Agriculture Reference
In-Depth Information
11
Agroforestry for Small
Landholders of Eastern
and Southern Africa
Tracy L. Beedy, George Nyamadzawo,
Eike Luedeling, Dong-Gill Kim,
Frank Place, and Kiros M. Hadgu
CONTENTS
11.1 Introduction .................................................................................................. 238
11.1.1 African Smallholders, Soil Management, and Food Security .......... 239
11.1.2 Definition and Objectives .................................................................240
11.1.3 Benefits and Constraints of Agroforestry .........................................240
11.1.4 Agroforestry Practices and Smallholder Cropping Systems ............ 242
11.1.4.1 Agroforestry Options ......................................................... 242
11.1.5 Tree-Crop Interactions ..................................................................... 247
11.1.5.1 Water Relationships ........................................................... 247
11.1.5.2 Weed Suppression .............................................................. 248
11.1.5.3 Soil Nutrient Content ......................................................... 248
11.2 Soil Fertility Replenishment ......................................................................... 248
11.2.1 Soil Fertility Replenishment with Agroforestry ............................... 248
11.2.1.1 Nitrogen Fixation ............................................................... 249
11.2.1.2 Other Macro- and Micronutrients ...................................... 250
11.2.1.3 Role of Fertilizer Trees as Nutrient Pumps and Safety
Nets .................................................................................... 250
11.2.2 Maize Yield Increases from Improved Soil Fertility ........................ 251
11.2.2.1 Improved Fallows ............................................................... 251
11.2.2.2 Intercrops ........................................................................... 253
11.2.2.3 Rotational Woodlots .......................................................... 254
11.2.2.4 Parkland Systems in Eastern and Southern Africa ............ 255
11.2.2.5
Faidherbia albida
: A Successful Parkland Species .......... 255
11.3 Accumulation of Carbon in Biomass and Soil ............................................. 257
11.3.1 Biomass Accumulation in Agroforestry in Eastern and Southern
Africa ................................................................................................ 257
11.3.1.1 Intercropping Agroforestry Systems .................................. 257
11.3.1.2 Improved Fallows ............................................................... 258
11.3.1.3 Rotational Woodlots and Tree Plantations ......................... 259
237
