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

Abstract

Low 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.

Understanding the Interdependence and Temporal Dynamics of Smallholders’ Adoption of Soil Conservation Practices: Evidence from Nigeria

“…This may be because inorganic fertilizers contain substantially higher amounts of nutrients, especially macro-nutrients for cereal crop performance which are readily available to crops than that from organic sources [4,64,70]. Yet, this result is not in tandem with the expected complementary use of organic and inorganic fertilizer within the framework of integrated soil fertility management practices [1,71]. The result also negates the findings of [55], where the application of inorganic fertilizer marginally increased the adoption of animal manure.…”

The Adoption of Improved Agricultural Technologies - a Meta-Analysis for Africa

“…Interestingly, the category of 'social capital/group interactions' is positive and significant in most cases for agroforestry and livestock practices. 8 Most observations in this category (90 per cent) come from papers publishes after 2005, which reflects the increasing understanding of the social context in the adoption literature (Munguia and Llewellyn, 2020;Vanlauwe et al, 2017). Most practices in these categories require bigger up-front investments (e.g.…”

“…Many of the technologies studied in the adoption literature have the potential to improve productivity and some also have expected resilience benefits. These include, improved crop varieties, soil and water management techniques and agroforestry to deal with a variety of climatic shocks that are expected to become more frequent and severe with climate change (Vanlauwe et al, 2017). Therefore, a systematic review of the barriers to the adoption of agricultural technologies in SSA is needed to provide a thorough understanding of the literature to date and support action towards achieving the SDGs.…”

“…Given the importance of understanding the determinants of modern input use and the use of sustainable land management practices in SSA, we develop further hypotheses to explore potentially opposing relationships between wealth and income indicators and the adoption of specific practices. We select these practices in the agronomy group because modern input use (seeds and fertilizers), which were at the core of the Green Revolution remains low (despite subsidy programmes in many countries), and the sustainable land management practices have been increasingly promoted with mixed results in the continent (Vanlauwe et al, 2017). We focus on wealth-signalling determinants here, as income/wealth is found to be positively correlated in adoption in many studies (Munguia and Llewellyn, 2020) and they can act as proxies of other behavioural characteristics that can help targeting.…”

Sustainable intensification of agriculture in sub-Saharan Africa: first things first

“…In combination with a suit of other constraints this resulted in particularly low uptake rates. The history of research on soil fertility management in SSA is full of such examples; good ideas that were scientifically sound but had little potential for wider-scale adoption [12] .…”