Grain Legumes and Green Manures for Soil Fertility in ... - cimmyt
Grain Legumes and Green Manures for Soil Fertility in ... - cimmyt
Grain Legumes and Green Manures for Soil Fertility in ... - cimmyt
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Table 3. Effect of <strong>for</strong>age legumes on soil organic carbon content (%)<br />
at Wedza <strong>and</strong> Buhera<br />
Treatments <strong>Soil</strong> organic carbon content (%)<br />
Natural Region II Natural Region IH<br />
Natural Region IV<br />
Maize 0.47 0.38 0.24 <br />
Maize/Cowpea 0.50 0.36 0.38 <br />
Maize/velvet bean 0.52 0.28 0.40 <br />
Maize/Lablab 0.41 0.37 0.25 <br />
Cowpea 0.43 0.28 0.67 <br />
Velvet bean 0.39 0.30 0.29 <br />
Lablab 0.56 0.31 0.42 <br />
Ley 0.48 0.51 0.28 <br />
Mean 0.47 0.35 0.35<br />
LSD (P < 0.05) n.s n.s ns<br />
n.s. - no significant differences among treatments.<br />
yield benefits. Monocropp<strong>in</strong>g of maize promotes<br />
unsusta<strong>in</strong>able crop yields as revealed by lower<br />
maize yields. Ley gave significant residual N benefits<br />
especially <strong>in</strong> lower ra<strong>in</strong>fall zones. Sole cropp<strong>in</strong>g<br />
<strong>and</strong> <strong>in</strong>tercropp<strong>in</strong>g had similar effects on soil organic<br />
C build up. Residual soil P differed significantly between<br />
treatments <strong>in</strong> the higher ra<strong>in</strong>fall region <strong>and</strong><br />
seemed to depend on the dem<strong>and</strong> of the crop comb<strong>in</strong>ations<br />
previously grown.<br />
Acknowledgements<br />
The authors are very grateful to the Biotechnology<br />
Trust of Zimbabwe (BTZ) <strong>for</strong> fund<strong>in</strong>g the research<br />
work upon which this paper is based on. There is<br />
also need to mention the co-operation of SPRL technical<br />
<strong>and</strong> field staff <strong>for</strong> the fieldwork a!1d soil analysis.<br />
We also acknowledge the ef<strong>for</strong>ts of extension<br />
officers <strong>and</strong> farmers <strong>in</strong> the participat<strong>in</strong>g wards.<br />
References<br />
Alemseged, Y.B., K<strong>in</strong>g, G.W., Coppock, V.L. <strong>and</strong><br />
Tothill, J.e. 1991. Maize-legume <strong>in</strong>tercropp<strong>in</strong>g<br />
<strong>in</strong> a Semi-Arid area of Sidamo Region, Ethiopia:<br />
Maize Response. pp. 77-84.<br />
Chalk, P. M. 1996. Nitrogen transfer from legumes<br />
to cereals <strong>in</strong> <strong>in</strong>tercropp<strong>in</strong>g. In: Ito, 0:, Johansen,<br />
e., Adu-Gyamfi, J. J., Katayama, K., Kumar Rao,<br />
J. V. D. K. <strong>and</strong> Tego, T. J. (eds.). Dynamics ofRoots<br />
<strong>and</strong> Nitrogen <strong>in</strong> Cropp<strong>in</strong>g Systems of the Semi-arid<br />
Tropics. ICRISATIJIRCAS, Hyderabad, India. pp.<br />
351-374.<br />
Dzowela, B.H. 1987. Maize stover improvement<br />
with legume <strong>for</strong>ages. In: Kategile, J.A., Said, A.<br />
N. <strong>and</strong> Dzowela B.H. (eds.), Animal Feed Resources<br />
<strong>for</strong> Small-scale Livestock Producers. Proceed<strong>in</strong>gs<br />
of the second P ANESA workshop held<br />
at ILARD, Kabete, Nairobi, Kenya. 11-15 November<br />
1985. IDRC Manuscript Report. pp. 174<br />
181.<br />
Table 4. Effect of <strong>for</strong>age legumes on available soil P205 content at<br />
Wedza <strong>and</strong> Buhera sites<br />
Treatments<br />
Available soil Pcontent (ppm)<br />
Natural Region II Natural Region III Natural Region IV<br />
Maize 7.13 9.14 8.30 <br />
Maize/cowpea 23.9 19.6 10.9 <br />
Maize/velvet bean 6.21 12.2 9.38 <br />
Maize/lablab 7.20 13.3 9.38 <br />
Cowpea 12.8 9.14 8.29 <br />
Velvetbean 20.3 21.2 11.1 <br />
Lablab 8.51 13.6 8.94 <br />
Ley 9.16 , 16.0 14.0 <br />
Mean 11.9 14.3 10.0 <br />
LSD (P < 0.05) ns ns<br />
n.s. - no sigmficant difference among treatments.<br />
Gryseels, G. <strong>and</strong> Anderson, F.M. 1983. Research on<br />
farm <strong>and</strong> livestock productivity <strong>in</strong> the central<br />
Ethiopia highl<strong>and</strong>s: Initial results, ILCA Research<br />
Report No.4.<br />
Manyawu, G.J. 1994. Agronomic evaluation of Lablab<br />
purpureus accessions <strong>in</strong>tercropped with maize<br />
(Zea mays) <strong>for</strong> gra<strong>in</strong> <strong>and</strong> <strong>for</strong>age production. Department<br />
of Research <strong>and</strong> Specialist Services, Division<br />
of Livestock <strong>and</strong> Pasture, Zimbabwe. Annual<br />
Report.<br />
Mukurumbira, L. M. 1985. Effects of rate of fertilizer<br />
nitrogen <strong>and</strong> previous gra<strong>in</strong> legume on maize<br />
yields. Zimbabwe Agricultural Journal 82: 177-179.<br />
Natarajan, M <strong>and</strong> Shumba, E.M ., 1989. Intercropp<strong>in</strong>g<br />
Research <strong>in</strong> Zimbabwe: Current status <strong>and</strong><br />
outlook <strong>for</strong> the future. In: Proceed<strong>in</strong>gs of a Workshop<br />
on Research Methods <strong>for</strong> Cereal- Legume <strong>in</strong>tercropp<strong>in</strong>g<br />
<strong>in</strong> Eastern <strong>and</strong> Southern Africa, Lilongwe,<br />
23-27 January 1989. CIMMYT <strong>and</strong> Southern Africa<br />
on-farm Research Network. Report No. 17:<br />
190-193.<br />
Peoples, M. B. <strong>and</strong> Herridge, D. F. 1990. Nitrogen<br />
fixation by legumes <strong>in</strong> tropical <strong>and</strong> sub- tropical<br />
agriculture. Advances <strong>in</strong> Agronomy 44: 155-223.<br />
Piha, M. 1995. <strong>Soil</strong> <strong>Fertility</strong> H<strong>and</strong>book. Department of<br />
<strong>Soil</strong> <strong>and</strong> Agricultural Eng<strong>in</strong>eer<strong>in</strong>g, University of<br />
Zimbabwe. 93 pp.<br />
Scoones, I. 1994. Liv<strong>in</strong>g with uncerta<strong>in</strong>ty. New directions<br />
<strong>in</strong> Pastoral development <strong>in</strong> Africa. pp.<br />
116-121.<br />
Skerman, P.I.; Cameron, D.G. <strong>and</strong> Riveros, F. 1988.<br />
Tropical Forage <strong>Legumes</strong>, F.A.o. Plant Production<br />
<strong>and</strong> Protection Series, No.2, F.A.O. of<br />
United Nations, Rome, Italy.<br />
Wanatabe, F. S. <strong>and</strong> Olsen, S. R. 1965. <strong>Soil</strong> Science<br />
Society ofAmerica Proc. 29: 677-678.<br />
168<br />
<strong>Gra<strong>in</strong></strong> legumes <strong>and</strong> <strong>Green</strong> <strong>Manures</strong> <strong>for</strong> <strong>Soil</strong> <strong>Fertility</strong> <strong>in</strong> Southern Africe