III. Problems with the First Green Revolution
Despite the production successes, the first green revolution faced or created a number of problems. The high yield varieties were very input intensive, especially in the use of pesticides and fertilizers, and they worked best on good soils with a high degree of water control (both irrigation and drainage). This input intensity raised many questions about the "sustainability" of high yield agriculture.
Second, the green revolution was mostly about rice and wheat. There were few gains for root-crops (cassava, potatoes, yams, sweet potatoes), traditional legumes such as lentils and cowpeas, fruits and vegetables, even other cereal grain staples suitable for the semiarid tropics, such as millets and sorghum. Thus most of Africa and a good deal of the Indian subcontinent, where the biggest problems and challenges of hunger and poverty exist, were left out of the first green revolution.
Third, productivity gains using traditional breeding techniques have apparently been exhausted for rice and wheat. "Best practice" yields at research and experiment stations have been flat for over a decade. There is even some evidence of "frontier yields" declining, which may be a problem of soil quality.6 Most of what we know about plants is how they function above the ground.
Hence, growth in cereal yields at the farm level in developing countries has slowed down significantly, from 2.9%/y from 1967 to 1982 to only 1.9%/y from 1982 to 1997. The International Food Policy Research Institute projects that these yields will grow at only 1.2%/y from 1997 to 2020.
Most fundamentally, because of the strong links between agricultural growth and performance in the rest of the economy, overall economic growth has slowed down as well. Indeed, a recent paper by Gaiha and Imai calculated the rate of growth in both agriculture and the overall economy required to meet the MDG.7 To cut the "head-count index of poverty" in half, economic growth must reach 3.6–4.4%/y, and, as both a component and stimulant, agricultural growth must reach 4.0–4.5%/y. But the actual growth rates from 1985 to 2000 for these two variables were only 0.6 and 0.3%/y, respectively. In summary, this brief review of recent agricultural history and poverty alleviation argues that we must find a way to get agriculture moving.8