Post-Harvest Management: A Cornerstone of Sustainable Food Systems

Hunger continues to affect millions of people across the world. The World Food Programme says about 309 million people in 71 countries are facing acute hunger. In Tanzania, malnourishment persists despite economic growth and improved food systems, and the 2024 Global Hunger Index scores the country as having a level of hunger that is serious (though neither alarming nor extremely alarming).

Given the scale of global hunger, it doesn’t come as a surprise that the fight against hunger was the top priority in the previous Millennium Development Goals (MDGs), which included the eradication of extreme poverty and hunger by 2015 as the top priority, MDG 1. Today, among the 17 Sustainable Development Goals (SDGs), “end hunger, achieve food security and improved nutrition and promote sustainable agriculture” remains a priority as SDG 2.

Increasing food production

Over the last decades, the international development cooperation community focused on achieving these goals through increasing food production (output) where hunger persisted. A good example is the Green Revolution in India, which started in the 1960s and resulted in tremendous increases of crop yields in famine-prone India and Bangladesh. In 2006 this concept was reinforced in Africa by setting up the Alliance for a Green Revolution in Africa (AGRA).

While the Green Revolution resulted in increased agricultural outputs in many areas, the success in some other areas was modest. This was partly because poorer farmers were not able to invest in and sustain the high external inputs (e.g., seeds, which were often hybrid, as well as chemical fertilizers and synthetic pesticides) required to grow the new crop varieties. At the same time, it was observed that many farmers, especially subsistence farmers and smallholders, lost considerable amounts of their crops due to poor post-harvest management.

Although reliable figures are difficult to obtain, a 2014 World Bank research paper estimated post-harvest losses for maize in sub-Saharan Africa at below 10%, which is considerably lower than estimates that put these losses at about 30%. However, 10% post-harvest losses are still too high, especially considering that such losses often disproportionally affect small farmers who are already coping with low yields on their farms.

New practices and policies to support post-harvest management

Many donor agencies for development cooperation switched to or added post-harvest management initiatives to their programs in the fight against hunger. The aim was to minimize post-harvest losses and thereby increase the net amount of food available.

The Swiss Agency for Development and Cooperation (SDC) promoted improved post-harvest management in Sub-Saharan Africa through several initiatives, including the Grain Postharvest Loss Prevention (GPLP) project, which was implemented by Helvetas in Tanzania between 2013 and 2020.

Helvetas’ work relies on the Inclusive Systems Approach to strive for impact that is socially, economically and politically sustainable—and that lasts and scales beyond our engagement. Now we’re reflecting on the GPLP project to see if the approach worked as intended, asking: What is the post-harvest management currently like in Tanzania, four years after the closure of the project? Have there been significant systemic changes as well as behavioral changes? What did Helvetas’ Tanzania programs do next to support food and agriculture related initiatives?

When GPLP phased out in 2020—the same year the World Bank announced that the Tanzanian economy had been upgraded from low to lower-middle income status—a National Post-harvest Management Strategy (NPHMS) existed together with an action plan. Outlined for a period of 10 years (2019-2029), this first NPHMS underpinned Tanzania’s understanding of post-harvest management, stating “there is now global consensus that mitigating food losses that occur between harvest and consumption offers the single most enormous opportunity to reduce hunger.”

To support the implementation of the strategy and to strengthen the coordination and cooperation between different post-harvest management stakeholders, the Tanzania Post-harvest Management Platform was formed. Both the strategy and the platform were tangible achievements the GPLP project considerably contributed to. Without GPLP, it stands to reason that neither the post-harvest strategy nor the platform would have been in place by the end of 2020.

From a technical standpoint, the project promoted a wide range of practices that included harvesting in the field and handling and storing on-farm until the consumption by the farm household or the sale in the market. Examples of good post-harvest management practices included:

• Transporting the crop immediately after harvest to the farm instead of ripening and drying it in the field where it risks getting contaminated and/or damaged by pest
• Drying the produce at the farm properly on dry, clean ground (preferably using a tarpaulin)
• Storing the maize under hermetic conditions (e.g., in metal silos instead of in porous polypropylene bags)

The latter was a successful component in an earlier post-harvest management initiative by SDC in Central America.

Post-harvest management was taken up by the government of Tanzania as a technical field that it integrated into the Department of Mechanization and Value Addition within the Ministry of Agriculture. The topic continues receiving adequate attention by the government, for example, under the Tanzania Initiative for Preventing Aflatoxin Contamination (TANIPAC) and through funding by the multi-donor Global Agriculture and Food Security Program.

Although there have been systemic changes with the government that give due attention to post-harvest management, overall adoption and application of post-harvest management practices by smallholder maize producers have remained low. Some critical early conclusions by Helvetas (see “Additional Reading” section) from the GPLP initiative have been that:

• The message of “gaining food and income” through “reducing losses” is difficult to convey. It’s easier to show an increase of food and income through an increase in crop yields.
• Although post-harvest practices such as proper cleaning and drying of the produce as well as storing it on farm are easy to apply, the adoption of respective technologies and/or equipment were often too expensive for smallholder farmers.
• The economic gains from post-harvest loss prevention were probably smaller than assumed, and hence not attractive enough for farmers.
• Women were more receptive to post-harvest management, linking it directly to increased home consumption and food security, while men perceived only limited economic gains.

Helvetas’ Tanzania country program capitalized on the expertise gained in post-harvest management and secured new initiatives like the project “Save Safe Food” under the Danida Market Development Partnership program and the applied research initiative “Evidence-based Scaling of Improved On-Farm Storage Among Smallholders,” which was implemented by a consortium led by the Informatics and Sustainability Research Group at the University of Zurich  and funded among others by the Liechtensteinische Entwicklungsdienst.

A game-changing storage solution

The continued engagement by the government as well as Helvetas in post-harvest management has happened in parallel with an evolution in the design of post-harvest initiatives (particularly in the objectives), where in addition to the quantitative aspect of reducing post-harvest losses the qualitative aspect of food quality came in. This also signified a change from pure food security aspects to additional food safety elements. In this regard, the government nowadays focuses on the prevention of aflatoxin contamination (e.g., through the TANIPAC initiative), while Helvetas puts emphasis on the pesticide-free on-farm storage of maize for home consumption by resource-poor farm households.

There remains a rather large risk for small farmers to be subjected to post-harvest losses within a particular agro-ecological zone, for a specific crop or due to weather hazards. But these risks to small farm households producing food crops for home consumption are not always that obvious. Therefore, creating awareness for post-harvest loss prevention and promoting adequate measures is quite difficult to realize, especially in an environment where there is still room to increase production.

The food quality and food safety aspects are less related to immediate post-harvest measures, and instead linked to issues that occur later because of poor storage of food crops. GPLP promoted the use of (small) metal silos, allowing farmers to improve the storage of maize on their farms, though the investment in a silo turned out to be a stumbling block for most farmers due to the costs.

The arrival of hermetic bags provided farmers with a viable alternative to metal silos. Promoting the adoption of hermetic bags to store maize on-farm was the main objective of the Save Safe Food project. Farmers in Tanzania typically store their maize in porous polypropylene bags (the “conventional” bags that cost USD 0.35 each) but have to treat the maize with poisonous storage chemicals. Storing maize in a hermetic bag doesn’t require any pesticides, though the price per bag is higher (USD 1.55).

“I can use these hermetic bags to store maize for up to three years without using chemicals,” said Daniel Bupere, a farmer from Majimoto village in Mpimbwe DC. “These bags have been a huge help to us farmers in terms of increasing our income and food security.”

The on-farm storage of grain (mainly maize) in hermetic bags is an effective and viable pro-poor post-harvest management measure to increase food security as well as food safety and should be further promoted among smallholders. Helvetas Tanzania advocates for this through its project “Evidence-based Scaling of Improved On-Farm Storage Among Smallholders,” which calls for the exemption of the hermetic bags from value added tax (VAT) to make them more affordable. This storage solution has produced many learnings, including:

• Investing in five hermetic bags allows a small farmer to keep the maize required for home consumption on the farm without compromising on quality, especially since no storage pesticides are required.
• In the past, due to a lack of adequate storage solutions, farmers sold most of their crop just after harvesting at low prices, only to buy maize later in the year for their own consumption at higher prices and probably lower quality.
• If some surplus remains on the farm, smallholders may still sell it later at a good price (due to its good quality), although the market is still hesitant to pay a premium for maize stored without chemicals.
• Many rural households with school-aged children contribute maize to the school feeding program. Therefore, good quality, pesticide-free maize also contributes to good quality, nutritious and healthy food for students.
• Large (commercial) maize farmers are less interested in investing in hermetic bags, partly because of the high costs involved since they would need a large number of bags. They prefer to store their maize either at the (fumigated) warehouse of a cooperative or they aim to directly sell the crop after harvesting due to a lack of storage capacity.

Given these learnings, further promotion of hermetic bags among mostly resource-poor smallholder farmers is fully justified. Helvetas engages at the system and policy level to reduce the price of the bags (e.g., through VAT exemption, since in Tanzania agricultural inputs such as seeds, fertilisers and pesticides are VAT exempt) and to look for payment models to make this investment more affordable, such as through deferred payment systems.

Creating lasting systems for food security

Looking back at Helvetas’ decades of post-harvest engagement in Tanzania, no particular intervention shifted the sector—but numerous new practices and policies did entrench post-harvest management into systems. Today, that work has expanded from rural to urban settings and includes healthy food initiatives like the Inclusive Cities for Nutrition project in Mbeya.

For a lower middle-income country like Tanzania, addressing food security and food safety remains a priority for a considerable part of the population—especially the 30% of children under 5 who are stunted from malnutrition. We should not forget that in Tanzania, where about 60% of the population are engaged in agriculture, these food producers also make up 60% of the country’s food consumers. Even AGRA, which started its journey based on the Green Revolution, now frames their activities as far more than a focus on increased output; like Helvetas, their efforts aim to sustainably grow Africa’s food systems.

About the Authors

Felix Bachmann is the former Country Director of Helvetas Tanzania.

Agnes Mahembe is the Programme Officer Food and Nutrition Security for Helvetas Tanzania.

Zacharia Nyahende is a Project Officer at Helvetas Tanzania.

Additional Reading

• Policy Advocacy in Post-Harvest Management
• The Post-Harvest Management Business Model
• Access to Finance Model to Boost Investment in Improved On-farm Post-harvest Storage Technologies
• Introducing a New Grain Storage Technology in Tanzania - The Case of Metal Silos at Household Level
• Adoption of Improved Post-Harvest Management Practices and Technologies in the Central Corridor of Tanzania