LegumeSELECT: Science-driven Evaluation of LEgume Choice for Transformed livelihoods

Growth in agricultural productivity lags behind population growth in Sub-Saharan Africa (SSA) making the region increasingly food and nutrition insecure. Legumes have great potential to deal with many of the constraints to improve smallholder livelihoods and natural resource status, either in the form of grains for home consumption or sale, fodder for livestock feed, protein for health and nutrition, available soil nutrients, or fuel wood. Finding niches for multi-purpose legumes could help alleviate poverty, increase food security, improve nutrition and enhance natural resource status. However, despite several decades of agricultural research for development, so far there has been only limited uptake of legumes by poorest farming households.

We will help redress this by developing an existing decision framework (LegumeCHOICE) aimed at increasing adoption of legumes in these systems. We will combine existing data with data we will generate here on relationships between legume performance (yield, ability to fix nitrogen, efficient use of nutrients and water) and interactions with their environment (such as influencing soil carbon and nitrogen stocks) under different conditions and managements, into an accessible database. This will form a robust LegumeCHOICE tool, that we will test for a range of specific contexts and will embed with ongoing development initiatives. It will help inform smallholder farmers as to which legumes to select based on desired purpose, anticipated performance for their own farm contexts, management and economics. This is an important step towards improving food and nutritional security, reducing poverty, and enhancing the production environment of smallholder farmers and rural populations, in particular women, in SSA.

Diversification of smallholder farming systems with multi-purpose legumes is a viable strategy towards the sustainable intensification of farming systems in Sub-Saharan Africa (SSA). However, the technical potential for legumes to alleviate key constraints in smallholder systems has not yet translated into practice. An existing decision framework 'LegumeCHOICE' has the right decision-making criteria to inform selection of legumes, and thereby help increase adoption of legumes in smallholder farming systems, but the scientific data in support of driving decisions and recommendations is currently limited in scope. Here we will strengthen this framework by integrating data mined from across SSA and trait based experimentation into an accessible database to form a robust tool, scenario test this for a range of specific contexts and embed this developed LegumeCHOICE tool with ongoing development initiatives.

In controlled environment experiments we will apply stable isotope and imaging approaches to understand legume species trait potentials (G) x soil type, nutrient/OM status, climate (E) x intercrop/residue management (M), on legume performance (yield, biological nitrogen fixation, efficient nutrient and water use). We will validate these relationships in researcher-managed on-farm interventions in Kenya, Ethiopia and DR Congo within specific biophysical and socioeconomic contexts. These generated trait-based relationships will be used to strengthen the predictive power of the LegumeCHOICE tool, providing greater confidence in ability to select the right legume for the right place and time, as an important step towards increasing the uptake of legumes in smallholder farming systems.

The LegumeCHOICE tool builds on an earlier initiative that operated between 2014 and 2017 in the same target areas and that initiated the development of the decision support framework, the collation of the initial datasets, and the preliminary evaluation of its proposed recommendations. The demand for the LegumeCHOICE decision support framework was raised by research and development partners, engaged in the Innovation Platforms of the Humidtropics CGIAR Research Program (CRP), which identified system intensification and diversification with legumes as priority entry themes for the program (see www.humidtropics.org). Since 2016, Humidtropics activities have been embedded in system Flagship Projects of the Roots, Tubers, and Banana (RTB), Maize, and Livestock CRPs.

As a result of this background, a number of project beneficiaries have been identified while others are new. At the academic level, these include: (i) national system scientists from Kenya, Ethiopia, and East DR Congo, who are engaged in strategic soil biological sciences and systems agronomy, (ii) CGIAR scientists with similar interests, (iii) UK scientists who are leading research programs on sustainable intensification, and (iv) early-career scientists who are developing their scientific skill sets in the priority research areas of the project. These various beneficiaries will benefit directly from the LegumeCHOICE tool through (i) access to state-of-the-art tools and approaches, including analytical equipment, to quantify the impact of legumes to nutrient and water dynamics and soil health status (applies mainly national system and early-career scientist), (ii) improved understanding of smallholder farming systems and the potential role of legumes in their sustainable intensification (applies mainly UK scientists), and (iii) access to analytical tools that allow the development of novel recommendations based on large datasets and prevalent decision criteria (applies mainly CGIAR and national system scientists).

At the societal level, direct beneficiaries include: (i) extension agents from already engaged development organizations and initiatives (through the earlier LegumeCHOICE project) that are working directly with the project on validating and piloting the decision support tool, (ii) farming households that are facilitated by these extension agents, (iii) extension agents and accompanied farming households from initiatives and organizations that are yet to engage with LegumeCHOICE. The potential impacts on the extension agents include: (i) access to tools that will assist in conveying more relevant information to smallholder farmers and (ii) improved understanding of the multiple benefits of legumes as related to legume types and the niches to which they are best suited. The potential impacts on farming families include, based on their production priorities: (i) improved benefits from legume integration in terms of extra grain yields for home consumption or income generation, (ii) increased access to high quality fodder, especially relevant for monogastric and dairy livestock, (iii) improved soil health conditions that will result in improved yields of associated crops, and (iv) better soil conservation. Not all these benefits will be expressed in all situations but at least two benefit sets should apply to all households engaged. Besides these direct beneficiaries, indirect beneficiaries likely consist of farming households and extension agents that have become aware of LegumeCHOICE products through spill-over processes that usually happen in societies with important social capital as in the target areas.