Abstract

To assess the quality of commercial organic fertilizers in Uganda market, a quick survey was conducted to establish the organic fertilizers being sold in Container village market in Kampala Capital City.   Different products were found being sold as organic fertilizers. Four of these fertilizers are two solid (Biochar and Fertiplus) and two liquid (Biogrow and Digrow) selected for a field study.  Field trials to assess the performance of the fertilizers and local farmyard manure on bush beans (Phaseolus vulgaris) were conducted at two locations (Kabanyolo and Nkozi) for two successive seasons in 2017 and 2018 using a randomized complete block design in four replications. Forty days after planting, fresh and dry weights were estimated while biomass and grain yield were determined at harvest. The results showed inconsistencies. For example, although Biochar was found to significantly (P=0.043) increase the mean fresh weight of bush beans in season 1 (2017) at both sites (Kabanyoro and Nkozi), this was not the case in season 2 (2018). Similar performance was found with the other treatments. The mean biomass did not increase significantly (P>0.05) in season 1 (2017) and season 2 (2018) at both locations. The results in season 2 (2018) showed no significant (P>0.05) increase in the mean yield. These results were attributed to the extreme weather conditions experienced in both seasons (severe drought during season 1 and heavy rains that led to prolonged vegetative growth during season 2). These field trials should be repeated under controlled environment to minimize the weather effect.

Key words:  Organic fertilizers, plant growth, yield.