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Agroforestry Systems

, Volume 13, Issue 1, pp 41–62 | Cite as

The potential of agroforestry to increase primary production in the Sahelian and Sudanian zones of West Africa

  • J.J. Kessler
  • H. Breman
Article

Abstract

The article presents a critical evaluation of agroforestry systems as regards their potential to increase primary production in the Sahelian and Sudanian zones of West Africa. The suggestion that trees would always and everywhere be profitable for the region will be counterproductive, the basis for disappointments and a waste of money. One has to consider carefully which properties of woody species could serve which objective, where and under what circumstances.

Primary production is limited by water availability in the north Sahelian zone only, elsewhere in the region nutrient availability is critical. Woody species influence the water balance via rainfall interception, the influence on evapotranspiration and the influence on water infiltration. The ultimate result for grasslands and crops depends upon local conditions; positive effects of windbreaks should be particularly attributed to protection against mechanical stress. Processes that influence nutrient availability under trees are those acting via redistribution, those reducing nutrient losses and those increasing soil fertility. Of the latter processes, serious limitations exist in the region concerned: nitrogen fixation is limited by phosphorus shortage mainly and deep rooting is very limited and so is possible uptake of minerals from deep soil layers.

The positive influence from woody species on soil fertility and primary production varies with average annual rainfall and soil type; its importance increases more than proportionally with rainfall going south. This positive influence is basically linked to the redistribution of nutrients and water, the internal nutrient cycling and the related enlarged plant-litter-soil nutrient cycle. Taking advantage of its effects is difficult and risks further depletion of soil fertility. Moreover, since woody species generally compete with the herb layer, it will be difficult to develop agroforestry in such a way that the positive influences are not overridden by negative ones. The potential to increase nutrient availability by agroforestry systems is limited and windbreaks are more beneficial under conditions which are rare in the region.

More research is needed to determine under which conditions introduction of woody species may be beneficial.

Key words

West Africa semi-arid areas trees and shrubs environmental protection agricultural productivity soil fertility nutrient cycling agrosilviculture silvo-pastoralism 

Le potentiel de l'agroforesterie pour augmenter la production primaire dans les zones sahélienne et soudanienne de l'Afrique de l'Quest

Résúme

Une évaluation critique de l'agroforesterie est présentée, en ce qui concerne la possibilité d'augmenter la production primaire dans les zones sahélienne et soudanienne de l'Afrique de l'Quest. La supposition que dans cette région des arbres seraient toujours et partout avantageux, n'est pas productive, mais plutôt une cause de déceptions et un gaspillage de ressources. Il faut se demander quelles propriétés des espéces ligneuses pourraient servir quels objectifs, oú et sous quelles conditions.

Seulement dans zoneone nord-sahélienne la production primaire est limitée par la disponibilité en eau; ailleurs c'est la disponsibilité des éléments nutritifs qui est la plus déterminante. Des espéces ligneuses influencent le bilan d'eau par l'interception de la pluie, par des modifications de l'evapotranspiration, et par une amélioration de l'infiltration d'eau. La conséquence pour les pâturages et les cultures dépend des conditions locales; les avantages de brise-vents dépendront notamment de la protection contre le stress mécanique. Des processus influençant la disponibilité des éléments nutritifs souls les arbres sont ceux agissant par la redistribution, par la diminution des pertes et par l'augmentation de la fertilité. Les derniers processus ont des limitations sérieuses dans la zone: la fixation d'azote est surtout limitée par le manque de phosphore et l'enracinemment profond paraît limité et ainsi la possibilité de profiter d'une disponibilité éventuelle de minéraux en profondeur.

L'influence positive des espéces ligneuses sur la fertilité du sol et la production primaire varie avec la pluviosité annuelle et le type de sol; son importance accroît plus que proportionnelle avec la pluviosité vers le sud. Cet influence positive est liée à la redistribution des éléments nutritifs et de l'eau, au recyclage interne des éléments nutritifs et le cycle agrandi y en être la conséquence, de ces éléments en plante-litière-sol. Pour profiter de ses effets est difficile et on risque l'épuisement supplémentaire des éléments nutritifs. En plus, suite à la concurrence entre les espéces ligneuses et la strate herbacée, c'est difficile à développer l'agroforesterie d'une telle façon que les avantages ne seront pas surpassés par les inconvéniences. Des brise-vents sont avantageux sous des conditions qui sont rares dans la zone.

Plus de recherche est nécessaire pour déterminer les conditions sous lesquelles l'introduction des espéces ligneuses peut être profitable.

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References

  1. 1.
    Ahuja, LD, Verma, CM, Sharma, SK and Lamba, TR (1978) Range management studies on the contribution of ground storey (grass) in afforested areas in arid regions. Annals of Arid Zone 17: 304–310Google Scholar
  2. 2.
    Anomymous (1980) A handbook of research. The Charleville Pastoral Laboratory, Department of Primary Industries, Queensland, Australia. 89 ppGoogle Scholar
  3. 3.
    Beer, J (1988) Litter production and nutrient cycling in coffee (Coffea arabica) or cacao (Theobroma cacao) plantation with shade trees. Agroforestry Systems 7: 103–114Google Scholar
  4. 4.
    Belsky, AJ, Amundson, RG, Duxbury, JM, Riha, SJ, Ali, AR and Mwanga, SM (1989) The effects of trees on their physical, chemical, and biological environments in a semi-arid savanna in Kenya. Journal of Applied Ecology 26: 1005–1024Google Scholar
  5. 5.
    Berckmoes, WML, Jager, EJ and Koné, Y (1988) L'intensification agricole au Mali-Sud. Souhait ou réalité? Farming systems research/Extension Symposium. Univ. ofArkansaa, Fayetteville, Arkansas, USA. 9–12 Oct. 1988. 27 ppGoogle Scholar
  6. 6.
    Bille, JC (1977) Etude de la production primaire nette d'une écosystéme sahélien. Travaux et documents de l'ORSTOM no. 65. ORSTOM, Paris. 82 ppGoogle Scholar
  7. 7.
    Boutrais, J (1980) L'arbre et le boeuf en zone soudano-guinéenne. In: L'arbre en Afrique Tropicale. Cah. ORSTOM, sér. Sci. Hum., Vol XVII, nos. 3–4: 233–246Google Scholar
  8. 8.
    Breman H et de Ridder N (Eds.) (in prep.) Manuel sur les pâturages des pays sahéliens. Karthala, Paris. 500 ppGoogle Scholar
  9. 9.
    Breman, H and Traoré (1986) Analyse des conditions de l'élevage et propositions de politiques et de programmes. République de Mali. Sahel D(87)302, OCDE/CILSS/Club du Sahel, Paris. 243 ppGoogle Scholar
  10. 10.
    Charney, JG (1975) Dynamics of deserts and drought in the Sahel. Quart J Met Soc 101: 193–202Google Scholar
  11. 11.
    Charreau, C and Vidal, P (1965) Influence de l'Acacia albida Del. sur le sol, nutrition minérale et rendements des mils Pennisetum au Sénégal. Agron Tropicale 20: 600–626Google Scholar
  12. 12.
    Christie, EK (1975) A note on the significance of Eucalyptus populnea for buffel grass production in infertile semi-arid rangelands. Trop Grasslands 9: 243–246Google Scholar
  13. 13.
    Connor, RW, Newman, JC and Cunningham, GM (1969) Soil erosion and pasture degeneration in central Australia. III. The assessment of grazing capacity. J of the Soil Conserv Service of NSW 25: 225–250Google Scholar
  14. 14.
    Connor, DJ (1983) Plant stress factors and their influence on production of agroforestry plant associations. In: Huxley PA, ed, Plant Research and Agroforestry. pp 249–256. ICRAF, NairobiGoogle Scholar
  15. 15.
    CTFT (1988) Faidherbia albida Del. Monographie. Centre Technique Forestier Tropical. Nogent-sur-Marne, France. 72 ppGoogle Scholar
  16. 16.
    Dancette, C and Poulain, JF (1969) Influence of Acacia albida on pedoclimatic factors and crop yields. African Soils 14: 143–184Google Scholar
  17. 17.
    Dommergues, YR (1987) The role of biological nitrogen fixation in agroforestry. In: Steppler, HA and Nair PKR, eds, Agroforestry, a decade of development. pp 245–271. ICRAF, NairobiGoogle Scholar
  18. 18.
    Ebersohn, JP and Lucas, P (1965) Trees and soil nutrients in southwestern Queensland. Qld J agric anim Sci 22: 431–435Google Scholar
  19. 19.
    FAO (1986) Brise-vent et rideaux abris avec référence particuliére aux zones séches. Cahier FAO Conservation 15. FAO, Rome. 385 ppGoogle Scholar
  20. 20.
    FAO (1978) Forestry for local community development. FAO Forestry Paper No. 7, Rome, Italy. 114 ppGoogle Scholar
  21. 21.
    Garcia-Moya, E and McKell, CM (1970) Contribution of shrubs to the nitrogen economy of a desert-wash plant community. Ecology 51(1): 81–88Google Scholar
  22. 22.
    Glover, PE (1951) The root systems of some British Somaliland plants I–IV. The East African Agricultural Journal Jan 1951: 154–172Google Scholar
  23. 23.
    Hall, DO and Coombs, J (1983) Biomass production in agroforestry for fuels and food. In: Huxley, PA, ed, Plant Research and Agroforestry. pp 137–160 ICRAF, NairobiGoogle Scholar
  24. 24.
    Houérou, HN Le (éd) (1980) Le rôle des ligneux fourragers dans les zones sahélienne et soudanienne. Colloque intern. fourragéres ligneux Afrique, 2–12 April 1980, Addis Ababa, Ethiopia. 491 ppGoogle Scholar
  25. 25.
    Huxley, PA (1983) The role of trees in agroforestry: some comments. In: Huxley, PA, ed, Plant Research and Agroforestry. pp 257–270. ICRAF, NairobiGoogle Scholar
  26. 26.
    ICRISAT (1989) ICRISAT West African Programs. Annual Report 1988. International Crops Research Institute for the Semi-arid Tropics, Niamey, Niger. 125 ppGoogle Scholar
  27. 27.
    Jonsson, K, Fidjeland, L, Maghambe, JA and Högberg, P (1988) The vertical distribution of fine roots of five tree species and maize in Morogoro, Tanzania. Agroforestry Systems 6: 63–69Google Scholar
  28. 28.
    Kang, BT, Wilson, GF and Lawson, LT (1984) Alley cropping: a stable alternative to shifting cultivation. IITA Special Publication. Ibadan, Nigeria. 22 ppGoogle Scholar
  29. 29.
    Kellman, M (1979) Soil enrichment by neotropical savanna trees. J of Ecology 67: 565–577Google Scholar
  30. 30.
    Kennard, DG and Walker, BH (1973) Relationships between the canopy and Panicum maximum in the vicinity of Fort Victoria. Rhod J of Agric Res 11: 145–153Google Scholar
  31. 31.
    Kerkhof, P (1990) Agroforestry in Africa, a survey of project experience. The PANOS Institute, London, UK. 216 ppGoogle Scholar
  32. 32.
    Kessler, JJ and Ohler, FMJ (1983) Interventions dans les pays du Sahel: une approche écologique. L'efficacité des mesures d'intervention dans les zones du Sahel et du Soudan en Afrique Occidentale et leur influence sur l'environment. Conservation de la Nature, LUW & CABO, Wageningen. 72 ppGoogle Scholar
  33. 33.
    Keulen, H van, Breman, H, Lek, TW van der, Menke, JW, Stroosnijder, L and Uithol, PWJ (1986) Prediction of actual primary production under nitrogen limitation. In: Modelling of extensive livestock production systems. Proc. of the ILCA/ARO/CABO Workshop, Bet Dagan, Israel. ILCA, Addis Ababa. 349 ppGoogle Scholar
  34. 34.
    Leyton, L (1987) Crop water use. In: Huxley, PA, ed, Plant Research and Agroforestry. pp 379–400. ICRAF, NairobiGoogle Scholar
  35. 35.
    Liu Xinmin, Wang Zhenxian, Tang Zongze and Zhao Yiefan (in press). Integrated transformation of desertified land in peripheral districts of cases. A case study in the northern part of the Linze oasis. In: Kosinksi La, Derrik Sewell WR and Chuanium W, eds, Land and Water Management: Chinese and Canadian perspectives. Institute of desert research, Academia Sinica, Lanzhou, ChinaGoogle Scholar
  36. 36.
    Lyles, L and Woodruff, NP (1960) Abrasive action of wind blown soil on plant seedlings. Agron Journal 52: 533–536Google Scholar
  37. 37.
    Maydell, H-J von (1987) Agroforestry in the dry zones of Africa: past, present and future. In: Steppler, HA and Nair, PKR, eds, Agroforestry, a decade of development. pp 89–116. ICRAF, NairobiGoogle Scholar
  38. 38.
    McTainsh, GH and Walker, PH (1982) Nature and distribution of harmattan dust. Z Geomorph 26(4): 417–435Google Scholar
  39. 39.
    Nair, PKR (1984) Soil productivity aspects of agroforestry. International Council for Research in Agroforestry, Nairobi. 85 ppGoogle Scholar
  40. 40.
    Penning de Vries, FWT et Djitèye, MA (Eds) (1982) La productivité des pâturages shahéliens. Une étude des sols, des végétations et de l'exploitation de cette ressource naturelle. Agric Res Rep 928. Pudoc, Wageningen. 525 ppGoogle Scholar
  41. 41.
    Pieri, C (1989) Fertilité des terres de savanes. Bilan de trente de recherche et de dévelopment agricoles au sud du Sahara. Ministère de la Coopération et CIRAD-IRAT. La Documentation Française, Paris. 444 ppGoogle Scholar
  42. 42.
    Poore, MED and Fries, C (1985) The ecological effects of Eucalyptus. FAO Forestry Paper 59. FAO, Rome. 87 ppGoogle Scholar
  43. 43.
    Pressland, AJ (1973) Rainfall partitioning by an arid woodland (Acacia aneura F. Muell) in south-western Queensland. Aust J Bot 21: 235–245Google Scholar
  44. 44.
    Radwanski, SA (1969) Improvement of red acid sands by the neem tree (Azadirachta indica) in Sokoto, North-Western State of Nigeria. Journal of Applied Ecology 6: 505–511Google Scholar
  45. 45.
    Raintree, JB and Warner, K (1986) Agroforestry pathways for the intensification of shifting cultivation. Agroforestry Systems 4: 39–54Google Scholar
  46. 46.
    Robinson, PJ (1986) The dependence of crop production on trees and forest land. In: Prinsley, RT and Swift MJ, eds, Amelioration of soil by trees, a review of current concepts and practices. pp 104–120. Commonwealth Science Council, LondonGoogle Scholar
  47. 47.
    Roose, E (1981) Dynamique actuelle de sols ferralitiques et ferrugineux tropicaux de l'Afrique occidentale. Travaux et Documents de l'ORSTOM 130. ORSTOM, Paris, 369 ppGoogle Scholar
  48. 48.
    Rosswall, T (Ed) (1980) Nitrogen cycling in West African Ecosystems. SCOPE/UNEP International Nitrogen Unit, Royal Swedish Academy of Sciences, Stockholm. 450 ppGoogle Scholar
  49. 49.
    Scott, RM (1961) Exchangeable bases of mature, well drained soils in relation to rainfall in East Africa. J of Soil Science, Vol 13(1): 1–9Google Scholar
  50. 50.
    Sidibé M (1976) Contribution à l'étude comparative de quelques modes de traitements appliqués sur les pâturages naturels du CNRZ de Sotuba. Mémoire de DEA, CPS/EN Sup, Bamako. 30 ppGoogle Scholar
  51. 51.
    Slatyer, RO (1961) Internal water balance of Acacia aneura F. Muell. in relation to environmental conditions. Plant-water relationships in arid and semi-arid conditions, Proc. of the Madrid Symposium, 24–30th Sept. '59. pp 137–146. UNESCO, ParisGoogle Scholar
  52. 52.
    SOW (1985) Potential food production increases from fertilizer aid. A9 case study of Burkina Faso, Ghana and Kenya. Vols I and II. CWFS, Wageningen. 48 & 77 ppGoogle Scholar
  53. 53.
    Sprent, JI (1986) Nitrogen fixing legume trees: problems and misconceptions. In: Prinsley, RT and Swift MJ, eds, Amelioration of soil by trees, a review concepts and practices. pp 68–71. Commonwealth Science Council, LondonGoogle Scholar
  54. 54.
    Stigter, CJ (1988) Microclimate management and manipulation in agroforestry. In: Wiersum, KF, ed, Viewpoints on Agroforestry, Second renewed edition. pp Agricultural University, WageningenGoogle Scholar
  55. 55.
    Togola, M, Cissé, MI and Breman, H (1975) Evolution de la végétation du ranch de Nioni depuis 1969. [Evaluation of vegetation on the Niono ranch since 1969.] In: Inventaire et cartographie des pâturages tropicaux Africains. Actes du colloque. Bamako-Mali, 3–8 mars 1975. pp 195–201. ILCA, Addis AbabaGoogle Scholar
  56. 56.
    Torres, F (1983) Role of woody perennials in animal agroforestry. Agroforestry Systems 1: 131–163Google Scholar
  57. 57.
    Walker, BH and Noy-Meir, J (1981) Aspects of the stability and resilience of savanna ecosystems. In: Huntley BJ and Walker, BH, eds, Ecology of tropical savannas. pp 560–608. Springer, BerlinGoogle Scholar
  58. 58.
    Weber, F and Hoskins, M (1983) Agroforestry in the Sahel. CILSS/USAID, NY, USA. 102 ppGoogle Scholar
  59. 59.
    White, F (1976) The vegetation map of Africa. Boissiera 24: 659–666Google Scholar
  60. 60.
    Wiersum, KF (1988) Viewpoints on Agroforestry. Second renewed edition. Agricultural University, Wageningen. 256 ppGoogle Scholar
  61. 61.
    Wijngaarden W van (1985) Elephants-trees-grass-graziers. ITC publication No. 4, Enschede. 159 ppGoogle Scholar
  62. 62.
    Wilson, JR, Catchpole, VR and Weier, KL (1986) Stimulation of growth and nitrogen uptake by shading rundown green panic pasture on brigalow clay soil. Tropical Grasslands Vol 20: 134–143Google Scholar
  63. 63.
    Young, A (1989) Agroforestry for soil conservation. Science and practice of agroforestry 4. CAB/ICRAF, Oxon, UK. 276 ppGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • J.J. Kessler
    • 1
  • H. Breman
    • 2
  1. 1.Department of Nature ConservationAgricultural University WageningenWageningenThe Netherlands
  2. 2.Center for Agrobiological ResearchWageningenThe Netherlands

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