The need to move from fallow-based to legume-based systems.Legume-based cropping system that combines suboptimum inorganic fertilizer rate can enhance nutrient-use efficiency and increase productivity

1. Manipulating cropping systems to improve soil fertility S. Boahen IITA – Mozambique Nampula

6. Effect of cereal-Legume rotation on some soil chemical properties in PROSAB Project sites SGS=Southern Guinea Savanna; NGS=Northern Guinea Savanna; SS=Sudan Savanna Kwari J.D. 2009 2.40 2.20 5.30 4.60 2.80 3.50 Cereal-cereal 2.10 1.68 4.54 3.26 3.73 3.92 Cereal-legume 0.78 3.70 5.48 2.95 3.33 2.88 2004-baseline Available P (mg/kg) 1.21 0.54 1.12 1.17 1.05 0.84 Cereal-cereal 1.17 1.03 1.47 1.27 1.35 0.86 Cereal-legume 1.49 0.98 1.68 1.93 1.96 1.09 2004-baseline Total N (g/kg) 5.4 9.3 15.7 13.1 13.9 10.9 Cereal-cereal 5.7 9.5 14.3 12.6 14.3 10.8 Cereal-legume 6.1 9.2 10.0 13.7 9.9 11.3 2004-baseline Organic C (g/kg) SS SS NGS NGS SGS SGS Nzuda Damboa Sabongari Maina Harii Mirnga Tilla Ngwa Yimirshika Marama Treatment

7. † Number of on-farm trails conducted Kayuki et al., 2007 Sorghum grain yield (Mg ha-1), following either sorghum, cowpea, or mucuna in rotation, at three locations in a semiarid area of eastern Uganda, 2004 and 2005 [Farmer-managed trials] 0.24 0.15 0.53 0.39 0.29 0.27 0.27 LSD (0.05) 2.75 1.47 2.81 3.00 1.76 3.98 2.64 Mucuna 2.33 1.36 2.05 2.43 1.65 3.49 2.30 Sorghum + 30 kg N ha -1 2.01 1.18 1.43 2.17 1.61 3.19 1.84 Cowpea 1.21 0.96 0.67 1.39 1.17 1.76 1.03 Sorghum 36 5 6 7 5 8 5† Overall 2005 2004 2005 2004 2005 2004 Previous crop and N rate Kapolin Opwatetta Kadesok

8. Aboveground DM yields (t ha-1) of pure and mixed species legume fallows and natural weed fallow at Dindi and Owano farms in western Kenya Ndufa et al., 2009

9. *** P ≤ 0.0001; Ndufa et al., 2009 Maize grain yield of four cropping seasons (SR = short rains, LR = long rains) after monoculture and mixed-species legume as compared with continuous cropping, N fertilizer (100 kg N ha -1 ) and natural weed fallow 0.90*** 0.24*** 0.38*** 0.31*** 0.42*** 0.32*** SED‡ 9.8 1.3 2.2 2.0 2.7 1.7 Maize –N 26.7 3.2 6.5 5.7 6.5 4.9 Maize + N 9.7 1.4 2.8 2.1 2.2 1.3 Natural Fallow 21.4 1.8 3.3 4.1 5.6 6.7 Ss + Ma 21.1 1.5 3.2 4.3 6.0 6.2 Ss + Cg 18.7 1.6 3.2 3.2 5.8 5.1 Ss + Cal 17.9 1.2 2.7 3.2 5.5 5.2 Ss + Cc 18.7 1.6 2.3 4.0 5.5 5.4 Sesbania sesban (Ss) 21.5 1.7 3.6 4.0 6.5 5.7 Siratro (Ma) 21.4 1.6 3.6 4.0 6.3 5.9 Crotalaria garhamania (Cg) 10.5 1.0 2.0 2.3 2.6 2.7 Colliandra colothyrus (Cal) 16.4 1.4 2.9 3.4 4.1 4.7 Pigeon Pea (CC) Total SR2001 LR2001 SR000 LR2000 SR1999 Treatment