The Post-Harvest Losses: The Consequences for Africa
Abstract
Introduction: The Food and Agricultural Organization predicts that about 1.3 billion tonnes of food are globally wasted or lost per year. This is equivalent to 30% of food produced for human consumption for the same period. Some reports have estimated that this lost or wasted food can be used to feed 1.6 billion people every year.
Problem Statement: Global food waste is a far-reaching problem with tremendous financial, ethical and environmental costs. The amount of food lost or wasted costs US$2.6 trillion annually and is more than enough to feed about 815 million hungry people in the world four times over.
Methodology: The study is mainly qualitative with some quantitative in scope making use of secondary data (literature from journals, working papers, unpublished theses, publications from government, World Bank and similar institutions) and global agribusiness industry.
Results: The review found out that, via meta-analysis, evidence of post-harvest losses in Africa is spotty and quantitative estimates are often derived from inadequate datasets. The major reason for many post-harvest losses estimates is weak assessment methodologies. The world’sincreasing population and demand for food, reducing food loss and waste is one of the challenges globally. Food loss and waste have significant negative food-security, economic and environmental impacts. The value of annual food loss and waste globally is about US$1 trillion and one billion tonnes in quantity. Conclusion: Although reduction of post-harvest food losses is a critical component of ensuring future global food security, however, production resources including land, water and energy are at the moment limited and inelastic.
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Introduction
Current world population (8.2 billion June 2025) is expected to reach 9.7 billion by 2050, withAfrica contributing more than half of that increase, further adding to global food security concerns [1]. This increase translates into 33% more human mouths to feed with the greatest demand growth in the poor communities of the world, Africa for example. According to [2], food supplies would need to increase by 70% (estimated at 2005 food production levels) in order to meet the food demand in 2050 [1]. A significant part of this growth will take place in developing countries, where steadily increasing urban population continue to create complex and lengthy food supply chains involving many actors, presenting challenges in developing safe, and nutritious food that is of good quality [3]. Post-harvest losses (PHL) are a measurable reduction in foodstuffs, which may affect quantity or quality [4]. For many households, such losses threaten food nutrition, and income security [5]. They also contribute to high food prices by removing part of the food from the supply chain. Food availability and accessibility can be increased by upping production, improving distribution, and reducing the losses. Thus, reduction of post-harvest food losses is a critical component of ensuring future global food security. However, production resources including land, water and energy are limited and inelastic [6].
The Food and Agricultural Organization (FAO) forecasts that about 1.3 billion tonnes of food are globally wasted or lost per year [7]. This is equivalent to thirty percent of food produced for human consumption for the same period. Some reports have estimated that this lost or wasted food could be used to feed 1.6 billion people every year [6].Food losses refer to the decrease inedible food mass throughout the part of the supply chain that specifically leads to edible food for human consumption [7]. They state that food waste or loss is measured only for products that are directed to human consumption, excluding feed and parts of products which are not edible. Reduction in these losses would increase the amount of food available for human consumption and enhance global food and nutrition security, a growing concern with rising food prices due to growing consumer demand, increasing demand for biofuel and other industrial uses and increased weather variability ([8]; [9]). A reduction in food losses also improves food and nutrition security by increasing the real income for all the consumers [10]. The loss of harvested food commodities can be qualitative or quantitative. Quantitative losses are easy to determine and report since they constitute a physical reduction in the marketable volume and can be easily measured. Globally, quantitative grain losses are estimated to be ten to twenty percent of the total volumes [6]. Qualitative losses refer to deterioration of nutritional quality, safety and grade. Qualitative loss data is hardly ever reported. But it is a loss that must concern everyone. For example, the levels of qualitative losses due to aflatoxin contamination, although not reported, have dire long-term effects on health. Chronic dietary exposure to low doses of aflatoxin is a known risk factor for liver cancer and other health-related issues. Over the past decades, significant forms and resources have been allocated to increase food production. For example, 95% of the research investments during the past 50 years were reported to have focused on increasing productivity and only five percent directed towards reducing losses ([11]; [12]; [13]). Increasing agricultural productivity is critical for ensuring global food and nutrition security, but this may not be sufficient [1]. Food production is currently being challenged by limited land, water and increased, weather variability due to climate change. To sustainably achieve the goals of food and nutrition security, food availability needs to be also increased through reductions in the post-harvest process at farm, retail and consumer levels [1]. Food losses do not merely reduce food available for human consumption but also cause negative externalities to society through costs of waste management, greenhouse gas production and loss of scarce resources used in their production [1]. Food loss is estimated to be equivalent to 6-10% of human-generated greenhouse gas emissions ([7]; [14]). A significant contributor of this problem is through methane gas generation in landfills where food waste decomposes anaerobically [15]. The United States Environmental Protection Agency (USEPA) reports that in the United States of America about 31 million tonnes of food waste accounted for 14% of the 2008 solid waste produced in the country [16] costs roughly US$1.3 billion to landfill ([17];[15]). A study by the Institute of Mechanical Engineers indicates that current agricultural practice uses 4.9 Gha (global hectares or 4,931million hectares) of the total 14.8 Gha (14,894 million hectares) of land surface on Earth [18]. Agricultural production in addition uses 2.5 trillion m3 of water per year and over 3% of the total global energy consumption [18]. With estimated food losses of about 30-50% of total production, this translates to wasting 1.47 – 1.96Gha of arable land, 0.75 – 1.25 trillion m3 of water and 1% to 1.5% of global energy [18].
Given the significant role food loss reductions could have toward sustainably contributing to global food security, it is important to have reliable measures of these losses. Unfortunately, most of the available post-harvest loss and food waste estimates are based on the anecdotal stories with few actual measured or estimated numbers. Moreover, these numbers, in turn, feed into estimates of food availability which are widely used in food and nutrition security assessments and policy analysis. The history of food waste is closely linked to globalization [19]. In an evermore networked world, supply chains get longer, and everything is available everywhere – Indian mangoes in Germany and American apples in Indonesia – the whole year round. On that often-long journey from farm to table, food is lost or wasted at every stage, and fresh foods such as fruits, vegetables, dairy and meat are particularly vulnerable[19].
Food loss typically refers to food lost in earlier stages of production such as harvest, storage and transportation. Food waste refers to items that are fit for human consumption but thrown away, often at supermarkets or by consumers. Food loss and waste and their ripple effects on the environment, society and economy have become an increasing global concern. With every gram of food produced and then wasted, there are associated wastages in water, energy, capital, nutrition and other related resources.
The total volume of water used to produce food that is lost on an annual basis is equivalent to the yearly flow of the Volga River in Russia which is (8060 cubic metres/second); it is three times the volume of Lake Geneva (89 km3)[19]. In terms of land, 28% of the global arable area (1.4 billion hectares of land) is used to produce food that is lost or wasted annually[19]. Furthermore, food waste has been noted to immensely contribute to climate change through greenhouse gas (GHG) emissions. The carbon footprint of wasted food is approximately 3.3 billion tonnes of carbon dioxide (CO ) released into the atmosphere 2 on an annual basis.
In Africa, PHL account for up to a fifth of harvests, thereby negating the benefits of investments aimed at ensuring increased productivity towards food and nutrition security[19]. The Inaugural Biennial Review Report (BRR) released by the African Union Commission in January 2018 shows that the continent is not on track in terms of its efforts towards the Reduction of PHL, having scored zero in 2017, against a target of 10% towards the 2025 target [19]. A key challenge related to this performance on postharvest management (PHM) is the inability of countries to capture and record data on physical losses, perhaps as a result of unavailability or weak national monitoring and evaluation systems as highlighted by the 2017 BRR. Generally, any loss of produce translates to lost production resources, mainly land, water, energy and inputs. It is also lost income for the various actors in the supply chain. A 2011 World Bank study estimated the value of African grain losses alone stands at USD4 billion. It has been shown that 470 million smallholder farmers suffer a decline of 15% income, while 25% of freshwater and 20% of farmland is wasted in unconsumed food [6].
Conclusion
This research review found out that estimates from [21] suggest that as much as 37% of food produced in Africa is lost between production and consumption. These high estimates have motivated international attention to PHL. Yet interventions typically focus on improving on-farm grain storage techniques for small-scale farmers. The estimates use extrapolation from purposively sampled (and often older) case studies that may focus on areas where PHL is largest[94]. More and better quantification of (on-farm) grain loss is needed (which can then be compared with the costs of improved post-harvest practices). Also needed is abetter understanding of farmers’ behaviour in adopting improved post-harvest technologies.
Globally, energy in agriculture has concentrated on increasing food production (95% of research over the last fifty years was focused on improving production. A paltry 5% was directed to research on reduction of PHL. The consequences for this has been the loss and wasted food to the tune of 1.3 billion metric tonnes per year, worldwide. This is enough to feed 1.6 billion people annually. The cost of this is about US$2.6 trillion per year. To this add the ethical and environmental costs which are difficult to quantify.
PHL contribute to high food prices by removing part of the food from the supply chain. Although food availability and accessibility can be increased by upping production, improving distribution and reducing the losses. However, production resources including land, water and energy are limited and inelastic.
A major obstacle in achieving PHL mitigation is the lack of clear understanding of the real magnitude of PHL, which makes it impossible to measure progress against any loss reduction goals. Uncertain estimates of PHL, coupled with imprecise understanding of the points in value chains where the losses occur as well as the socio-economic factors for the losses could end in policy errors and sub-optimal choices of mitigation approaches. VI. RECOMMENDATIONS There are several implications for policymakers, farmer organisations and agricultural industries. First, policymakers might rethink the net social welfare impact of PHL and be very methodical when assessing the causes. The opportunity costs of mitigating loss appear to be a third critical component to causes, in addition to uncontrollable events and technical inadequacies. Second, policy goals of fixed levels of PHL may be unrealistic without a proper understanding of the management context facing farmers, especially a system of production that includes multiple cropping.
Below are a brief summary of recommendations to betaken note of: Reducing PHL presents a cost-effective opportunity to improve resource efficiency in the food system and help mitigate the risks of natural resource depletion. In addition, reducing PHL would ensure more sustainable use of resources thereby putting less pressure on ecosystems, including soils and water. Addressing fish losses and waste, including discards is necessary to reduce the impacts of fisheries on aquatic ecosystems. Food losses in low-income countries are often connected to the lack of access to energy, particularly in the post-harvest phase. In order to make the transition towards sustainable food value chains that reduce both food losses and fossil fuel dependence in food systems, it is necessary to upscale clean or low-carbon technologies. Increased deployment of the technologies that use renewable energy would improve the sustainability of food systems, while reducing losses in developing countries. Efforts that reduce PHL of food are essential to enhance global climate action because of their collective contributions to three overall objectives: mitigating climate change by reducing GHG emissions associated with PHL; strengthening resilience to cope with climate change and increasing net production output; PHL reduction measures, in the contest of resilient and low-emission food systems, should therefore be integrated into climate change strategies and action plans as additional opportunities towards achieving mitigation and adaptation objectives. Reducing the amount of food that is lost or wasted calls for harmonized policies and integrated food system approaches that consider all risks, challenges, opportunities and potential trade-offs. Creating an enabling environment requires a re-examination of existing policies and regulatory frameworks, including incentive schemes. Identifying policy gaps and ensuring policy coherence across sectors is key to inclusive pleasing processes for addressing the drivers and underlying causes of PHL. Bringing together governments, food producers and investors can help identify challenges and opportunities for addressing inefficiencies in food systems and accelerate the deployment of sustainable technologies in food value chains. Combining such efforts with sustainable practices and consumption patterns can pave way towards safeguarding environmental resources and ultimately needing the goals and targets set out in the 2030 Agenda for Sustainable Development. Emphasis must be targeted at improving access to finance, while encouraging appropriate policy incentives and building management capacities.
For the future of food in Africa the following are recommended [20] and [21]: Food production will have to increase by 60%, while adapting to climate change 80% of the necessary production increases must come from intensification and not from opening up new land. 70% of African population will live in urban centres; extending food value chains Loss reduction can be a more resource efficient response to food shortage than increased production. Silver lands of Zambia are working with smallholder farmer communities to help provide grain storage facilities (silos). They reckon that in Sub-Saharan Africa, around 30% of food is lost during handling and storage, this is compared to six percent in North America. Poor storage facilities force farmers to often sell at hardest time when prices are at their lowest thus eroding their returns. Providing key storage infrastructure is essential to prevent PHL and ensure supply of quality grains. VII. ETHICS APPROVAL AND CONSENT TO PARTICIPATE Human and Animal Rights No animal/humans were used for studies that are base of this research.
Consent for Publication Not applicable.
CONFLICT OF INTEREST The author (Douglas Ncube PhD) certify that he has no affiliations with or involvement in any organisation or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership; employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
