1. Walker, Kenneth R., “Provincial grain output in China, 1952–57: a statistical compilation,” Research Notes and Studies, No. 3 (London: Contemporary China Institute, School for Oriental and African Studies, University of London, 1977)Google Scholar; Field, Robert Michael and Kilpatrick, James A., “Chinese grain production: an interpretation of the data,” The China Quarterly (06 1978), pp. 369–84Google Scholar;

2. Among these were Field and Kilpatrick, Audrey Donnithorne, Kenneth Walker and Bruce Stone.

3. It should be noted in passing that Chinese conception of “foodgrain equivalence” differs from that of the Food and Agriculture Organization of the United Nations (FAO). China divides all root and tuber crops by five to approximate grain equivalent weight, although data for root and tuber crops converted as such now exclude cassava. FAO estimates grain equivalent weight by applying differential factors to natural weight statistics for each root and tuber crop, based on comparative data on caloric content by unit weight: white potatoes–20%; sweet potatoes–25%; cassava–30·3%.

4. Tongjiju, Zhongguo Guojia (Statistical Bureau of China), Zhongguo tongji nianjian–1983 (Statistical Yearbook of China–1983) (Xianggang: Xianggang jingji daobao shechuban, 1983), p. 583Google Scholar;

5. See, e.g. Stone, Bruce, “China's 1985 foodgrain production target: issues and prospects” in Tang, Anthony M. and Stone, Bruce, Food Production in the People's Republic of China, Research Report No. 15 (Washington, D.C.: International Food Policy Research Institute, 1980), pp. 88 and 157Google Scholar; for efforts at establishing consistency among provincial data see Walker, Kenneth R., “China's grain production 1975–80 and 1952–57: some basic statistics,” The China Quarterly, No. 86 (06 1981), pp. 241 and 243–47CrossRefGoogle Scholar;

6. According to the survey of 16,786 farms directed by John Lossing Buck between 1929 and 1933,0–2% of cropped area was sown with taro and 01% with yams. South China, where taro and yam cultivation is most extensive, was somewhat under-represented in Buck's sample. But, of course, other areas where these crops are not grown at all (e.g., the Manchurian provinces of the north-east and Inner Mongolia) were completely excluded [Buck, John Lossing, Land Utilization in China (Study) (Nanking: Nanking University Press, 1973)]Google Scholar;

7. See e.g. Dilishi, Anhui Shifan Daxue (Anhui Normal University, Geography Department) (ed.), Anhui nongye dili (Agricultural Geography of Anhui) (Hefei: Anhui kexue jishu chubanshe, 1980), pp. 36 and 40Google Scholar; and Yanjiusuo, Zhongguo Kexueyuan Chengdu Dili (Chinese Academy of Sciences, Chengdu Institute of Geography) (ed.), Sichuan nongye dili (Agricultural Geography of Sichuan) (Chengdu: Sichuan renmin chubanshe, 1980), p. 71Google Scholar; and Kexueyuan, Henansheng Nongyeting Henansheng Nonglin (Henan Province Agricultural Office, Henan Academy of Agriculture and Forestry Sciences) (eds.), Hongshu (Sweet Potato) (Zhengzhou: Henan renmin chubanshe, 1980), p. 1Google Scholar;

8. See, for example, Bianxiezu, Guangxi Nongye Dili, Guangxi nongye dili, pp. 64, 68 and 76Google Scholar; and Yanjiusuo, Zhongguo Kexueyuan Chengdu Dili, Sichuan nongye dili, pp. 71–72 and 82–83Google Scholar; and Henansheng Nongyeting Henansheng Nonglin Kexueyuan, Hongshu.

9. Sweet potatoes probably entered China originally from India and Burma through Yunnan Province. Two books published, respectively, in 1563 and 1574 discuss sweet potatoes in Yunnan. In 1594 overseas Chinese troops brought sweet potatoes back to the Fujian Province coast. There seem to be other distinct contacts in the mid 17th and mid 18th centuries. Nongyeting, Fujiansheng (Fujian Province Agricultural Office), Ganshu (Sweet Potato) (Fuzhou: Fujian kexue jishu chubanshe, 1980), p. 3Google Scholar; and Kexueyuan, Henansheng Nongyeting Henansheng Nonglin, Hongshu, pp. 1 and 2Google Scholar; The earliest recorded mention of white potatoes in China was in a book published in Fujian Province in 1700 which described potato cultivation in northern Fujian and southwestern Zhejiang Provinces: Heilongjiang Nongye Kexueyuan, Yanjiusuo, Keshan Nongye (Heilongjiang Province Academy of Agricultural Sciences), Malingshu zaipei jishu (White Potato Cultivation Technology) (Beijing: Nongye chubanshe, 1982), p. 7Google Scholar;

10. Kexueyuan, Henansheng Nongyeting Henansheng Nonglin, Hongshu, p. 5Google Scholar;

11. According to Yanjiusuo, Zhongguo Kexueyuan Chengdu Dili, Sichuan nongye dili, p. 72Google Scholar; area sown with hongtiao in 1977 was 18·9 million mu and production was 8–34 billion jin (on a grain equivalent basis). Area sown with shulei was 29·852 million mu in 1979 while production was 11·62 billion jin. See, Gang, He et al. (eds.), Zhongguo Nongyebu (Chinese Ministry of Agriculture), Zhongguo nongye nianjian, 1980 (Agricultural Yearbook of China, 1980) (Beijing: Nongye chubanshe, 1980), p. 105Google Scholar;

12. E.g. according to crop-specific statistics in Hanxian, Luo et al. (eds.), Zhongguo nongye nianjian, 1981, p. 26Google Scholar; Shanghai Municipal Area grew only 200 hectares of root and tuber crops in 1980. Yet as late as June 1977, The Vegetable Farming Systems Delegation organized by the United States National Academy of Sciences was given data indicating that about 20% of Shanghai's vegetable area was sown with root and tuber crops [Plucknett, Donald L. and Beemer, Halsey (eds.), Vegetable Farming Systems in the People's Republic of China (Boulder: Westview, 1981)]Google Scholar; According to a 1959 distribution, more than 1/4 of these plantings were likely to be radishes and turnips, never included among “foodgrain” roots and tubers [Yanjiusuo, Shanghai Nongye, Shanghai sucai pinzhongzhi (Shanghai: Shanghai nongye yanjiusuo, 1959)]Google Scholar; If “foodgrain” root and tuber crops sown among vegetable plantings were included in crop-specific root and tuber data, the above information would imply that less than 1500 hectares of land in Shanghai Municipal Area is sown with vegetable crops. This is surely a considerable underestimate. The 200 hectares of “foodgrain” root and tuber crop plantings therefore refer only to field crops and not to roots and tubers cultivated among vegetable plantings.

13. Gang, He et al. (eds.), Zhongguo Nongyebu, Zhongguo nongye nianjian, 1980, p. 102Google Scholar;

14. Kexueyuan, Zhongguo, Dili Yanjiusuo, Jingji Dili Yanjiushi (Chinese Academy of Sciences, Institute of Geography, Economic Geography Research Room), Zhongguo nongye dili zonglun (A General Discussion of China's Agricultural Geography) (Beijing: Kexue chubanshe, 1980), p. 129Google Scholar; The source verifies that virtually all of China's cassava is grown in Guangdong and Guangxi.

15. Jingzhi, Sun (ed.), Huanan dichu jingji dili (Economic Geography of South China) (Beijing: Kexue chubanshe, 1959)Google Scholar;

16. Zhongguo Kexueyuan, Dili Yanjiusuo, Zhongguo nongye dili zonglun.

17. Quance, Leroy, Director, Statistics Division, Food and Agriculture Organization of the United Nations, correspondence, 5 07 1983Google Scholar;

18. Muqiao, Xue et al. (eds.), Zhongguo jingji nianjian (1982) (Almanac of China's Economy (1982)) (Beijing: Jingji guanli zazhi shechuban, 1982), p. VII–47Google Scholar;

19. Tongjiju, Zhongguo Guojia, Zhongguo tongji nianjian–1981, p. 394Google Scholar;

20. Kawano, Cock and, “Cassava in China,” pp. 1–2Google Scholar;

21. Guangxi nongye dili indicates that area planted with cassava in 1976 was 214% and foodgrains (excluding cassava) 82·66% of total sown area (p. 64). Total foodgrain sown area in 1976 was 4,334,666 hectares (summed from data for constituent districts on p. 70).

22. Ibid. pp. 64, 76 and 83.

23. Shen, Yan (ed.) Nongye tongji, p. 105Google Scholar;

24. Tongjiju, Zhongguo Guojia, Zhongguo tongji nianjian – 1983, p. 583Google Scholar;

25. Wiens, Thomas B., “Agricultural statistics in the People's Republic of China,” in Eckstein, Alexander (ed.), Quantitative Measures of China's Economic Output (Ann Arbor: University of Michigan Press, 1980), pp. 44–107 and 275–326Google Scholar;

26. See, supra fn 5.

27. For the most part no chemical fertilizers are allocated for root and tuber crop production except on state farms. However, in several provinces such as Sichuan, some proportion of available chemical fertilizers are allocated on the basis of total sown area regardless of crop. But even in these cases, the fertilizer may not necessarily be applied to root and tuber crops. In fact, it is often said that potatoes produced with chemical fertilizers do not taste good. In general, if fertilizers are applied to root and tuber crops, they are more likely organic manures. However, the requirements in this regard are substantial. Research in Henan Province suggests that sweet potato yields in the range of 18·75–26·25 tons per hectare require 30–45 tons per hectare of manure. (Kexueyuan, Henansheng Nongyeting Henansheng Nonglin, Hongshu, p. 74Google Scholar;)

28. FAO, 1981 FAO Production Yearbook.

29. Nongyeting, Fujiansheng, Ganshu, p. 4Google Scholar;

30. Buck, John Lossing, Land Utilization in China, Atlas, p. 82Google Scholar;

31. Fujiansheng Nongyeting, Ganshu.

32. Cock James, director, Cassava Program, International Center for Tropical Agriculture, conversation, Palmira, Colombia, April 1983; and correspondence, 24 June 1983.

33. Cassava cultivation in Dongguan county declined from 47,361 mu in 1978 to 42,252 mu in 1982. In Fucheng commune within the county, area sown with cassava fell from 7,500 mum 1980 to 5,506 mu in 1981, but recovered to 6,515 mu in 1982. On the other side of the Delta, in Taishan county, large-scale cassava cultivation began after 1979 along with a concerted expansion of pig-raising. Average yields throughout Dongguan county have increased from 11·7 tons per hectare in 1978 to 15·8 tons in 1982, reflecting more than weather differences. In the Delta, cassava is sometimes processed to a powder and mixed with other fodder items, most notably corn imported from the United States. The above data were given to Graham Johnson during visits of Guangdong in December 1981 and summer 1983 (Graham Johnson, Department of Anthropology and Sociology, University of British Columbia, correspondence, 19 September 1983); Cock and Kawano, “Cassava in China.”

34. Cock and Kawano, “Cassava in China;” James Cock, conversation and correspondence.

35. Kawano, Cock and, “Cassava in China,” p. 1Google Scholar; Graham Johnson, correspondence, 19 September 1983.

36. Trairatvorakul, Prasarn, “Food demand and the structure of the Thai food system,” Ph.D. dissertation, Harvard University, Graduate School of Business Administration, 1981, pp. 229–31Google Scholar;

37. European Community, Analytic Tables of Foreign Trade, Vol. A (Luxembourg: Statistical Office of the European Communities, various years)Google Scholar compiled in Koester, Ulrich, Policy Options for the Grain Economy of the European Community: Implications for Developing Countries, Research Report No. 35 (Washington, D.C.: IFPRI, 1982), p. 34Google Scholar;

38. Corbet, Hugh, “Excesses of the CAP and Thailand's manioc,” The World Economy, 09 1982, pp. 208–210Google Scholar; Siamwalla, Ammar, “More aspects of the manioc agreement between Brussels and Bangkok,” The World Economy, 03 1983, pp. 89–90Google Scholar; Grote, H., “Mūssen Tierhalter fur Fehlentwicklungen biissen?” “Must animal breeders suffer from misguided farm policies,” DLG Mitteilungen (German Agricultural Association Reports), 07, pp. 415–19Google Scholar;

39. The Thai farm-gate price for cassava more than doubled in 1979 and 1980 compared with the 1978 level. See Thailand, Ministry of Agriculture and Cooperatives, Selected Economic Indicators Relating to Agriculture (Bangkok: MAC), p. 58Google Scholar and Thailand, MAC, Agricultural Statistics of Thailand, Crop Year 1980/81 (Bangkok: MAC, 1981), p. 24Google Scholar; This would have placed the Thai farm-gate price above the Chinese compulsory procurement price for cassava.

40. Koester, Policy Options.

41. “Manioc imports into E.C. up 27 per cent in year; more by China,” Milling and Baking News, 8 December 1981.

42. Reuter International News Services cited in “EC may raise China manioc quota,” Hong Kong Standard, 26 October 1982.

43. The extraction rate for dried cassava is typically around 40% of fresh root weight. Pelletized cassava may be 89% of dried weight (Trairatvorakul, “Food demand and the Thai food system”).