POPULATION PRESSURE AND CROP ROTATIONAL CHANGES AMONG THE TIV OF NIGERIA

ABSTRACT

Shifting agriculture and the carrying capacity of the land are critically important in developing tropical areas. Signs of breakdown in shifting agricultural systems, such as decreasing crop yield and soil fertility, have long been recognized. Among the Tiv another indication of breakdown is manifest when proved cropping sequences are deliberately altered. The first dot map of Tiv population depicts high densities in the south-central part of the division, and the annual rate of increase of population among the Tiv is calculated at a little more than three percent. The areas of high population density display evidence of a degraded environment, and in these same areas a new crop rotational sequence has evolved. This altered cropping pattern, known as “bugh bu,”appears to be the result of the carrying capacity of the land being exceeded; it is found in areas with population densities of about 400 per square mile (154.4 per square kilometer).

Notes

1 This study is part of more extensive fieldwork conducted in 1960–1961 with support from the Foreign Field Research Program, National Academy of Sciences—National Research Council. I wish to express my appreciation to Professor Paul Bohannan, Northwestern University, for his comments on an early draft of the dot map of population of Tiv Division.

2 P. H. Nye and D. J. Greenland, The Soil Under Shifting Cultivation, Technical Communication No. 51, Commonwealth Bureau of Soils, Harpenden (Bucks, England: Commonwealth Agricultural Bureau, 1960), p. v.

3 P. Fordham, The Geography of African Affairs (Baltimore: Penguin Books, 1965), p. 103.

4 P. and L. Bohannan, The Tiv of Central Nigeria (London: International African Institute, 1953), p. 9.

5 Tax Records, Native Authority Tax Office, Gboko, Tiv Division, Nigeria. I wish to express my appreciation to Dr. Herman Gray, Sudan United Mission, Mkar Hospital, Tiv Division, for obtaining and forwarding to me the population data for fiscal years 1961–1962, 1966–1967 and 1967–1968.

6 Bohannan, op. cit., footnote 4, p. 9.

7 Demographic Yearbook 1967 (New York: United Nations, 1968), p. 100. A recent final report of the Committee on Education and Human Resource Development, Education and World Affairs, estimates that the rate of increase for the whole of Nigeria will reach approximately three percent in 1968; see Nigerian Human Resource Development And Utilization (New York: Education And World Affairs, 1967), p. 28.

8 The fiscal year runs from April 1 to March 31.

9 The data for fiscal year 1967–1968 were not included in the computation of the annual rate of increase, for the population increase during that single year was approximately six percent. Such a single-year increase is unlikely, and it can possibly be explained in terms of an error in the data, improvement of data collection methods and more accurate reflection of Tiv population, or by immigration. It seems unlikely that data collection methods improved and greater precision of population census occurred during a year when Nigeria was involved in internecine conflict. Rather, it seems likely that Tivland may have been the recipient of Tiv refugees from other parts of Nigeria in chaos and turmoil. As this sudden single-year increase in population reflects unusual conditions and because the Tiv have been emigrating, especially to Adamawa Province, computation of the average annual rate of population increase is based on 1959–1960 to 1966–1967 data.

10 Bohannan, op. cit., footnote 4, p. 10.

11 P. and L. Bohannan, Tiv Economy (Evanston, Illinois: Northwestern University Press, 1968), p. 93.

12 Bohannan, op. cit., footnote 4, p. 10; also, Dr. Herman Gray, Letter, April 26, 1968.

13 Bohannan, op. cit., footnote 4, p. 12.

14 Northern Nigeria: Density Of Population (Lagos: Federal Survey Department, 1958).

15 See footnote 5.

16 Although my data indicate that Mbaduku is the most densely populated of all the clan areas of Tiv Division, Professor Paul Bohannan in personal communication has noted that parts of Shangev Ya may be even more densely populated (letter, dated September 17, 1968); my data for Shangev Ya indicate a population density of 281 per square mile compared to 602 for Mbaduku. Despite the appreciably lower average density of population for Shangev Ya, Professor Bohannan's awareness of higher population densities in parts of the clan, such as Iyon, may be masked by areas of low density in the remainder of the clan area.

17 Tiv Division Notebook, Agricultural Office, Gboko, Tiv Division.

18 Bohannan, op. cit., footnote 4, p. 50.

19 Although my observations and information indicate that seventy-one mounds compose the traditional length of the “dechi,” the Bohannans (op. cit., footnote 11, p. 45) note the traditional length to be fifty-eight mounds; they also found a range from fifty to eighty in the number of mounds in the “dechi.”

20 Bohannan, op. cit., footnote 11, pp. 57–64.

21 Bohannan, op. cit., footnote 11, p. 48.

22 Bohannan, op. cit., footnote 11, p. 53.

23 Bohannan, op. cit., footnote 4, p. 53.

24 Bohannan, op. cit., footnote 11, p. 63.

25 H. Irving, “Fertilizer Experiments with Yams in Eastern Nigeria, 1947–1951,”Tropical Agriculture, Vol. 33 (1956), p. 68.

26 Nye and Greenland, op. cit., footnote 2, p. 96.

27 Nye and Greenland, op. cit., footnote 2, p. 96; also H. Vine, “Developments in the Study of Soils and Shifting Agriculture in Tropical Africa,” in R. P. Moss (Ed.), The Soil Resources Of Tropical Africa (Cambridge: Cambridge University Press, 1968), p. 105.

28 Nye and Greenland, op. cit., footnote 2, p. 96.

29 Nye and Greenland, op. cit., footnote 2, p. 96.

30 Nye and Greenland, op. cit., footnote 2, p. 109.

31 A number of studies have given insight into the ecology and viability of shifting agricultural systems in Africa; see, for example, P. De Schlippe, Shifting Cultivation in Africa: The Zande System of Agriculture (London: Routledge & Kegan Paul, 1956); M. Yudelman, Africans on The Land (Cambridge: Harvard University Press, 1964); W. Allan, The African Husbandman (Edinburgh: Oliver & Boyd, 1965); H. A. Oluwasanmi, Agriculture and Nigerian Economic Development (Ibadan: Oxford University Press, 1966). Other recent studies of population pressures and related problems have come from West Africa; see J. M. Hunter, “Population Pressure in a Part of the West African Savanna: A Study of Nangodi, Northeast Ghana,”Annals, Association of American Geographers, Vol. 57 (1967), pp. 101 14; J. M. Hunter, “The Social Roots of Dispersed Settlement in Northern Ghana,”Annals, Association of American Geographers, Vol. 57 (1967), pp. 338 49. The same author has suggested a method using sex ratios to determine the carrying capacity of the land under traditional systems of agriculture; see J. M. Hunter, “Ascertaining Population Carrying Capacity Under Traditional Systems of Agriculture in Developing Countries,”The Professional Geographer, Vol. 18 (1966), pp. 151 54.

32 W. A. Hance, “The Race Between Population and Resources,”Africa Report, Vol. 13 (1968), pp. 6 12. Hance argues that population pressure in Africa is a much more serious and widespread phenomenon than has generally been accepted. He contends that population densities less than twenty-six per square mile may, depending upon the environment and culture, result in population pressure on the land. Thus, recognizing the variable carrying capacity of the land that results from the combination of cultural and environmental factors, Hance notes evidence of degradation of the environment, deterioration of the diet, and increasing problems of nutrition and health, and he estimates that forty-seven percent of the area of Africa and forty-five percent of its population are now experiencing population pressure.