By one estimate, to feed the continent’s ballooning population, crop production will need to increase by 260% by 2050.
How integrated soil fertility management can boost crop production
The African Union made an initial attempt to tackle low soil fertility and expand crop production back in 2006 by adopting the 12-point “Abuja Declaration on Fertilizer for the African Green Revolution”. The African nations agreed to raise fertilizer use from 8 kg per hectare at the time to 50 kg per hectare by 2015. However, the countries fell well short of their target as average fertilizer use was a meager 11 kg per hectare across the continent in 2014.
It became increasingly clear that fertilization alone cannot improve Africa’s soils and yields. Policymakers and scientists started shifting their focus to integrated soil fertility management instead as it offered a holistic approach to sustainable management of soil resources and production of more diverse and nutritious food.
Integrated soil fertility management comprises three key components.
The first one focuses on the agronomy of crops and inorganic fertilizers. This component involves, among other things, the selection of improved crop varieties and crop rotations and the rate and timing of inorganic inputs.
The second one targets interventions on organic resource management, including the return of crop residues, manure, compost and other types of organic waste, next to rotation or intercropping with legumes and use of micro-organisms promoting plant growth.
The last one deals with any other amendments that may be needed to remove limitations to productivity such as soil acidity, micronutrient deficiency, soil erosion and compaction, or pests and diseases.
Studies show that integrated soil fertility management significantly enhances uptake of nutrients and productivity of crops. Moreover, the approach considers such factors as the cost and profitability of external inputs as well as market risks.
A 10-year study on millet by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in the semi-arid belt of Niger demonstrated that when stover residues were mulched along with inputs of NPK fertilizers, total biomass productivity was between two and seven times larger than when the same inputs were applied separately.
“As an integral part of integrated soil fertility management, crop diversification is key to reducing the risks of crop failure and food insecurity. It can improve soil fertility and ecosystem health.”
“Studies show that integrated soil fertility management significantly enhances uptake of nutrients and productivity of crops.”
The results of a large-scale pilot program across the moist savannas in Nigeria showed that maize and soybean rotations and strategic use of N and P fertilizers gave a net return of USD 539 per hectare as compared to USD 422 per hectare when only maize was cultivated, and similar rates of fertilizers were used. It was also shown that the gains in food production and income from practicing integrated soil fertility management significantly benefited the intake of calories and proteins by smallholder farmers. Therefore, it is important that smallholder farmers diversify their crops.
As an integral part of integrated soil fertility management, crop diversification is key to reducing the risks of crop failure and food insecurity. It can improve soil fertility and ecosystem health. More importantly, it will help to boost food security and nutrition of smallholder farmers and increase their incomes as it provides different opportunities.
Crop diversification and integrated soil fertility management are also better suited to safeguarding crop production against the adverse effects of climate change. Through the combination of organic inputs with fertilizers, the approach helps to reduce the sensitivity of crop production to climate-change-related impacts. Crop diversification ensures a more balanced diet to local communities and less sensitivity to climate variation, particularly in terms of temperature.
Under its mandate for marginal environments, that is the areas of the world characterized by soil degradation, water scarcity and other negative factors, the International Center for Biosaline Agriculture (ICBA) advocates crop diversification. In particular the center promotes climate-resilient crops like quinoa, pearl millet and sorghum, among others, for agriculture in Africa. Quinoa, for example, is a highly nutritious crop that withstands drought and salinity, so it has a lot of potential for improving food security and nutrition in the region.
ICBA has also developed a number of technologies for soil reclamation and improvement. ICBA scientists have conducted studies on biochar production and potential use of sludge and biosolids in, among other things, agriculture, forestry and floriculture. Biochar can be an important tool to increase soil productivity in areas with severely depleted soils, scarce organic resources, and inadequate water and nutrient supplies. Since 2015 researchers have worked on a low-cost technology to turn green waste into biochar, a charcoal used as a soil amendment and stored in the soil as a means of removing carbon dioxide from the atmosphere. The results of field trials in desert conditions demonstrate that biochar helps to increase fresh biomass of pearl millet by up to 46% and soil water-holding capacity by up to 40%, resulting in reduced loss of irrigation water and nutrients.
Despite their significant benefits for food security, income generation and environmental protection, the adoption of integrated soil fertility management practices by smallholder farmers is usually low and incomplete. The main reasons include high transaction costs of input and produce trade; low awareness and common disbeliefs about the benefits of integrated soil fertility management; shortage of credit facilities for making initial investments; aversion to risks surrounding the profitability of inputs; cost and availability of labor; land size and property rights; weak social networks and pervasive distrust; lack of information about soil fertility and rainfall forecasts; and scarcity of crop residues due to their use for livestock production.
To scale out integrated soil fertility management across African smallholder farming systems, there is a need to strengthen research on and dissemination of practices at local, national and regional levels. It is also necessary to generate more detailed information on soil fertility to customize practices and maximize the benefits of integrated soil fertility management, as well as provide decision-support tools that consider resources and production objectives of rural households.
Therefore, it is important to develop and update soil fertility atlases, including data on major macronutrients (NPK) and micronutrients (Fe, Cu, Mn, Zn). These atlases will help to better target areas where fertility improvement efforts are needed most to increase crop productivity.
Smallholder farmers also need to know about and have access to optimal fertilizer blends tailored to the requirements of different soils and crops. The example of Ethiopia boosting agricultural productivity through fertilizer blends is very tangible in that not only does it challenge the benefit of DAP and Urea long-standing compositions, but also showcases the benefit of investing in soil mapping and understanding of its chimio-physical properties. The work conducted by ATA, OCP, and BMGF started a new era of sustainable agricultural production in Ethiopia. This could only be achieved with the right policies and right capacity development of farmers and other land users.
Above all, smallholder farmers need support from governments. As fertilizer prices are higher in Africa than in Asia, Europe and North America, subsidies can help them afford inorganic inputs and thus increase crop production as organic inputs and improved crop varieties alone are not enough to overcome soil nutrient depletion. These subsidies will also contribute to developing the fertilizer market in the region by creating economies of scale.
Further to increasing productivity, fertilizers also improve the overall quality of food to fight malnutrition. Indeed, when fertilizer is used according to the principles of 4R nutrient management (right source, place, rate, time) stewardship, research has shown that it contributes to human nutrition via access to nutrients.
As malnutrition worldwide is a serious issue, particularly in Africa, which affects acutely children, using fertilizers to fight it is a very pertinent strategy. Essential micronutrients that are critical for the human body, including zinc, selenium and boron, could eventually be provided through fertilizer application.
Africa’s problems are multifaceted. So should be their solutions. Integrated soil fertility management is just one of the many whose potential is yet to be realized. If the African nations are serious about tackling food and nutrition insecurity, they should act sooner rather than later.
“Africa’s problems are multifaceted. So should be their solutions.”