How to reduce postharvest crop losses in the agricultural supply chain
Posted on November, 19, 2021 at 08:18 am
The global population is projected to reach ten billion by 2050.1 This will require a 56 percent increase in food production from 2010 levels,2 but studies have warned that agricultural production worldwide will have trouble meeting this additional demand for food.3 Challenges include constraints on crop yields due to decreasing marginal productivity gains, soil degradation, extreme weather events, soil-nutrient deficiencies, and increased pestilence.4
Despite increasing pressures on food supply, about one-third of the total food produced for human consumption is wasted.5 More than 40 percent of this loss occurs throughout commodity supply chains at the postharvest level (between harvest and the consumer) in many developing economies, including those in Africa, Asia, and Latin America.6 In response to these losses, some regions have set ambitious targets to reduce this waste. For example, member states of the African Union have pledged to halve postharvest food losses by 2025.7
Reducing postharvest grain loss could lead to a virtual land gain equivalent to three times the cropland area of France. In this article, we discuss the extent of postharvest losses around the world and propose steps stakeholders could take to reduce waste. Such measures could lead to cost savings for grain-trading companies, as well as to potential land gains for countries at a high risk of grain loss.
Sizing the crop losses
While postharvest losses affect all major crops, including fruits, vegetables, and pulses, losses in rice, wheat, and other cereal grains—which account for 70 percent of all calories consumed8 —are particularly striking. For instance, one study estimated that up to 400 million metric tons of grain, or 20 percent of global grain production, were lost in 2018.9
In Malawi, 20 percent of maize grain was lost after harvest in 2015, equivalent to 550,000 tons of maize and worth $150 million.10 For smallholder farmers in Asia, rice postproduction processes from harvesting to milling are estimated to incur losses of 20 to 30 percent of the rice grain produced.11 In the Arab world, 30 percent of cereal production is lost between production and consumption, with one study estimating that 34 percent of the total wheat supply in Jordan is lost, costing the country more than $100 million per year.12 In Brazil, postharvest grain losses are estimated to range from 5 to 30 percent, mainly driven by poor storage conditions.13 Globally, we estimate that the value of lost grain may be worth up to $60 billion.
A key challenge in reducing grain losses is that the magnitude of postharvest grain loss varies significantly depending on factors such as geographic location, climate, and the prevalence of pests. Moreover, the severity of losses varies at different stages of the supply chain, complicating the adoption of a unified approach to the issue (Exhibit 1). In Peru, for instance, where postharvest losses are estimated to be between 15 and 27 percent, 90 percent of farmers dry their crops in the field, directly on the ground, which exposes them to rodents, birds, and insects.14 Meanwhile, in Thailand, where an estimated 19 percent of cereal grain is lost, the largest fraction of wastage occurs during handling and storage.15