Growth and Change in Food Demands

The average Chinese farm is about the size of an American football field. On one hand this seems appropriate, given the abundance of labor, lack of capital, and already high unemployment in rural China. On the other hand, there is debate over the position of Prosterman et al (1996) who contend the average Chinese farm family is relatively well off. In our May 1997 visit with Professor Guang Zhou, then President of the Chinese Academy of Science and now Vice President of the Peoples Congress, we were urged to consider the plight of the rural Chinese people, many of whom by most accounts are struggling with near-poverty living conditions.

Rice and wheat are two major grains grown in China which historically have been staples in the Chinese diet. Yields of rice have increased by 100 kg ha^-1y^-1 in the past 30 years, although the growth in yields has slowed to 30 kg ha^-1y^-1 since 1984. Similarly, yields of wheat increased by an average of 83 kg ha^-1y^-1 from 1960 to 1993, but only 50 kg ha^-1y^-1 from 1984 to 1993.

Wang and Zhao (1995), who use global climate models to project changes in vegetation that would accompany global warming by 2050, estimate that areas available for triple cropping would increase by 22%, double cropping would be unchanged, and area suitable for only single cropping would be reduced by 23%. They conclude that agricultural production could increase in 2050 in northeast China due to more favorable temperatures and double cropping replacing single cropping patterns. Eastern China, however, in spite of higher precipitation, would experience higher evaporative losses due to higher temperature. They assert that lack of water availability will curtail yield increases that might accompany a generally more favorable climate. The combination of higher evaporative demand coupled with triple cropping in regions now hosting only two crops annually surely will put significant demands on irrigation water supplies.

The several global climate model simulations that I have scanned suggest a warmer and drier future for China. Copious sulfur emissions will have a short-term cooling effect on the climate but over the long term, CO₂-driven warming likely will prevail. Some models suggest less-than-present spring and early summer rainfall, which could jeopardize the required natural rain and irrigation-water supplies for a more intensified agricultural production system. There is a clear need for higher resolution information on China's future climate. Our IITAP Project to Intercompare Regional Climate Simulations (Takle, 1995), funded by the US Electric Power Research Institute is developing the capacity to provide information on climate change that is critically needed for agricultural and water-resource planners. We have initiated discussions with scientists from the Chinese National Climatic Center about deploying the latest regional models to simulate China's future climate.

Of possibly more severe consequence than long-term averages is the potential for year-to-year fluctuations, particularly in agricultural production, due to extreme meteorological events. This became quite apparent in 1991 when floods in Anhui and Sichuan caused possibly tens of billions of RMB damage, affected 80% of the people in Anhui, marooned 9 million people and destroyed 1.5 million homes (Smil, 1996b). Our climate models also could be used to study future occurrences of such events.

Farmland is being lost in China due to urbanization and other non-crop use from 1986-93 at a rate of about 500,000 ha y^-1, which is an area about 4 times the size of Story County per year. Most of China's agriculture relies on irrigation, and this will likely increase with increases in multiple cropping and use of more marginal lands. However, Wang (1989) reported that 20% of the 878 major rivers in China already are polluted to the point that the water is unsuitable even for irrigation. These and other constrains will put limitations of growth of food production in China.

Table 1 gives a comparison between China and the US in per-capita use of grain and consumption of livestock products. Americans account for nearly 3 times the grain consumption of the Chinese. Although average Chinese consumption of pork nearly matches US levels, consumption of poultry, milk, eggs, and especially beef, lag far behind US amounts. Other Asian countries having moved up the development path have dramatically increased consumption of livestock products, principally beef. Table 2 gives an estimate of grain requirements for various animal products. Beef stands out as a particularly grain-intensive means of producing food for human consumption. Since 1980, consumption in all categories of Table 1 has increased in China (Smil, 1996a). Brown (1994) contends this raises a red flag to international food markets.

To put this issue into perspective, I have calculated the potential impact of increased beef consumption in China (Takle, 1998). Supplying every Chinese citizen one MacDonald's Quarter Pounder per week would require half of the US corn crop and a sewage treatment plant for cattle wastes 4.5 times the entire aggregate US human wastewater treatment capacity (if we treated animal wastes like human wastes). If they were all raised in Iowa, we would have over half a million cattle per county.

There are significant opportunities for improving Chinese agriculture to enhance its internal food-producing capacity. These include:

• More efficient use of irrigation (both pricing structure and reduced water losses)
• More efficient production, distribution, and application of fertilizers
• Reduction in grain loss during harvesting, threshing, drying, storage, transport and processing
• Better nutrition for more efficient animal feeding
• More efficient alcohol production
• Efficient management/utilization of waste streams

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