Conservation agriculture and smallholder farming in Africa: The heretics' view

Field Crops Research

Volumn 114, Issue 1, 2009, Pages 23-34

  Giller, Ken E ^a,b   Witter, Ernst ^b,c   Corbeels, Marc ^b,d   Tittonell, Pablo ^a,d  

^a WAGENINGEN UNIVERSITY   (Netherlands)

^b Tropical Soil Biology and Fertility Institute   (Zimbabwe)

^c SWEDISH UNIVERSITY OF AGRICULTURAL SCIENCES   (Sweden)

^d Research Unit Agroecology and Sustainable intensification of Annual Crops   (France)

Author keywords

Adoption; Crop residue; Mulch; No tillage; Soil carbon; Soil conservation; Sub Saharan Africa; Zero tillage

Indexed keywords

AGRICULTURAL ECONOMICS; AGRICULTURAL PRODUCTION; ALTERNATIVE AGRICULTURE; CROP RESIDUE; CROP YIELD; EROSION CONTROL; FARMING SYSTEM; HERBICIDE; RESEARCH AND DEVELOPMENT; SOCIOECONOMIC CONDITIONS; SOIL CARBON; SOIL CONSERVATION; SOIL DEGRADATION; SOIL FERTILITY; ZERO TILLAGE;

AFRICA;

EID: 69449101358     PISSN: 03784290     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.fcr.2009.06.017     Document Type: Review

References (127)

1. Abdalla M.A., and Mohamed A.E. The response of two-sorghum cultivars to conventional and conservation tillage systems in central Sudan. AMA - Agric. Mech. Asia, Afr. Lat. Am. 38 (2007) 67-71
2. Abiven S., and Recous S. Mineralisation of crop residues on the soil surface or incorporated in the soil under controlled conditions. Biol. Fertil. Soils 43 (2007) 849-852
3. Adjei-Nsiah S., Kuyper T.W., Leeuwis C., Abekoe M.K., and Giller K.E. Evaluating sustainable and profitable cropping sequences with cassava and four legume crops: effects on soil fertility and maize yields in the forest/savannah transitional agro-ecological zone of Ghana. Field Crop Res. 103 (2007) 87-97
4. Adu-Gyamfi J.J., Myaka F.A., Sakala W.D., Odgaard R., Vesterager J.M., and Hogh-Jensen H. Biological nitrogen fixation and nitrogen and phosphorus budgets in farmer-managed intercrops of maize-pigeonpea in semi-arid southern and eastern Africa. Plant Soil 295 (2007) 127-136
5. Affholder F., Jourdain D., Morize M., Dan Dinh Q., and Ricome A. Eco-intensification dans les montagnes du Vietnam. Contraintes à l'adoption de la culture sur couvertures végétales. Cahiers Agricultures 17 (2008) 289-296
6. African Conservation Tillage Network, 2008. 2009-06-26 www.act-africa.org/.
7. Aina P.O., Lal R., and Roose E.J. Tillage methods and soil and water conservation in West Africa. Soil Till. Res. 20 (1991) 165-186
8. Akinyemi J.O., Akinpelu O.E., and Olaleye A.O. Performance of cowpea under three tillage systems on an Oxic Paleustalf in southwestern Nigeria. Soil Till. Res. 72 (2003) 75-83
9. Alabi S., and Akintunde O. Effect of tillage method on soil properties and performance of groundnut (Arachis hypogaea L.) in Southwestern Nigeria. J. Sust. Agric. Environ. 6 (2004) 22-29
10. Allmaras R.R., and Dowdy R.H. Conservation tillage systems and their adoption in the United States. Soil Till. Res. 5 (1985) 197-222
11. Asefa T., Tanner D., and Bennie A. Effects of stubble management, tillage and cropping sequence on wheat production in the south-eastern highlands of Ethiopia. Soil Till. Res. 76 (2004) 69-82
12. Bationo A., Kihara J., Vanlauwe B., Waswa B., and Kimetu J. Soil organic carbon dynamics, functions and management in West African agro-ecosystems. Agric. Syst. 94 (2007) 13-25
13. Baudron F., Mwanza H.M., Triomphe B., and Bwalya M. Conservation Agriculture in Zambia: A Case Study of Southern Province (2007), African Conservation Tillage Network, Centre de Coopération Internationale de Recherche Agronomique pour le Dévelopment, Food and Agricultural Organization of the United Nations, Nairobi, Kenya
14. Bebe B.O., Udo H.M.J., and Thorpe W. Development of smallholder dairy systems in the Kenya highlands. Outlook Agric. 31 (2002) 113-120
15. Benites J.R., and Ashburner J.E. FAO'S role in promoting conservation agriculture. Conserv. Agric.: Environ. Farmers Exp. Innov. Socio-Econ. Policy (2003) 139-153
16. Benoit-Cattin M., Calkins P., Kebe D., and Sabatier J.-L. Perspectives de la modélisation des systèmes agraires cotonnières du Mali: l'exemple des régions cotonnières du Mali. Cahiers de la Recherches Développement 29 (1991) 14-29
17. Biamah E.K., Gichuki F.N., and Kaumbutho P.G. Tillage methods and soil and water conservation in eastern Africa. Soil Till. Res. 27 (1993) 105-123
18. Bolliger, A., 2007. Is Zero-till an appropriate agricultural alternative for disadvantaged smallholders of South Africa? A study of surrogate systems and strategies, smallholder sensitivities and soil glycoproteins. PhD Thesis. University of Copenhagen, Copenhagen, p. 67.
19. Bolliger A., Magid J., Amado T.J.C., Neto F.S., Ribeiro M.D.D., Calegari A., Ralisch R., and de Neergaard A. Taking stock of the Brazilian "zero-till revolution": a review of landmark research and farmers' practice. Adv. Agron. 91 (2006) 47-110
20. 2-fixation and residual benefits to two successive maize crops in Zimbabwe. Plant Soil 262 (2004) 303-315
21. Chivenge P.P., Murwira H.K., Giller K.E., Mapfumo P., and Six J. Long-term impact of reduced tillage and residue management on soil carbon stabilization: implications for conservation agriculture on contrasting soils. Soil Till. Res. 94 (2007) 328-337
22. Christoffoleti P.J., de Carvalho S.J.P., Lopez-Ovejero R.F., Nicolai M., Hidalgo E., and da Silva J.E. Conservation of natural resources in Brazilian agriculture: implications on weed biology and management. Crop Prot. 26 (2007) 383-389
23. Corbeels M., Scopel E., Cardoso A., Bernoux M., Douzet J.M., and Neto M.S. Soil carbon storage potential of direct seeding mulch-based cropping systems in the Cerrados of Brazil. Global Change Biol. 12 (2006) 1773-1787
24. Conservation Technology Information Center (CTIC). What's Conservation Tillage? (1999), CTIC, Core 4 Program, Lafayette, IN, USA
25. Davis K.E. Extension in sub-Saharan Africa: overview and assessment of past and current models, and future prospects. J. Int. Agric. Ext. Educ. 15 (2008) 15-28
26. Dercon S. Wealth, risk and activity choice: cattle in western Tanzania. J. Dev. Econ. 55 (1998) 1-42
27. Derpsch R. Conservation tillage, no-tillage and related technologies. Conserv. Agric. Environ. Farm. Exp. Innov. Socio-Econ. Policy (2003) 181-190
28. Diels J., Vanlauwe B., Van der Meersch M.K., Sanginga N., and Merckx R. Long-term soil organic carbon dynamics in a subhumid tropical climate: C-13 data in mixed C-3/C-4 cropping and modeling with ROTHC. Soil Biol. Biochem. 36 (2004) 1739-1750
29. Drechsel P., Gyiele L., Kunze D., and Cofie O. Population density, soil nutrient depletion, and economic growth in sub-Saharan Africa: a Malthusian nexus?. Ecol. Econ. 38 (2001) 251-258
30. Dugue P., Vall E., Lecomte P., Klein H., and Rollin D. Evolution of relationships between agriculture and livestock in the savannas of West and Central Africa. A new framework for analysis and intervention for improving modes of intervention and favouring innovation. Oleagineux 11 (2004) 268-276
31. Ehui S., and Pender J. Resource degradation, low agricultural productivity, and poverty in sub-Saharan Africa: pathways out of the spiral. Agric. Econ. 32 (2005) 225-242
32. Erenstein, O., 1999. The economics of soil conservation in developing countries: the case of crop residue mulching. PhD Thesis. Wageningen Agricultural University, Wageningen, Netherlands.
33. Erenstein O. Crop residue mulching in tropical and semi-tropical countries: an evaluation of residue availability and other technological implications. Soil Till. Res. 67 (2002) 115-133
34. Erenstein O. Smallholder conservation farming in the tropics and sub-tropics: a guide to the development and dissemination of mulching with crop residues and cover crops. Agric. Ecosyst. Environ. 100 (2003) 17-37
35. Erkossa T., Stahr K., and Gaiser T. Soil tillage and crop productivity on a Vertisol in Ethiopian highlands. Soil Till. Res. 85 (2006) 200-211
36. FAO. Investing in Sustainable Agricultural Intensification. The Role of Conservation Agriculture. A Framework for Action (2008), Food and Agriculture Organization of the United Nations, Rome
37. FAO, 2008b. Conservation Agriculture. 2008-07-08 http://www.fao.org/ag/ca/index.html.
38. Farage P.K., Ardo J., Olsson L., Rienzi E.A., Ball A.S., and Pretty J.N. The potential for soil carbon sequestration in three tropical dryland farming systems of Africa and Latin America: a modelling approach. Soil Till. Res. 94 (2007) 457-472
39. Feller C., and Beare M.H. Physical control of soil organic matter dynamics in the tropics. Geoderma 79 (1997) 69-116
40. Fowler R., and Rockström J. Conservation tillage for sustainable agriculture-an agrarian revolution gathers momentum in Africa. Soil Till. Res. 61 (2001) 93-107
41. Gill K.S., and Aulakh B.S. Wheat yield and soil bulk-density response to some tillage systems on an Oxisol. Soil Till. Res. 18 (1990) 37-45
42. Giller K.E. Nitrogen Fixation in Tropical Cropping Systems (2001), CAB International, Wallingford, UK
43. Giller K.E., and Cadisch G. Future benefits from biological nitrogen-fixation-an ecological approach to agriculture. Plant Soil 174 (1995) 255-277
44. Giller K.E., Rowe E.C., de Ridder N., and van Keulen H. Resource use dynamics and interactions in the tropics: scaling up in space and time. Agric. Syst. 88 (2006) 8-27
45. Govaerts B., Verhulst N., Castellanos-Navarrete A., Sayre K.D., Dixon J., and Dendooven L. Conservation agriculture and soil carbon sequestration: between myth and farmer reality. Crit. Rev. Plant Sci. 28 (2009) 97-122
46. Gowing J.W., and Palmer M. Sustainable agricultural development in sub-Saharan Africa: the case for a paradigm shift in land husbandry. Soil Use Manage. 24 (2008) 92-99
47. Haggblade S., and Tembo G. Conservation farming in Zambia. EPTD Discussion Paper (2003), Environment and Production Technology Division, International Food Policy Research Institute
48. Heal O.W., Anderson J.W., and Swift M.J. Plant litter quality and decomposition: an historical overview. In: Cadisch G., and Giller K.E. (Eds). Driven by Nature: Plant Litter Quality and Decomposition (1997), CAB International, Wallingford, UK 3-30
49. Hebblethwaite J., Soza R., Faye A., and Hutchinson N. No-till and reduced tillage for improved crop production in sub-Saharan Africa. Achieving greater impact from research investments in Africa. Proceedings of the Workshop Developing African Agriculture: Achieving Greater Impact from Research Investments. Addis Ababa, Ethiopia, September 26-30, 1995 (1996) 195-199
50. Hobbs P.R. Conservation agriculture: what is it and why is it important for future sustainable food production?. J. Agric. Sci. 145 (2007) 127-137
51. Hobbs P.R., Sayre K., and Gupta R. The role of conservation agriculture in sustainable agriculture. Philos. Trans. Roy. Soc. B 363 (2008) 543-555
52. Ikpe F.N., Powell J.M., Isirimah N.O., Wahua T.A.T., and Ngodigha E.M. Effects of primary tillage and soil amendment practices on pearl millet yield and nutrient uptake in the Sahel of West Africa. Exp. Agric. 35 (1999) 437-448
53. Ito M., Matsumoto T., and Quinones M.A. Conservation tillage practice in sub-Saharan Africa: the experience of Sasakawa Global 2000. Crop Prot. 26 (2007) 417-423
54. Jarecki M.K., and Lal R. Crop management for soil carbon sequestration. Crit. Rev. Plant Sci. 22 (2003) 471-502
55. Kanmegne, J., 2004. Slash and burn agriculture in the humid forest zone of Southern Cameroon: soil quality dynamics, improved fallow management and farmers' perceptions. Tropenbos-Cameroon Series xii.
56. Kasasa P., Mpepereki S., Musiyiwa K., Makonese F., and Giller K. Residual nitrogen benefits of promiscuous soybeans to maize under field conditions. Afr. Crop Sci. J. 7 (1999) 375-382
57. Kaumbutho P., and Kienzle J. Conservation Agriculture As Practised in Kenya: Two Case Studies (2007), African Conservation Tillage Network, Centre de Coopération Internationale de Recherche Agronomique pour le Développement, Food and Agriculture Organization of the United Nations, Nairobi, Kenya
58. Kayode J., and Ademiluyi B. Effect of tillage methods on weed control and maize performance in southwestern Nigeria. J. Sust. Agric. 23 (2004) 39-45
59. Kerr R.B., Snapp S., Chirwa M., Shumba L., and Msachi R. Participatory research on legume diversification with Malawian smallholder farmers for improved human nutrition and soil fertility. Exp. Agric. 43 (2007) 437-453
60. Knowler D., and Bradshaw B. Farmers' adoption of conservation agriculture: a review and synthesis of recent research. Food Pol. 32 (2007) 25-48
61. Kronen M. Water harvesting and conservation techniques for smallholder crop production systems. Soil Till. Res. 32 (1994) 71-86
62. Lahmar R. Adoption of conservation agriculture in Europe: lessons of the KASSA project. Land Use Policy (2009) 10.1016/j.landusepol.2008.02.001
63. Lahmar R., and Triomphe B. Key lessons from international experiences about conservation agriculture and considerations for its implementation in dry areas. In: Stewart B.I., Asfary A.F., Belloum A., Steiner K., and Friedrich T. (Eds). Conservation Agriculture for Sustainable Land Management to Improve the Livelihood of People in Dry Areas. (2008), ACSAD & GTZ 123-140
64. Lal R. Influence of 6 years of no-tillage and conventional plowing on fertilizer response of maize (Zea mays L.) on an Alfisol in the tropics. Soil Sci. Soc. Am. J. 43 (1979) 399-403
65. Lal R. Soil surface management in the tropics for intensive land use and high and sustained production. Adv. Soil Sci. 5 (1986) 1-109
66. Lal R. Tillage and agricultural sustainability. Soil Till. Res. 20 (1991) 133-146
67. Lal R. Soil erosion impact on agronomic productivity and environment quality. Crit. Rev. Plant Sci. 17 (1998) 319-464
68. Lal R. Soil quality changes under continuous cropping for seventeen seasons of an Alfisol in western Nigeria. Land Degrad. Dev. 9 (1998) 259-274
69. Lal R., Follett F., Stewart B.A., and Kimble J.M. Soil carbon sequestration to mitigate climate change and advance food security. Soil Sci. 172 (2007) 943-956
70. In: Lavelle P., Brussaard L., and Hendrix P. (Eds). Earthworm Management in Tropical Agroecosystems (1999), CAB International, Wallingford
71. Leeuwis C. Communication for Rural Innovation. Rethinking Agricultural Extension (with contributions by A. Van den Ban) (2004), Blackwell Science, Oxford
72. Locke M.A., Reddy K.N., and Zablotowicz R.M. Weed management in conservation crop production systems. Weed Biol. Manage. 2 (2002) 123-132
73. Logan T.J., Lal R., and Dick W.A. Tillage systems and soil properties in North America. Soil Till. Res. 20 (1991) 241-270
74. Mando A., Ouattara B., Sedogo M., Stroosnijder L., Ouattara K., Brussaard L., and Vanlauwe B. Long-term effect of tillage and manure application on soil organic fractions and crop performance under Sudano-Sahelian conditions. Soil Till. Res. 80 (2005) 95-101
75. Mapfumo P., Chikowo R., Giller K.E., Mugendi D.N., Kimetu J.M., Palm C.A., and Mutuo P. Closing the Loop: Identifying N sources and minimizing N losses in leguminous cropping systems. Final Project Report to the Rockefeller Foundation (2001), University of Zimbabwe, Harare
76. Martin C., Castella J.C., Hoang Lan A., Eguienta Y., and Tran Trong H. A participatory simulation to facilitate farmers' adoption of livestock feeding systems based on conservation agriculture in the uplands of northern Vietnam. Int. J. Agric. Sust. 2 (2004) 118-132
77. Mashingaidze, A.B., Govere, I., Rohrbach, D., Hove, L., Twomlow, K., Mazvimavi, K., 2006. Review of NGO Efforts to Promote Conservation Agriculture in Zimbabwe, 2005/2006 Season (unpublished, pre-edited draft).
78. Mazvimavi, K., Twomlow, S., Belder, P., Hove, L., 2008. An Assessment of the Sustainable Uptake of Conservation Farming in Zimbabwe. Global Theme on Agroecosystems Report no. xx.
79. Mbagwu J. Mulch and tillage effects on water transmission characteristics of an Ultisol and maize grain yield in SE Nigeria. Pedologie 40 (1990) 155-168
80. Moyo, A., 2002. Assessment of the effect of soil erosion on nutrient loss from granite-derived sandy soils under different tillage systems in Zimbabwe. PhD Thesis University of Zimbabwe, Harare, Zimbabwe.
81. Mpepereki S., Javaheri F., Davis P., and Giller K.E. Soyabeans and sustainable agriculture-promiscuous soyabeans in southern Africa. Field Crops Res. 65 (2000) 137-149
82. Munyati, M., 2000. Conservation tillage for sustainable crop production. Results from on-station research in Natural Region II of Zimbabwe (unpublished).
83. Mutekwa V., and Kusangaya S. Contribution of rainwater harvesting technologies to rural livelihoods in Zimbabwe: the case of Ngundu ward in Chivi District. Water SA 32 (2006) 437-444
84. Nhamo, N., 2007. The contribution of different fauna communities to improved soil health: a case of Zimbabwean soils under conservation agriculture. PhD Thesis. Rheinischen Friedrich-Wilhelms-Universitat, Bonn, Germany, p. 128.
85. Nicou R., Charreau C., and Chopart J.L. Tillage and soil physical properties in semiarid West Africa. Soil Till. Res. 27 (1993) 125-147
86. Nyagumbo, I., 2002. The effects of three tillage systems on seasonal water budgets and drainage of two zimbabwean soils under maize. PhD Thesis, University of Zimbabwe, Harare, Zimbabwe.
87. Ojiem J., Ridder N., Vanlauwe B., and Giller K.E. Socio-ecological niche: a conceptual framework for integration of legumes in smallholder farming systems. Int. J. Agric. Sust. 4 (2006) 79-93
88. Ojiem J.O., Vanlauwe B., de Ridder N., and Giller K.E. Niche-based assessment of contributions of legumes to the nitrogen economy of Western Kenya smallholder farms. Plant Soil 292 (2007) 119-135
89. Palm C.A., Giller K.E., Mafongoya P.L., and Swift M.J. Management of organic matter in the tropics: translating theory into practice. Nutr. Cycl. Agroecosyst. 61 (2001) 63-75
90. Powell J.M., Pearson R.A., and Hiernaux P.H. Crop-livestock interactions in the west African drylands. Agron. J. 96 (2004) 469-483
91. Rockström J., and Barron J. Water productivity in rainfed systems: overview of challenges and analysis of opportunities in water scarcity prone savannahs. Irrig. Sci. 25 (2007) 299-311
92. Rockström J., Kaumbutho P., Mwalley P., and Temesgen M. Conservation farming among small-holder farmers in E. Africa: adapting and adopting innovative land management options. Conservation agriculture, a worldwide challenge. Proceedings of the First World Congress on Conservation Agriculture, vol. 1: Keynote Contributions. Madrid, Spain, October 1-5, 2001 (2001) 363-374
93. Rockström J., Kaumbutho P., Mwalley J., Nzabi A.W., Temesgen M., Mawenya L., Barron J., Mutua J., and Damgaard-Larsen S. Conservation farming strategies in East and Southern Africa: yields and rain water productivity from on-farm action research. Soil Till. Res. 103 (2008) 23-32
94. Roose E., and Barthes B. Organic matter management for soil conservation and productivity restoration in Africa: a contribution from Francophone research. Nutr. Cycl. Agroecosyst. 61 (2001) 159-170
95. Rufino M.C., Tittonell P., van Wijk M.T., Castellanos-Navarrete A., Delve R.J., de Ridder N., and Giller K.E. Manure as a key resource within smallholder farming systems: analysing farm-scale nutrient cycling efficiencies with the NUANCES framework. Livestock Sci. 112 (2007) 273-287
96. Sakala, W.D., 1998. Nitrogen dynamics in maize/pigeonpea intercropping in Malawi. 1998. PhD Thesis. Wye College, University of London.
97. Sakala W.D., Cadisch G., and Giller K.E. Interactions between residues of maize and pigeonpea and mineral N fertilizers during decomposition and N mineralization. Soil Biol. Biochem. 32 (2000) 679-688
98. Samaké O., Smaling E.M.A., Kropff M.J., Stomph T.J., and Kodio A. Effects of cultivation practices on spatial variation of soil fertility and millet yields in the Sahel of Mali. Agric. Ecosyst. Environ. 109 (2005) 335-345
99. Sanginga N., Okogun J.A., Vanlauwe B., Diels J., and Dashiell K. Contribution of nitrogen fixation to the maintenance of soil fertility with emphasis on promiscuous soybean maize-based cropping systems in the moist savanna of West Africa. In: Tian G., Ishida F., and Keatinge J.D.H. (Eds). Sustaining Soil Fertility in West Africa (2001), ASA, Wisconsin 157-178
100. In: Scoones I. (Ed). Dynamics & Diversity: Soil Fertility Management and Farming Livelihoods in Africa: Case Studies from Ethiopia, Mali and Zimbabwe. (2001), Earthscan Publications Ltd., London
101. Scopel E., Macena F., Corbeels M., Affholder F., and Maraux F. Modelling crop residue mulching effects on water use and production of maize under semi-arid and humid tropical conditions. Agronomie 24 (2004) 1-13
102. Scopel E., Findeling A., Guerra E.C., and Corbeels M. Impact of direct sowing mulch-based cropping systems on soil carbon, soil erosion and maize yield. Agron. Sust. Dev. 25 (2005) 425-432
103. Shetto R., and Owenya M. Conservation Agriculture As Practised In Tanzania: Three Case Studies (2007), African Conservation Tillage Network, Centre de Coopération Internationale de Recherche Agronomique pour le Développement, Food and Agriculture Organization of the United Nations, Nairobi, Kenya
104. Siziba, S., 2008. Assessing the adoption of conservation agriculture in Zimbabwe's smallholder sector. PhD Thesis. University of Hohenheim, Germany.
105. Steiner K., Derpsch R., and Koller K. Sustainable management of soil resources through zero tillage. Agric. Rural Dev. 5 (1998) 64-66
106. Stewart C.E., Paustian K., Conant R.T., and Plante A.F. Soil carbon saturation: concept, evidence and evaluation. Biogeochemistry 86 (2007) 19-31
107. Stoorvogel J.J., and Smaling E.A. Research on soil fertility decline in tropical environments: integration of spatial scales. Nutr. Cycl. Agroecosyst. 50 (1998) 151-158
108. Sumberg J. Constraints to the adoption of agricultural innovations-is it time for a re-think?. Outlook Agric. 34 (2005) 7-10
109. Swift M.J., Heal O.W., and Anderson J.M. Decomposition in Terrestrial Ecosystems (1979), Blackwell Scientific Publications, Oxford, UK
110. Tadesse N., Ahmed S., and Hulluka M. The effects of minimum tillage weeds and yield of durum wheat in central Ethiopia. Trop. Agric. 73 (1996) 242-244
111. Temesgen M., Rockström J., Savenije H.H.G., Hoogmoed W.B., and Alemu D. Determinants of tillage frequency among smallholder farmers in two semi-arid areas in Ethiopia. Phys. Chem. Earth 33 (2008) 183-191
112. Tittonell P., Vanlauwe B., Leffelaar P.A., Rowe E.C., and Giller K.E. Exploring diversity in soil fertility management of smallholder farms in western Kenya. I. Heterogeneity at region and farm scale. Agric. Ecosyst. Environ. 110 (2005) 149-165
113. Tittonell P., Vanlauwe B., de Ridder N., and Giller K.E. Heterogeneity of crop productivity and resource use efficiency within smallholder Kenyan farms: soil fertility gradients or management intensity gradients?. Agric. Syst. 94 (2007) 376-390
114. Tittonell P., van Wijk M.T., Rufino M.C., Vrugt J.A., and Giller K.E. Analysing trade-offs in resource and labour allocation by smallholder farmers using inverse modelling techniques: a case-study from Kakamega district, western Kenya. Agric. Syst. 95 (2007) 76-95
115. Tittonell P., Vanlauwe B., Corbeels M., and Giller K.E. Yield gaps, nutrient use efficiencies and response to fertilisers by maize across heterogeneous smallholder farms of western Kenya. Plant Soil 313 (2008) 19-37
116. Triomphe B.J., Kienzle S., Bwalya M., and Damgaard-Larsen S. Case study project background and method. In: Baudron F., Mwanza H.M., Triomphe B., and Bwalya M. (Eds). Conservation Agriculture in Zambia: A Case Study of Southern Province. Conservation Agriculture in Africa Series (2007), African Conservation Tillage Network, Centre de Coopération Internationale de Recherche Agronomique pour le Dévelopment, Food and Agricultural Organization of the United Nations, Nairobi, Kenya IX-XX
117. Triplett G.B., and Warren A.D. No-tillage crop production: a revolution in agriculture!. Agron. J. 100 (2008) S-153-S-165
118. Tulema B., Aune J.B., Johnsen F.H., and Vanlauwe B. The prospects of reduced tillage in tef (Eragrostis tef Zucca) in Gare Arera, West Shawa Zone of Oromiya, Ethiopia. Soil Till. Res. 99 (2008) 58-65
119. De Vleeschauwer D., Lal R., and Malafa R. Effects of amounts of surface mulch on physical and chemical properties of an Alfisol from Nigeria. J. Sci. Food Agric. 31 (1980) 730-738
120. Vogel H. Tillage effects on maize yield, rooting depth and soil-water content on sandy soils in Zimbabwe. Field Crops Res. 33 (1993) 367-384
121. Vogel H. An evaluation of five tillage systems for smallholder agriculture in Zimbabwe. Der Tropenlandwirt 94 (1993) 21-36
122. Vogel H. Weeds in single-crop conservation farming in Zimbabwe. Soil Till. Res. 31 (1994) 169-185
123. Vogel H. The need for integrated weed management-systems in smallholder conservation farming in Zimbabwe. Der Tropenlandwirt 96 (1995) 35-56
124. Wall P. Tailoring conservation agriculture to the needs of small farmers in developing countries: an analysis of issues. J. Crop Improv. 19 (2007) 137-155
125. Wezel A., and Rath T. Resource conservation strategies in agro-ecosystems of semi-arid West Africa. J. Arid Environ. 51 (2002) 383-400
126. Zingore S., Manyame C., Nyamugafata P., and Giller K.E. Long-term changes in organic matter of woodland soils cleared for arable cropping in Zimbabwe. Eur. J. Soil Sci. 56 (2005) 727-736
127. Zingore S., Murwira H.K., Delve R.J., and Giller K.E. Influence of nutrient management strategies on variability of soil fertility, crop yields and nutrient balances on smallholder farms in Zimbabwe. Agric. Ecosyst. Environ. 119 (2007) 112-126