innovations as key to the green revolution in africa3a978-90-481-2543-2%2f… · agriculture (ciat)...

Innovations as Key to the Green Revolutionin Africa

Andre Bationo · Boaz Waswa ·Jeremiah M. Okeyo · Fredah Maina ·Job KiharaEditors

Innovations as Keyto the Green Revolutionin Africa

Exploring the Scientific Facts

123

EditorsAndre BationoAlliance for a Green Revolution in Africa

(AGRA)Soil Health Program6 Agostino Neto RoadAirport Residential AreaPMB KIA 114, Airport-AccraGhanaabationo@agra-alliance.org

Boaz WaswaTropical Soil Biology and Fertility Institute

of the International Centre for TropicalAgriculture (TSBF-CIAT)

Nairobi, Kenyabswaswa@yahoo.com

Jeremiah M. OkeyoTropical Soil Biology & Fertility (TSBF)African Network for Soil Biology

and Fertility (AfNet)c/o ICRAF, Off UN AvenueP.O. Box 30677-00100Nairobi, Kenyajmosioma@gmail.com

Fredah MainaKenya Agricultural Research InstituteSocio-economics and BiometricsP.O. Box 14733-00800Nairobi, Kenyafredah.maina@yahoo.com

Job KiharaTropical Soil Biology & Fertility (TSBF)African Network for Soil Biology

and Fertility (AfNet)c/o ICRAF, Off UN AvenueP.O. Box 30677-00100Nairobi, Kenyaj.kihara@cgiar.org

Please note that some manuscripts have been previously published in the journal ‘NutrientCycling in Agroecosystems’ Special Issue “Innovations as Key to the Green Revolution inAfrica: Exploring the Scientific Facts”. (Chapters 13, 14, 19, 20, 23, 36, 42, 57, 59, 78, 80and 113)

Printed in 2 volumesISBN 978-90-481-2541-8 e-ISBN 978-90-481-2543-2DOI 10.1007/978-90-481-2543-2Springer Dordrecht Heidelberg London New York

Library of Congress Control Number: 2011930869

© Springer Science+Business Media B.V. 2011No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or byany means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without writtenpermission from the Publisher, with the exception of any material supplied specifically for the purpose ofbeing entered and executed on a computer system, for exclusive use by the purchaser of the work.

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Preface

Africa remains the only continent that did not fully benefit from the effects of theGreen Revolution experienced in the 1960s. With the 2015 deadline for the mil-lennium development goals (MDGs) rapidly approaching, the number of hungryin Africa is increasing again. Africa accounts for half of the 12 million childrenunder the age of 5 years dying each year as a consequence of chronic hunger. Foodproduction has not been able to keep pace with the ever growing human popula-tion in sub-Saharan Africa. The low and declining productivity can be attributed toAfrica’s impoverished agricultural resource base, unfavourable socioeconomic andpolicy environments for investment in agricultural sector development as well as theemerging challenges associated with unfavourable weather and climate change.

Over the last few years, various local, regional and international forums have beenheld to discuss how Africa’s Green Revolution can be achieved. The African headsof state and governments have developed the Comprehensive African AgriculturalDevelopment Program (CAADP) as a framework for agricultural growth, food secu-rity and rural development. CAADP has set a goal of 6% annual growth rate inagricultural production to reach the UN’s millennium development goal of halvingpoverty and hunger by 2015. The African Heads of State Fertilizer Summit held inAbuja Nigeria in June 2006 led to the Abuja Declaration on Fertilizer for the AfricanGreen Revolution. The Summit identified three most critical issues that need to beaddressed if millions of African farmers are to increase utilization of fertilizer. Theseare access, affordability and the use of incentives. The Summit recognized that giventhe strategic importance of fertilizers in achieving the African Green Revolution, thereis need to increase the level of use of fertilizer from the current average of 8 kgha−1 to an average of at least 50 kg ha−1 by 2015. Similar sentiments were echoedat the African Green Revolution Conference in Oslo where it was resolved to takeconcrete and concerted action towards the development of self-sustaining changesin African agricultural growth through the use of enhanced approaches to public–private partnerships. Achievement of the desired growth in agricultural productioncalls for deliberate effort to increase access and affordability of inorganic fertilizers,seed, pesticides and profitable soil, water and nutrient management technologies bythe smallholder farmers in Africa. All these components can best be explained underthe integrated soil fertility management (ISFM) approach.

Crop diversification is an important instrument for economic growth. Through theuse of biotechnology, high-yielding crop varieties have been bred with potential tosignificantly increase production. NERICA, “New Rice for Africa”, for example,is a new rice variety that has been bred through the application of biotechnology

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and offers great potential for transforming agriculture in the continent. Other high-yielding crop varieties such as maize, sorghum, millet, cowpea, soya bean, cassava,and cotton with additional benefits of being disease and insect resistant have alsobeen bred and these have the potential for increasing food production and incomesif accessed by smallholder farmers in the continent. Smallholder farmers should beempowered to confront the rapidly evolving production, consumption and marketingsystems in the global systems. Farmers need to be linked to input–output marketsand supported in order to access the required seed, fertilizer, and pesticides and alsoaccess market information and better prices for their produce. Further, there is needfor change in paradigms in development practice where participation, diversity andself-reflection are incorporated in agricultural research and development. There isneed therefore to build strong institutions among all actors in the natural resourcemanagement (NRM) sector as basis for influencing change.

Whereas numerous investments have been made in agriculture research in the con-tinent, little impact has been seen especially with wide adoption of the promisingsoil fertility and food production technologies. There is need for a shift in paradigmfrom the linear model of research-to-development to the systems approach. This callsfor agricultural innovation, which is the application of new and existing scientificand technological (S&T) knowledge to achieve the desired growth in agriculturalproduction and overall economic development in Africa.

It is against the above backdrop that the African Network for Soil Biology andFertility (AfNet) in collaboration with the Soil Fertility Consortium for SouthernAfrica (SOFECSA) organized this international symposium entitled Innovations asKey to the Green Revolution in Africa: Exploring the Scientific Facts. The overall goalof this symposium was to bring together scientists, agricultural extension staff, NGOsand policy makers from all over Africa to deliberate on the scientific facts and shareknowledge and experiences on the role of innovation in soil fertility replenishment asa key to the Green Revolution in Africa.

The specific objectives of the symposium were the following:

1. To assess the potential and feasibility of use of external input and improved soiland crop management to achieve the African Green Revolution

2. To identify and learn about innovative approaches needed to build rural inputmarket infrastructure

3. To review the main policy, institutional, financial, infrastructural and marketconstraints that limit access to innovations by poor farmers

4. To evaluate strategies for scaling out innovations to millions of poor farmers in thecontinent

The symposium was organized under four main themes, namely the following:

1. Constraints and opportunities towards the African Green Revolution2. Potential and feasibility of use of external input and improved soil and crop

management to achieve the African Green Revolution3. Factors that limit access to and adoption of innovations by poor farmers4. Innovations and their scaling-up/out in Africa

The symposium held in Arusha, Tanzania (17–21 September 2007), was attendedby over 230 participants drawn from 20 African countries (Benin, Botswana, Burkina

Preface vii

Faso, Cameroon, Democratic Republic of Congo, Ethiopia, Ghana, Niger, Uganda,Ivory Coast, Kenya, Malawi, Mali, Namibia, Nigeria, Rwanda, Senegal, SouthAfrica, Tanzania and Zimbabwe), Europe (Belgium, France, Netherlands, Norway,Scotland and Sweden), North and South America (Canada, Colombia and USA),Asia (Japan) and Australia. The symposium was also attended by representativesfrom the Bill and Melinda Gates Foundation; CG centres (The World AgroforestryCentre – ICRAF, International Centre for Research in Semiarid Tropics – ICRISAT,International Institute of Tropical Agriculture – IITA, Africa Rice Center – WARDA,International Maize and Wheat Improvement Centre – CIMMYT, InternationalLivestock Research Institute – ILRI, International Centre for Tropical Agriculture –IITA, CIAT); advanced research organizations (Norwegian Institute of Agriculture,JIRCAS); international NGOs (Catholic Relief Services, IFDC, UNDP, AFRICARE,AVRDC – The World Vegetable Centre, United Nations Economic Commission forAfrica – UNECA); universities (KTH University, Cornell University, WageningenUniversity, Columbia University, University of Aberdeen and La Trobe University)and the private sector (YARA, IFA, Chemplex Corporation Ltd).

This book presents papers of the symposium organized under the above fourthemes. It is worth noting that a selection of 12 papers at this symposium have beenpublished in the special issue of Nutrient Cycling in Agroecosystem Journal (Volume88, No. 1) titled: Innovations as Key to the Green Revolution in Africa: Exploring theScientific Facts.

It is the our hope that the knowledge and wealth of experiences presented in thisbook and the special issue will enlighten the reader and other development partners inSSA to make informed choices that will result in the desired growth in the agriculturalsector.

Nairobi, Kenya Nteranya SangingaNairobi, Kenya Akin Adesina

Acknowledgements

The organizers would like to thank the Alliance for a Green Revolution in Africa(AGRA), the Canadian International Development Agency (CIDA), the InternationalDevelopment Research Centre (IDRC), the Ford Foundation (FF), InternationalFoundation for Science (IFS), the Technical Centre for Agricultural and RuralCooperation (CTA), the Rockefeller Foundation, Syngenta Foundation, Forum forAgricultural Research in Africa (FARA), the International Centre for TropicalAgriculture (CIAT) and the Tropical Soil Biology and Fertility (TSBF) for their finan-cial contributions towards the organization of the symposium. We would also liketo thank the Ministry of Agriculture Food Security and Cooperatives, Tanzania, forhosting this symposium and the local organizing committee for the logistical support.

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Contents

Volume 1

Part I Constraints and Opportunities for the African Green Revolution

New Challenges and Opportunities for Integrated Soil FertilityManagement in Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3A. Bationo and B.S. Waswa

Meeting the Demands for Plant Nutrients for an African GreenRevolution: The Role of Indigenous Agrominerals . . . . . . . . . . . . . 19A.U. Mokwunye and A. Bationo

The Geological Basis of Farming in Africa . . . . . . . . . . . . . . . . . . 31P. van Straaten

The Challenges Facing West African Family Farms in AccessingAgricultural Innovations: Institutional and Political Implications . . . . . 49S.J. Zoundi and L. Hitimana

Achieving an African Green Revolution: A Perspectivefrom an Agri-Input Supplier . . . . . . . . . . . . . . . . . . . . . . . . . 63E. Makonese and K. Sukalac

The African Green Revolution and the Role of Partnershipsin East Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71J.R. Okalebo, C.O. Othieno, S.O. Gudu, P.L. Woomer, N.K. Karanja,C. Serrem, H.K. Maritim, N. Sanginga, A. Bationo, R.M. Muasya,A.O. Esilaba, A. Adesina, P.O. Kisinyo, A.O. Nekesa, M.N. Thuita,and B.S. Waswa

Optimizing Agricultural Water Management for the GreenRevolution in Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83B.M. Mati

Ex-ante Evaluation of the Impact of a Structural Changein Fertilizer Procurement Method in Sub-Saharan Africa . . . . . . . . . 95J. Chianu, A. Adesina, P. Sanginga, A. Bationo, and N. Sanginga

Preparing Groups of Poor Farmers for Market Engagement:Five Key Skill Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103J. Ashby, G. Heinrich, G. Burpee, T. Remington, S. Ferris,K. Wilson, and C. Quiros

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Fertilizer Microdosing and “Warrantage” or Inventory CreditSystem to Improve Food Security and Farmers’ Incomein West Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113R. Tabo, A. Bationo, B. Amadou, D. Marchal, F. Lompo, M. Gandah,O. Hassane, M.K. Diallo, J. Ndjeunga, D. Fatondji, B. Gerard,D. Sogodogo, J.-B.S. Taonda, K. Sako, S. Boubacar, A. Abdou,and S. Koala

African Green Revolution Requires a Secure Source ofPhosphorus: A Review of Alternative Sources and ImprovedManagement Options of Phosphorus . . . . . . . . . . . . . . . . . . . . . 123A.S. Jeng

Part II Potential and Feasibility of Use of ExternalInput and Improved Soil and CropManagement to Achieve the African Green Revolution

Soybean Varieties, Developed in Lowland West Africa, RetainTheir Promiscuity and Dual-Purpose Nature Under HighlandConditions in Western Kenya . . . . . . . . . . . . . . . . . . . . . . . . . 133B. Vanlauwe, J. Mukalama, R.C. Abaidoo, and N. Sanginga

Long-Term Effect of Continuous Cropping of Irrigated Riceon Soil and Yield Trends in the Sahel of West Africa . . . . . . . . . . . . 145B.V. Bado, A. Aw, and M. Ndiaye

Conservation Tillage, Local Organic Resources, and NitrogenFertilizer Combinations Affect Maize Productivity, Soil Structureand Nutrient Balances in Semi-arid Kenya . . . . . . . . . . . . . . . . . 155J. Kihara, A. Bationo, D.N. Mugendi, C. Martius, and P.L.G. Vlek

Long-Term Land Management Effects on Crop Yields and SoilProperties in the Sub-humid Highlands of Kenya . . . . . . . . . . . . . . 169C.N. Kibunja, F.B. Mwaura, D.N. Mugendi, D.K. Wamae,and A. Bationo

Integrated Management of Fertilizers, Weed and Rice GenotypesCan Improve Rice Productivity . . . . . . . . . . . . . . . . . . . . . . . . 175B.V. Bado, K. Traore, M.E. Devries, A. Sow,and S. Gaye

Integrated Soil Fertility Management for Increased MaizeProduction in the Degraded Farmlands of the Guinea SavannaZone of Ghana Using Devil-Bean (Crotalaria retusa)and Fertilizer Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183B.D.K. Ahiabor, M. Fosu, E. Atsu, I. Tibo, and I. Sumaila

Effect of Organic Inputs and Mineral Fertilizer on Maize Yieldin a Ferralsol and a Nitisol Soil in Central Kenya . . . . . . . . . . . . . . 191M. Mucheru-Muna, D.N. Mugendi, P. Pypers, J. Mugwe,B. Vanlauwe, R. Merckx, and J.B. Kung’u

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Effects of Conservation Tillage, Crop Residue and CroppingSystems on Changes in Soil Organic Matter and Maize–LegumeProduction: A Case Study in Teso District . . . . . . . . . . . . . . . . . . 205H. Anyanzwa, J.R. Okalebo, C.O. Othieno, A. Bationo, B.S. Waswa,and J. Kihara

Benefits of Integrated Soil Fertility and Water Managementin Semi-arid West Africa: An Example Study in Burkina Faso . . . . . . 215R. Zougmoré, A. Mando, and L. Stroosnijder

Survival and Soil Nutrient Changes During 5 Years of Growthof 16 Faidherbia albida Provenances in Semi-Arid BaringoDistrict, Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227O.G. Dangasuk, S.O. Gudu, and J.R. Okalebo

The ‘Secret’ Behind the Good Performance of Tithonia diversifoliaon P Availability as Compared to Other Green Manures . . . . . . . . . . 235S.T. Ikerra, E. Semu, and J.P. Mrema

Biological Nitrogen Fixation Potential by Soybeans in Two Low-PSoils of Southern Cameroon . . . . . . . . . . . . . . . . . . . . . . . . . . 245M. Jemo, C. Nolte, M. Tchienkoua, and R.C. Abaidoo

Roles for Herbaceous and Grain Legumes, Kraal Manure,and Inorganic Fertilizers for Soil Fertility Managementin Eastern Uganda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255K.C. Kaizzi, J. Byalebeka, C.S. Wortmann, and M. Mamo

The Effects of Integration of Organic and Inorganic Sourcesof Nutrient on Maize Yield in Central Kenya . . . . . . . . . . . . . . . . 265A.N. Kathuku, S.K. Kimani, J.R. Okalebo, C.O. Othieno, and B. Vanlauwe

Forage Legume–Cereal Double Cropping in Bimodal RainfallHighland Tropics: The Kenyan Case . . . . . . . . . . . . . . . . . . . . . 271M.J. Khaemba, S.M. Mwonga, L.M. Mumera, and L. Nakhone

Effects of Conservation Tillage, Fertilizer Inputs and CroppingSystems on Soil Properties and Crop Yield in Western Kenya . . . . . . . 281H.K. Githinji, J.R. Okalebo, C.O. Othieno, A. Bationo,J. Kihara, and B.S. Waswa

Effect of Manure Application on Soil Nitrogen Availability toIntercropped Sorghum and Cowpea at Three Sites in Eastern Kenya . . . 289F.M. Kihanda and G.P. Warren

The Effect of Organic-Based Nutrient Management Strategies onSoil Nutrient Availability and Maize Performance in Njoro, Kenya . . . . 299J.J. Lelei, R.N. Onwonga, and B. Freyer

Using Forage Legumes to Improve Soil Fertility for EnhancedGrassland Productivity of Semi-arid Rangelands of KajiadoDistrict, Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309P.N. Macharia, C.K.K. Gachene, and J.G. Mureithi

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Potential of Cowpea, Pigeonpea and Greengram to ContributeNitrogen to Maize in Rotation on Ferralsol in Tanga – Tanzania . . . . . 317A.E.T. Marandu, J.P. Mrema, E. Semu, and A.S. Nyaki

Model Validation Through Long-Term Promising SustainableMaize/Pigeon Pea Residue Management in Malawi . . . . . . . . . . . . . 325C.D. Mwale, V.H. Kabambe, W.D. Sakala, K.E. Giller, A.A. Kauwa,I. Ligowe, and D. Kamalongo

Use of Tithonia Biomass, Maize Residues and Inorganic Phosphatein Climbing Bean Yield and Soil Properties in Rwanda . . . . . . . . . . 335N.L. Nabahungu, J.G. Mowo, A. Uwiragiye, and E. Nsengumuremyi

The Potential of Increased Maize and Soybean Productionin Uasin Gishu District, Kenya, Resulting from Soil AcidityAmendment Using Minjingu Phosphate Rock and Agricultural Lime . . 343A.O. Nekesa, J.R. Okalebo, C.O. Othieno, M.N. Thuita, A. Bationo,and B.S. Waswa

Residual Effects of Contrasting Organic Residues on MaizeGrowth and Phosphorus Accumulation over Four CroppingCycles in Savanna Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349O.C. Nwoke, R.C. Abaidoo, G. Nziguheba, and J. Diels

Interactive Effects of Selected Nutrient Resources andTied-Ridging on Plant Growth Performance in a Semi-aridSmallholder Farming Environment in Central Zimbabwe . . . . . . . . . 357J. Nyamangara and I. Nyagumbo

In Vitro Selection of Soybean Accessions for Inductionof Germination of Striga hermonthica (Del.) Benth Seedsand Their Effect on Striga hermonthica Attachmenton Associated Maize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365J.A. Odhiambo, B. Vanlauwe, I.M. Tabu, F. Kanampiu, and Z. Khan

Innovations in Cassava Production for Food Security and ForestConservation in Western Côte D’ivoire . . . . . . . . . . . . . . . . . . . 373A. Ayemou, A. Tschannen, I. Kone, D. Allou, B. Akpatou, and G. Cisse

Promoting Uses of Indigenous Phosphate Rock for Soil FertilityRecapitalisation in the Sahel: State of the Knowledge on theReview of the Rock Phosphates of Burkina Faso . . . . . . . . . . . . . . 381M. Bonzi, F. Lompo, N. Ouandaogo, and P.M. Sédogo

Selecting Indigenous P-Solubilizing Bacteria for Cowpeaand Millet Improvement in Nutrient-Deficient Acidic Soilsof Southern Cameroon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391H. Fankem, M. Abba, L. Ngo Nkot, A. Deubel, W. Merbach,F.-X. Etoa, and D. Nwaga

Evaluation of Human Urine as a Source of Nitrogenin the Co-composting of Pine Bark and Lawn Clippings . . . . . . . . . . 399A.O. Fatunbi and P.N.S. Mnkeni

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Extractable Bray-1 Phosphorus and Crop Yields as Influencedby Addition of Phosphatic Fertilizers of Various SolubilitiesIntegrated with Manure in an Acid Soil . . . . . . . . . . . . . . . . . . . 409E.W. Gikonyo, A.R. Zaharah, M.M. Hanafi, and A.R. Anuar

Seedbed Types and Integrated Nutrient Management Optionsfor Cowpea Production in the Southern Rangelands of Semi-aridEastern Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421C.M. Githunguri, A.O. Esilaba, L.M. Kimotho, and L.M. Mutuku

Land and Water Management Research and Developmentin Arid and Semi-arid Lands of Kenya . . . . . . . . . . . . . . . . . . . . 427J.K. Itabari, K. Kwena, A.O. Esilaba, A.N. Kathuku, L. Muhammad,N. Mangale, and P. Kathuli

Evaluation of Establishment, Biomass Productivity and Qualityof Improved Fallow Species in a Ferralic Arenosol at CoastalRegion in Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439C. Walela, J.K. Ndufa, K. Balozi, O.V. Oeba, and M. Welimo

Assessment of Potato Bacterial Wilt Disease Status in North RiftValley of Kenya: A Survey . . . . . . . . . . . . . . . . . . . . . . . . . . 449T.K. Kwambai, M.E. Omunyin, J.R. Okalebo, Z.M. Kinyua,and P. Gildemacher

Soil Fertility Variability in Relation to the Yields ofMaize and Soybean Under Intensifying Cropping Systemsin the Tropical Savannas of Northeastern Nigeria . . . . . . . . . . . . . . 457J.D. Kwari, A.Y. Kamara, F. Ekeleme, and L. Omoigui

An Evaluation of Lucerne Varieties Suitable for DifferentAgro-ecological Zones in Kenya . . . . . . . . . . . . . . . . . . . . . . . 465B.A. Lukuyu, J.N. Methu, D. Mwangi, J. Kirui, S.W. Mwendia,J. Wamalwa, A. Kavatha, G.N. Ngae, and G.N. Mbure

Water Harvesting and Integrated Nutrient Management Optionsfor Maize–Cowpea Production in Semi-arid Eastern Kenya . . . . . . . . 473J.M. Miriti, A.O. Esilaba, A. Bationo, H.K. Cheruiyot,A.N. Kathuku, and P. Wakaba

The Potential of Ipomoea stenosiphon as a Soil FertilityAmeliorant in the Semi-arid Tropics . . . . . . . . . . . . . . . . . . . . . 481T. Mombeyarara, H.K. Murwira, and P. Mapfumo

Effect of Al Concentration and Liming Acid Soils on the Growthof Selected Maize Cultivars Grown on Sandy Soils in Southern Africa . . 491C. Musharo and J. Nyamangara

The Role of Biological Technologies in Land QualityManagement: Drivers for Farmer’s Adoption in the CentralHighlands of Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501J.K. Mutegi, D.N. Mugendi, L.V. Verchot, and J.B. Kung’u

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Biophysical Characterization of Oasis Soils for Efficient Use ofExternal Inputs in Marsabit District: Their Potentials and Limitations . . 513E.M. Muya, J.K. Lelon, M.G. Shibia, A.O. Esilaba, M. Okoti,G.N. Gachini, and A.L. Chek

Multi-functional Properties of Mycorrhizal Fungifor Crop Production: The Case Study of Banana Developmentand Drought Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523D. Nwaga, A. Tenkouano, K. Tomekpe, R. Fogain, D.M. Kinfack,G. Tsané, and O. Yombo

Effect of Phosphorus Sources and Rates on Sugarcane Yieldand Quality in Kibos, Nyando Sugar Zone . . . . . . . . . . . . . . . . . . 533J.O. Omollo and G.O. Abayo

Natural and Entropic Determinants of Soil Carbon Stocks in TwoAgro-Ecosystems in Burkina Faso . . . . . . . . . . . . . . . . . . . . . . 539S. Youl, E. Hien, R.J. Manlay, D. Masse, V. Hien, and C. Feller

Integrated soil fertility management involving promiscuousdual-purpose soybean and upland NERICA enhanced riceproductivity in the savannas . . . . . . . . . . . . . . . . . . . . . . . . . 553S.O. Oikeh, P. Houngnandan, R.C. Abaidoo, I. Rahimou, A. Touré,A. Niang, and I. Akintayo

Nitrogen Use in Maize (Zea mays)–Pigeonpea (Cajanus cajans)Intercrop in Semi-arid Conditions of Kenya . . . . . . . . . . . . . . . . . 563S.W. Wanderi, M.W.K. Mburu, S.N. Silim, and F.M. Kihanda

Nitrogen and phosphorus capture and recovery efficiencies,and crop responses to a range of soil fertility managementstrategies in sub-Saharan Africa . . . . . . . . . . . . . . . . . . . . . . . 571R. Chikowo, M. Corbeels, P. Mapfumo, P. Tittonell, B. Vanlauwe,and K.E. Giller

Greenhouse Evaluation of Agronomic Effectivenessof Unacidulated and Partially Acidulated PhosphateRock from Kodjari and the Effect of Mixed Crop on Plant P Nutrition . . 591E. Compaore, J.-C. Fardeau, and J.-L. Morel

Effect of Continuous Mineral and Organic Fertilizer Inputsand Plowing on Groundnut Yield and Soil Fertility in aGroundnut–Sorghum Rotation in Central Burkina Faso . . . . . . . . . . 597E. Compaore, P. Cattan, and J.-B.S. Taonda

Soil Inorganic N and N Uptake by Maize Following Applicationof Legume Biomass, Tithonia, Manure and Mineral Fertilizerin Central Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605J. Mugwe, D.N. Mugendi, M. Mucheru-Muna, and J.B. Kung’u

Changes in δδδ15N and N Nutrition in Nodulated Cowpea (Vignaunguiculata L. Walp.) and Maize (Zea mays L.) Grown in MixedCulture with Exogenous P Supply . . . . . . . . . . . . . . . . . . . . . . 617P.A. Ndakidemi and F.D. Dakora

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Cation Flux in Incubated Plant Residues and Its Effect on pHand Plant Residue Alkalinity . . . . . . . . . . . . . . . . . . . . . . . . . 631G.M. Sakala, D.L. Rowell, and C.J. Pilbeam

A Study of the Agronomic Efficiency of Human Stool and Urineon Production of Maize and Egg Plant in Burkina Faso . . . . . . . . . . 641M. Bonzi, F. Lompo, I.D. Kiba, A. Kone, N. Ouandaogo, and P.M. Sédogo

Potential for Reuse of Human Urine in Peri-urban Farming . . . . . . . . 651O. Semalulu, M. Azuba, P. Makhosi, and S. Lwasa

Towards Sustainable Land Use in Vertisols in Kenya: Challengesand Opportunities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661E.C. Ikitoo, J.R. Okalebo, and C.O. Othieno

Potential Nitrogen Contribution of Climbing Bean to SubsequentMaize Crop in Rotation in South Kivu Province of DemocraticRepublic of Congo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677L. Lunze and M. Ngongo

Investigation on the Germination of Zanthoxylum gilletii (AfricanSatinwood) Seed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 683M.M. Okeyo, J.O. Ochoudho, R.M. Muasya, and W.O. Omondi

Combining Ability for Grain Yield of Imidazolinone-ResistantMaize Inbred Lines Under Striga (Striga hermonthica) Infestation . . . . 693I.H. Rwiza, M. Mwala, and A. Diallo

Identification of Plant Genetic Resources with High PotentialContribution to Soil Fertility Enhancement in the Sahel, withSpecial Interest in Fallow Vegetation . . . . . . . . . . . . . . . . . . . . . 701S. Tobita, H. Shinjo, K. Hayashi, R. Matsunaga, R. Miura, U. Tanaka,T. Abdoulaye, and O. Ito

Within-Farm Variability in Soil Fertility Managementin Smallholder Farms of Kirege Location, Central Highlands of Kenya . 707J.M. Muthamia, D.N. Mugendi, and J.B. Kung’u

Residual Effects of Applied Phosphorus Fertilizer on Maize GrainYield and Phosphorus Recovery from a Long-Term Trialin Western Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 717W.M.H. Kamiri, P. Pypers, and B. Vanlauwe

Combined Effect of Organic and Inorganic Fertilizers on SoilChemical and Biological Properties and Maize Yield in Rubona,Southern Rwanda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 729A. Mukuralinda, J.S. Tenywa, L.V. Verchot, and J. Obua

Phenotypic Characterization of Local Maize Landracesfor Drought Tolerance in Kenya . . . . . . . . . . . . . . . . . . . . . . . 741I.M. Tabu, S.W. Munyiri, and R.S. Pathak

Targeting Resources Within Diverse, Heterogeneous and DynamicFarming Systems: Towards a ‘Uniquely African Green Revolution’ . . . 747P. Tittonell, B. Vanlauwe, M. Misiko, and K.E. Giller

xviii Contents

Exploring Crop Yield Benefits of Integrated Water and NutrientManagement Technologies in the Desert Margins of Africa:Experiences from Semi-arid Zimbabwe . . . . . . . . . . . . . . . . . . . 759I. Nyagumbo and A. Bationo

Population dynamics of mixed indigenous legume fallows andinfluence on subsequent maize following mineral P application insmallholder farming systems of Zimbabwe . . . . . . . . . . . . . . . . . 773T.P. Tauro, H. Nezomba, F. Mtambanengwe, and P. Mapfumo

Formulating Crop Management Options for Africa’sDrought-Prone Regions: Taking Account of Rainfall RiskUsing Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 785J. Dimes

Residue quality and N fertilizer do not influence aggregatestabilization of C and N in two tropical soils with contrasting texture . . . 795R. Gentile, B. Vanlauwe, A. Kavoo, P. Chivenge, and J. Six

Interaction Between Resource Quality, Aggregate Turnover,Carbon and Nitrogen Cycling in the Central Highlands of Kenya . . . . . 807A. Kavoo, D.N. Mugendi, G. Muluvi, B. Vanlauwe, J. Six,R. Merckx, R. Gentile, and W.M.H. Kamiri

Performances of Cotton–Maize Rotation System as Affected byPloughing Frequency and Soil Fertility Management in Burkina Faso . . 817K. Ouattara, G. Nyberg, B. Ouattara, P.M. Sédogo, and A. Malmer

Developing Standard Protocols for Soil Quality Monitoringand Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833B.N. Moebius-Clune, O.J. Idowu, R.R. Schindelbeck, H.M. van Es,D.W. Wolfe, G.S. Abawi, and B.K. Gugino

Increasing Productivity Through Maize–Legume Intercroppingin Central Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 843M. Mucheru-Muna, D.N. Mugendi, P. Pypers,J. Mugwe, B. Vanlauwe, R. Merckx, and J.B. Kung’u

Contributions of Cowpea and Fallow to Soil FertilityImprovement in the Guinea Savannah of West Africa . . . . . . . . . . . 859B.V. Bado, F. Lompo, A. Bationo, Z. Segda,P.M. Sédogo, and M.P. Cescas

Volume 2

Part III Limitations to Access and Adoption of Innovationsby Poor Farmers

Some Facts About Fertilizer Use in Africa: The Caseof Smallholder and Large-Scale Farmers in Kenya . . . . . . . . . . . . . 869P.F. Okoth, E. Murua, N. Sanginga, J. Chianu, J.M. Mungatu,P.K. Kimani, and J.K. Ng’ang’a

Contents xix

Farm Input Market System in Western Kenya: Constraints,Opportunities, and Policy Implications . . . . . . . . . . . . . . . . . . . 879J. Chianu, F. Mairura, and I. Ekise

Gender Differentials in Adoption of Soil Nutrient ReplenishmentTechnologies in Meru South District, Kenya . . . . . . . . . . . . . . . . . 887E.G. Kirumba, D.N. Mugendi, R. Karega, and J. Mugwe

Enhancing Agricultural Production Potential Through Nutritionand Good Health Practice: The Case of Suba District in Kenya . . . . . . 897O. Ohiokpehai, T. Hongo, J. Kamau, G. Were, J. Kimiywe,B. King’olla, D. Mbithe, L. Oteba, G. Mbagaya, and O. Owuor

Linking Policy, Research, Agribusiness and Processing Enterpriseto Develop Mungbean (Vigna radiata) Production as Export Cropfrom Senegal River Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . 905M. Cisse, M. Diouf, T. Gueye, and A. Fall

Prioritizing Research Efforts to Increase On-Farm IncomeGeneration: The Case of Cassava-Based Farmers in Peri-urbanSouthern Cameroon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 913J.W. Duindam and S. Hauser

Policy Framework for Utilization and Conservationof Below-Ground Biodiversity in Kenya . . . . . . . . . . . . . . . . . . . 921C. Achieng, P.F. Okoth, A. Macharia, and S. Otor

Policy Issues Affecting Integrated Natural Resource Managementand Utilization in Arid and Semi-arid Lands of Kenya . . . . . . . . . . . 927J.W. Munyasi, A.O. Esilaba, L. Wekesa, and W. Ego

Stakeholder Characterisation of the Biophysicaland Socio-economic Potential of the Desert Margins in Kenya . . . . . . . 935J.W. Onyango, A.O. Esilaba, and P.K. Kimani

Soil Fertility Management in the Region of Gourma, BurkinaFaso, West Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 947M. Traoré, T.G. Ouattara, E. Zongo, and S. Tamani

Understanding Cassava Yield Differences at Farm Level: Lessonsfor Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 957A. Babirye and A.M. Fermont

Organic Matter Utilisation and the Determinants of OrganicManure Use by Farmers in the Guinea Savanna Zone of Nigeria . . . . . 965A. Bala, A.O. Osunde, and A.J. Odofin

Innovativeness of Common Interest Groups in North Rift Kenya:A Case of Trans-Nzoia District . . . . . . . . . . . . . . . . . . . . . . . . 975L.W. Mauyo, J.M. Wanyama, C.M. Lusweti, and J.N. Nzomoi

Economic Analysis of Improved Potato Technologies in Rwanda . . . . . 985R.J. Mugabo, D. Mushabizi, M. Gafishi, J. Chianu, and E. Tollens

xx Contents

Assessment of Occupational Safety Concerns in Pesticide UseAmong Small-Scale Farmers in Sagana, Central Highlands, Kenya . . . . 993P. Mureithi, F. Waswa, and E. Kituyi

Variation in Socio-economic Characteristics and NaturalResource Management in Communities with Different PotatoMarket Linkages in the Highlands of Southwestern Uganda . . . . . . . . 999R. Muzira, B. Vanlauwe, S.M. Rwakaikara, T. Basamba,J. Chianu, and A. Farrow

Crop Rotation of Leguminous Crops as a Soil Fertility Strategyin Pearl Millet Production Systems . . . . . . . . . . . . . . . . . . . . . . 1009L.N. Horn and T.E. Alweendo

Participatory Variety Selection of Pulses Under Different Soiland Pest Management Practices in Kadoma District, Zimbabwe . . . . . 1015L. Rusinamhodzi and R.J. Delve

Economic Returns of the “MBILI” Intercropping Comparedto Conventional Systems in Western Kenya . . . . . . . . . . . . . . . . . 1023M.N. Thuita, J.R. Okalebo, C.O. Othieno, M.J. Kipsat, and A.O. Nekesa

Bio-socio-economic Factors Influencing Tree Productionin Southeastern Drylands of Kenya . . . . . . . . . . . . . . . . . . . . . . 1035L. Wekesa, J. Mulatya, and A.O. Esilaba

Economic Evaluation of the Contribution of Below-GroundBiodiversity: Case Study of Biological Nitrogen Fixation by Rhizobia . . 1043J. Chianu, J. Huising, S. Danso, P.F. Okoth, and N. Sanginga

Farmers’ Perception of Soil Fertility Depletion and Its Influenceon Uptake of Integrated Soil Nutrient Management Techniques:Evidence from Western Kenya . . . . . . . . . . . . . . . . . . . . . . . . 1055M. Odendo, G. Obare, and B. Salasya

Taking Soil Fertility Management Technologies to the Farmers’Backyard: The Case of Farmer Field Schools in Western Kenya . . . . . 1061M. Odendo and G. Khisa

Status and Trends of Technological Changes Among Small-ScaleFarmers in Tanzania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1069E.J. Maeda

The Dilemma of Using Fertilizer to Power the Green Revolutionin Sub-Saharan Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1077D.K. Musembi

Overcoming Market Constraint for Pro-poor AgriculturalGrowth in the Eastern DR Congo, South Kivu . . . . . . . . . . . . . . . 1083P.M. Njingulula and E. Kaganzi

Constraints in Chickpea Transportation in the Lake Zoneof Tanzania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1091A. Babu, T. Hyuha, and I. Nalukenge

Contents xxi

Part IV Innovation Approaches and Their Scaling Up/Out in Africa

Micro-dosing as a pathway to Africa’s Green Revolution:evidence from broad-scale on-farm trials . . . . . . . . . . . . . . . . . . 1101S. Twomlow, D. Rohrbach, J. Dimes, J. Rusike, W. Mupangwa,B. Ncube, L. Hove, M. Moyo, N. Mashingaidze, and P. Mahposa

The Dryland Eco-Farm: A Potential Solution to the MainConstraints of Rain-Fed Agriculture in the Semi-AridTropics of Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1115D. Fatondji, D. Pasternak, A. Nikiema, D. Senbeto, L. Woltering,J. Ndjeunga, and S. Abdoussalam

Effect of Zai Soil and Water Conservation Technique on WaterBalance and the Fate of Nitrate from Organic AmendmentsApplied: A Case of Degraded Crusted Soils in Niger . . . . . . . . . . . . 1125D. Fatondji, C. Martius, P.L.G. Vlek, C.L. Bielders, and A. Bationo

Counting Eggs? Smallholder Experiments and Tryouts as SuccessIndicators of Adoption of Soil Fertility Technologies . . . . . . . . . . . . 1137M. Misiko and P. Tittonell

Improving Smallholder Farmers’ Access to Informationfor Enhanced Decision Making in Natural ResourceManagement: Experiences from Southwestern Uganda . . . . . . . . . . 1145K.F.G. Masuki, J.G. Mowo, R. Sheila, R. Kamugisha, C. Opondo,and J. Tanui

Market Access: Components, Interactions, and Implicationsin Smallholder Agriculture in the Former Homeland Areaof South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1161A. Obi, P. Pote, and J. Chianu

Improving African Agricultural Market and Rural LivelihoodThrough Warrantage: Case Study of Jigawa State, Nigeria . . . . . . . . . 1169M.A. Adamu and J. Chianu

The Desert Margins Programme Approaches in UpscalingBest-Bet Technologies in Arid and Semi-arid Lands in Kenya . . . . . . . 1177A.O. Esilaba, M. Okoti, D.M. Nyariki, G.A. Keya, J.M. Miriti,J.N. Kigomo, G. Olukoye, L. Wekesa, W. Ego, G.M. Muturi,and H.K. Cheruiyot

Soil Organic Inputs and Water Conservation Practices Are theKeys of the Sustainable Farming Systems in the Sub-SahelianZone of Burkina Faso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1193E. Hien, D. Masse, W.T. Kabore, P. Dugue, and M. Lepage

Intercropping Grain Amaranth (Amaranthus dubius)with Soybean (Glycine max) for Sustainability and ImprovedLivelihoods in Western Kenya . . . . . . . . . . . . . . . . . . . . . . . . 1203M.N. Ng’ang’a, O. Ohiokpehai, R.M. Muasya, and E. Omami

xxii Contents

Soil Conservation in Nigeria: Assessment of Pastand Present Initiatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1211B. Junge, O. Deji, R.C. Abaidoo, D. Chikoye, and K. Stahr

Effect of Farmer Resource Endowment and ManagementStrategies on Spatial Variability of Soil Fertility in ContrastingAgro-ecological Zones in Zimbabwe . . . . . . . . . . . . . . . . . . . . . 1221E.N. Masvaya, J. Nyamangara, R.W. Nyawasha, S. Zingore,R.J. Delve, and K.E. Giller

Empowering Farmers in Monitoring and Evaluationfor Improved Livelihood: Case Study of Soil and WaterManagement in Central Kenya . . . . . . . . . . . . . . . . . . . . . . . . 1231F.M. Matiri and F.M. Kihanda

Effectiveness of “PREP-PAC” Soil Fertility ReplenishmentProduct on Performance of the Diversified Maize–LegumeIntercrops in Western Kenya . . . . . . . . . . . . . . . . . . . . . . . . . 1241E.J. Rutto, J.R. Okalebo, C.O. Othieno, M.J. Kipsat, and A. Bationo

Risk Preference and Optimal Crop Combinations for SmallholderFarmers in Umbumbulu District, South Africa: An Applicationof Stochastic Linear Programming . . . . . . . . . . . . . . . . . . . . . . 1249M. Kisaka-Lwayo

Scaling Out Integrated Soil Nutrient and Water ManagementTechnologies Through Farmer Participatory Research:Experiences from Semi-arid Central Zimbabwe . . . . . . . . . . . . . . 1257I. Nyagumbo, J. Nyamangara, and J. Rurinda

Reducing the Risk of Crop Failure for Smallholder Farmersin Africa Through the Adoption of Conservation Agriculture . . . . . . . 1269C. Thierfelder and P.C. Wall

Dissemination of Integrated Soil Fertility ManagementTechnologies Using Participatory Approaches in the CentralHighlands of Kenya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1279D.N. Mugendi, J. Mugwe, M. Mucheru-Muna, R. Karega, J. Muriuki,B. Vanlauwe, and R. Merckx

Success Stories: A Case of Adoption of Improved Varietiesof Maize and Cassava in Kilosa and Muheza Districts,Eastern Tanzania . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1297C.Z. Mkangwa, P.K. Kyakaisho, and C. Milaho

The Role of Forest Resources in the Strategies of RuralCommunities Coping with the HIV/AIDS Epidemicin Sub-Saharan Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1303J.B. Kung’u

Farmer Managed Natural Regeneration in Niger: A Keyto Environmental Stability, Agricultural Intensification,and Diversification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1311M. Larwanou and C. Reij

Contents xxiii

Achieving a Green Revolution in Southern Africa: Role of Soiland Water Conservation in Enhancing Agricultural Productivityand Livelihoods in Semi-arid Areas of Malawi . . . . . . . . . . . . . . . 1321A. Kabuli and M.A.R. Phiri

Managing Soil and Water Through Community TreeEstablishment and Management: A Case of Agabu and KandotaVillages in Ntcheu District, Malawi . . . . . . . . . . . . . . . . . . . . . . 1331H.J. Kabuli and W. Makumba

Adoption and Up-Scaling of Water Harvesting TechnologiesAmong Small-Scale Farmers in Northern Kenya . . . . . . . . . . . . . . 1337M.G. Shibia, G.S. Mumina, M. Ngutu, M. Okoti, and Helge Recke

Social and Economic Factors for the Adoption of AgroforestryPractices in Lake Victoria Catchment, Magu, Tanzania . . . . . . . . . . 1345A.J. Tenge, M.C. Kalumuna, and C.A. Shisanya

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1353

About the Organizers

The African Network for Soil Biology and Fertility (AfNet)

The African Network for Soil Biology and Fertility (AfNet) was established in1988 as a pan-African network of researchers in sub-Saharan Africa. AfNet is thesingle most important implementing agency of Tropical Soil Biology and FertilityInstitute of the International Centre for Tropical Agriculture (TSBF-CIAT) in Africa.More recently, a Memorandum of Understanding (MOU) was signed between theForum for Agricultural Research in Africa (FARA) and The International Centre forTropical Agriculture (CIAT) for hosting AfNet under the umbrella of FARA. Sinceits inception, AfNet has grown steadily and the current membership stands at over400 scientists. The network aims at strengthening and sustaining stakeholder capacityto generate, share and apply soil fertility management knowledge and skills to con-tribute to the welfare of farming communities in the Africa. This is achieved throughthe adoption of the integrated soil fertility management (ISFM), a holistic approach tosoil fertility that embraces the full range of driving factors and consequences, namelybiological, physical, chemical, social, economic and policy aspects of soil fertility.

The main activities of AfNet are the following:

(i) Research and development activities: Network trials are scattered in morethan 100 sites across the continent. The research is undertaken in collabora-tion with national agricultural research systems (NARS), scientists, farmers,non-governmental organizations (NGOs), local and foreign universities andadvanced research institutes (AROs). Other partners include the CGIAR cen-tres, system-wide programmes (SWPs), challenge programmes (CPs) and othernetworks. The main research themes include soil fertility management, nutri-ent use efficiency, conservation agriculture, targeting of recommendations tofarmers and scaling-up success stories, among others.

(ii) Capacity building: AfNet’s capacity building agenda is achieved throughdegree-oriented training (M.Sc. and Ph.D. research) in the domain of ISFMas well as through short courses. Over the years, AfNet offered several train-ing courses on topics such as participatory research and scaling-up, decisionsupport systems (DSSAT), proposal and scientific writing, presentation skills,soil erosion and carbon sequestration and nutrient monitoring (NUTMON) inagro-ecosystems, markets and agroenterprise development.

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xxvi About the Organizers

(iii) Information dissemination: In an effort to facilitate exchange of informa-tion among all stakeholders, AfNet has published several books, newslet-ters, brochures and posters. AfNet has successfully organized nine interna-tional symposia where researchers from across the continent were able toshare their research experiences. AfNet has also established The EssentialElectronic Agricultural Library (TEEAL) to facilitate information dissemina-tion to researchers and students.

The AfNet Coordination Unit is comprised of the coordinator, two research assis-tants and one administrative assistant. The AfNet Steering Committee consists of amulti-disciplinary and gender-balanced team of African scientists drawn from theeastern, southern, central and western Africa regions.

Soil Fertility Consortium for Southern Africa (SOFECSA)

The Soil Fertility Consortium for Southern Africa (SOFECSA) is a multi-institutionaland interdisciplinary regional organization founded in 2005 to develop and pro-mote technical and institutional innovations that enhance contributions of integratedsoil fertility research and development to sustainable food security and livelihoodoptions in southern Africa. SOFECSA is an impact-oriented consortium operational-ized through a 15-member technical management/steering committee in collaborationwith the host institution (CIMMYT, southern Africa), a regional coordinator andsupport staff, and country-level teams drawn from diverse stakeholders.

Contributors

R.C. Abaidoo Soil Research Laboratory, International Institute of TropicalAgriculture, Ibadan, Nigeria; C/O LW Lambourn & Co., Carolyn House, Croydon,UK, r.abaidoo@cgiar.org

G.S. Abawi Department of Plant Pathology, Cornell University, Ithaca, NY, USA,gsa1@cornell.edu

G.O. Abayo Agronomy Programme, Crop Development Department, Kenya SugarResearch Foundation (KESREF), Kisumu, Kenya, abayogo@yahoo.com

M. Abba Faculty of Science and Biotechnology Centre, University of Yaoundé I,812, Yaoundé, Cameroon, maimounaabba@yahoo.co.uk

A. Abdou International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, a.abdou@cgiar.org

T. Abdoulaye JIRCAS, Tsukuba, Ibaraki, Japan; INRAN, Niamey, Niger,t.abdoulaye@cgiar.org

S. Abdoussalam International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, s.abdoussalam@cgiar.org

C. Achieng Department of Environmental Science, Kenyatta University, Nairobi,Kenya; School of Environmental Studies and Human Sciences, Kenyatta University,Nairobi, Kenya, cellineoduor@yahoo.com

M.A. Adamu Green Sahel Agro Venture, Gumel, Jigawa State, Nigeria,muhddansista@yahoo.com

A. Adesina Alliance for a Green Revolution in Africa (AGRA), Nairobi, Kenya,aadesina@agra-alliance.org

B.D.K. Ahiabor CSIR-Savanna Agricultural Research Institute, Tamale, Ghana,bahiabor@yahoo.com

I. Akintayo Africa Rice Center (WARDA), Cotonou, Benin, i.akintayo@cgiar.org

B. Akpatou Centre Swisse de Recherche Scientifique en Côte d’Ivoire (CSRS),Abidjan, Côte d’Ivoire; University of Cocody, Abidjan, Côte d’Ivoire,bertin.akpatou@csrs.ci

D. Allou University of Cocody, Abidjan, Côte d’Ivoire; Centre National deRecherche Agronomique (CNRA), Lamé, Côte d’Ivoire, desire.allou@gmail.com

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xxviii Contributors

T.E. Alweendo Division Plant Production Research, Ministry of Agriculture, Waterand Forestry, Government Office Park, Windhoek, Namibia,Alweendot@mawf.gov.na; alweendotwewaadha@yahoo.com

B. Amadou FAO Projet Intrants, Niamey, Niger, malbachi61@yahoo.fr

A.R. Anuar Faculty of Agriculture, Department of Land Management, UniversitiPutra Malaysia, Serdang, Selangor, Malaysia, anuar@Agri.upm.edu.my

H. Anyanzwa Department of Soil Science, Moi University, Eldoret, Kenya,hellenanyz@yahoo.com

J. Ashby Alianza Cambio Andino (Andean Change Program), International PotatoCenter (CIP), Cali, Colombia, jacashby@gmail.com

E. Atsu CSIR-Savanna Agricultural Research Institute, Tamale, Ghana,Ericatsu@yahoo.com

A. Aw Africa Rice Center (AfricaRice), Sahel Regional Station, Saint-Louis BP 96,Senegal, aaw@usaid-yaajeende.org

A. Ayemou Centre Suisse de Recherche Scientifique en Côte d’Ivoire (CSRS),Abidjan, Côte d’Ivoire; University of Abobo-Adjamé, Abidjan, Côte d’Ivoire,amandine.sopie@gmail.com

M. Azuba Kampala City Council District Urban Agriculture Office, Kampala,Uganda, azubam@yahoo.com

A. Babirye International Institute of Tropical Agriculture (IITA-Uganda),Kampala, Uganda, annetbabirye2@yahoo.com

A. Babu Agricultural Research Institute Ukiriguru, Mwanza, Tanzania,adventinababu@yahoo.com

B.V. Bado Sahel Regional Station, Africa Rice Center (AfricaRice), BP 96,Saint-Louis, Senegal; Institute of Environment and Agricultural Research (INERA),BP 910, Bobo-Dioulasso, Burkina Faso, V.Bado@cgiar.org

A. Bala School of Agriculture and Agricultural Technology, Federal University ofTechnology Minna, Minna, Niger State Nigeria, Abdullahi_bala@yahoo.com

K. Balozi Kenya Forestry Research Institute, Gede Regional Research Centre,Malindi, Kenya, balozibk@hotmail.com

T. Basamba Department of Soil Science, Makerere University, Kampala, Uganda,ateenyitwaha@hotmail.com

A. Bationo Alliance for a Green Revolution in Africa (AGRA), Accra, Ghana,abationo@agra-alliance.org

C.L. Bielders Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya,charles.bielders@uclouvain.be

M. Bonzi Institute of the Environment and Agricultural Research (INERA),Ouagadougou, Burkina Faso, bouabonzi@yahoo.fr

S. Boubacar Sasakawa Global 2000 (SG 2000), Bamako, Mali,b_sandinan@yahoo.fr

Contributors xxix

G. Burpee Catholic Relief Services, Baltimore, MD, USA, gaye.burpee@crs.org

J. Byalebeka Kawanda Agricultural Research Institute (KARI), NationalAgricultural Research Organization (NARO), Kampala, Uganda,jbyalebeka@yahoo.co.uk

P. Cattan Agricoles et de Formation de Kamboinsé, Institute of the Environmentand Agricultural Research Institute (INERA), Centre de RecherchesEnvironnementales, Ouagadougou, Burkina Faso; Station deNeufchateau-Sainte-Marie, CIRAD, Capesterre-Belle-Eau, France,philippe.cattan@cirad.fr

M.P. Cescas FSSA, Université Laval, Québec City, QC, Canada,Michel.Cescas@fsaa.ulaval.ca

A.L. Chek Kenya Agricultural Research Institute (KARI), National AgriculturalResearch Laboratories, Nairobi, Kenya, kss@iconnect.co.ke

H.K. Cheruiyot Desert Margins Programme, Kenya Agricultural ResearchInstitute, Nairobi, Kenya, hkcheruiyot@kari.org

J. Chianu Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), UN Avenue, Gigiri, Nairobi, Kenya,jchianu@yahoo.com

R. Chikowo Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Mt Pleasant, Harare, Zimbabwe, rchikowo@agric.uz.ac.zw;regischikowo@yahoo.co.uk

D. Chikoye International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria,d.chikoye@cgiar.org

P. Chivenge Department of Plant Sciences, University of California, One ShieldsAve., Davis, CA, USA, pchivenge@gmail.com

G. Cisse Swiss Tropical and Public Health Institute (Swiss TPHI), Bâle,Switzerland, gueladio.cisse@unibas.ch

M. Cisse Institut Sénégalais de Recherches Agricoles (ISRA), Saint-Louis,Senegal, sbamand@yahoo.com

E. Compaore LSE/ENSAIA, Vandoeuvre-lès-Nancy Cedex, France; Station deRecherches Agricoles de Farako-Bâ, Environment and Agricultural ResearchInstitute (INERA), Bobo-Dioulasso, Burkina Faso, ecompaorez@hotmail.com

M. Corbeels Département Persyst, Centre de Coopération Internationale enRecherche Agronomique pour le Développement (CIRAD), Av Agropolis TAB-102/02, Montpellier Cedex 5, France, corbeels@cirad.fr

F.D. Dakora Science Faculty, Tswane University of Technology, Pretoria, SouthAfrica, dakorafd@tut.ac.za

O.G. Dangasuk Department of Biological Sciences, Moi University, Eldoret,Kenya, georgedangasuk@yahoo.com

S. Danso Tropical Soil Biology and Fertility Institute of the International Centre forTropical Agriculture (TSBF-CIAT), Nairobi, Kenya, danso@libr.ug.edu.gh

xxx Contributors

O. Deji Department of Agricultural Extension and Rural Development, ObafemiAwolowo University, Ile-Ife, Osun, Nigeria, odeji2001@yahoo.com

R.J. Delve Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Mt Pleasant, Harare, Zimbabwe,rdelve@earo.crs.org

A. Deubel Institute of Soil Science and Plant Nutrition, Martin-Luther UniversityHalle-Wittenberg, Halle, Germany, deubel@landw.uni-halle.de

M.E. Devries Sahel Regional Station, Africa Rice Centre, BP 96 Saint Louis,Senegal, michielerikdevries@gmail.com

M.K. Diallo International Crops Research Institute for the Semi-Arid Tropics(ICRISAT), Niamey, Niger, m.diallo@icrisatne.ne

A. Diallo African Livelihoods Program, CIMMYT, Nairobi, Kenya,a.o.diallo@cgiar.org

J. Diels Division of Soil and Water Management, Department of Land Managementand Economics, KU Leuven, Leuven, Belgium, jan.diels@ees.kuleuven.be

J. Dimes International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe, j.dimes@cgiar.org

M. Diouf TROPICASEM/TECHNISEM, Km 5,6 Bd du Centenaire de la communede Dakar, BP 999 Dakar, Sénégal, meissa.diouf@tropicasem.sn

P. Dugue CIRAD TERA, Montpellier Cedex 01, France, patrick.dugue@cirad.fr

J.W. Duindam International Institute of Tropical Agriculture, Yaoundé, Cameroon,jelleduindam@hotmail.com

W. Ego Kenya Agricultural Research Institute, Kiboko Research Centre, Makindu,Kenya; Desert Margins Programme, Kenya Agricultural Research Institute (KARI),Nairobi, Kenya, egowk@yahoo.com

F. Ekeleme Michael Okpara University of Agriculture, Umudike, Nigeria,fekeleme@yahoo.co.uk

I. Ekise Tropical Soil Biology and Fertility Institute of the International Centre forTropical Agriculture (TSBF-CIAT), Nairobi, Kenya, iekise@hotmail.com

A.O. Esilaba Desert Margins Programme, Kenya Agricultural Research Institute(KARI), Nairobi, Kenya, aoesilaba@kari.org; aesilaba@gmail.com

F.-X. Etoa Department of Biochemistry, University of Yaoundé I, 812, Yaoundé,Cameroon, fxetoa@yahoo.fr

A. Fall Institut Sénégalais de Recherches Agricoles (ISRA), Route desHydrocarbures Bel-Air, BP 3120 Dakar, Senegal, fallalio@refer.sn

H. Fankem Department of Plant Biology, Faculty of Science, University ofDouala, P.O. Box 24157 Douala, Cameroon, fankemhenri@yahoo.fr

J.-C. Fardeau Département Environnement et Agronomie, INRA, Versailles,France, fardeau@versailles.inr.fr

Contributors xxxi

A. Farrow International Center for Tropical Agriculture, Kampala, Uganda,a.farrow@cgiar.org

D. Fatondji International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, d.fatondji@cgiar.org;d.fantondji@gmail.com

A.O. Fatunbi Agronomy Department, Agricultural and Rural DevelopmentResearch Institute (ARDRI), University of Fort Hare, Eastern Cape, South Africa,afatunbi@ufh.ac.za

C. Feller ENGREF:DFRT/UR IRD 179 SeqBio, Montpellier Cedex, France,feller@ird.fr

A.M. Fermont International Institute of Tropical Agriculture (IITA-Uganda),Kampala, Uganda, a.fermont@cgiar.org

S. Ferris Agriculture and Environment, Catholic Relief Services (CRS), Baltimore,MD, USA, shaun.ferris@crs.org

R. Fogain Centre Africain de Recherche sur le Bananier et Plantain (CARBAP),Njombé, Cameroon, rfogain7@yahoo.fr

M. Fosu CSIR-Savanna Agricultural Research Institute, Tamale, Ghana,mathiasfosu@yahoo.co.uk

B. Freyer Division of Organic Farming, University of Natural Resources andApplied Life Sciences, Vienna, Austria, bernhard.freyer@boku.ac.at

C.K.K. Gachene University of Nairobi, Nairobi, Kenya, gachene@uonbi.ac.ke

G.N. Gachini Kenya Agricultural Research Institute (KARI), National AgriculturalResearch Laboratories, Nairobi, Kenya, kss@iconnect.co.ke

M. Gafishi Institut des Sciences Agronomiques du Rwanda (ISAR), Musanze,Rwanda, mkgafishi@yahoo.fr

M. Gandah The Regional coordinator of the AGRA funded microdosing project,(ICRISAT), Niamey, Niger, m.gandah@cgiar.org

K.E. Gathoni Department of Environmental Science, Kenyatta University, Nairobi,Kenya, gathoni_edith@yahoo.com

S. Gaye Sahel Regional Station, Africa Rice Centre, BP 96 Saint Louis, Senegal,soulgaye@hotmail.com

R. Gentile Department of Plant Sciences, University of California, One ShieldsAve., Davis, CA, USA; Departments of Agronomy and Range Science, University ofCalifornia, Davis, CA, USA, rgentile@ucdavis.edu

B. Gerard International Livestock Research Institute (ILRI), Addis Ababa,Ethiopia, b.gerard@cgiar.org

E.W. Gikonyo Institute of Tropical Agriculture, Universiti Putra Malaysia,Serdang, Selangor, Malaysia, estgikonyo@yahoo.com

P. Gildemacher International Potato Center, Nairobi, Kenya, p.gildemacher@kit.nl

xxxii Contributors

K.E. Giller Plant Production Systems, Department of Plant Sciences, WageningenUniversity, Wageningen, The Netherlands, ken.giller@wur.nl

H.K. Githinji Department of Soil Science, Moi University, Eldoret, Kenya,harrikag@yahoo.com

C.M. Githunguri Katumani Research Centre, Kenya Agricultural ResearchInstitute, Machakos, Kenya, cgithunguri@kari.org; cyrusgithunguri@yahoo.com

S.O. Gudu Department of Soil Science, Moi University, Eldoret, Kenya,samgudu2002@yahoo.com

T. Gueye Ecole Nationale Supérieure d’Agriculture (ENSA)/Université de Thiès,BP A296, Thiès, Sénégal, tgueye@univ-thies.sn

B.K. Gugino Penn State Cooperative Extension, University Park, PA 16802, Ithaca,NY, USA, bkgugino@psu.edu

M.M. Hanafi Institute of Tropical Agriculture, Universiti Putra Malaysia, Serdang,Selangor, Malaysia, mmhanafi@Agri.upm.edu.my

O. Hassane International Crops Research Institute for the Semi-Arid Tropics(ICRISAT), Niamey, Niger, o.hassane@icrisatne.ne

S. Hauser International Institute of Tropical Agriculture, Kinshasa, DemocraticRepublic of Congo, s.hauser@cgiar.org

K. Hayashi JIRCAS, Tsukuba, Ibaraki, Japan; ICRISAT West & Central Africa,Niamey, Niger, khayash@jircas.affrc.go.jp

G. Heinrich Agriculture and Environment, Catholic Relief Services (CRS),Baltimore, MD, USA, gheinrich@saro.crs.org

E. Hien SVT Department, University of Ouagadougou, Ouagadougou, BurkinaFaso; Université de Ouagadougou, UFR/SVT, Ouagadougou 03, Burkina Faso,edmond.hien@ird.fr

V. Hien INERA/CREAF, Kamboinse, Burkina Faso, vhien@ird.bf;vhien@fasonet.bf

L. Hitimana Secretariat of the Sahel and West Africa Club (SWAC/OECD), 2 rueAndré Pascal, 75775 Paris, Cedex 16, France, leonidas.hitimana@oecd.org

T. Hongo Kenyatta University, Nairobi, Kenya, tamollo@yahoo.com

L.N. Horn Division of Plant Production Research, Ministry of Agriculture, Waterand Forestry, Government Office Park, Luther Str. Windhoek, Namibia,lnhorn@yahoo.com

P. Houngnandan Faculté des Sciences Agronomiques (FSA), Universitéd’Abomey-Calavi (UAC), Recette Principale, Cotonou, Benin

L. Hove International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe

J. Huising Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, j.huising@cgiar.org

Contributors xxxiii

T. Hyuha Department of Agricultural Economics, Makerere University, Kampala,Uganda, thyuha@yahoo.com; thyuha@mak.ac.ug

O.J. Idowu Department of Extension Plant Sciences, New Mexico StateUniversity, Las Cruces, NM 88011, USA, jidowu@ad.nmsu.edu

S.T. Ikerra Mlingano Agricultural Research Institute, Tanga, Tanzania,susikera@yahoo.com

E.C. Ikitoo Department of Soil Science, Moi University, Eldoret, Kenya,ikitoo.caleb@gmail.com

J.K. Itabari Katumani Research Centre, Kenya Agricultural Research Institute,Machakos, Kenya, itabarijustus@yahoo.co.uk

O. Ito JIRCAS, Tsukuba, Ibaraki, Japan, osamuito@jircas.affrc.go.jp

M. Jemo International Institute of Tropical Agriculture, Humid Forest EcoregionalCentre (HFC), Yaounde, Cameroon, m.jemo@cgiar.org; mjemo2001@yahoo.com

A.S. Jeng Soil & Environment Division, Bioforsk – Norwegian Institute forAgricultural and Environmental Research, Fredrik A Dahls vei 20A, N-1432 Aas,Norway, Alhaji.Jeng@bioforsk.no

B. Junge University of Oldenburg, Germany, birte.junge@uni-oldenburg.de

V.H. Kabambe Bunda College of Agriculture, Lilongwe, Malawi,kabambev@yahoo.com

W.T. Kabore Université de Ouagadougou, UFR/SVT, Ouagadougou 03, BurkinaFaso; IRD, UR SeqBio, DMP Program, Ouagadougou, Burkina Faso,kathewin@yahoo.fr

A. Kabuli Soil Fertility Consortium for Southern Africa, Bunda College ofAgriculture, Lilongwe, Malawi, amonmw@yahoo.com

H.J. Kabuli Department of Agricultural Research, Chitedze Research Station,Ministry of Agriculture and Food Security, Lilongwe, Malawi,hjinazali@yahoo.com

E. Kaganzi CIAT/Enabling Rural Innovation (ERI), Kampala, Uganda,e.kaganzi@cgiar.org

K.C. Kaizzi Kawanda Agricultural Research Institute (KARI), NationalAgricultural Research Organization (NARO), Kampala, Uganda,kckaizzi@gmail.com

M.C. Kalumuna Agricultural Research Institute, Mlingano, Tanga, Tanzania,M.C.Kalumunakokwijuka@yahoo.co.uk

D. Kamalongo Chitedze Research Station, Department of Agricultural ResearchServices, Ministry of Agriculture and Food Security, Lilongwe, Malawi,dkamalongo@hotmail.com

A.Y. Kamara International Institute of Tropical Agriculture, Ibadan, Nigeria,akamara@cgiar.org

J. Kamau Kenyatta University, Nairobi, Kenya, joycekamau28@yahoo.com

xxxiv Contributors

W.M.H. Kamiri Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya,wangechikamiri@yahoo.com

R. Kamugisha African Highland Initiative, Kampala, Uganda,rkamu2000@yahoo.co.uk

F. Kanampiu CIMMYT, Nairobi, Kenya, f.kanampiu@cgiar.org

N.K. Karanja University of Nairobi, Nairobi, Kenya, nancy.karanja@cgiar.org

R. Karega School of Environmental Studies and Human Sciences, KenyattaUniversity, Nairobi, Kenya, rkarega@yahoo.co.uk

A.N. Kathuku Kenya Agricultural Research Institute, National AgriculturalResearch Centre, Nairobi, Kenya; Desert Margins Programme, Nairobi, Kenya,angelandan2000@yahoo.com

P. Kathuli Katumani Research Centre, Kenya Agricultural Research Institute,Machakos, Kenya, peterkathuli@yahoo.com

A.A. Kauwa (Deceased) Chitedze Research Station, Department of AgriculturalResearch Services, Ministry of Agriculture and Food Security, Lilongwe, Malawi

A. Kavatha Land O’ Lakes Regional Office, Nairobi, Kenya,agnes@landolakes.co.ke

A. Kavoo Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, agneskavoo@yahoo.com

G.A. Keya Desert Margins Programme, Kenya Agricultural Research Institute,Nairobi, Kenya, gakeya@kari.org

Z. Khan ICIPE, Mbita, Kenya, zkhan@icipe.org

M.J. Khaemba Department of Crops, Horticulture and Soil Sciences, EgertonUniversity, Egerton, Kenya, khaemba03@yahoo.com

G. Khisa Ministry of Agriculture, Kakamega, Kenya, khisagodrick@yahoo.co.uk

I.D. Kiba Institute of the Environment and Agricultural Research Institute(INERA), Ouagadougou, Burkina Faso, ikiba@yahoo.fr

C.N. Kibunja Kenya Agricultural Research Institute, NARL-KARI, Nairobi,Kenya, catherine.kibunja@yahoo.com

J.N. Kigomo Kenya Forestry Research Institute, Nairobi, Kenya,kigomo2@yahoo.com

F.M. Kihanda Kenya Agricultural Research Institute (KARI), Embu RegionalResearch Centre, Embu, Kenya, kihandafm@yahoo.com

J. Kihara Zentrum für Entwicklungsforschung (ZEF), University of Bonn, Bonn,Germany; Tropical Soil Biology and Fertility Institute of the International Centre forTropical Agriculture (TSBF-CIAT), Nairobi, Kenya, jkiharam@yahoo.com;j.kihara@cgiar.org

S.K. Kimani Kenya Agricultural Research Institute, National AgriculturalResearch Centre, Nairobi, Kenya, skimani@africaonline.co.ke

Contributors xxxv

P.K. Kimani Kenya Soil Survey (KSS), Kenya Agricultural Research Institute(KARI), Nairobi, Kenya, pkkims@yahoo.com

J. Kimiywe Kenyatta University, Nairobi, Kenya, jokimiywe@yahoo.com

L.M. Kimotho Katumani Research Centre, Kenya Agricultural Research Institute,Machakos, Kenya, klmkimotho@yahoo.com

D.M. Kinfack Centre Africain de Recherche sur le Bananier et Plantain(CARBAP), Njombé, Cameroon; Faculty of Science and Biotechnology Centre,University of Yaoundé I, 812, Yaoundé, Cameroon, kinfack29@yahoo.fr

B. King’olla Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, b.wawaka@cgiar.org

Z.M. Kinyua National Agricultural Laboratories, Kenya Agricultural ResearchInstitute, Nairobi, Kenya, kinyuazm@gmail.com

M.J. Kipsat Department of Marketing and Economics, Moi University, Eldoret,Kenya, mjkipsat@yahoo.com

J. Kirui Land O’ Lakes Regional Office, Nairobi, Kenya, j.kirui@cgiar.org

E.G. Kirumba Department of Environmental Science, Kenyatta University,Nairobi, Kenya, gathoni_edith@yahoo.com

M. Kisaka-Lwayo Agricultural Economics Discipline, School of AgriculturalSciences and Agribusiness, University of KwaZulu-Natal, Pietermaritzburg, SouthAfrica, maggiekisaka@yahoo.com

P.O. Kisinyo Department of Soil Science, Moi University, Eldoret, Kenya,kisinyopeter@yahoo.com

E. Kituyi Department of Chemistry, University of Nairobi, Nairobi, Kenya,ekituyi@uonbi.ac.ke

S. Koala AfNet-TSBF, International Center for Tropical Agriculture (CIAT),Nairobi, Kenya, s.koala@cgiar.org

I. Kone Centre Swisse de Recherche Scientifique en Côte d’Ivoire (CSRS),Abidjan, Côte d’Ivoire; University of Cocody, Abidjan, Côte d’Ivoire,inza.kone@csrs.ci

A. Kone Institute of the Environment and Agricultural Research Institute (INERA),Ouagadougou, Burkina Faso, Kone.adama@reseaucrepa.org

J.B. Kung’u Department of Environmental Sciences, School of EnvironmentalStudies, Kenyatta University, Nairobi, Kenya, kungu_james@yahoo.com

T.K. Kwambai National Agricultural Research Centre, Kenya AgriculturalResearch Institute, Kitale, Kenya, tkkwambai2003@yahoo.com

J.D. Kwari Department of Soil Science, University of Maiduguri, Maiduguri,Nigeria, jdkwari@yahoo.co.uk

K. Kwena Kenya Agricultural Research Institute, Katumani Research Centre,Machakos, Kenya, kwenakizito@yahoo.com

xxxvi Contributors

P.K. Kyakaisho District Agriculture and Livestock Office, Muheza, Tanzania,kassian03@yahoo.co.uk; kennemma@hotmail.com

M. Larwanou Faculté d’Agronomie, Université Abdou Moumouni de Niamey,Niamey, Niger, m.larwanou@coraf.org

J.J. Lelei Department of Crops, Horticulture and Soils, Egerton University, Njoro,Kenya, Joycendemo@yahoo.com

J.K. Lelon Kenya Forestry Research Institute, Nairobi, Kenya, jklelon@yahoo.com

M. Lepage IRD, UR SeqBio, DMP Program, 01 BP 182, Ouagadougou, BurkinaFaso, lepage@ird.bf

I. Ligowe Chitedze Research Station, Department of Agricultural ResearchServices, Ministry of Agriculture and Food Security, Lilongwe, Malawi,ivyligowe@yahoo.co.uk

F. Lompo Institute of Environment and Agricultural Research (INERA),Ouagadougou, Burkina Faso, lompoxa1@yahoo.fr

B.A. Lukuyu Kenya Agricultural Research Institute, Nairobi, Kenya,b.lukuyu@cgiar.org

L. Lunze Centre de Recherche de Mulungu, INERA, D.S. Bukavu, D.R. Congo,llunze@yahoo.fr

C.M. Lusweti Kenya Agricultural Research Institute (KARI), Kitale Centre,Kitale, Kenya, lusweticharles@yahoo.com

S. Lwasa Kampala City Council District Urban Agriculture Office, Kampala,Uganda, s.lwasa@cgiar.org

P.N. Macharia KARI-Kenya Soil Survey, Nairobi, Kenya, kss@iconnect.co.ke

A. Macharia Department of Environmental Science, School of EnvironmentalStudies and Human Sciences, Kenyatta University, Nairobi, Kenya,amacharia@nema.go.ke

E.J. Maeda Ministry of Agriculture Food Security and Cooperatives, Tanzania,elizabeth.maeda@kilimo.go.tz

P. Mahposa International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe

F. Mairura Tropical Soil Biology and Fertility, Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, F.Mairura@cgiar.org

P. Makhosi National Agricultural Research Laboratories (NARL), Kampala,Uganda, landuse@infocom.co.ug

E. Makonese International Fertilizer Industry Association (IFA), Paris, France;Chemplex Corporation Ltd., Harare, Zimbabwe, makonesee@chemplex.co.zw

W. Makumba Department of Agricultural Research, Chitedze Research Station,Ministry of Agriculture and Food Security, Lilongwe, Malawi,w.makumba@africa-online.net

Contributors xxxvii

A. Malmer Department of Forest Ecology and Management, Swedish Universityof Agricultural Sciences (SLU), Umea, Sweden, Anders.Malmer@slu.se

M. Mamo Department of Agronomy and Horticulture, University of NebraskaLincoln, Lincoln, NE, USA, Mmartha@unlnotes.unl.edu

A. Mando Division of Afrique, An International Center for Soil Fertility andAgricultural Development (IFDC), Lome, Togo, amando@ifdc.org

N. Mangale Kenya Agricultural Research Institute, Katumani Research Centre,Machakos, Kenya, nmangale2005@yahoo.com

R.J. Manlay ENGREF:DFRT/UR IRD 179 SeqBio, Montpellier Cedex, France,raphael.manlay@agroparistech.fr

P. Mapfumo Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Mount Pleasant, Harare, Zimbabwe; Soil Fertility Consortium forSouthern Africa (SOFECSA), CIMMYT, Southern Africa, Mount Pleasant, Harare,Zimbabwe, p.mapfumo@cgiar.org

A.E.T. Marandu Mlingano Agricultural Research Institute, Tanga, Tanzania,atanasiom@yahoo.co.uk

D. Marchal FAO Projet Intrants, Niamey, Niger, Paule.marchal@laposte.net

H.K. Maritim (Deceased) Department of Soil Science, Moi University, Eldoret,Kenya

C. Martius Zentrum für Entwicklungsforschung (ZEF), University of Bonn, Bonn,Germany, c.martius@cgiar.org

N. Mashingaidze International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe

D. Masse IRD Institut de Recherche pour le Développement, UR 179 SeqBio,Montpellier Cedex, France; IRD, UR SeqBio, DMP Program, Ouagadougou,Burkina Faso, dominique.masse@ird.fr

K.F.G. Masuki African Highland Initiative, Kampala, Uganda,k.masuki@cgiar.org

E.N. Masvaya Department of Soil Science and Agricultural Engineering,University of Zimbabwe, Mt Pleasant, Harare, Zimbabwe, e.masvaya@cgiar.org

B.M. Mati Improved Management of Agricultural Water in Eastern & SouthernAfrica (IMAWESA), Nairobi, Kenya, b.mati@cgiar.org

F.M. Matiri Kenya Agricultural Research Institute (KARI), Embu, Kenya,francis_matiri@yahoo.com

R. Matsunaga JIRCAS, Tsukuba, Ibaraki, Japan; ICRISAT West & Central Africa,Niamey, Niger, ryoichi_matsunaga@affrc.go.jp

L.W. Mauyo Masinde Muliro University of Science and Technology, P.O. BOX190-50100, Kakamega, Kenya, lmauyo@yahoo.com

G. Mbagaya Moi University, Eldoret, Kenya, gmbagaya@mu.ac.ke

xxxviii Contributors

D. Mbithe Kenyatta University, Nairobi, Kenya, dorcusmbithe@yahoo.com

G.N. Mbure Kenya Agricultural Research Institute, Nairobi, Kenya,mbureg@yahoo.com

M.W.K. Mburu Kenya Agricultural Research Institute (KARI), Embu, Kenya,mwambui2011@gmail.com

W. Merbach Institute of Soil Science and Plant Nutrition, Martin-LutherUniversity Halle-Wittenberg, Halle, Germany, merbach@landw.uni-halle.de

R. Merckx Department of Earth and Environmental Sciences, KatholiekeUniversiteit Leuven, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium,roel.merckx@ees.kuleuven.be

J.N. Methu Land O’ Lakes Regional Office, Nairobi, Kenya, j.methu@asareca.org

C. Milaho District Agriculture and Livestock Office, Kilosa, Tanzania,cmilaho@yahoo.com

J.M. Miriti Desert Margins Programme, Kenya Agricultural Research Institute,Nairobi, Kenya, jmmiriti@yahoo.co.uk; angelandan2000@yahoo.com

M. Misiko Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, m.misiko@cgiar.org

R. Miura Kyoto University, Kyoto, Japan, miurar@kais.kyoto-u.ac.jp

C.Z. Mkangwa Ilonga Agricultural Research Institute, Kilosa, Tanzania,mkangwa@yahoo.co.uk

P.N.S. Mnkeni Faculty of Science and Agriculture, University of Fort Hare,Eastern Cape, South Africa, pmnkeni@ufh.ac.za

B.N. Moebius-Clune Department of Crop and Soil Sciences, Cornell University,Ithaca, NY, USA, bnm5@cornell.edu

A.U. Mokwunye United Nations University (UNU), Institute for Natural Resourcesin Africa, Accra, Ghana, uzo.mokwunye@alumni.illinois.edu

T. Mombeyarara Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Harare, Zimbabwe,t.mombeyarara@cgiar.org

J.-L. Morel LSE/ENSAIA, Vandoeuvre-lès-Nancy Cedex, France,Jean-Louis.Morel@ensaia.inpl-nancy.fr

J.G. Mowo African Highland Initiative, Kampala, Uganda, j.mowo@cgiar.org

M. Moyo International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe

J.P. Mrema Mlingano Agricultural Research Institute, Tanga, Tanzania;Department of Soil Science, Sokoine University of Agriculture, Morogoro,Tanzania, jmrema@suanet.ac.tz

F. Mtambanengwe Department of Soil Science and Agricultural Engineering,University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe,fmtamba@agric.uz.ac.zw

Contributors xxxix

R.M. Muasya Department of Seed, Crops and Horticultural Sciences, MoiUniversity, Eldoret, Kenya, rmuasya@africaonline.co.ke

M. Mucheru-Muna Department of Environmental Sciences, School ofEnvironmental Studies, Kenyatta University, Nairobi, Kenya,moniquechiku@yahoo.com

R.J. Mugabo Institut des Sciences Agronomiques du Rwanda (ISAR), Musanze,Rwanda, mugabojosa@yahoo.fr

D.N. Mugendi Department of Environmental Sciences, School of EnvironmentalStudies, Kenyatta University, Nairobi, Kenya, dmugendi@yahoo.com

J. Mugwe Department of Agricultural Resource management, School ofAgriculture and Enterprise Development (SAED), Kenyatta University, Nairobi,Kenya, jaynemugwe@yahoo.com

L. Muhammad Kenya Agricultural Research Institute, Katumani Research Centre,Machakos, Kenya, luttam2002@yahoo.com

J. Mukalama Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya,jmukalama@yahoo.com

A. Mukuralinda World Agroforestry Centre (ICRAF), Rwanda,mukuratha@yahoo.com

J. Mulatya Kenya Forestry Research Institute, Nairobi, Kenya, director@kefri.org

G. Muluvi Kenyatta University, Nairobi, Kenya, muluvi.geoffrey@ku.ac.ke

L.M. Mumera Department of Crops, Horticulture and Soil Sciences, EgertonUniversity, Egerton, Kenya, lmmumera@africaonline.com; dvcaf@egerton.ac.ke

G.S. Mumina Kenya Agricultural Research Institute, National Arid LandsResearch Centre, Marsabit, Kenya; Egerton University, Njoro, Kenya,muminalu@yahoo.com

J.M. Mungatu Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), c/o ICRAF, UN Avenue, Gigiri,Nairobi, Kenya, kmungatu@yahoo.com

J.W. Munyasi Kenya Agricultural Research Institute, Kiboko Research Centre,Makindu, Kenya, munyasijoseph@yahoo.com

S.W. Munyiri Department of Crop, Horticulture and Soils, Egerton University,Egerton, Njoro, Kenya, wanja_munyiri@yahoo.co.uk

W. Mupangwa International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe

P. Mureithi Department of Environmental Studies and Community Development,Kenyatta University, Nairobi, Kenya, petmukariuki@yahoo.co.uk

J.G. Mureithi KARI Headquarters, Nairobi, Kenya, JGMureithi@kari.org

J. Muriuki District Agricultural Office, Meru South District, Ministry ofAgriculture, Chuka, Kenya, justinmuriuki@yahoo.co.uk

xl Contributors

E. Murua Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), c/o ICRAF, UN Avenue, Gigiri, Nairobi,Kenya, libbymurua2002@yahoo.com

H.K. Murwira Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Harare, Zimbabwe,h.murwira@cgiar.org

D.K. Musembi Kenya Agricultural Research Institute (KARI), Kiboko ResearchCentre, Makindu, Kenya, dkmusembi@yahoo.com

D. Mushabizi Institut des Sciences Agronomiques du Rwanda (ISAR), Musanze,Rwanda, mushabizi@yahoo.fr

C. Musharo Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Mount Pleasant, Harare, Zimbabwe, cmusharo@yahoo.com

J.K. Mutegi World Agroforestry Centre (ICRAF), Nairobi, Kenya,mutegijames@yahoo.com

J.M. Muthamia Department of Environmental Sciences, Kenyatta University,Nairobi, Kenya, muthamiajoses@yahoo.com

L.M. Mutuku Katumani Research Centre, Kenya Agricultural Research Institute,Machakos, Kenya, mwangagilawrence@yahoo.com

G.M. Muturi University of Nairobi, Nairobi, Kenya, gmuturi@kefri.org

E.M. Muya National Agricultural Research Laboratories, Kenya AgriculturalResearch Institute (KARI), Nairobi, Kenya, edwardmuya@yahoo.com;kss@iconnect.co.ke

R. Muzira National Agricultural Research Organization, Mbarara, Uganda,nrmuzira@yahoo.com

M. Mwala School of Agricultural Sciences, University of Zambia, Lusaka,Zambia, mmwala@yahoo.com

C.D. Mwale Chitedze Research Station, Department of Agricultural ResearchServices, Ministry of Agriculture and Food Security, Lilongwe, Malawi,cyprianmwale@yahoo.com

D. Mwangi Kenya Agricultural Research Institute, Nairobi, Kenya,DMMwangi@kari.org

F.B. Mwaura University of Nairobi, Nairobi, Kenya, fbmwaura@uonbi.ac.ke

S.W. Mwendia Kenya Agricultural Research Institute, Nairobi, Kenya,smwendia@une.edu.au

S.M. Mwonga Department of Crops, Horticulture and Soil Sciences, EgertonUniversity, Egerton, Kenya, smwonga@yahoo.com

N.L. Nabahungu ISAR-Rwanda, Butare, Rwanda, nabahungu@yahoo.com

L. Nakhone Department of Crops, Horticulture and Soil Sciences, EgertonUniversity, Egerton, Kenya, lenahnakhone@yahoo.com

Contributors xli

I. Nalukenge Department of Agricultural Economics, Makerere University,Kampala, Uganda, imeldanalukenge@yahoo.com; inalukenge@mak.ac.ug

B. Ncube WATERnet, Department of Civil Engineering, University of Zimbabwe,Harare, Zimbabwe

P.A. Ndakidemi Research & Technology Promotion, Cape Peninsula University ofTechnology, Keizersgracht, Cape Town, South Africa, ndakidemip@cput.ac.za

M. Ndiaye Africa Rice Center (AfricaRice), Sahel Regional Station, Saint-LouisBP 96, Senegal, a_malick_nd@yahoo.fr

J. Ndjeunga International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, ndjeungajupiter@gmail.com

J.K. Ndufa Kenya Forestry Research Institute, Gede Regional Research Centre,Malindi, Kenya, jndufa@africaonline.co.ke

A.O. Nekesa Department of Soil Science, Moi University, Eldoret, Kenya,amarishas@yahoo.com

H. Nezomba Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Mount Pleasant, Harare, Zimbabwe, hnezomba@agric.uz.ac.zw

M.N. Ng’ang’a Department of Seed, Crops and Horticultural Sciences, MoiUniversity, Eldoret, Kenya, marionnduta@yahoo.com

J.K. Ng’ang’a Kenya Agricultural Research Institute, National AgriculturalResearch Centre, P.O. Box 14733, Nairobi, Kenya, joxkiarie@yahoo.com

G.N. Ngae Kenya Agricultural Research Institute, Nairobi, Kenya,gnngae@gmail.com

M. Ngongo Centre de Recherche de Mulungu, INERA, D.S. Bukavu, D.R. Congo,nmulangwa@yahoo.com

M. Ngutu Kenya Agricultural Research Institute, National Arid Lands ResearchCentre, Marsabit, Kenya; Egerton University, Njoro, Kenya, mnthiani@yahoo.com

A. Niang Africa Rice Center (WARDA), Cotonou, Benin, abibou.niang1@cgiar.org

A. Nikiema International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, a.nikiema@cgiar.org;a.nikiema@gmail.com

P.M. Njingulula Socio-economist INERA-Mulungu, Kivu, DR Congo,pnjingulula@yahoo.fr

L. Ngo Nkot Department of Plant Biology, University of Douala, 24157, Douala,Cameroon, lnkot@yahoo.fr

C. Nolte FAO, Plant Production and Protection Division (AGP), Rome, Italy,cknmail@yahoo.co.uk; Christian.nolte@fao.org

E. Nsengumuremyi ISAR-Rwanda, Butare, Rwanda, nsenguemile@yahoo.fr

D. Nwaga Faculty of Science and Biotechnology Centre, University of Yaoundé I,812, Yaoundé, Cameroon, dnwaga@yahoo.fr

xlii Contributors

O.C. Nwoke Department of Agronomy, Osun State University, Osogbo, Nigeria,c.nwoke@cgiar.org; o.chik@yahoo.com

I. Nyagumbo Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Mount Pleasant, Harare, Zimbabwe, inyagumbo@agric.uz.ac.zw

A.S. Nyaki Mlingano Agricultural Research Institute, Tanga, Tanzania,adolfnyaki@yahoo.com

J. Nyamangara Department of Soil Science and Agricultural Engineering,University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe; Chitedze ResearchStation, Tropical Soil Biology and Fertility Institute of the International Centre forTropical Agriculture (TSBF-CIAT), Lilongwe, Malawi, jnyamangara@yahoo.co.uk;j.nyamangara@cgiar.org

D.M. Nyariki University of Nairobi, Nairobi, Kenya, Dicksonnyariki@yahoo.com

R.W. Nyawasha Department of Soil Science and Agricultural Engineering,University of Zimbabwe, Mt Pleasant, Harare, Zimbabwe,rwnyawasha@yahoo.co.uk

G. Nyberg Department of Forest Ecology and Management, Swedish University ofAgricultural Sciences (SLU), SE-901 83, Umea, Sweden, Gert.Nyberg@slu.se

G. Nziguheba Soil Research Laboratory, International Institute of TropicalAgriculture, Ibadan, Nigeria, gnziguheba@iri.columbia.edu

J.N. Nzomoi Central Bank of Kenya, Nairobi, Kenya, nnzomoi@yahoo.co.uk

G. Obare Department of Agricultural Economics and Agri-Business Management,Egerton University, Njoro, Kenya, ga.obare@yahoo.com; g.obare@hotmail.com

A. Obi Department of Agricultural Economics and Extension, University of FortHare, Alice, Eastern Cape, South Africa, aobi@ufh.ac.za

J. Obua Makerere University, Kampala, Uganda, j.obua@vicres.net

J.O. Ochoudho School of Agriculture and Biotechnology, Moi University, Eldoret,Kenya, juliusochuodho@yahoo.com

M. Odendo Kenya Agricultural Research Institute (KARI), Regional ResearchCentre, Kakamega, Kenya, Odendos@yahoo.com

J.A. Odhiambo Department of Crops, Horiculture and Soils, Egerton University,Egerton, Kenya, otishanan@yahoo.com

A.J. Odofin School of Agriculture and Agricultural Technology, Federal Universityof Technology Minna, Minna, Niger State Nigeria, ayoodofin@yahoo.com

O.V. Oeba Kenya Forestry Research Institute, Gede Regional Research Centre,Malindi, Kenya, voeba@yahoo.co.uk

O. Ohiokpehai Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya,oohiokpehai@yahoo.com

S.O. Oikeh Africa Rice Center (WARDA), Cotonou, Benin,S.Oikeh@aatf-africa.org

Contributors xliii

J.R. Okalebo Department of Soil Science, Moi University, Eldoret, Kenya,rokalebo@yahoo.com

M.M. Okeyo Kenya Forestry Research Institute (KEFRI), Nairobi, Kenya;Londiani Regional Research Centre, Londiani, Kenya, mikemairura@yahoo.com

P.F. Okoth Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), UN Avenue, Gigiri, Nairobi, Kenya,p.okoth@cgiar.org

M. Okoti Desert Margins Programme, Kenya Agricultural Research Institute(KARI), Nairobi, Kenya, michaeldominion2003@yahoo.com

G. Olukoye (Deceased) Kenyatta University, Nairobi, Kenya

E. Omami Department of Seed, Crops and Horticultural Sciences, Moi University,Eldoret, Kenya, elizabethomami@yahoo.com

L. Omoigui University of Agriculture, Makurdi, Nigeria, lomoigui@yahoo.co.uk

J.O. Omollo Agronomy Programme, Crop Development Department, Kenya SugarResearch Foundation (KESREF), Kisumu, Kenya, jac.omollo@gmail.com

W.O. Omondi Kenya Forestry Research Institute (KEFRI), Nairobi, Kenya,williamomondi2004@yahoo.co.uk

M.E. Omunyin Department of Seed, Crops and Horticultural Sciences, MoiUniversity, Eldoret, Kenya, omunyinem2712@hotmail.com

R.N. Onwonga Department of Land Resource Management and AgriculturalTechnology, University of Nairobi, Nairobi, Kenya, ronwonga@yahoo.com

J.W. Onyango Irrigation and Drainage Research Programme, Kenya AgriculturalResearch Institute (KARI), Nairobi, Kenya, joabwamari@yahoo.com

C. Opondo African Highland Initiative, Kampala, Uganda, opondo08@yahoo.com

A.O. Osunde School of Agriculture and Agricultural Technology, FederalUniversity of Technology Minna, Minna, Niger State Nigeria,akimosunde@yahoo.co.uk

L. Oteba Kenyatta University, Nairobi, Kenya, oteba-lawrence@yahoo.com

C.O. Othieno Department of Soil Science, Moi University, Eldoret, Kenya,cotieno19@yahoo.com

S. Otor Department of Environmental Science, School of Environmental Studiesand Human Sciences, Kenyatta University, Nairobi, Kenya, cjotor@yahoo.com

N. Ouandaogo Institute of the Environment and Agricultural Research (INERA),Ouagadougou, Burkina Faso, ouandaogo_noufou@yahoo.fr

K. Ouattara Institute of Environment and Agricultural Research (INERA), 04 BP8645 Ouagadougou 04, Burkina Faso, korodjouma_ouattara@hotmail.com

B. Ouattara Department of Natural Resource Management, Institute ofEnvironment and Agricultural Research (INERA), 04 BP 8645 Ouagadougou 04,Burkina Faso, badiori.ouattara@coraf.org

xliv Contributors

T.G. Ouattara Bureau National des Sols (BUNASOLS), Ouagadougou, BurkinaFaso, ouattarag@yahoo.fr

O. Owuor Moi University, Eldoret, Kenya, jbokeyo@yahoo.com

D. Pasternak International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, d.pasternak@cgiar.org

R.S. Pathak Department of Crop, Horticulture and Soils, Egerton University,Egerton, Njoro, Kenya, ramspathak@yahoo.com

M.A.R. Phiri Faculty of Development Studies, Bunda College of Agriculture,Lilongwe, Malawi, marphiri1996@yahoo.com

C.J. Pilbeam Cranfield University School of Management, Bedford, UK,colin.pilbeam@cranfield.ac.uk

P. Pote Department of Agricultural Economics and Extension, University of FortHare, Eastern Cape, South Africa, PPote@ufh.ac.za

P. Pypers Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, p.pypers@cgiar.org

C. Quiros International Center for Tropical Agriculture (CIAT), Cali, Colombia,cquiros@cgiar.org

I. Rahimou Faculté des Sciences Agronomiques (FSA), Universitéd’Abomey-Calavi (UAC), Recette Principale, Cotonou, Benin

H. Recke Kenya Agricultural Research Institute Headquarters, European UnionCoordination Unit, Nairobi, Kenya, h.recke@cgiar.org

C. Reij Vrije Universiteit Amsterdam, Amsterdam, The Netherlands,CP.Reij@cis.vu.nl

T. Remington Agriculture and Environment, Catholic Relief Services (CRS),Baltimore, MD, USA, tom.remington@crs.org

D. Rohrbach World Bank, Lilongwe, Malawi

D.L. Rowell Department of Soil Science, The University of Reading, Reading, UK,d.l.rowell@reading.ac.uk

J. Rurinda Department of Soil Science and Agricultural Engineering, Universityof Zimbabwe, Harare, Zimbabwe, jairurinda@yahoo.co.uk

J. Rusike Chitedze Research Station, International Institute for TropicalAgriculture, Lilongwe, Malawi

L. Rusinamhodzi Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Harare, Zimbabwe,l.rusinamhodzi@cgiar.org

E.J. Rutto Department of Soil Science, Moi University, Eldoret, Kenya,emyruto@yahoo.com

S.M. Rwakaikara Department of Soil Science, Makerere University, Kampala,Uganda, mcrsilver2002@yahoo.co.uk

Contributors xlv

I.H. Rwiza Agriculture Research Institute Ukiriguru, Mwanza, Tanzania,rwizaih@hotmail.com

W.D. Sakala (Deceased) Chitedze Research Station, Department of AgriculturalResearch Services, Ministry of Agriculture and Food Security, Lilongwe, Malawi

G.M. Sakala Zambia Agriculture Research Institute, Mount Makulu ResearchStation, Chilanga, Zambia; Department of Soil Science, The University of Reading,Reading, UK, godfreysakala@yahoo.co.uk

K. Sako European Development for Rural Development (EUCORD)-FormerWinrock International, Bamako, Mali, skaramoko@yahoo.fr

B. Salasya Kenya Agricultural Research Institute (KARI), Regional ResearchCentre, Kakamega, Kenya, beatsakwa@yahoo.com

N. Sanginga Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), UN Avenue, Gigiri, Nairobi, Kenya,n.sanginga@cgiar.org

P. Sanginga CIAT-Africa, Kawanda Agricultural Research Institute, Kampala,Uganda, Psanginga@idrc.or.ke

R.R. Schindelbeck Department of Crop and Soil Sciences, Cornell University,Ithaca, NY14853, USA, rrs3@cornell.edu

P.M. Sédogo Department of Natural Resource Management, Institute ofEnvironment and Agricultural Research (INERA), 04 BP 8645 Ouagadougou 04,Burkina Faso, michel_sedogo@yahoo.fr

Z. Segda Institute of Environment and Agricultural Research (INERA),Ouagadougou, Burkina Faso, zacharie.segda@yahoo.fr

O. Semalulu National Agricultural Research Laboratories (NARL), Kampala,Uganda, o.semalulu@gmail.com

E. Semu Mlingano Agricultural Research Institute, Tanga, Tanzania; Departmentof Soil Science, Sokoine University of Agriculture, Morogoro, Tanzania,esemu@suanet.ac.tz; semu@yahoo.com

D. Senbeto International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, d.senbeto@cgiar.org

C. Serrem Department of Soil Science, Moi University, Eldoret, Kenya,cserrem@yahoo.com

R. Sheila African Farm Radio Research Initiative (AFFFRI), Developing CountriesFarm Radio Network, Ottawa, ON, Canada, shrao@farmradio.org

M.G. Shibia Kenya Agricultural Research Institute (KARI), National Arid LandsResearch Centre, Marsabit, Kenya, schibier@yahoo.com

H. Shinjo Kyoto University, Kyoto, Japan, shinhit@kais.kyoto-u.ac.jp

C.A. Shisanya Kenyatta University, Nairobi, Kenya, shisanya@yahoo.com

S.N. Silim Kenya Agricultural Research Institute (KARI), Embu, Kenya,s.silim@cgiar.org

xlvi Contributors

J. Six Department of Plant Sciences, University of California, One Shields Ave.,Davis, CA, USA; Departments of Agronomy and Range Science, University ofCalifornia, Davis, CA, USA, jwsix@ucdavis.edu

D. Sogodogo Institut d’ Economie Rurale (IER), Cinzana, Mali,sdiakalia@yahoo.fr

A. Sow Sahel Regional Station, Africa Rice Centre, BP 96 Saint Louis, Senegal,a.sow@cgiar.org

K. Stahr Institute of Soil Science and Land Evaluation, University of Hohenheim,Stuttgart, Germany, karl.stahr@uni-hohenheim.de

L. Stroosnijder Erosion and Soil & Water Conservation Group, WageningenUniversity, Wageningen, The Netherlands, leo.stroosnijder@wur.nl

K. Sukalac Information and Communications, IFA, Paris, France,ksukalac@fertilizer.org

I. Sumaila CSIR-Savanna Agricultural Research Institute, Tamale, Ghana,sumdanib@yahoo.com

R. Tabo Forum for Agricultural Research in Africa (FARA), Accra, Ghana,rtabo@fara-africa.org

I.M. Tabu Department of Crops, Horiculture and Soils, Egerton University,Egerton, Kenya, immtabu@yahoo.com

S. Tamani Bureau National des Sols (BUNASOLS), Ouagadougou, Burkina Faso,tamani.sohar@yahoo.fr

U. Tanaka Kyoto University, Kyoto, Japan, uerutnk@kais.kyoto-u.ac.jp

J. Tanui African Highland Initiative, Kampala, Uganda, j.tanui@cgiar.org

J.-B.S. Taonda Institut de l’ Environnement et de Recherches Agricoles, INERA,Kamboinse, Ouagadougou, Burkina Faso, staonda2@yahoo.fr

T.P. Tauro Department of Soil Science and Agricultural Engineering, University ofZimbabwe, Mount Pleasant, Harare, Zimbabwe; Department of Research andSpecialist Services (DR&SS), Chemistry and Soil Research Institute, Causeway,Harare, Zimbabwe, phirilani2@yahoo.co.uk

M. Tchienkoua Institut de la Recherche Agricole pour le Développement (IRAD),Yaounde, Cameroon, mtchienko@yahoo.com

A.J. Tenge The University of Dodoma, Dodoma, Tanzania, ajtenge@yahoo.co.uk

A. Tenkouano International Institute of Tropical Agriculture (IITA), Humid ForestEcoregional Center, Yaoundé, Cameroon, a.tenkouano@cgiar.org

J.S. Tenywa Makerere University, Kampala, Uganda, jtenywa@agri.mak.ac.ug

C. Thierfelder CIMMYT Zimbabwe, Mount Pleasant, Harare, Zimbabwe,c.thierfelder@cgiar.org

M.N. Thuita Department of Soil Science, Moi University, Eldoret, Kenya,thuitam@yahoo.com

Contributors xlvii

I. Tibo CSIR-Savanna Agricultural Research Institute, Tamale, Ghana,ibrahimtibo@yahoo.com

P. Tittonell Plant Production Systems, Department of Plant Sciences, WageningenUniversity, Wageningen, The Netherlands; Tropical Soil Biology and FertilityInstitute of the International Centre for Tropical Agriculture (TSBF-CIAT), Nairobi,Kenya, Pablo.Tittonell@wur.nl

S. Tobita JIRCAS, Tsukuba, Ibaraki, Japan, bita1mon@jircas.affrc.go.jp

E. Tollens Faculty of Bioscience Engineering, Center for Agricultural and FoodEconomics, Catholic University of Leuven, Leuven, Belgium,Eric.Tollens@ees.kuleuven.be

K. Tomekpe Centre Africain de Recherche sur le Bananier et Plantain (CARBAP),Njombé, Cameroon, tomekpe@carbap-africa.org

A. Touré Africa Rice Center (WARDA), Cotonou, Benin

K. Traore Sahel Regional Station, Africa Rice Centre, BP 96 Saint Louis, Senegal,k.traore@cgiar.org

M. Traoré Bureau National des Sols (BUNASOLS), Ouagadougou, Burkina Faso,madouchef@yahoo.fr

G. Tsané International Institute of Tropical Agriculture (IITA), Humid ForestEcoregional Center, Yaoundé, Cameroon; Faculty of Science and BiotechnologyCentre, University of Yaoundé I, 812, Yaoundé, Cameroon, tsanegodefroy@yahoo.fr

A. Tschannen Centre Swisse de Recherche Scientifique en Côte d’Ivoire (CSRS),Abidjan, Côte d’Ivoire, andres.tschannen@gmail.com

S. Twomlow International Crops Research Institute for the Semi Arid Tropics(ICRISAT), Bulawayo, Zimbabwe, s.twomlow@cgiar.org

A. Uwiragiye ISAR, Kiruhura District, Butare, Rwanda,uwiragiyeambroise@yahoo.fr

H.M. van Es Department of Crop and Soil Sciences, Cornell University, Ithaca,NY, USA, hmv1@cornell.edu

B. Vanlauwe Tropical Soil Biology and Fertility Institute of the InternationalCentre for Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya,b.vanlauwe@cgiar.org

P. van Straaten School of Environmental Sciences, University of Guelph, Guelph,ON, Canada, pvanstra@uoguelph.ca

L.V. Verchot World Agroforestry Centre (ICRAF), Nairobi, Kenya,l.verchot@cgiar.org

P.L.G. Vlek Center for Development Research–ZEF, University of Bonn, Bonn,Germany, p.vlek@uni-bonn.de

P. Wakaba Kenya Agricultural Research Institute Muguga South, Nairobi, Kenya,petermwakaba@yahoo.com

C. Walela Kenya Forestry Research Institute, Gede Regional Research Centre,Malindi, Kenya, cwalela@une.edu.au

xlviii Contributors

P.C. Wall CIMMYT, Harare, Zimbabwe, p.wall@cgiar.org

D.K. Wamae Kenya Agricultural Research Institute (KARI), Nairobi, Kenya,kdwamae@yahoo.com

J. Wamalwa Kenya Agricultural Research Institute, Nairobi, Kenya,jwamalwa60@yahoo.com

S.W. Wanderi Kenya Agricultural Research Institute (KARI), Embu, Kenya,wanderi_susan@yahoo.com

J.M. Wanyama Kenya Agricultural Research Institute (KARI), Kitale Centre,Kitale, Kenya, jmasindektl@yahoo.com

G.P. Warren Department of Soil Science, The University of Reading, Reading,UK, g.p.warren@reading.ac.uk

B.S. Waswa Tropical Soil Biology and Fertility Institute of the International Centrefor Tropical Agriculture (TSBF-CIAT), Nairobi, Kenya, bswaswa@yahoo.com

F. Waswa Department of Environmental Planning, Management and CommunityDevelopment, Kenyatta University, Nairobi, Kenya, wfuchaka@yahoo.com

L. Wekesa Kenya Forestry Research Station, Kibwezi, Kenya,weknus@yahoo.com

M. Welimo Kenya Forestry Research Institute, Gede Regional Research Centre,Malindi, Kenya, mwelimo@yahoo.com

G. Were Moi University, Eldoret, Kenya, gmwere@yahoo.com

K. Wilson Fletcher School of Law and Diplomacy, Tufts University, Boston, MA,USA, kimberley.wilson@tufts.edu

D.W. Wolfe Department of Horticulture, Cornell University, Ithaca, NY, USA,dww5@cornell.edu

L. Woltering International Crops Research Institute for the Semi-Arid Tropics(ICRISAT) Sahelian Center, Niamey, Niger, lennartwoltering@yahoo.com

P.L. Woomer FORMAT Kenya, Nairobi, Kenya, plwoomer@gmail.com

C.S. Wortmann Department of Agronomy and Horticulture, University ofNebraska Lincoln, Lincoln, NE, USA, cswortman@unlnotes.unl.edu

O. Yombo Faculty of Science and Biotechnology Centre, University of Yaoundé I,812, Yaoundé, Cameroon, yombono@yahoo.fr

S. Youl IFDC-Ouaga 11 BP 82 CMS, Ouagadougou 11, Burkina Faso,syoul@ifdc.org

A.R. Zaharah Faculty of Agriculture, Department of Land Management, UniversitiPutra Malaysia, Serdang, Selangor, Malaysia, Zaharah@Agri.upm.edu.my

S. Zingore Chitedze Research Station, Tropical Soil Biology and Fertility Instituteof the International Centre for Tropical Agriculture (TSBF-CIAT), Lilongwe,Malawi, szingore@ipni.net

Contributors xlix

E. Zongo Bureau National des Sols (BUNASOLS), Ouagadougou, Burkina Faso,Zongoedouard60@yahoo.fr

R. Zougmoré Institute for Environment and Agricultural Research (INERA),Ouagadougou 04, Burkina Faso, robert.zougmore@messrs.gov.bf

S.J. Zoundi Secretariat of the Sahel and West Africa Club (SWAC/OECD), 2 rueAndré Pascal, 75775 Paris, Cedex 16, France, sibirijean.zoundi@oecd.org