The key to China’s success was the economic reforms in 1978 thatdismantled its system of agricultural collectives, known as productionteams, and replaced them with family farms. In each village, the land wasallocated among families, giving them long-term leases on their piece ofland. The move harnessed the energy and ingenuity of China’s ruralpopulation, raising the grain harvest by half from 1977 to 1986. With itsfast-expanding economy raising incomes, with population growth slowing,and with the grain harvest climbing, China eradicated most of its hungerin less than a decade--in fact, it eradicated more hunger in a shorterperiod of time than any country in history.
While hunger has been disappearing in China, it has been spreadingthroughout much of the developing world, notably sub-Saharan Africa andparts of the Indian subcontinent. As a result, the number of people indeveloping countries who are hungry has increased from a recent historicallow of 800 million in 1996 to over 1 billion today. Part of this recentrise can be attributed to higher food prices and the global economiccrisis. In the absence of strong leadership, the number of hungry peoplein the world will rise even further, with children suffering the most.
Dealing with this problem requires addressing the long-term trends leadingto growth in demand for food outpacing growth in supply. One key to thethreefold expansion in the world grain harvest since 1950 was the rapidadoption in some developing countries of high-yielding wheats and rices(originally developed in Japan) and hybrid corn (from the United States).The spread of these highly productive seeds, combined with a tripling ofirrigated area and an 11-fold increase in world fertilizer use, tripledthe world grain harvest. Growth in irrigation and fertilizer useessentially removed soil moisture and nutrient constraints on much of theworld’s cropland.
Now the outlook is changing. Farmers are faced with shrinking supplies ofirrigation water, a diminishing response to additional fertilizer use,rising temperatures from global warming, the loss of cropland to nonfarmuses, rising fuel costs, and a dwindling backlog of yield-raisingtechnologies. At the same time, they also face fast-growing demand forfarm products from the annual addition of 79 million people a year, thedesire of some 3 billion people to consume more livestock products, andthe millions of motorists turning to crop-based fuels to supplementtightening supplies of gasoline and diesel fuel. Farmers and agronomistsare now being thoroughly challenged.
The shrinking backlog of unused agricultural technology and the associatedloss of momentum in raising cropland productivity are found worldwide.Between 1950 and 1990, world grain yield per hectare climbed by 2.1percent a year, ensuring rapid growth in the world grain harvest. From1990 to 2008, however, it rose only 1.3 percent annually. This is partlybecause the yield response to the additional application of fertilizer isdiminishing and partly because irrigation water is limited.
This calls for fresh thinking on how to raise cropland productivity. Oneway is to breed crops that are more tolerant of drought and cold. U.S.corn breeders have developed corn varieties that are moredrought-tolerant, enabling corn production to move westward into Kansas,Nebraska, and South Dakota. Kansas, the leading U.S. wheat-producingstate, has used a combination of drought-resistant varieties in some areasand irrigation in others to expand corn planting to where the state nowproduces more corn than wheat.
Another way of raising land productivity, where soil moisture permits, isto increase the area of multicropped land that produces more than one cropper year. Indeed, the tripling in the world grain harvest since 1950 isdue in part to impressive increases in multiple cropping in Asia. Some ofthe more common combinations are wheat and corn in northern China, wheatand rice in northern India, and the double or triple cropping of rice insouthern China and southern India.
The spread in double cropping of winter wheat and corn on the North ChinaPlain helped boost China’s grain production to where it rivaled that ofthe 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 riceannually yields 8 tons per hectare.
Forty years ago, North India produced only wheat, but with the advent ofthe earlier maturing high-yielding wheats and rices, wheat could beharvested in time to plant rice. This wheat/rice combination is now widelyused throughout the Punjab, Haryana, and parts of Uttar Pradesh. Thispractice yields a combined 5 tons of grain per hectare, helping to feedIndia’s 1.2 billion people.
A concerted U.S. effort to both breed earlier maturing varieties anddevelop cultural practices that would facilitate multiple cropping couldsubstantially boost crop output. If China’s farmers can extensively doublecrop wheat and corn, then U.S. farmers could do the same if agriculturalresearch and farm policy were reoriented to support it.
Elsewhere, Western Europe, with its mild winters and high-yielding winterwheat, might also be able to double crop more with a summer grain, such ascorn, or with a winter oilseed crop. Brazil and Argentina have an extendedfrost-free growing season that supports extensive multicropping, oftenwheat or corn with soybeans.
In many countries, including the United States, most of those in WesternEurope, and Japan, fertilizer use has reached a level where using more haslittle effect on crop yields. There are still some places, however, suchas most of Africa, where additional fertilizer would help boost yields.Unfortunately, sub-Saharan Africa lacks the infrastructure to transportfertilizer economically to the villages where it is needed. As a result ofnutrient depletion, grain yields in much of sub-Saharan Africa arestagnating.
One encouraging response to this situation in Africa is the simultaneousplanting of grain and leguminous trees. At first the trees grow slowly,permitting the grain crop to mature and be harvested; then the saplingsgrow quickly to several feet in height, dropping leaves that providenitrogen and organic matter, both sorely needed in African soils. The woodis then cut and used for fuel. This simple, locally adapted technology,developed by scientists at the International Centre for Research inAgroforestry in Nairobi, has enabled farmers to double their grain yieldswithin a matter of years as soil fertility builds.
Despite local advances, the overall loss of momentum in expanding foodproduction is unmistakable. It will force us to think more seriously aboutstabilizing population, moving down the food chain, and using the existingharvest more productively. Achieving an acceptable worldwide balancebetween food and people may now depend on stabilizing population as soonas possible, reducing the unhealthily high consumption of animal productsamong the affluent, and restricting the conversion of food crops toautomotive fuels. It also calls for a concerted effort to raise water useproductivity, similar to the gains achieved for land use, and to stabilizeclimate to avoid crop-withering temperatures and more frequent droughts.These efforts combined can help put us on the path to ensuring enough foodfor all.