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 Agabi, J. A; Abang, S. O and Animashaum A (1995). Nigerian environment, Macmillan, Ibadan, Nigeria. 350pp.
 Agboola, S. A. (1997). An agricultural atlas of Nigeria. Oxford Unversity press, (London) a. Pp 131.
 Abdil Aziz M. Abou-Elele; Usman, A; Abd El-Razek and Khali, H. E (2012). Yield and its components of maize/soybean intercropping systems as affected by planting time and Distribution, Australia J. of Agric and applied Sc. 6(13) : 238-245.
 Addo-Quaye,A. A; Dankwa, A. A. and Ocloo, G. K (2011). Growth analysis of component Crops in ; A maize-soybean intercropping system as affected by time of planting and spatial arrangement, ARPN J. of Agric and Biol. Sc. 6(6): 34-44.
 Adeniyan, O. N and Ayoola O. T (2006). Growth and yield performance of improved soybean varieties as influenced by intercropping with maize and cassava in two contrasting Locations in south east Nigeria. Afri. J. of biotech. 5(20): 1886-1889.
 Akanda, M. E. and Quayyaum, M. A. (1982). Effect of intercropping soybean, mungbean, black gram and groundnut with maize. Bangladesh J. of Agric. Sc. 84: 71- 78.
 Adiku, S. G. K.; Carbury, P. S.; Rose, C. W; Miccoumn, R. L and Brandock, R (1995).
 Baker, E. F. I (1978). Population, time and crop mixture. Proceedings of an International workshop on intercropping, ICRISAT. Hyederabei, 10-13 Jan. 1979, Pp 32-60.
 Biabani, A; Hashin, M. and Herbert, S. J. (2008). Agronomic performance of two Intercropped soybean cultivars. Inter. J. plant production. 2(3): 215-221.
 Dalai, R. C. (1977). Effect of intercropping maize with soybean on grain yield. Trop. Agric (Trinidad) 54 (2): 189-191.
 Duncan, S. R; Suchapangh, W. J. (Jr) and Shroyer , J. P. (1991). Relay intercropping soybean Into wheat. In: Kansas J. prod. On agric. 3: 51-55.
 Elmore, R. W. and Jacobs, T. A. (1984). Yield component of sorghum and soybeans of varying plant height when intercropped. Agron. J. 76: 561-564.
 Ennin, S. A; Clegg, M. D. and francis, C. A. (2002). Resource utilization in soybean/maize Intercrop. African Crop Sc. J. 10 (3): 251-261.
 Enyi, B. A. C. (1973). Effect of intercropping maize or sorghum with cowpea, pigeon pea or beans. Exptal. Agric. 9: 82-90.
 Fisher, N.M. (1977). Studies in mixed cropping 11: Population pressure in maize-bean Mixture. Exptal. Agric. 13: 185-191.
 M. (Fisher , N. 1980). A note on agronomic research with soybean at the institute for Agric. Res. Ahmadu Bello University, Zaria in: proceedings for annual meeting of Soybean Scientist. Nov. 3-4 1980 Zaria. Pp 34-40.
 Francis, C. A (1978). Multiple cropping potentials of bean and maize. Hort. Sc. 113: 12-17.
 Francis, C. A (1986). Introduction, destribution and importance of multiple Cropping. In: Francis C. A (ed). Multiple cropping systems. Macmillan, New York, Pp 1-19.
 GENSTAT, (2003). GENSTAT release 4. 23, Lowes Agricultural Trust Rothamsted Experimental Station.
 Henriet, J. G. A; Van, E. K; Blade, S. F. and Singh, B. B. (1997). Quantitative assessment of traditional cropping systems in the Sudan Savanna of Nigeria1. Rapid survey of prevalent cropping systems. Savanna J. of Agric. Sc. 14: 27-45.
 IITA (1986). (International Institute of Tropical Agriculture) towards sustainable Agriculture. Annual report.
 IITA (1989). (International Institute of Tropical Agriculture) Crop establishment manual.
 Ijoyah, M. O; Ogar, A. O and Ojo, A. O (2013). Soybean-maize intercropping on yield and system productivity in Makurdi, Central Nigeria. Sci. J. crop Sci. 2(4 ): 82-86.
 Kalu, B. A. (1993). Crop recommendation for Benue state. BNARDA Ext. Bult No. 2.
 Langer, R. H. M and Hill, G. B (1991). Agricultural plants. Cambridge University press, U. K. 431pp.
 Li, L; Sun, T. H; Zhang, F. S; Li, X. L; Yang, S. C and Rengel, Z (2006). Wheat/maize or wheat/soybean intercropping. In: Yield advantages and inter specific reaction on nutrients. Field crops Res. 71: 123-237.DOI: https://doi.org/10.1016/s0378-4290(01)00156-3
 Muoneke, C. O; Ogwuche, M. A. O and Kalu B (2007). Effect of maize planting density on the performance of maize/soybean intercropping systems in guinea savannah Agro ecosystem. Afri. J. of agric, Res. 2(12): 667-677.
 Mead, R. and Willey, R. W. (1980). The concept of Land Equivalent Ratio, and Advantages in yield from intercropping. Exptal. Agric. 16: 217-228.DOI: https://doi.org/10.1017/s0014479700010978
 Metwally, A. A; El-Metwally, A; habbak, K. E and Abdil wahab, S. T (2009). Yield and Land equivalent ratio of intercrop soybean with maize under different intercropping pattern and high population densities. Egypt J. Agron. 31(2): 199-222.
 Mudita, I. I; Chiduza, C; Richardson-Kageler, S. J and Murungu, F. S (2008).
 NARP (1994). National Agric. Research Plan for Nigeria (Northwest Zone) Draft plan as Cited by Akin Adebayo. NOMA, 6th May, 1996. Institute of Agric. Research, Samaru, pp.7-9.
 Ofori, O and Stern, W. R. (1987). Relative sowing time and density component crops in maize- cowpea intercrop systems. Exptal. Agric. 23: 41-52.DOI: https://doi.org/10.1017/s0014479700001113
 Olufajo, O.O. (1986). Plant density relationship in maize/cowpea intercrop in Nigeria. Trop. Grain legume bulletin. 32: 40-50.
 Olufajo, O.O. (1995). Sorghum/ soybean intercropping as affected by cultivar and Plant arrangement. Samaru J. of Agric. 12: 3-11.
 Olufajo, O.O. and Singh, B.B. (2002).
 Polthanee, A; Promsaena, K. and Laokan, A. (2011). Influence of low light intensity on Growth and yield of four soybean cultivars during wet and dry seasons of north West Thailand. Agric. Sci. 2: 61-67.DOI: https://doi.org/10.4236/as.2011.22010
 Raji,J. A (2007). Intercropping soybean and maize in a derived savannah ecology Afri. J. of Biotech. 6(16): 1885-1887.
 Remison, S. U. (1982). Neighborhood effects between maize and cowpeas sown simultaneously and at intervals in rain forest zone of Nigeria. India J. of Agric Sc. 52: 500-505.
 Soliman, M. M; Rabie, E. M and Ragheb, S. S (2007). Response of soybean yield to late Sowing date. Arab. Unver. J. Agric. Sc. Ain. Shams univer. Cairo. 15(1): 51-59.
 Singh, B.B. and Ajeigbe, H.A. (2002).
 Storck, H; Bezabih, E; berhanna, A; Andrzeja, B. and S and himelis, W.H. (1991).
 Sullivan, P (2003). Intercropping principles and production practices, Agron. Systems Guide. http. attar. ncat. org/attar. pub/PDF/intercrop. pdf.
 Tayo, T.C. (1977). Comparative analysis of growth, development and yield of three Soybean varieties. J. of Agric. Science (Cambridge) 88: 151-157.
 Ugen, M.A. and Wien, H.C. (1986). The effect of mature proportion and fertilizer Nitrogen on Morphology, insect pest damage, competition and yield advantage maize/bean Intercrop. Africa Crop Sc. J. 4: 41-49.
 Umeh, S. I; Mbah, B.N. (2010). Intercrop performance of different varieties of soybean (Glycine max (L. ) merill) in cassava( Manihot esculenta) based cropping system within the derived savannah zone. Afri. J. Biotech. 9(50): 8636-8642.DOI: https://doi.org/10.4314/as.v9i3.65748
 Willey, R.W. (1997). Intercropping- its importance and research needs 1: Competition and Yield advantage. Field Crop Abstract. 32: 1-10.
 Willey, R. W and Rao, M.R. (1980). A competitive Ratio for qualifying competition Between intercrops. Exptal. Agric. 16: 117-125.DOI: https://doi.org/10.1017/s0014479700010802
 Zhang, F and Li, F (2003). Using competitive and facilitations interaction in intercropping Systems enhances crop productivity and nutrient use efficiency. Plant and Soil. 248: 305-312.DOI: https://doi.org/10.1023/a:1022352229863