Abstract
• 5 t ha −1 of micro-dosed manure approx. doubled the yields compared to the control. • Micro-dosed NPK (70 kg N ha −1 ) meanwhile increased yields 3–4 times. • Legume supplemented diet increased manure quality, and also yield season 4. Animal manure provides plant nutrients and also affects soil nutrient availability, pH buffering and soil physical properties through its contribution to soil organic matter pools. However, the quality and quantity of manure are often low on smallholder farms in sub-Saharan Africa and the initial effect of manuring on crop yield may be small or even negative. In a two-factorial experiment over four seasons in southern Rwanda, the fertiliser value to a maize crop of manures produced by cattle fed a basal diet of only Chloris gayana grass or a mixed C. gayana-Acacia angustissima diet was compared with that of NPK 17−17−17 and no fertiliser. The potential liming effect of the manures was also evaluated through inclusion (or not) of travertine as the second factor. All amendments were applied only to maize planting holes. The crop failed in season 1 due to drought, but manure application (5 t ha −1 ) approximately doubled maize yield compared with the unfertilised control during seasons 2–4, while NPK (70 kg N ha −1 ) increased yield by 3- to 4-fold, with corresponding improvements in crop performance indicators. The mixed diet increased manure quality and maize yield compared with the grass diet in season 4. Liming showed a consistent tendency to improve crop performance indicators and yield, but significant differences were only identified in some cases, possibly because the pH increase was small. The results suggest that in regions where manure availability is limiting, application of reduced rates only to planting holes may be an efficient technology. Enhanced animal feed can result in higher quality manure, and ultimately increase crop yield, if nutrient losses during manure handling and storage can be limited.
Highlights
In sub-Saharan Africa (SSA), agriculture plays an important function in economic growth and rural livelihoods
The small and only occasionally significant difference in maize yield observed between limed and non-limed treatments in the present study suggests, somewhat surprisingly, that soil pH was not a major limiting factor for the maize variety used in the experiment or that the pH increase over the study period was not sufficient to significantly increase crop performance
Due to the low response to liming, the ca pacity of the manure to affect maize performance and yield via raised pH was not strongly tested in the present study. In this four-season study in Rwanda, the highest maize yields were attained with NPK fertiliser applied to the planting holes
Summary
In sub-Saharan Africa (SSA), agriculture plays an important function in economic growth and rural livelihoods. With increasing population in the region, dietary changes and a need for production of e.g. fibre and fuel on a finite area of land exploitable for agriculture, the productivity of current agricultural land needs to increase. To this end, the supply of plant nutrients to farmland via inorganic fertilisers and organic sources, if possible in combination, needs to increase. The fertiliser rates recommended by agronomists are beyond the reach of many smallholder farmers, which has led to the development of micro-dosing technology (Bationo et al, 2012; Ibrahim et al, 2016; Tovihoudji et al, 2017). The positive ef fect of micro-dose fertilisation has been well documented for cereal crops and is reported to result in higher fertiliser use efficiency and require a smaller financial investment, making it a suitable technology for resource-poor smallholder farmers (Aune et al, 2007; Hayashi et al, 2008; Bagayoko et al, 2011; Camara et al, 2013)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
