Journal ArticleDOI
Meta-analysis of maize yield response to woody and herbaceous legumes in sub-Saharan Africa
TLDR
It is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows, indicating that legume rotations may play an important role in reducing fertilizer requirements.Abstract:
A number of studies have tested the effect of woody and herbaceous legumes on soil fertility and maize yields in sub-Saharan Africa. However, their effects on maize productivity are much debated because results have been variable. A meta-analysis was conducted with the aim of evaluating the evidence in support of yield benefits from woody and herbaceous green manure legumes. A total of 94 peer-reviewed publications from West, East and southern Africa qualified for inclusion in the analysis. Maize yield from herbaceous green manure legumes (54 publications), non-coppicing legumes (48 publications), coppicing woody legumes (10 publications), natural fallows (29 publications), and fully fertilized monoculture maize (52 publications) were compared. Mixed linear modelling using yield differences (D) and response ratios (RR) indicated that the response to legumes is positive. The mean yield increase (D) over unfertilized maize was highest (2.3 t ha−1) and least variable (CV = 70%) in fully fertilized maize, while it was lowest (0.3 t ha−1) and most variable (CV = 229%) in natural fallows. The increase in yield over unfertilized maize was 1.6 t ha−1 with coppicing woody legumes, 1.3 t ha−1 with non-coppicing woody legumes and 0.8 t ha-1 with herbaceous green manure legumes. Doubling and tripling of yields relative to the control (RR > 2) was recorded in coppicing species (67% of the cases), non-coppicing legumes (45% of the cases), herbaceous green manure legumes (16% of the cases) and natural fallows (19% of the cases). However, doubling or tripling of yields occurred only in low and medium potential sites. Amending post-fallow plots with 50% of the recommended fertilizer dose further increased yields by over 25% indicating that legume rotations may play an important role in reducing fertilizer requirements. Except with the natural fallow, the 95% confidence intervals of D and RR were higher than 1 and 0, respectively indicating significant and positive response to treatments. Therefore, it is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows.read more
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Journal ArticleDOI
Does plant diversity benefit agroecosystems? A synthetic review
Deborah K. Letourneau,Deborah K. Letourneau,Inge Armbrecht,Beatriz Salguero Rivera,James Montoya Lerma,Elizabeth Jiménez Carmona,Martha Constanza Daza,Selene Escobar,Víctor Galindo,Catalina Gutiérrez,Catalina Gutiérrez,Sebastián Duque López,Jessica Lopez Mejia,Aleyda Maritza Acosta Rangel,Janine Herrera Rangel,Leonardo Rivera,Carlos Arturo Saavedra,Carlos Arturo Saavedra,Alba Marina Torres,Aldemar Reyes Trujillo +19 more
TL;DR: This first use of meta-analysis to evaluate the effects of diversification schemes, a potentially more powerful tool than tallies of significant positive and negative outcomes (vote-counting), revealed stronger overall effects on all parameters measured compared to previous reviews.
Journal ArticleDOI
Evergreen Agriculture: a robust approach to sustainable food security in Africa
Dennis Garrity,Festus K. Akinnifesi,Oluyede C. Ajayi,Sileshi G. Weldesemayat,Jeremias Mowo,Antoine Kalinganire,Mahamane Larwanou,Jules Bayala +7 more
TL;DR: In this article, the authors reviewed the experiences and their broader implications for African food security, as manifestations of Evergreen agriculture, a fresh approach to achieving food security and environmental resilience, which is defined as the integration of particular tree species into annual food crop systems.
Journal ArticleDOI
Input subsidies to improve smallholder maize productivity in Malawi: toward an african green revolution.
Glenn Denning,Patrick Kabambe,Pedro A. Sanchez,Alia Malik,Rafael Flor,Rebbie Harawa,Phelire Nkhoma,Colleen Zamba,Clement Banda,Chrispin Magombo,Michael J. Keating,Justine Wangila,Jeffrey D. Sachs +12 more
TL;DR: Small-scale farmers in Malawi are benefiting from fertilizer and seed subsidies, which have enabled them to improve maize productivity and achieve food security.
Journal ArticleDOI
The role of knowledge, attitudes and perceptions in the uptake of agricultural and agroforestry innovations among smallholder farmers in sub-Saharan Africa
TL;DR: In this paper, the authors present an analytical framework that combines both extrinsic and intrinsic factors in farmers' decisions to adopt new agricultural technologies and apply the framework to agroforestry adoption as a case study.
References
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