Roughly 7.2 billion people now inhabit the Earth, and by 2050, that number could reach 9.6 billion. Adequately feeding them could require increasing food production by two-thirds or more. In part, this is because food is poorly distributed around the world, with widespread obesity and food waste among wealthier populations, but an estimated 870 million people undernourished. Also, as incomes rise, people tend to eat more meat, and animal feed requires a disproportionate amount of crops.
Humankind has met such a challenge before, with the Green Revolution, which dramatically reduced hunger in the last half-century even as the world population more than doubled. The approaches that raised yields before, however, cannot significantly raise them beyond current levels, and the environmental impact of agriculture is exceeding a “safe operating space” for humanity. Thus, attention is increasingly focused on closing yield gaps –the difference between potential yields, and the actual yields that farmers achieve on their fields.
Large yield gaps are most apparent in Sub-Saharan Africa, which benefited very little from the Green Revolution, but significant yield gaps also remain across the low-income countries and among lower-income farmers in less-poor countries. There appears to be a particularly large untapped potential to raise yields substantially by improving water partitioning on rainfed lands. Yet decades of experience with agricultural development have shown that the approaches taken to date fall short not only on environmental sustainability, but also in terms of social sustainability, as the benefits are not distributed equitably, and access to land, technology and inputs are all major barriers for the poor.