Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-03T05:19:26.809Z Has data issue: false hasContentIssue false
  • English
  • Français

FERTILIZATION STRATEGIES IN CONSERVATION AGRICULTURE SYSTEMS WITH MAIZE–LEGUME COVER CROP ROTATIONS IN SOUTHERN AFRICA

Published online by Cambridge University Press:  20 June 2016

W. MUPANGWA ,
C. THIERFELDER  and
A. NGWIRA
W. MUPANGWA*
Affiliation:
CIMMYT, P.O. Box MP 163, Mount Pleasant, Harare, Zimbabwe
C. THIERFELDER
Affiliation:
CIMMYT, P.O. Box MP 163, Mount Pleasant, Harare, Zimbabwe
A. NGWIRA
Affiliation:
Chitedze Research Station, P.O. Box 158, Lilongwe, Malawi
*
§Corresponding author. Email: [email protected]; [email protected]
Get access Rights & Permissions [Opens in a new window]

Summary

Multilocation experiments were established to determine the best strategy for using inorganic fertilizer in conservation agriculture (CA) systems that use green manure cover crops, namely sunhemp, velvet bean and cowpea grown in rotation with maize. The objectives of the study were to determine (i) the effect of half and full rates of basal fertilizer on maize and legume biomass yields, (ii) the residual effects of unfertilized, half and fully fertilized green manure legumes on maize grown after the legumes, and (iii) the residual effect of unfertilized, half and fully fertilized green manure legumes combined with basal and topdressing fertilizer on maize yields. Experimental design was a randomized complete block with basal fertilizer as a treatment in the green manure legumes phase. Previously, in the maize phase, green manure legume species were the main treatment with basal fertilizer as a subtreatment (sunhemp, velvet bean and cowpea: 0, 75, 150 kg ha−1 and 0, 50, 100 kg ha−1, respectively). Nitrogen was applied in the maize phase at 0, 23, 46, 69 kg N ha−1 as a sub-subtreatment in Malawi. Results showed that inorganic fertilizer is the most effective when applied to the maize, not green manure legumes. Biomass of green manure legumes, sunnhemp 8084 kg ha−1, velvet bean 7678 kg ha−1 and cowpea 4520 kg ha−1, was not significantly affected by application of basal fertilizer. Maize production increased after the application of green manure legumes with maize-after-maize, maize-after-velvet bean, maize-after-sunnhemp and maize-after-cowpea, yielding 3804, 5440, 5446 and 5339 kg ha−1, respectively. Nitrogen increased maize yield regardless of the previously used green manure legumes species. Our results suggest that farmers should apply fertilizer to maize and grow green manure legumes on residual soil in CA systems. Despite growing green manure legumes, smallholders should apply nitrogen topdressing to maize grown using the green manure legumes in some agro-ecologies.

Type
Research Article
Information
Experimental Agriculture , Volume 53 , Issue 2 , April 2017 , pp. 288 - 307
Check for updates
Copyright
Copyright © Cambridge University Press 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Cairns, J. E., Sonder, K., Zaidi, P. H., Verhulst, N., Mahuku, G., Babu, R., Nair, S. K., Das, B., Govaerts, B., Vinayan, M. T., Rashid, Z., Noor, J. J., Devi, P., San Vicente, F. and Prasanna, B. M. (2012). Maize production in a changing climate: Impacts, adaptation, and mitigation strategies. In Advances in Agronomy, 1–58 (Ed Sparks, D.). Burlington: Academic Press.Google Scholar
Cassman, K. G., Singleton, P. W. and Linquist, B. A. (1993). Input/output analysis of the cumulative soybean response to phosphorus on an Ultisol. Field Crops Research 34:23–36.Google Scholar
Chivenge, P., Mwale, M. and Murwira, H. (2003). Biomass production of green manures and grain legumes in soils of different characteristics in Zambia and Zimbabwe. In Grain Legumes and Green Manures for Soil Fertility in Southern Africa: Taking Stock of Progress, 137–141 (Ed Waddington, S. R.). Conference Proceedings, 8–11 October 2002, Leopard Rock Hotel, Vumba. Soil Fertility Network and CIMMYT, Zimbabwe. A Publication of the Soil Fertility Management and Policy Network for Maize-Based Cropping Systems in Southern Africa.Google Scholar
Cobo, J. G., Gerd, D. and Cadisch, G. (2010). Nutrient balances in African land use systems across different spatial scales: A review of approaches, challenges and progress. Agriculture, Ecosystem and Environment 136:1–15.Google Scholar
Dube, E. D. N., Madanzi, T., Kapenzi, A. and Masvaya, E. (2014). Root length density in maize/cowpea intercropping under a basin tillage system in a semi-arid area of zimbabwe. American Journal of Plant Sciences 5:1499–1507.Google Scholar
Giller, K. E. (2001). Nitrogen Fixation in Tropical Cropping Systems. New York: CABI Publishing.Google Scholar
Giller, K. E., Cadisch, G., Ehaliotis, C., Adams, E., Sakala, W. and Mafongoya, P. L. (1997). Building soil nitrogen capital in Africa. In Replenishing Soil Fertility in Africa, 151–192 (Eds Buresh, J. R., Sanchez, P. A. and Calhoun, F.). Soil Science Society of America Special Publication No 51. Soil Science Society of America and American Society of Agronomy, Madison, Wisconsin, USA.Google Scholar
Giller, K. E., Mpepereki, S., Mapfumo, P., Kasasa, P., Sakala, W., Phombeya, H., Itimu, O., Cadisch, G., Gilbert, R. A. and Waddington, S.R. (2000). In Nitrogen Fixation: From Molecules to Crop Productivity, 525–530 (Ed F. O. Waddington Pedrosa). Netherlands: Kluwer Academic Publishers.Google Scholar
Giller, K. E., Witter, E., Corbeels, M. and Tittonell, P. (2009). Conservation agriculture and smallholder farming in Africa: The heretic’s view. Field Crops Research 114:23–34.Google Scholar
Gowing, J. W. and Palmer, M. (2008). Sustainable agricultural development in sub-Saharan Africa: The case for a paradigm shift in land husbandry. Soil Use Management 24:92–99.Google Scholar
Grabowski, P. P. and Kerr, J. M. (2014). Resource constraints and partial adoption of conservation agriculture by hand-hoe farmers in Mozambique, International Journal of Agricultural Sustainability 12 (1):37–53, DOI: 10.1080/14735903.2013.782703.Google Scholar
Grant, P. M. and Rowell, A. W. G. (1976). Studies on Sulphur fertilizers for Rhodesian crops. 1. Effect of sulphur in fertilizer compounds on the yield and sulphur status of maize. Rhodesian Journal of Agricultural Research 14 (2):101–109.Google Scholar
Gwiriri, L., Gora, A. and Hamadziripi, L. (2015). Forage farming changes lives of Zimbabwe smallholder farmers. http://news.ilri.org/2015/12/21/forages-zimclifs/. Visited on 15 January 2016.Google Scholar
Hikwa, D., Murata, M., Tagwira, F., Chiduza, C., Murwira, H., Muza, L. and Waddington, S. R. (1998). Performance of green manure legumes on exhausted soils in northern Zimbabwe: A Soil Fertility Network Trial, 81–84. In Soil Fertility Research for Maize based Farming Systems in Malawi and Zimbabwe. Proceedings of the Soil Fertility Research Results and Planning Workshop, 7–11 July 1997, Africa University, Mutare, Zimbabwe (Eds Waddington, S. R., Murwira, H. K., Kumwenda, J. D. T., Hikwa, D. and Tagwira, F.). Soil Fert Net and CIMMYT-Zimbabwe, Harare, Zimbabwe.Google Scholar
Jayne, T. S., Govereh, J., Wanzala, M. and Demeke, M. (2003). Fertilizer market development: A comparative analysis of Ethiopia, Kenya and Zambia. Food Policy 28:293–316.Google Scholar
Jayne, T. S., Mather, D. and Mghenyi, E. (2010). Principal challenges confronting smallholder agriculture in Sub-Saharan Africa. World Development 38 (10):1384–1398.Google Scholar
Jeranyama, P., Hesterman, O. B., Waddington, S. R. and Harwood, R. R. (2000). Relay-Intercropping of Sunnhemp and Cowpea into a smallholder maize system in Zimbabwe. Agronomy Journal 92:239–244.Google Scholar
Jeranyama, P., Waddington, S. R., Hesterman, O. B. and Harwood, R. R. (2007). Nitrogen effects on maize yield following groundnut in rotation on smallholder farms in sub-humid Zimbabwe. African Journal of Biotechnology 6 (13):1503–1508.Google Scholar
Kadyampakeni, D. M. (2014). Soil, water and nutrient management options for climate change adaptation in southern Africa. Agronomy Journal 106 (1):100–110.Google Scholar
Kaizzi, C. K., Ssali, H. and Vlek, P. L. G. (2006). Differential use and benefits of Velvet bean (Mucuna pruriens var. utilis) and N fertilizers in maize production in contrasting agro-ecological zones of E. Uganda. Agricultural Systems 88:44–60.Google Scholar
Kamanga, B. C. G., Waddington, S. R., Robertson, M. J. and Giller, K. E. (2010). Risk analysis of maize-legume crop combinations with smallholder farmers varying in resource endowment in central Malawi. Experimental Agriculture 46 (1):1–21.Google Scholar
Kanonge, G., Mtambanengwe, F., Manzeke, M. G., Nezomba, H. and Mapfumo, P. (2015). Assessing the potential benefits of organic and mineral fertiliser combinations on legume productivity under smallholder management in Zimbabwe. South African Journal of Plant and Soil 32 (4):241–248.Google Scholar
Komwihangilo, D. M., Lekule, F. P., Kajembe, G. C., Mgheni, D. M. and Petersen, P. H. (2007). Implications of local knowledge in the utilization of forage resources in mixed livestock systems of Eastern Tanzania. International Journal of Agricultural Sustainability, 5 (4):269–279.Google Scholar
Kumwenda, J. D. T. and Gilbert, R. (1998). Biomass production by legume green manures on exhausted soils in Malawi: A Soil Fertility Network Trial, 85–86. In Soil Fertility Research for Maize based Farming Systems in Malawi and Zimbabwe. Proceedings of the Soil Fertility Research Results and Planning Workshop. 7–11 July 1997, Africa University, Mutare, Zimbabwe (Eds Waddington, S. R., Murwira, H. K., Kumwenda, J. D. T., Hikwa, D. and Tagwira, F.). Soil Fert Net and CIMMYT-Zimbabwe, Harare, Zimbabwe.Google Scholar
Kumwenda, J. D. T., Saka, A. R., Snap, S. S., Ganunga, R. P. and Benson, T. (1998). Effects of organic legume residues and inorganic fertilizer nitrogen on maize yield in Malawi. In Soil Fertility Research for Maize based Farming Systems in Malawi and Zimbabwe, 165–171 (Eds Waddington, S., Murwira, H. K., Kumwenda, J. D. T., Hikwa, D. and Tagwira, F.) Proceedings of the Soil Fertility Research Results and Planning Workshop. 7–11 July 1997, Mutare, Zimbabwe: Africa University.Google Scholar
Lukuyu, B., Gachuiri, C. K., Lukuyu, M. N., Lusweti, C. and Mwendia, S. (2012). In Feeding Dairycattle in East Africa, Nairobi, Kenya: East Africa Dairy Development Project.Google Scholar
Maasdorp, B. V. and Titterton, M. (1997). Nutritional improvement of maize silage for dairying: mixed-crop silages from sole and intercropped legumes and a long-season variety of maize. I. Biomass yield and nutritive value. Animal Feed Science and Technology 69:241–261.Google Scholar
Mandumbu, R., Jowah, P., Karavina, C. and Tibugari, H. (2011). Integrated weed management in Zimbabwe's smallholder sector, where are we?: A review. Modern Applied Science 5 (5):111–117.Google Scholar
Mapfumo, P., Mtambanengwe, F. and Vanlauwe, B. (2007). Organic matter quality and management effects on enrichment of soil organic matter fractions in contrasting soils in Zimbabwe. Plant Soil 296,137–150.Google Scholar
Mhlanga, B., Cheesman, S., Chauhan, B. S. and Thierfelder, C. (2016). Weed emergence as affected by maize (Zea mays L.)-cover crop rotations in contrasting arable soils of Zimbabwe under conservation agriculture. Crop Protection 81:47–56.Google Scholar
Mhlanga, B., Cheesman, S., Maasdorp, B., Muoni, T., Mabasa, S., Mangosho, E. and Thierfelder, C. (2015). Weed community responses to rotations with cover crops in maize-based conservation agriculture systems of Zimbabwe. Crop Protection 69:1–8.Google Scholar
Morris, M. L. (2007). Fertilizer use in African Agriculture: Lessons Learned and Good Practice Guidelines. World Bank Publications. The World Bank, Washington DC.Google Scholar
Mukwereza, L., Manyawu, G., Ndhlovu, F. and Zisengwe, C. (2010). Future directions for livestock production in the smallholder farming sector of Zimbabwe: A study commissioned by FAO/PRP. Food and Agriculture Organization of the United Nations and GRM/Protracted Relief Programme. June 2010, Harare, Zimbabwe. FAO, Rome, Italy.Google Scholar
Muoni, T., Rusinamhodzi, L. and Thierfelder, C. (2013). Weed control in conservation agriculture systems of Zimbabwe: Identifying economical best strategies. Crop Protection 53:23–28.Google Scholar
Mupangwa, W. and Thierfelder, C. (2013). Intensification of conservation agriculture systems for increased livestock feed and maize production in Zimbabwe. International Journal of Agricultural Sustainability. doi.org/10.1080/14735903.2013.859836.Google Scholar
Mupangwa, W., Walker, S. and Twomlow, S. (2011). Start, end and length of the growing seasons in semi-arid southern Zimbabwe. Journal of Arid Environments 75:1097–1104.Google Scholar
Muza, L. (2003). Green manuring in Zimbabwe from 1900 to 2002. In Grain Legumes and Green Manures for Soil Fertility in Southern Africa: Taking Stock of Progress, 103–111 (Ed S. R. Muza Waddington) Conference Proceedings, 8–11 October 2002, Zimbabwe: Leopard Rock Hotel, Vumba. Soil Fert. Net and CIMMYT.Google Scholar
Ncube, B., Twomlow, S. J., Dimes, J. P., van Wijk, M. T. and Giller, K. E. (2009). Resource flow, crops and soil fertility management in smallholder farming systems in semi-arid Zimbabwe. Soil Use and Management 25:78–90.Google Scholar
Ncube, B., Twomlow, S., van Wijk, M. T., Dimes, J. P. and Giller, K. E. (2007). Productivity and residual benefits of grain legumes to sorghum under semi-arid conditions in south-western Zimbabwe. Plant Soil 299:1–15.Google Scholar
Ndufa, J. K., Gathumbi, S. M., Kamiri, H. W., Giller, K. E. and Cadisch, G. (2009). Do mixed-species legume fallows provide long-term maize yield benefit compared with monoculture legume fallows? Agronomy Journal 101:1352–1362.Google Scholar
Ngwira, A. R., Aune, J. B. and Mkwinda, S. (2012). On-farm evaluation of yield and economic benefits of short term maize-legume intercropping systems under conservation agriculture in Malawi. Field Crops Research 132:149–157.Google Scholar
Njarui, D. M. G. and Mureithi, J. G. (2010). Evaluation of lablab and velvet bean fallows in a maize production system for improved livestock feed supply in semiarid tropical Kenya. Animal Production Science 50:193–202.Google Scholar
Nyamapfene, K. (1991). Soils of Zimbabwe. Harare, Zimbabwe: Nehanda Publishers (Pvt) Ltd, 75–79.Google Scholar
Nyamushamba, G. B., Mapiye, C., Tada, O., Halimani, T. E. and Muchenje, V. (2016). Conservation of indigenous cattle genetic 1 resources in Southern Africa's 2 smallholder areas: turning threats into opportunities. Asian-Australasian Journal of Animal Sciences. DOI: 10.5713/ajas.16.0024.Google Scholar
Odhiambo, J. J. O. (2011). Potential use of green manure legume cover crops in smallholder maize production systems in Limpopo province, South Africa. African Journal of Agricultural Research 6 (1):107–112.Google Scholar
Owenya, M. Z., Mariki, W. L., Kienzle, J., Friedrich, T. and Kassam, A. (2011). Conservation agriculture (CA) in Tanzania: the case of the Mwangaza B CA farmer field school (FFS), Rhotia Village, Karatu District, Arusha. International Journal of Agricultural Sustainability 9 (1):145–152.Google Scholar
Pircher, T., Almekinders, C. J. M. and Kamanga, B. C. G. (2013). Participatory trials and farmers’ social realities: Understanding the adoption of legume technologies in a Malawian farmer community. International Journal of Agricultural Sustainability 11 (3):252–263.Google Scholar
Place, F., Barrett, C. B., Freeman, H. A., Ramisch, J. J. and Vanlauwe, B. (2003). Prospects for integrated soil fertility management using organic and inorganic inputs: evidence from smallholder African agricultural systems. Food Policy 28:365–378.Google Scholar
Reddy, K. C., Visser, P. L., Klaij, M. C. and Renard, C. (1994). The effect of sole and traditional intercropping of millet and cowpea on soil and crop productivity. Experimental Agriculture 30:83–88.Google Scholar
Robertson, M. J., Sakala, W., Benson, T. and Shamudzarira, Z. (2005). Simulating response of maize to previous velvet bean (Mucuna pruriens) crop and nitrogen fertilizer in Malawi. Field Crops Research 91:91–105.Google Scholar
Rowhani, P., Lobell, D. B., Linderman, M. and Ramankuttya, N. (2011). Climate variability and crop production in Tanzania. Agricultural and Forest Meteorology 151:449–460.Google Scholar
Rusinamhodzi, L., Corbeels, M., Nyamangara, J. and Giller, K. E. (2012). Maize–grain legume intercropping is an attractive option for ecological intensification that reduces climatic risk for smallholder farmers in central Mozambique. Field Crops Research 136:12–22.Google Scholar
Sakala, W. and Mhango, W. (2003). Green manure and food legumes research to increase soil fertility and maize yields in Malawi: a review. In Grain legumes and green manures for soil fertility in Southern Africa: Taking stock of progress, 95–101. (Ed , S. R. Waddington, ) Conference Proceedings, 8–11 October 2002, Zimbabwe: Leopard Rock Hotel, Vumba. Soil Fert. Net and CIMMYT.Google Scholar
Sanchez, P. A., Shepherd, K. D., Soule, M. J., Place, F. M., Buresh, R. J., Izac, A. N., Mokwunye, A. U., Kwesiga, F. R., Ndiritu, C. G. and Woomer, P. L. (1997). Soil fertility replenishment in Africa: An investment in natural resource capital. In Replenishing Soil Fertility in Africa, 1–46. (Eds R. J. Woomer Buresh, P. A. Buresh Sanchez, F. Sanchez Calhoun). Soil Science Society America Special Publication 51. Soil Science Society of America and American Society of Agronomy. Madison, Wisconsin, USA.Google Scholar
Sanginga, N., Ibewiro, B., Houngnandan, B., Vanlauwe, B., Okogum, J. A., Akobundu, I. D. and Versteeg, M. (1996). Evaluation of symbiotic properties and nitrogen contribution of mucuna to maize grown in the derived savanna of West Africa. Plant Soil 179:119–129.Google Scholar
Sileshi, G., Maghembe, J. A., Rao, M. R., Ogol, C. and Sithanantham, S. (2000). Insects feeding on Sesbania species in natural stands and agroforestry systems in southern Malawi. Agroforestry Systems 49:41–52.Google Scholar
Smaling, E. A., Nandwa, S. M. and Janssen, B. H. (1997). Soil fertility in Africa is at stake. In Replenishing Soil Fertility in Africa, 47–61. (Eds Buresh, R. J., Sanchez, P. A. and Calhoun, F.). Soil Science Society America Special Publication 51. Soil Science Society of America and American Society of Agronomy. Madison, Wisconsin, USA.Google Scholar
Snapp, S. S., Blackie, M. J., Gilbert, R. A., Bezner-Kerr, R. and Kanyama-Phiri, G. (2010). Biodiversity can support a greener revolution in Africa. PNAS 107 (48):40–45.Google Scholar
Snapp, S. S., Rohrbach, D. D., Simtowe, F. and Freeman, H. A. (2002). Sustainable soil management options for Malawi: Can smallholder farmers grow more legumes?. Agriculture, Ecosystem & Environment 91:159–174.Google Scholar
Sommer, R., Bossio, D., Desta, L., Dimes, J., Kihara, J., Koala, S., Mango, N., Rodriguez, D., Thierfelder, C. and Winowiecki, L. (2013). Profitable and Sustainable Nutrient Management Systems for East and Southern African Smallholder Farming Systems–Challenges and Opportunities. CIAT, Cali, Colombia. http://ciat-library.ciat.cgiar.org:8080/jspui/handle/123456789/8557. Accessed 21st May 2014.Google Scholar
Statistix (2008) Statistix 9: Analytical Software. www.statistix.com, Tallahassee, USA.Google Scholar
Tadross, M., Hewitson, B. C. and Usman, M. T. (2005). The interannual variability of onset of the maize growing season over South Africa and Zimbabwe. Journal of Climate 18:3356–3372.Google Scholar
Thierfelder, C., Cheesman, S. and Rusinamhodzi, L. (2012). A comparative analysis of conservation agriculture systems: Benefits and challenges of rotations and intercropping in Zimbabwe. Field Crops Research 137:237–250.Google Scholar
Thierfelder, C. and Wall, P. (2010). Rotation in conservation agriculture systems in Zambia: Effects on soil quality and water relations. Experiemntal Agriculture 46 (3):309–325.Google Scholar
Twomlow, S. J. (2004). Increasing the role of legumes in smallholder farming systems - The Future Challenge. In Symbiotic Nitrogen Fixation: Prospects for Application in Tropical Agroecosystems, 29–46, (Ed Serraj, R.). NH, USA: Science Publishers.Google Scholar
Twomlow, S., Rohrbach, D., Dimes, J., Rusike, J., Mupangwa, W., Ncube, B., Hove, L., Moyo, M., Mashingaidze, N. and Mahposa, P. (2010). Micro-dosing as a pathway to Africa’s Green Revolution: evidence from broad-scale on-farm trials. Nutrient Cycling in Agroecosystems 88:3–15.Google Scholar
Twomlow, S. J., Steyn, J. T. and du Preez, C. C. (2006). Dryland farming in southern Africa. In (Eds Petersen, G. A., Unger, W. P. and Payne, W. A.). Dryland Agriculture. 2nd edn., Chapter 19. 769–836. Madison, Wisconsin, USA: Agronomy Monograph No. 23. American Society of Agronomy.Google Scholar
Unganai, L. S., Troni, J., Manatsa, D. and Mukarakate, D. (2013). Tailoring seasonal climate forecasts for climate risk management in rainfed farming systems of south-east Zimbabwe. Climate and Development, doi: 10.1080/17565529.2013.801823.Google Scholar
Valbuena, D., Erenstein, O., Homann-Kee Tui, S., Abdoulaye, T., Claessens, L., Duncan, A. J., Gérard, B., Rufino, M. C., Teufel, N., van Rooyen, A. and van Wijk, M. T. (2012). Conservation agriculture in mixed crop–livestock systems: Scoping crop residue trade-offs in sub-saharan Africa and South Asia. Field Crops Research 132:175–184.Google Scholar
van der Velde, M., Folberth, C., Balkovic, J., Ciais, P., Fritz, S., Janssens, I. A., Obersteiner, M., See, L., Skalsky, R. V., Xiong, W. and Penuelsa, J. (2014). African crop yield reductions due to increasing unbalanced nitrogen and phosphorus consumption. Global Change Biology doi: 10.1111/gcb.12481.Google Scholar
Vanlauwe, B. and Giller, K. E. (2006). Popular myths around soil fertility management in sub-Saharan Africa. Agriculture, Ecosystems and Environment 116:34–46.Google Scholar
Vlek, P. L. G. (1990). The role of fertilizers in sustaining agriculture in sub-Saharan Africa. Fertilizer Research 26:327–339.Google Scholar
Weil, R. R. and Mughogho, S. K. (2000). Sulphur nutrition of maize in 4 regions of Malawi. Agronomy Journal 92:649–656.Google Scholar
Waddington, S. R., Karigwindi, J. and Chifamba, J. (1998). Productivity and profitability of maize + groundnuts rotations when compared to continuous maize under smallholder management in Zimbabwe, 43–52. In Soil ertility Research for Maize based Farming Systems in Malawi and Zimbabwe. Proceedings of the Soil Fertility Research Results and Planning Workshop. 7–11 July 1997, Africa University, Mutare, Zimbabwe (Eds Waddington, S. R., Murwira, H. K., Kumwenda, J. D. T., Hikwa, D. and Tagwira, F.). Soil Fert Net and CIMMYT-Zimbabwe, Harare, Zimbabwe.Google Scholar
Whitbread, A. M., Jiri, O. and Maasdorp, B. (2004). The effect of managing improved fallows of Mucuna pruriens on maize production and soil carbon and nitrogen dynamics in sub-humid Zimbabwe. Nutrient Cycling in Agro-Ecosystems 69:59–71.Google Scholar
Zingore, S., Murwira, H. K., Delve, R. J. and Giller, K. E. (2007). Soil type, management history and current resource allocation: Three dimensions regulating variability in crop productivity on African smallholder farms. Field Crops Research 101:296–305.Google Scholar