EPTD Discussion Paper No. 115

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ABSTRACT This case study explores the development, dissemination, adoption, and impact of improved tree fallows in rural western Kenya. The processes of technology development and dissemination throughout the region are described and analyzed. To analyze adoption and impact, the paper applies a variety of different data collection methods as well as samples from both pilot areas where researchers maintained a significant presence and non-pilot areas where farmers learned of the technologies through other channels. Sample sizes for the quantitative analysis ranged from almost 2,000 households for measuring the adoption process to just over 100 households for measuring impact indicators. Qualitative methods included long-term case studies for 40 households and focus group discussions involving 16 different groups. The paper describes the ways in which farmers used and modified improved fallow practices. Discussion also examines the types of households using fallows and benefiting from their use. Empirical results suggest that improved fallows almost always double on-farm maize yields. In addition, the data indicates that poor households use improved fallows at much greater rate (about 30 percent) than they do fertilizer (8 percent), though, on average, the size of fallow plots remains small, at 440m . As a result, despite these promising signs, the improved fallow systems were not found to be linked to improved household level food security or poverty indicators primarily, primarily because the size of the fields under the agroforestry systems was on average, quite small. Conclusion To conclude, improved fallows represent a technically effective and financially profitable technology that is attractive to poor households with little cash available for ...

  • Report number: Discussion Paper no. 160, Affiliation: Washington, DC: IFPRI, (FCND (Food Consumption and Nutrition Division)
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    ABSTRACT: Two provenances of Sesbania sesban var. nubica (Kakamega and Chipata) were planted in fallows for 1, 2 and 3 years at 0.5 m × 0.5 m, 0.7 m × 0.7 and 1.0 m × 1.0 m spacing. Maize crop (MM604) was grown after fallow period at 0, 37, 74 and 112 kg N ha−1 to evaluate the effects of nitrogen (N) and fallow on grain yield. There were no significant differences between the two provenances of S. sesban. Wood biomass after 1, 2 and 3 years fallow at close spacing was 8.3, 17.6 and 21.4 t ha−1 for the Kakamega provenance and 10.8, 14.5 and 21.2 t ha−1 for the Chipata provenance. Litter fall in both provenances ranged from 0.6 t ha−1 in June to 0.01 t ha−1 in November. Stand mortality increased with plant density and fallow years: 27% in the first year and about 90% by the end of the third year. Weed biomass ranged from 6.8 t ha−1 to 6.0 t ha−1 at close and wide spacing respectively.Maize grain yield without N was 2.27, 5.59 and 6.02 t ha−1 after 1, 2 and 3 years fallow respectively compared with the control plots with 1.6, 1.2. 1.8 t ha−1 after 1, 2 and 3 years of continuous cropping. Even with addition of 112 kg N ha−1, yield in the control plots declined from 6.09 to 4.88 and 4.28 t ha−1 after 1, 2 and 3 years of continuous cropping. In the planted fallows at 112 kg N ha−1, maize yield increased from 6.75 to 7.16 and 7.57 t ha−1 following 1, 2 and 3 years fallow. It is concluded that short fallow rotations of 1–3 years using S. sesban have a potential in increasing maize yield even without fertilizers. Thus, increasing the fallow period decreases the effectiveness of inorganic fertilizers but increases grain yield for low fertilizer input.
    Forest Ecology and Management 04/1994; DOI:10.1016/0378-1127(94)90294-1 · 2.67 Impact Factor

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