Soil improvement by trees in sub-Saharan Africa

Agroforestry Systems

Volumn 38, Issue 1-3, 1997, Pages 51-76

  Buresh, R J ^a   Tian, G ^b  

^a WORLD AGROFORESTRY CENTRE ICRAF   (Kenya)

^b INTERNATIONAL INSTITUTE OF TROPICAL AGRICULTURE   (Nigeria)

Author keywords

Nitrogen; Nutrient cycling; Phosphorus; Soil fertility; Soil organic matter

Indexed keywords

CALLIANDRA; CALLIANDRA CALOTHYRSUS; EUCALYPTUS; EUCALYPTUS GRANDIS; SESBANIA SESBAN;

EID: 0031462406     PISSN: 01674366     EISSN: None     Source Type: Journal    
DOI: 10.1023/a:1005948326499     Document Type: Article

References (132)

1. Adejuyigbe CO, Tian G and Adeoye GO (1998) Potentials of woody fallows in restoration of soil microarthropods in a degraded tropical soil. Agroforestry Systems (in press)
2. Adderley WP, Jenkins DA, Sinclair FL, Stevens PA and Verinumbe I (1997) The influence of soil variability on tree establishment at an experimental agroforestry site in North East Nigeria. Soil Use and Management 13: 1-8
3. Barrios E, Buresh RJ and Sprent JI (1996a) Organic matter in soil particle size and density fractions from maize and legume cropping systems. Soil Biology and Biochemistry 28: 185-193
4. Barrios E, Buresh RJ and Sprent JI (1996b) Nitrogen mineralization in density fractions of soil organic matter from maize and legume cropping systems. Soil Biology and Biochemistry 28: 1459-1465
5. Barrios E, Kwesiga F, Buresh RJ and Sprent JI (1997) Light fraction soil organic matter and available nitrogen following trees and maize. Soil Science Society of America Journal 61: 826-831
6. Belsky AJ, Mwonga SM, Amundson RG, Duxbury JM and Ali AR (1993) Comparative effects of isolated trees on their undercanopy environments in high- and low-rainfall savannas. Journal of Applied Ecology 30: 143-155
7. Bernhard-Reversat F (1987) Litter incorporation to soil organic matter in natural and planted tree stands in Senegal. Pedobiologia 30: 401-417
8. Bernhard-Reversat F (1993) Dynamics of litter and organic matter at the soil-litter interface in fast-growing tree plantations on sandy ferrallitic soils (Congo). Acta Oecologica 14: 179-195
9. Bolan NS (1991) A critical review on the role of mycorrhizal fungi in the uptake of phosphorus by plants. Plant and Soil 134: 189-207
10. Braun A (1995) Nutrient flows in fallow systems and maize in western Kenya. MSc thesis. Wageningen Agricultural University, Wageningen, The Netherlands
11. Breman H and Kessler JJ (1995) Woody plants in agro-ecosystems of semi-arid regions. Springer-Verlag, Berlin, Germany
12. Brouwer J and Bouma J (1997) Soil and crop growth variability in the Sahel: highlights of research (1990-95) at ICRISAT Sahelian Center. Information Bulletin No. 49. ICRISAT, Patancheru, Andhra Pradesh, India and Agricultural University of Wageningen, Wageningen, The Netherlands
13. Brouwer J, Fussell LK and Herrmann L (1993) Soil and crop growth micro-variability in the West African semi-arid tropics: a possible risk-reducing factor for subsistence farmers. Agriculture, Ecosystems and Environment 45: 229-238
14. Brouwer J and Powell JM (1995) Soil aspects of nutrient cycling in a manure application experiment in Niger. In: Powell JM, Fernández-Rivera S, Williams TO and Renard C (eds) Livestock and Sustainable Nutrient Cycling in Mixed Farming Systems of Sub-Saharan Africa. Volume II. Technical Papers. ILCA, Addis Ababa, Ethiopia
15. Buresh RJ (1995) Nutrient cycling and nutrient supply in agroforestry systems. In: Dudal R and Roy RN (eds) Integrated Plant Nutrition Systems, pp 155-164. FAO Fertilizer and Plant Nutrition Bulletin No. 12. Rome, Italy
16. Buresh RJ, Smithson PC and Hellums DT (1997) Building soil P capital in sub-Saharan Africa. In: Buresh RJ and Sanchez PA (eds) Replenishing Soil Fertility in Africa. SSSA Special Publication 51. SSSA and ASA, Madison, WI, USA (in press)
17. Cahn MD, Bouldin DR and Cravo MS (1992) Nitrate sorption in the profile of an acid soil. Plant and Soil 143: 179-183
18. Chien SH and Menon RG (1995) Factors affecting the agronomic effectiveness of phosphate rock for direct application. Fertilizer Research 41: 227-234
19. Cooper PJM, Leakey RRB, Rao MR and Reynolds L (1996) Agroforestry and the mitigation of land degradation in the humid and sub-humid tropics of Africa. Experimental Agriculture 32: 235-290
20. Craswell ET, Sajjipongse A, Howlett DJB and Dowling AJ (1997) Agroforestry in the management of sloping lands in Asia and the Pacific. Agroforestry Systems 38: 121-137
21. Dalland A, Våje PI, Matthews RB and Singh BR (1993) The potential of alley cropping in improvement of cultivation systems in the high rainfall areas of Zambia. III. Effects on soil chemical and physical properties. Agroforestry Systems 21: 117-132
22. Danso SKA, Bowen GD and Sanginga N (1992) Biological nitrogen fixation in trees in agroecosystems. Plant and Soil 141: 177-196
23. Deans JD, Lindley DK and Munro RC (1994) Deep beneath the trees in Senegal. In: Annual Report of the Institute of Terrestrial Ecology 1993-1994, pp 12-14. NERC, Swindon, UK
24. Deckers J (1993) Soil fertility and environmental problems in different ecological zones of the developing countries of Sub-Saharan Africa. In: van Reuler H and Prins WH (eds) The Role of Plant Nutrients and Sustainable Food Production in Sub-Saharan Africa, pp 37-52. Vereniging van Kunstmest Producenten, Leidschendam, The Netherlands
25. Dommergues YR (1995) Nitrogen fixation by trees in relation to soil nitrogen economy. Fertilizer Research 42: 215-230
26. Fernandes ECM, Garrity DP, Szott LT and Palm CA (1994) Use and potential of domesticated trees for soil improvement. In: Leakey RRB and Newton AC (eds) Tropical Trees: The Potential for Domestication and the Rebuilding of Forest Resources, pp 137-147. HMSO, London, UK
27. Franzel S (1998) Socioeconomic factors affecting the adoption potential of improved fallows in Africa. Agroforestry Systems (in press)
28. Friend MT and Birch HF (1960) Phosphate responses in relation to soil tests and organic phos-phorous. Journal of Agricultural Science 54: 341-347
29. Gachengo CN (1996) Phosphorus release and availability on addition of organic materials to phosphorus fixing soils. M Phil thesis, Moi University, Eldoret, Kenya
30. Geiger SC, Vandenbeldt RJ and Manu A (1994) Variability in the growth of Faidherbia albida: the soils connection. Soil Science Society of America Journal 58: 227-231
31. Giller KE (1997) Tropical legumes: providers and plunderers of nitrogen. In: Bergström L and Kirchmann H (eds) Carbon and Nitrogen Cycling in Natural and Agricultural Tropical Ecosystems. CAB International, Wallingford, UK (in press)
32. Giller KE and Cadisch G (1995) Future benefits from biological nitrogen fixation: An ecological approach to agriculture. Plant and Soil 174: 255-277
33. Giller KE, Cadisch G, Ehaliotis C, Adams E, Sakala WD and Mafongoya PL (1997) Building soil nitrogen capital in sub-Saharan Africa. In: Buresh RJ and Sanchez PA (eds) Replenishing Soil Fertility in Africa. SSSA Special Publication 51. SSSA and ASA, Madison, WI, USA (in press)
34. Haggar JP, Warren GP, Beer JW and Kass D (1991) Phosphorus availability under alley cropping and mulched and unmulched sole cropping systems in Costa Rica. Plant and Soil 137: 275-283
35. Handreck KA (1997) Phosphorus requirements of Australian native plants. Australian Journal of Soils Research 35: 241-289
36. Hands MR, Harrison AF and Bayliss-Smith T (1995) Phosphorus dynamics in slash-and-burn and alley cropping systems of the humid tropics. In: Tiessen H (ed) Phosphorus in the Global Environment; Transfers, Cycles and Management. Scope 54, pp 155-170. John Wiley and Sons Ltd, New York
37. Haque I, Powell JM and Ehui SK (1995) Improved crop-livestock production strategies for sustainable soil management in tropical Africa. In: Lal R and Stewart BA (eds) Soil Management: Experimental Basis for Sustainability and Environmental Quality, pp 293-345. CRC Press, Boca Raton, FL
38. Hartemink AE, Buresh RJ, Jama B and Janssen BH (1996) Soil nitrate and water dynamics in sesbania fallow, weed fallows, and maize. Soil Science Society of America Journal 60: 568-574
39. Hassink (1994) Active organic matter fractions and microbial biomass as predictors of N mineralization. In: Neeteson JJ and Hassink J (eds) Nitrogen Mineralization in Agricultural Soils, pp 1-15. AB-DLO Thema's 1. DLO Research Institute for Agrobiology and Soil Fertility, Wageningen/Haren, The Netherlands
40. Hassink J (1995) Decomposition rate constants of size and density fractions of soil organic matter. Soil Science Society of America 59: 1631-1635
41. Hauser S (1993a) Root distribution of Dactyladenia (Acioa) barteri and Senna (Cassia) siamea in alley cropping on Ultisol. I. Implication for field experimentation. Agroforestry Systems 24: 111-121
42. Hauser S (1993b) Distribution and activity of earthworms and contribution to nutrient recycling in alley cropping. Biology and Fertility of Soils 15: 16-20
43. Horst WJ, Kühne R and Kang BT (1995) Nutrient use in Leucaena leucocephala and Cajanus cajan in maize/cassava alley cropping on Terre de Barre, Benin Republic. In: Kang BT, Osiname AO and Larbi A (eds) Alley Farming Research and Development, pp 122-136. Alley Farming Network for Tropical Africa, Ibadan, Nigeria
44. Hulugalle NR and Kang BT (1990) Effect of hedgerow species in alley cropping systems on surface soil physical properties of an Oxic Paleustalf in southwestern Nigeria. Journal of Agricultural Science (Cambridge, UK) 114: 301-307
45. Hulugalle NR and Ndi JN (1993) Effects of no-tillage and alley cropping on soil properties and crop yields in a Typic Kandiudult of southern Cameroon. Agroforestry Systems 22: 207-220
46. IAEA (1975) Root activity patterns of some tree crops. Technical Report Series No. 170. International Atomic Energy Agency, Vienna
47. ICRAF (1993) Annual report 1992. International Centre for Research in Agroforestry, Nairobi, Kenya
48. ICRAF (1996) Annual report 1995. International Centre for Research in Agroforestry, Nairobi, Kenya
49. ICRAF (1997) Annual report 1996. International Centre for Research in Agroforestry, Nairobi, Kenya
50. Iyamuremye F and Dick RP (1996) Organic amendments and phosphorus sorption by soils. Advances in Agronomy 56: 139-185
51. Jama B, Buresh RJ, Ndufa JK and Sheperd KD (1998) Vertical distribution of roots and soil nitrate: Tree species and phosphorus effects. Soil Science Society of America Journal (in press)
52. Jama B, Swinkels RA and Buresh RJ (1997) Agronomic and economic evaluation of organic and inorganic sources of phosphorus in western Kenya. Agronomy Journal 89: 597-604
53. Jones RB, Wendt JW, Bunderson WT and Itimu OA (1996) Leucaena + maize alley cropping in Malawi. Part 1: Effects of N, P, and leaf application on maize yields and soil properties. Agroforestry Systems 33: 281-294
54. Jonsson K, Fidjeland L, Maghembe JA and Högberg P (1988) The vertical distribution of fine roots of five tree species and maize in Morogoro, Tanzania. Agroforestry Systems 6: 63-69
55. Jonsson K, Stahl L and Högberg P (1996) Tree fallows: a comparison between five tropical tree species. Biology and Fertility of Soils 23: 50-56
56. Juo ASR, Caldwell JO and Kang BT (1994) Place for alley cropping in sustainable agriculture in the humid tropics. 15th World Congress of Soil Science, Acapulco, Mexico, 7a: 98-109
57. Juo ASR, Franzluebbers K, Dabiri A and Ikhile B (1995) Changes in soil properties during long-term fallows and continuous cultivation after forest clearing in Nigeria. Agriculture, Ecosystems and Environment 56: 9-18
58. Juo ASR, Franzluebbers K, Dabiri A and Ikhile B (1996) Soil properties and crop performance on a kaolinitic Alfisol after 15 years of fallow and continuous cultivation. Plant and Soil 180: 209-217
59. Kang BT (1997) Alley cropping-soil productivity and nutrient recycling. Forest Ecology and Management 91: 75-82
60. Kang BT, Akinnifesi FK and Ladipo DO (1994) Performance of selected woody agroforestry species grown on an Alfisol and an Ultisol in the humid lowland of West Africa, and their effects on soil properties. Journal of Tropical Forest Science 7: 303-312
61. Kang BT, Reynolds L and Atta-Krah AN (1990) Alley Farming. Advances in Agronomy 43: 315-359
62. Kang BT, Salako FK, Akobundu IO, Pleysier JL and Chianu JN (1997) Amelioration of a degraded Oxic Paleustalf by leguminous and natural fallows. Soil Use and Management 13: 130-135
63. Kessler JJ and Breman H (1991) The potential of agroforestry to increase primary production in the Sahelian and Sudanian zones of West Africa. Agroforestry Systems 13: 41-62
64. Kiepe P and Rao MR (1994) Management of agroforestry for the conservation and utilization of land and water resources. Outlook in Agriculture 23(1): 17-25
65. Kihanda FM (1996) The role of farm yard manure in improving maize production in the sub-humid highlands of Central Kenya. PhD diss., University of Reading, Reading, UK
66. Kipleting KM (1996) Root and inorganic nitrogen distribution in an Alfisol under different landuse systems. MSc thesis. Moi University, Eldoret, Kenya
67. Kwesiga F and Coe R (1994) The effect of short rotation Sesbania sesban fallows on maize yield. Forest Ecology and Management 64: 199-208
68. Kwesiga FR, Franzel S, Place F, Phiri D and Simwanza CP (1998) Sesbania sesban improved fallows in eastern Zambia: their inception, development and farmer enthusiasm. Agroforestry Systems (in press)
69. Ladha JK, Peoples MB, Garrity DP, Capuno VT and Dart PJ (1993) Estimating dinitrogen fixation of hedgerow vegetation using the nitrogen-15 natural abundance method. Soil Science Society of America Journal 57: 732-737
70. Lal R (1989a) Agroforestry systems and soil surface management of a tropical Alfisol. IV: Effect on soil physical and mechanical properties. Agroforestry Systems 8: 197-215
71. Lal R (1989b) Agroforestry systems and soil surface management of a tropical Alfisol: V: Water infiltrability, transmissivity and soil water sorptivity. Agroforestry Systems 8: 217-238
72. MacDicken KG (1994) Selection and management of nitrogen-fixing trees. Winrock International, Morrilton, Arkansas and FAO, Bangkok
73. Mafongoya PL, Giller KE and Palm CA (1997) Decomposition and nitrogen release patterns of tree prunings and litter. Agroforestry Systems 38: 77-97
74. Mason PA and Wilson J (1994) Harnessing symbiotic associations: vesicular-arbuscular mycorrhizas. In: Leakey RRB and Newton AC (eds) Tropical Trees: The Potential for Domestication and the Rebuilding of Forest Resources, pp 165-175. HMSO, London, UK
75. Mekonnen K (1996) Rooting characteristics and inorganic nitrogen distribution in three landuse systems on an Oxisol in western Kenya. MSc thesis. Moi University, Eldoret, Kenya
76. Mekonnen K, Buresh RJ and Jama B (1997) Root and inorganic nitrogen distributions in sesbania fallow, natural fallow and maize fields. Plant and Soil 188: 319-327
77. Michori P (1993) Nitrogen budget under coffee. PhD diss., University of Reading, Reading, UK [British Thesis Service DX 175716]
78. Mordelet P, Abbadie L and Menaut JC (1993) Effects of tree clumps on soil characteristics in a humid savanna of West Africa (Lamto, Côte d'Ivoire). Plant and Soil 153: 103-111
79. Mulongoy K, Kunda KN and Chiang CNK (1993) Effect of alley cropping and fallowing on some soil fertility parameters in southern Nigeria. In: Mulongoy K and Merckx R (eds) Soil Organic Matter Dynamics and Sustainability of Tropical Agriculture, pp 47-55. John Wiley & Sons and Sayce Publishing, Chichester, UK
80. Nagarajah S and Nizar BM (1982) Wild sunflower as a green manure for rice in the mid country wet zone. Tropical Agriculturalist 138: 69-79
81. Nair PKR, Kang BT and Kass DCL (1995) Nutrient cycling and soil-erosion control in agroforestry systems. In: Juo ASR and Freed RD (eds) Agriculture and the Environment: Bridging Food Production and Environmental Protection in Developing Countries, pp 117-138. ASA Special Publication 60. ASA, CSSA and SSSA, Madison, WI, USA
82. Nyathi P and Campbell BM (1993) The acquisition and use of miombo litter by small-scale farmers in Masvingo, Zimbabwe. Agroforestry Systems 22: 43-48
83. Nziguheba G, Palm CA, Buresh RJ and Smithson PC (1998) Soil phosphorus fractions and adsorption as affected by organic and inorganic sources. Plant and Soil (in press)
84. Nyberg G and Högberg P (1995) Effects of young agroforestry trees on soils in on-farm situations in western Kenya. Agroforestry Systems 32: 45-52
85. Palm CA (1995) Contribution of agroforestry trees to nutrient requirements of intercropped plants. Agroforestry Systems 30: 105-124
86. Palm CA, McKerrow AJ, Glasener KM and Szott LT (1991) Agroforestry systems in lowland tropics: Is phosphorus important?. In: Tiessen H, Lopez-Hernandez D and Salcedo IH (eds) Phosphorus Cycles in Terrestrial and Aquatic Ecosystems, Regional Workshop 3: South and Central America, pp 134-141. Saskatchewan Institute of Pedology, University of Saskatchewan, Saskatoon, Canada
87. Palm CA, Myers RJK and Nandwa S (1997) Combined use of organic and inorganic nutrient sources for soil fertility maintenance and replenishment. In: Buresh RJ and Sanchez PA (eds) Replenishing Soil Fertility in Africa. SSSA Special Publication 51. SSSA and ASA, Madison, WI, USA (in press)
88. Rao MR, Nair PKR and Ong CK (1997) Biophysical interactions in tropical agroforestry systems. Agroforestry Systems 38: 3-50
89. Rhoades CC (1997) Single-tree influences on soil properties in agroforestry: lessons from natural and savanna ecosystems. Agroforestry Systems 35: 71-94
90. Romanya J, Khanna PK and Raison RJ (1994) Effects of slash burning on soil phosphorus fractions and sorption and desorption of phosphorus. Forest Ecology and Management 65: 89-103
91. Ruhigwa BA, Gichuru MP, Mambani B and Tariah NM (1992) Root distribution of Acioa barteri, Alchornea cordifolia, Cassia siamea and Gmelina arborea in an acid Ultisol. Agroforestry Systems 19: 67-78
92. Ruhigwa BA, Gichuru MP, Tariah NM, Isirimah NO and Douglas DC (1993) Spatial variability in soil chemical properties under Dactyladenia barteri, Alchornea cordifolia, Senna siamea and Gmelina arborea hedgerows on an acid Ultisol. Experimental Agriculture 29: 365-372
93. Sanchez PA (1995) Science in agroforestry. Agroforestry Systems 30: 5-55
94. Sanchez PA, Shepherd KD, Soule MJ, Place FM, Buresh RJ, Izac A-MN, Mokwunye AU, Kwesiga FR, Ndiritu CG and Woomer PL (1997a) Soil fertility replenishment in Africa: an investment in natural resource capital. In: Buresh RJ and Sanchez PA (eds) Replenishing Soil Fertility in Africa. SSSA Special Publication 51. SSSA and ASA, Madison, WI, USA (in press)
95. Sanchez PA, Buresh RJ and Leakey RRB (1997b) Trees, soils and security. Philosophical Transactions of the Royal Society, Series B 352: 949-961
96. Sanchez PA and Leakey RRB (1997) Land-use transformation in Africa: three determinants for balancing food security with natural resource utilization. European Journal of Agronomy 7: 1-9
97. Sanchez PA and RH Miller (1986) Organic matter and soil fertility management in acid soils of the tropics. Transactions 13th International Congress Soil Science, Hamburg, 6: 609-625
98. Sanchez PA and Palm CA (1996) Nutrient cycling and agroforestry in Africa. Unasylva 185 47: 24-28
99. 15N labelling techniques. Plant and Soil 127: 169-178
100. 15N-labeling approaches and reference trees. Biology and Fertility of Soils 23: 26-32
101. Sanginga N, Danso SKA, Zapata F and Bowen GD (1994) Field validation of intraspecific variation in phosphorus use efficiency and nitrogen fixation by provenances of Gliricidia sepium grown in low P soils. Applied Soil Ecology 1: 127-138
102. 2 fixation by the Gliricidia sepium/Rhizobium spp. symbiosis in a calcareous soil. Biology and Fertility of Soils 11: 273-278
103. 2 fixation in alley cropping systems: Estimation and contribution to N balance. Plant and Soil 174: 119-141
104. Schroth G (1995) Tree root characteristics as criteria for species selection and systems design in agroforestry. Agroforestry Systems 30: 125-143
105. Schroth G, Kolbe D, Pity B and Zech W (1995) Searching for criteria for the selection of efficient tree species for fallow improvement, with special reference to carbon and nitrogen. Fertilizer Research 42: 297-314
106. Schroth G and Zech W (1995) Root length dynamics in agroforestry with Gliricidia sepium as compared to sole cropping in the semi-deciduous rainforest zone of West Africa. Plant and Soil 170: 297-306
107. Siaw DEKA, Kang BT and Okali DUU (1991) Alley cropping with Leucaena leucocephala (Lam.) De Wit and Acioa barteri (Hook. f.) Engl. Agroforestry Systems 14: 219-231
108. Smaling, EMA, Fresco LO and de Jager A (1996) Classifying, monitoring and improving soil nutrient stocks and flows in African agriculture. Ambio 25: 492-496
109. Stone EL and Kalisz PJ (1991) On the maximum extent of tree roots. Forest Ecology and Management 46: 59-102
110. Stoorvogel JJ, Smaling EMA and Janssen BH (1993) Calculating soil nutrient balances in Africa at different scales. I. Supra-national scale. Fertilizer Research 35: 227-235
111. Strømgaard P (1992) Immediate and long-term effects of fire and ash-fertilization on a Zambian miombo woodland soil. Agriculture, Ecosystems and Environment 41: 19-37
112. Swinkels RA, Franzel S, Shepherd KD, Ohlsson E and Ndufa JK (1997) The economics of short rotation improved fallows: evidence from areas of high population density in western Kenya. Agricultural Systems 55: 99-121
113. Szott LT, Fernandes ECM and Sanchez PA (1991) Soil-plant interactions in agroforestry systems. Forest Ecology and Management 45: 127-152
114. Szott LT, Palm CA and Buresh RJ (1998) Ecosystem fertility and fallow function. Agroforestry Systems (in press)
115. Tian G, Brussaard L and Kang BT (1993a) Biological effects of plant residues with contrasting chemical compositions under humid tropical conditions: effects on soil fauna. Soil Biology and Biochemistry 25: 731-737
116. Tian G, Brussaard L and Kang BT (1995) An index for assessing the quality of plant residues and evaluating their effects on soil and crop in the (sub-) humid tropics. Applied Soil Ecology 2: 25-32
117. Tian G, Kang BT and Brussaard L (1992) Biological effects of plant residues with contrasting chemical compositions under humid tropical conditions - decomposition and nutrient release. Soil Biology and Biochemistry 24: 1051-1060
118. Tian G, Kang BT and Brussaard L (1993b) Mulching effect of plant residues with chemically contrasting compositions on maize growth and nutrients accumulation. Plant and Soil 153: 179-187
119. Torquebiau EF and Kwesiga F (1996) Root development in a Sesbania sesban fallow-maize system in Eastern Zambia. Agroforestry Systems 34: 193-211
120. Trouve C, Mariott A, Schwartz D and Guillet B (1994) Soil organic carbon dynamics under Eucalyptus and Pinus planted on savannas in the Congo. Soil Biology and Biochemistry 26: 287-295
121. van Bodegom P (1995) Water, nitrogen and phosphorus dynamics in three fallow systems and maize in western Kenya. MSc thesis. Wageningen Agricultural University, Wageningen, The Netherlands
122. van der Meersch MK, Merckx R and Mulongoy K (1993) Evolution of plant biomass and nutrient content in relation to soil fertility changes in two alley cropping systems. In: Mulongoy K and Merckx R (eds) Soil Organic Matter Dynamics and Sustainability of Tropical Agriculture, pp 143-154. John Wiley & Sons and Sayce Publishing, Chichester, UK
123. Vanlauwe, B, Swift MJ and Merckx R (1996) Soil litter dynamics and N use in a leucaena (Leucaena leucocephala Lam. (De Witt)) alley cropping system in southwestern Nigeria. Soil Biology and Biochemistry 28: 739-749
124. van Noordwijk M (1989) Rooting depth in cropping systems in the humid tropics in relation to nutrient use efficiency. In: van der Heide J (ed) Nutrient Management for Food Crop Production in Tropical Farming Systems, pp 129-144. Institute for Soil Fertility, Haren, The Netherlands
125. van Noordwijk M, Lawson G, Soumare A, Groot JJR and Hairiah K (1996) Root distribution of trees and crops: competition and/or complementarity. In: Ong CK and Huxley P (eds) Tree-Crop Interactions, a Physiological Approach, pp 319-364. CAB International, Wallingford, UK
126. Wallace JS (1996) The water balance of mixed tree-crop systems. In: Ong CK and Huxley P (eds) Tree-Crop Interactions, a Physiological Approach, pp 73-158. CAB International, Wallingford, UK
127. Weil RR and Mughogho SK (1993) Nutrient cycling by Acacia albida (syn. Faidherbia albida) in agroforestry systems. In: Ragland J and Lal R (eds) Technologies for Sustainable Agriculture in the Tropics, pp 97-108. ASA Special Publication 56, ASA, CSSA and SSSA, Madison, WI
128. Wendt JW, Jones RB, Bunderson WT and Itimu OA (1996) Leucaena + maize alley cropping in Malawi. Part 1: Residual P and leaf management effects on maize nutrition and soil properties. Agroforestry Systems 33: 295-305
129. Wild A (1972) Nitrate leaching under bare fallow at a site in northern Nigeria. Journal of Soil Science 23: 315-324
130. Wong MTF and Nortcliff S (1995) Seasonal fluctuations of native available N and soil management implications. Fertilizer Research 42: 13-26
131. Wong MTF, Wild A and Juo ASR (1987) Retarded leaching of nitrate measured in monolith lysimeters in south-east Nigeria. Journal of Soil Science 38: 511-518
132. Young A (1997) Agroforestry for soil management. CAB International, Wallingford, UK and ICRAF, Nairobi, Kenya