We can cut carbon emissions by one third by replacing fossil fuels with renewable energy sources for electricity and heat production." –Lester R. Brown, Janet Larsen, Jonathan G. Dorn, and Frances Moore, Time for Plan B: Cutting Carbon Emissions 80 Percent by 2020
Chapter 9. Feeding Eight Billion People Well: Raising Land Productivity
Investment in agriculture by international development agencies has lagged badly over the last two decades. Some of the stronger developing countries, such as China and Brazil, moved ahead on their own, but many suffered. 2
Prior to 1950, expansion of the food supply came almost entirely from expanding cropland area. Then as frontiers disappeared and population growth accelerated after World War II, the world quickly shifted to raising land productivity. Between 1950 and 2008 grain yields nearly tripled, climbing from 1.1 to 3.2 tons per hectare. In one of the most spectacular achievements in world agricultural history, farmers doubled the grain harvest between 1950 and 1973. Stated otherwise, during this 23-year-span, growth in the grain harvest equaled that of the preceding 11,000 years. 3
After several decades of rapid rise, however, it is now becoming more difficult to raise land productivity. From 1950 to 1990, world grainland productivity increased by 2.1 percent per year, but from 1990 until 2008 it went up by only 1.3 percent annually. 4
Gains in land productivity have come primarily from three sources—the growing use of fertilizer, the spread of irrigation, and the development of higher-yielding varieties. As farmers attempted to remove nutrient constraints on crop yields, fertilizer use climbed from 14 million tons in 1950 to 175 million tons in 2008. In some countries, such as the United States, several in Western Europe, and Japan, fertilizer use has leveled off. It may do so soon in China and India as well, for each of them now uses more fertilizer than the United States does. 5
Farmers remove soil moisture limits on crop yields by irrigating, using both surface water from rivers and underground water. World irrigated area increased from 94 million hectares in 1950 to 278 million hectares in 2000. Since then, it has increased very little. Future gains from irrigation will likely come more from raising irrigation efficiency than from expanding irrigation water supplies. 6
The third source of higher land productivity is higher-yielding varieties. The initial breakthrough came when Japanese scientists succeeded in dwarfing both wheat and rice plants in the late nineteenth century. This decreased the share of photosynthate going into straw and increased that going into grain, often doubling yields. 7
With corn, now the world’s largest grain crop, the early breakthrough came with hybridization in the United States. As a result of the dramatic advances associated with hybrid corn, and the recent, much more modest gains associated with genetic modification, corn yields are still edging upward. 8
Most recently, Chinese scientists have developed commercially viable hybrid rice strains. While they have raised yields, the gains have been small compared with the earlier gains from dwarfing the rice plant. 9
There are distinct signs of yields leveling off in the higher-yield countries that are using all available technologies. With wheat, the first of the big three grains to be cultivated, it appears that once the yield reaches 7 tons per hectare it becomes difficult to go much higher. This is borne out by the plateauing of wheat yields at that level in France, Europe’s largest wheat producer, and in Egypt, Africa’s largest producer. 10
In the Asian rice economy, the highest yields are in Japan, China, and South Korea. All three have moved above 4 tons per hectare, but moving above 5 tons is difficult. Japan reached 4 tons per hectare in 1967 but has yet to reach 5 tons. In China, rice yields appear to be plateauing as they approach the Japanese level. South Korea has leveled off right around 5 tons. 11
Among the three grains, corn is the only one where the yield is continuing to rise in high-yield countries. In the United States, which accounts for 40 percent of the world corn harvest, yields are now approaching an astonishing 10 tons per hectare. Even though fertilizer use has not increased since 1980, corn yields continue to edge upward as seed companies invest huge sums in corn breeding. Iowa, with corn yields among the world’s highest, now produces more grain than Canada does. 12
Despite dramatic past leaps in grain yields, it is becoming more difficult to expand world food output. There is little productive new land to bring under the plow. Expanding the irrigated area is difficult. Returns on the use of additional fertilizer are diminishing in many countries.
Agricultural endowments vary widely by country. Achieving high grain yields means having an abundance of soil moisture, either from rainfall, as in the corn-growing U.S. Midwest and wheat-growing Western Europe, or from irrigation, as in Egypt, China, and Japan. Countries with chronically low soil moisture, as in Australia, much of Africa, and the Great Plains in North America, have not experienced dramatic grain yield advances. U.S. corn yields today are nearly four times wheat yields, partly because wheat is grown under low rainfall conditions. India’s wheat yields are now close to double those of Australia not because India’s farmers are better but because they have more water to work with. 13
Some developing countries have dramatically boosted farm output. In India, after the monsoon failure of 1965 that required the import of a fifth of the U.S. wheat crop to avoid famine, a highly successful new agricultural strategy was adopted. It included replacing grain ceiling prices that catered to the cities with grain support prices to encourage farmers to invest in raising land productivity. The construction of fertilizer plants was moved from the government sector into the private sector, where the plants could be built quickly. The high-yielding wheats that were developed in Mexico and that had already been tested in India were introduced by the shipload. This combination of positive developments enabled India to double its wheat harvest in seven years. No major country before or since has managed to double the harvest of a staple food in such a short period of time. 14
A similar situation developed in Malawi, a country of 15 million people, after the drought of 2005 that left many hungry and some starving. In response, the government issued coupons to small farmers, entitling them to 200 pounds of fertilizer at a greatly reduced price, and free packets of improved seed corn, the national food staple. Costing some $70 million per year and funded partly by outside donors, this fertilizer and seed subsidy program helped nearly double Malawi’s corn harvest within two years, leading to an excess of grain. Fortunately this grain could be profitably exported to nearby Zimbabwe, which was experiencing acute grain shortages. 15
Some years earlier, a similar initiative had been undertaken in Ethiopia. It too led to a dramatic growth in production. But because there was no way either to distribute the harvest to remote areas or to export the surplus, this led to a crash in prices—a major setback to the country’s farmers and to Ethiopia’s food security. This experience also underlines a major challenge to agricultural development in much of Africa, namely the lack of infrastructure, such as roads to get fertilizer to farmers and their products to market. 16
In the more arid countries of Africa, such as Chad, Mali, Mauritania, and Namibia, there is not enough rainfall to raise yields dramatically. Modest yields are possible with improved agricultural practices, but in many of these countries there has not been a green revolution for the same reason there has not been one in Australia—namely, low soil moisture and the associated limit on fertilizer use.
The shrinking backlog of unused agricultural technology and the associated loss of momentum in raising yields is worldwide, signaling a need for fresh thinking on how to raise cropland productivity. One way is to breed crops that are more tolerant of drought and cold. U.S. corn breeders have developed corn varieties that are more drought-tolerant, enabling corn production to move westward into Kansas, Nebraska, and South Dakota. For example, Kansas, the leading U.S. wheat-producing state, now produces more corn than wheat. Similarly, corn production is moving northward in North Dakota and Minnesota. 17
Another way to raise land productivity, where soil moisture permits, is to expand the area of land that produces more than one crop per year. Indeed, the tripling in the world grain harvest from 1950 to 2000 was due in part to widespread increases in multiple cropping in Asia. Some of the more common combinations are wheat and corn in northern China, wheat and rice in northern India, and the double or triple cropping of rice in southern China and southern India. 18
The spread of double cropping of winter wheat and corn on the North China Plain helped boost China’s grain production to where it now rivals that of the United States. Winter wheat grown there yields 5 tons per hectare. Corn also averages 5 tons. Together these two crops, grown in rotation, can yield 10 tons per hectare per year. China’s double-cropped rice yields over 8 tons per hectare. 19
Forty or so years ago, grain production in northern India was confined largely to wheat, but with the advent of the earlier maturing high-yielding wheats and rices, wheat could be harvested in time to plant rice. This combination is now widely used throughout the Punjab, Haryana, and parts of Uttar Pradesh. The wheat yield of 3 tons and rice yield of 2 tons combine for 5 tons of grain per hectare, helping to feed India’s 1.2 billion people. 20
In North America and Western Europe, which in the past have restricted cropped area to control surpluses, there may be some potential for double cropping that has not been fully exploited. In the United States, the end of idling cropland to control production in 1996 opened new opportunities for multiple cropping. The most common U.S. double cropping combination is winter wheat with soybeans in the summer. Since soybeans fix nitrogen in the soil, making it available to plants, this reduces the amount of fertilizer applied to wheat. 21
A concerted U.S. effort to both breed earlier-maturing varieties and develop cultural practices that would facilitate multiple cropping could boost crop output. If China’s farmers can extensively double crop wheat and corn, then U.S. farmers—at a similar latitude and with similar climate patterns—could do more if agricultural research and farm policy were reoriented to support it.
Western Europe, with its mild winters and high-yielding winter wheat, might also be able to double crop more with a summer grain, such as corn, or an oilseed crop. Elsewhere, Brazil and Argentina, which have extensive frost-free growing seasons, commonly multicrop wheat or corn with soybeans. 22
One encouraging effort to raise cropland productivity in Africa is the simultaneous planting of grain and leguminous trees. At first the trees grow slowly, permitting the grain crop to mature and be harvested; then the saplings grow quickly to several feet in height, dropping leaves that provide nitrogen and organic matter, both sorely needed in African soils. The wood is then cut and used for fuel. This simple, locally adapted technology, developed by scientists at the International Centre for Research in Agroforestry in Nairobi, has enabled farmers to double their grain yields within a matter of years as soil fertility builds. 23
Another often overlooked issue is the effect of land tenure on productivity. In China, this issue was addressed in March 2007 when the National People’s Congress passed legislation protecting property rights. Farmers who had previously occupied their land under 30-year leases would gain additional protection from land confiscation by local officials who, over the years, had seized land from some 40 million farmers, often for construction. Secure land ownership encourages farmers to invest in and improve their land. A survey by the Rural Development Institute revealed that farmers in China with documented land rights were twice as likely to make long-term investments in their land, such as adding greenhouses, orchards, or fishponds. 24
In summary, while grain production is falling in some countries, either because of unfolding water shortages or spreading soil erosion, the overwhelming majority still have a substantial unrealized production potential. The challenge is for each country to fashion agricultural and economic policies in order to realize its unique potential. Countries like India in the late 1960s or Malawi in the last few years give a sense of how to exploit the possibilities for expanding food supplies.
2. U.N. Food and Agriculture Organization (FAO), “FAO-OECD to Weigh Investments Against Hunger,” press release (Rome: 4 May 2009); Shenggen Fan and Mark W. Rosegrant, Investing in Agriculture to Overcome the World Food Crisis and Reduce Poverty and Hunger (Washington, DC: International Food Policy Research Institute (IFPRI), June 2008).
3. USDA, PS&D, op. cit. note 1; U.N. Population Division, World Population Prospects, The 2008 Revision Population Database, electronic database, at esa.un.org/unpp, updated 11 March 2009.
4. USDA, PS&D, op. cit. note 1.
5. Historical data compiled by Worldwatch Institute from FAO, Fertilizer Yearbook (Rome: various years), and by Earth Policy Institute from International Fertilizer Industry Association (IFA), IFADATA, electronic database at www.fertilizer.org/ifa/ifadata/search, retrieved 3 February 2009; current data from Patrick Heffer, Medium-Term Outlook for World Agriculture and Fertilizer Demand 2007/08 – 2012/13 (Paris: IFA, June 2008), p. 34, and from IFA, Fertilizer Consumption 2007/08 – 2012/13 Country Reports (Paris: June 2008), pp. 8, 19, 21.
6. Irrigation data for 1950–60 compiled from Lester R. Brown, “Eradicating Hunger: A Growing Challenge,” in Lester R. Brown et al., State of the World 2001 (New York: W. W. Norton & Company, 2001), pp. 52–53; data for 1961–2007 from FAO, ResourceSTAT, electronic database at faostat.fao.org, updated April 2009.
7. Lester R. Brown, Increasing World Food Output: Problems and Prospects, Foreign Agricultural Economic Report No. 25 (Washington, DC: USDA, Economic Research Service (ERS), 1965), pp. 13–14; L. T. Evans, Crop Evolution, Adaptation and Yield (Cambridge, U.K.: Cambridge University Press, 1993), pp. 242–44.
8. USDA, PS&D, op. cit. note 1; Margriet F. Caswell et al., Agricultural Biotechnology: An Economic Perspective (Washington, DC: USDA, ERS, 1998), p. 19; Kenneth G. Cassman and Adam J. Liska, “Food and Fuel for All: Realistic or Foolish?” Biofuels, Bioproducts and Biorefining, vol. 1, no. 1 (2007), pp. 18–23.
9. World Food Prize Foundation, “A World-Brand Name: Yuan Longping, The Father of Hybrid Rice,” at www.worldfoodprize.org/laureates/yuan-spotlight.htm, viewed 15 July 2009.
10. USDA, PS&D, op. cit. note 1; FAO, FAOSTAT, electronic database, at faostat.fao.org, updated June 2009.
11. USDA, PS&D, op. cit. note 1.
12. IFA, IFADATA, op. cit. note 5; IFA, Country Reports, op. cit. note 5, pp. 8, 19, 21; USDA, PS&D, op. cit. note 1; USDA, National Agricultural Statistics Service (NASS), Crop Production 2008 Summary (Washington, DC: January 2009), p. 5.
13. USDA, PS&D, op. cit. note 1.
14. Lester R. Brown, Eco-Economy (New York: W. W. Norton & Company, 2001), pp. 145–46; Thomas R. Sinclair, “Limits to Crop Yield?” in American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Physiology and Determination of Crop Yield (Madison, WI: 1994), pp. 509–32; USDA, PS&D, op. cit. note 1.
15. U.N. Population Division, op. cit. note 3; World Bank, “Malawi, Fertilizer Subsidies and the World Bank,” at web.worldbank.org, viewed 14 July 2008; Celia W. Dugger, “Ending Famine, Simply by Ignoring the Experts,” New York Times, 2 December 2007; USDA, PS&D, op. cit. note 1.
16. Ben Block, “African Leaders Pursue ‘Malawi Miracle’,” Eye on Earth, at www.worldwatch.org, 26 May 2009.
17. USDA, op. cit. note 12, pp. 5, 13.
18. USDA, PS&D, op. cit. note 1; 1950 data from USDA, in Worldwatch Institute, Signposts 2001, CD-ROM (Washington, DC: 2001).
19. Jorge Sanchez and Jiang Junyang, China Grain and Feed Annual 2009 (Beijing: USDA, March 2009); USDA, PS&D, op. cit. note 1.
20. A. Govindian, India Grain and Feed Annual 2009 (New Delhi: USDA, February 2009); USDA, PS&D, op. cit. note 1; U.N. Population Division, op. cit. note 3.
21. Richard Magleby, “Soil Management and Conservation,” in USDA, Agricultural Resources and Environmental Indicators 2003 (Washington, DC: February 2003), Chapter 4.2, p. 14.
22. USDA, PS&D, op. cit. note 1; Randall D. Schnepf et al., Agriculture in Brazil and Argentina (Washington, DC: USDA ERS, 2001), pp. 8–10.
23. Pedro Sanchez, “The Climate Change–Soil Fertility–Food Security Nexus,” summary note (Bonn: IFPRI, 4 September 2001).
24. Edward Cody, “Chinese Lawmakers Approve Measure to Protect Private Property Rights,” Washington Post, 17 March 2007; Jim Yardley, “China Nears Passage of Landmark Property Law,” New York Times, 9 March 2007; Zhu Keliang and Roy Prosterman, “From Land Rights to Economic Boom,” China Business Review, July–August 2006.
Copyright © 2009 Earth Policy Institute