Assessment of Technology Options Addressing Agricultural Production Constraints in Western Kenya

Abstract

Poor soil fertility and weed infestation are among major constraints facing agricultural production in Western Kenya. Recommended technologies differ in resource requirement and their effectiveness are seasonal site-specific. On-farm experiments were conducted during 2008/09 cropping seasons on two soil types of western Kenya using maize as a test crop. Seven technology options were assessed on agronomic performance, resource requirement, and economic returns. Maize grain yield differed between cropping seasons with generally higher yields during long rainy season, and across soil types with organic manure-based options performing better on Ultisol than on Alfisol. Response of soil parameters reflected the amount of added nutrients and soil type with strongest effect of added N on Alfisol and of added P on Ultisol. All options significantly reduced weed biomass in the maize fields in the long (>90%) than in the short rainy seasons (>50%). Green manure-based option required more labour while mineral fertilizer-based options required largest capital. The economic netbenefit varied between -112 and +892 € ha -1 with highest values in organic manure-based options during short rainy season and in mineral fertilizer-based options during long rainy season. This example illustrates the need to define sitespecific technology evaluation for successful targeting of technology options.

Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania

“…Such trends raise the question if organic amendments in general and leguminous green manures in particular have not loomed larger in scientists' minds than in those of farmers. In consequence, since the mid-1990s, scientists have analyzed the agronomic and socio-economic constraints to adopting organic amendments at farm level and tried to define niche environments where organic amendments outcompete mineral nutrient sources [40].…”