2011年-世界发展银行全球_Missing_Food___The_Case_of_Postharvest_Grain_Losses_in_Sub-Saharan_Africa_116页_1mb

Summary of "Missing Food: The Case of Postharvest Grain Losses in Sub-Saharan Africa"

Core Content

This report, published by the World Bank in April 2011, focuses on postharvest grain losses (PHL) in Sub-Saharan Africa (SSA). It highlights the economic, technical, and social dimensions of PHL and emphasizes the need for integrated, system-based interventions to reduce these losses and improve food security and rural livelihoods.

Main Findings

1. Magnitude of PHL in SSA

• Grains remain a crucial component of food security and rural livelihoods in SSA.
• Approximately 70% of typical incomes in SSA come from crop production, with grain crops accounting for 37% of this.
• Annual grain production in SSA is estimated at 112 million tons, although records are incomplete for some countries and crops.
• Physical losses of grain (before processing) can range from 10 to 20%, with nutritional losses (e.g., aflatoxin contamination) and monetary losses (e.g., loss in sales value) also significant.
• Based on APHLIS estimates, PHL in Eastern and Southern Africa is valued at US$1.6 billion per year, which is 13.5% of total grain production value (US$11 billion).
• Assuming similar losses in Central and West Africa, PHL in SSA could reach US$4 billion annually, or 15% of the estimated US$27 billion grain production value.

2. Impact of PHL

• PHL reduces real income for consumers and wastes valuable inputs such as fertilizer, water, and labor.
• It contributes to high food prices by reducing the supply of grains.
• PHL has environmental implications, as resources used to produce unutilized grain are wasted.
• Nutritional and health risks arise from contaminated grain, especially with aflatoxins.

3. Causes of PHL

• Technical causes include poor harvesting methods, inadequate drying and storage techniques, and lack of appropriate storage facilities.
• Governance-related causes involve weak policies, lack of warehouse receipt systems, and mismanagement in grain handling and storage.
• Social and cultural factors also play a role, such as preferences for traditional storage methods and gender-specific adoption challenges.

Key Technologies and Practices

1. Promising Technologies

• Hermetic storage solutions: Sealed bags, metal silos, and mud silos.
• Improved drying techniques (e.g., yard drying, crib drying).
• Warehouse receipt systems (WRS) to improve market access and grain security.
• Mechanized harvesting and cleaning equipment to reduce losses during processing.

2. Successful Interventions

• Community cereal banks have emerged in recent years, offering a model for collective grain storage.
• Triple bagging of cowpea has been successfully implemented in West and Central Africa.
• Metal silos have shown promise in Central America but face challenges in adoption in SSA.

Responses to PHL Reduction

1. Government and Donor Interventions

• Historically, PHL reduction was seen as a stand-alone intervention aimed at improving household food security.
• This approach was dominant in the 1970s and 1980s but has since evolved to include market-oriented strategies.

2. Market-Oriented Approaches

• These approaches focus on linking farmers to markets and improving value chain coordination.
• Emphasis is placed on technical assistance and improved farm management.
• Warehouse receipt systems and institutional arrangements have been introduced to support better grain handling and storage.

3. Challenges in Adoption

• Many technologies have failed due to:
  • Financial unsustainability
  • Misidentification of key constraints
  • Lack of cultural acceptability
  • Assumptions of rapid change

Lessons Learned and Way Forward

1. Key Lessons

• Incentive structures are critical for the adoption of PHL reduction technologies.
• Socio-cultural factors must be considered, especially gender dimensions.
• Learning alliances and collaboration among stakeholders are essential for sustainable change.
• Systemic interventions that address the entire grain value chain are more effective than isolated efforts.

2. Recommendations

• Develop comprehensive value chain strategies that include both on-farm and off-farm improvements.
• Improve access to finance and technical capacity for smallholder farmers.
• Promote cultural acceptability of new storage technologies.
• Establish learning alliances to foster knowledge sharing and collaboration.
• Support institutional and policy reforms to enhance market access and grain security.

Conclusion

Postharvest grain losses in SSA remain significant and underestimated, with substantial economic, social, and environmental impacts. While various technologies and practices are available to reduce PHL, their adoption is low, often due to financial, cultural, and institutional barriers. A system-based approach, integrating technical, economic, and social perspectives, is essential for effective PHL reduction and improving food security. The report underscores the importance of collaboration, policy support, and community engagement in addressing this critical issue.