The agronomic and economic benefits of fertilizer and mulch use in highland banana systems in Uganda

Banana is the most important food crop in Uganda. However, there has been a decline in productivity, attributed to declining soil fertility, drought, pests and diseases and crop management factors. This study aimed to explore the possibility of increasing yields through the use of fertilizer and mulch, and to evaluate the benefits of these inputs across the major banana producing regions in Uganda. This study was carried out in 179 smallholder plots in Central, South, Southwest and East Uganda in 2006/7. Half of the plots were ‘demonstration plots’ of an agricultural development project, while the other half were neighboring farmer plots that acted as ‘control’. Demonstration plots received mineral fertilizer (100% of plots), averaging 71 N, 8 P, 32 K kg ha−1 yr−1 and external mulch from grass and crop residues (64% of plots), whereas control plots received no mineral fertilizer and little external mulch (26% of plots). Demonstration plots had significantly (P ⩽ 0.05) higher yields than control plot in Central, South and Southwest, but average yield increases varied from 4.8 t ha−1 yr−1 (Southwest) to 8.0 (Central), and 10.0 (South). Average weevil corm damage (3%) and nematode-induced root necrosis (7%) was low and similar for both plot types, so yield increases could only be explained by the use of fertilizer and mulch. The highest demonstration plot yield increases were observed where fertilizer addressed key nutrient deficiencies identified using the compositional nutrient diagnosis approach. Farm gate bunch prices declined from 0.17 (Central Uganda) to 0.07 USD kg−1 (Southwest Uganda). Consequently, average marginal rate of return (MRR) of fertilizer and mulch use ranged from 0.1 (Southwest) to 5.8 (Central). The technologies were likely to be acceptable to farmers (MRR ⩾ 1.00) up to 160 km away from the capital. Fertilizer use is likely to be acceptable in all regions (MRR = 0.7–9.4) if local fertilizer prices of 2006/7 (average USD 0.56 kg−1 of fertilizer) declined by 50%. Doubling of fertilizer prices is likely to make fertilizer use unacceptable beyond 100 km away from the capital. The study concludes that there is scope for increased input use in banana systems in Uganda, but that regional variations in crop response, input/output prices, and price fluctuations have to be taken into account

Coffee-Banana Intercropping: Implementation guidance for policymakers and investors

Coffee-Banana Intercropping (VBI) addresses all 3 pillars of CSA in a multifaceted way. CBI in both Arabica nad Robusta generates 50% more revenue then either coffee or banana monocrop. Farmers' risk is reduced by practising CBI, making them more resilient to climate change impacts. Transformational changes are needed in the attitude towards CBI, to support scaling up of the practice

Opportunities and pitfalls for researchers to contribute to the design of evidence-based agricultural policies: lessons from Uganda

Article purchased; Published online: 15 May 2018Agricultural policies in sub-Saharan Africa have paid insufficient attention to sustainable intensification. In Uganda, agricultural productivity has stagnated with aggregate increases in crop production being attributed to expansion of cultivated land area. To enhance sustainable crop intensification, the Ugandan Government collaborated with stakeholders to develop agricultural policies using an evidence-based approach. Previously, evidence-based decision-making tended to focus on the evidence base rather than evidence and its interactions within the broader policy context. We identify opportunities and pitfalls to strengthen science engagement in agricultural policy design by analysing the types of evidence required, and how it was shared and used during policy development. Qualitative tools captured stakeholders' perspectives of agricultural policies and their status in the policy cycle. Subsequent multi-level studies identified crop growth constraints and quantified yield gaps which were used to compute the economic analyses of policy options that subsequently contributed to sub-national program planning. The study identified a need to generate relevant evidence within a short time 'window' to influence policy design, power influence by different stakeholders and quality of stakeholder interaction. Opportunities for evidence integration surfaced at random phases of policy development due to researchers’ ’embededness’ within co-management and coordination structures

Yield gap analyses to inform policy on sustainable crop intensification pathways in Uganda

Smallholder potato yields in Uganda are low (<4.7 tha-1) compared to 25 tha-1 attainable on-station yields, attributed to: poor quality seed, low soil fertility, pests and diseases, limited knowledge and weak policy environment. Potatoes however represent about half of the total monetary value of crop production in Uganda’s Southwestern highlands.Development and policy actors wish to intensify potato systems to sustain rural livelihoods and high population growing at 3.4% per annum. The agronomy study was undertaken to understand how genotype x environment x management interactions affect potato yields at plot, farm and community levels to generate evidence for stimulating policy action relevant to crop intensification. The objectives of the study were to; (1) analyze the magnitude of the yield gap by determining attainable and actual potato yields, (2) establish the resource utilization (land, seed quality and fertilizers) and management practices for potato production (3) develop policy recommendations to largest potato yield to support increase and improve potato production systems in Uganda. The study was conducted in 2014- 2015 in the highlands of Southwestern Uganda using a total of 283 households in rainfed potato farms surveyed for: production and crop management, access to services and technologies. Households were selected using stratified cluster sampling. Yield data obtained were compared to on-station yields to establish the yield gap. Results show a large yield gaps (60-80%) exist between average farmer and best on-station yield. The results suggest that seed is the major limiting constraint in potato cropping systems. Households using good quality seed potato obtained an average 11.1 tha-1 versus 6.4 tha-1 for those using poor quality seed. On-station yields reach 25 tha-1. It can be concluded that Uganda has the potential to more than double the yield if an enabling policy environment of increasing access to quality seed for potato is created. This can be through the National Seed Policy to guide production marketing, distribution and access to quality seed for smallholder potato farmers. Sustainable intensification would require easy access to key yield augmenting inputs used in a stepwise approach starting with quality seed and then other complementary inputs

Looking back and moving forward: 50 years of soil and soil fertility management research in sub-Saharan Africa

Article purchased; Published online: 02 Nov 2017Low and declining soil fertility has been recognized for a long time as a major impediment to intensifying agriculture in sub-Saharan Africa (SSA). Consequently, from the inception of international agricultural research, centres operating in SSA have had a research programme focusing on soil and soil fertility management, including the International Institute of Tropical Agriculture (IITA). The scope, content, and approaches of soil and soil fertility management research have changed over the past decades in response to lessons learnt and internal and external drivers and this paper uses IITA as a case study to document and analyse the consequences of strategic decisions taken on technology development, validation, and ultimately uptake by smallholder farmers in SSA. After an initial section describing the external environment within which soil and soil fertility management research is operating, various dimensions of this research area are covered: (i) ‘strategic research’, ‘Research for Development’, partnerships, and balancing acts, (ii) changing role of characterization due to the expansion in geographical scope and shift from soils to farms and livelihoods, (iii) technology development: changes in vision, content, and scale of intervention, (iv) technology validation and delivery to farming communities, and (v) impact and feedback to the technology development and validation process. Each of the above sections follows a chronological approach, covering the last five decades (from the late 1960s till today). The paper ends with a number of lessons learnt which could be considered for future initiatives aiming at developing and delivering improved soil and soil fertility management practices to smallholder farming communities in SSA