Abaidoo, R. C., George, T., Bohlool, B. B. & Singleton, P. W. (1989). Influence of elevation and applied nitrogen on rhizosphere colonization and competition for nodule occupancy by different rhizobial strains on field-grown soybean and common bean. Canadian Journal of Microbiology 36, 92–96.
Anderson, G. D. (1967). Increasing coconut yields and income on the sandy soils of the Tanganyika coast. East African Agricultural and Forestry Journal 32, 310–314.
Anderson, G. D. (1969). Responses of maize to the application of compound fertilizers on farmer's fields in ten districts of Tanzania. East African Agricultural and Forestry Journal 34, 382–397.
Anderson, G. D. (1970 a). Fertility studies on a sandy loam in semi-arid Tanzania. I. Effects of nitrogen, phosphorus and potassium fertilizers on yields of maize and soil nutrient status. Experimental Agriculture 6, 1–12.
Anderson, G. D. (1970 b). Fertility studies on a sandy loam in semi-arid Tanzania. II. Effects of phosphorus, potassium and lime on yields of groundnuts. Experimental Agriculture 6, 213–222.
Anderson, G. D. (1974). Bean responses to fertilizers on Mt. Kilimanjaro in relation to soil and climatic conditions. East African Agricultural and Forestry Journal 39, 272–288.
Cochran, W. G. & Cox, G. M. (1957). Experimental Designs. 2nd edition. pp. 218–219. New York: John Wiley and Sons.
Due, J. M., Rugambisa, J., Tilahun, N. & Schwartz, R. (1985). Beans (Phaseolus vulgaris) in the farming systems in Tanga Region, Tanzania, 1985. Technical Report No. 6. Department of Rural Economy, Sokoine University of Agriculture, Morogoro, Tanzania and Department of Agricultural Economics, University of Illinois, USA.
Evans, A. C. (1963). Soil fertility studies in Tanganyika II. Continued applications of fertilizer on the red and redbrown loams of the Nachingwea series. East African Agricultural and Forestry Journal 28, 228–230.
Fox, R. L. & Kang, B. T. (1977). Some major fertility problems of tropical soils. In Exploiting the Legume Rhizobium Symbiosis in Tropical Agriculture (Eds Vincent, J. M., Whitney, A. S. & Bose, L. J.), pp. 183–210. College of Tropical Agriculture, University of Hawaii, Miscellaneous Publication No. 145.
Giller, K., Amuee, F. & Brodrick, S. J. (1989). SoilFactors Affecting Nitrogen Fixation and Production of Phaseolus vulgaris in East Africa. Report to the UK Overseas Development Administration, Wye College, University of London.
Howeler, R. H. (1983). Analisis de Tejida Vegetal en el Diagnostico de Problemas Nutrilionales de Algunos Cultivos Tropicales. Cali, Colombia: Centro Intemacional de Agricultura Tropical.
Le Mare, P. H. (1963). A comparison of the minus-one and 211 designs for the exploratory investigation of fertilizer requirements. East African Agricultural and Forestry Journal 28, 213–218.
Le Mare, P. H. (1972). A long term experiment on soil fertility and cotton yield in Tanzania. Experimental Agriculture 8, 299–310.
Le Mare, P. H. (1984). Limitations imposed by nutrient supply in tropical African soils. In Advancing Agricultural Production in Africa. Proceedings of CAB's First Scientific Conference. Arusha, Tanzania, 12–18 February 1984 (Ed. Hawksworth, D. L.), pp. 357–361. Slough: Commonwealth Agricultural Bureaux.
Ministry of Agriculture Fisheries and Food (1985). Ministry of Agriculture, Fisheries and Food Reference Book 209, London: HMSO.
Ministry of Agriculture Fisheries and Food (1986). The Analysis of Agricultural Materials. Reference Book 427 London: HMSO.
Stoorvogel, J. J. & Smaling, E. M. A. (1990). Assessment of Soil Nutrient Depletion in Sub-Saharan Africa: 1983–2000. Volume 1: Main Report (second edition). Report 28, Winand Staring Centre, Wageningen.
Wild, A. & Jones, L. H. P. (1988). Mineral nutrition of crop plants. In RusselFs Soil. Conditionsand Plant Growth (Ed. Wild, A.), Eleventh edition. pp. 69–112. Harlow: Longman Group.
Williams, E. V. (1978). New techniques for the digestion of biological materials – application to the determination of tin, iron and lead in canned foods. Journal of Food Technology 13, 367–384.