References
- Brophy , Laura S. , Heichel , G.H. and Russelle , M.P. 1987 . Nitrogen transfer from forage legumes to grass in a systematic planting design . Crop Sci. , 27 : 753 – 758 .
- Dakora , Felix D. , Aboyinga , Roland A. , Manama , Yahaya and Apaseku , James . 1987 . Assessment of N2 fixation in groundnut (Arachis hypogaea L.) and cowpea (Vigna unguiculata L. Walp) and their relative N contribution to a succeeding maize crop in Northern Ghana . MIRCEN J. , 3 : 389 – 399 .
- Dakora , Felix D. , Akanuwe , James A. and Mahama , Yahaya . 1988 . Enhanced N2 fixation and N transfer in cowpea‐millet intercrop in northern Ghana . Acta Micro. Pol. , 37 : 337 – 343 .
- Eaglesham , A.R.J. , Ayanaba , A. , Ranga Rao , V. and Eskew , D.L. 1981 . Improving the nitrogen nutrition of maize by intercropping with cowpea . Soil Biol. Biochem. , 13 : 169 – 171 .
- Goering , H.K. and Van Soest , P.J. 1975 . Forage Fiber Analysis , Agr. Handbook No. 379 A.R.S., U.S.D.A. . 1975
- Haystead , A. 1980 . “ Measurement of nitrogen isotopes by mass spectrometry ” . In Modern instrumental techniques in soil analysis , Edited by: Smith , K.A. New York : Marcel Dekker .
- Haystead , A. 1981 . “ Nitrogen fixation and transfer In: Sward measurement handbook ” . Edited by: Hodgson , J. , Baker , R.D. , Davies , Alison , Laidlaw , A.S. and Leaver , J.D. 229 – 240 .
- Nelson , D.A. and Sommers , L.E. 1973 . Determination of total nitrogen in plant material . Agron. J. , 65 : 109 – 112 .
- Ott , Lyman . 1988 . An introduction to statistical methods and data analysis , 441 – 446 . Boston : PWS‐Kent Publishing Company .
- Patra , D.D. , Sachdev , M.S. and Subbiah , B.V. 1986 . 15N studies on the transfer of legume‐fixed nitrogen to associated cereals in intercropping systems . Biol. Fertil. Soils , 2 : 165 – 171 .
- SAS . 1987 . SAS/STAT™ Guide for personal computers , 6th ed. , Cary, N.C. : Statistical Analysis System Institute, Inc. .
- Ta , T.C. , Faris , M.A. and MacDowall , F.D.H. 1989 . Evaluation of 15N methods to measure nitrogen transfer from alfalfa to companion timothy . Plant and Soil , 114 : 243 – 247 .
- Van Kessel , C. and Roskowski , J.P. 1988 . Row spacing effects on N2‐fixation, N‐yield and soil‐N uptake of intercropped cowpea and maize . Plant and Soil , 111 : 17 – 23 .
- Virtanen , A.I. , Hausen , S.v. and Laine , T. 1937 . Excretion of nitrogen in associated cultures of legumes and non‐legumes . Jour. Agr. Sci. , 27 : 584 – 610 .
- Wilson , P.W. and Wyss , Orville . 1937 . Mixed cropping and the excretion of nitrogen by leguminous plants . Soil Sci. Soc. Ara. Proc. , 2 : 289 – 297 .