In Eastern and Southern Africa (ESA), smallholder rain-fed systems are vital, yet they are challenged by land degradation, soil fertility decline, and climate risks. To address these challenges, crop diversification has been promoted as a potential pathway to enhance productivity, improve nutritional security, and offer a viable pathway out of poverty and hunger. This study explores crop diversification among 150 smallholder households in the Kasungu, Mchinji, and Lilongwe districts of Malawi, where the project Sustainable Intensification of Maize Legume Systems in East and Southern Africa (SIMLESA) has engaged the smallholder farmers in conservation agriculture (CA)-based sustainable intensification participatory research and development for seven years since 2010. This study used Simpson’s diversity index (SDI) to estimate crop diversification, and a multiple linear regression model (MLRM) to analyze how smallholder farmers’ socio-economic characteristics influence adoption. The findings show a prevalence of small farms of less than 1.5 hectares, with most farmers perceiving crop diversification as beneficial for soil fertility. Key adoption constraints include labor shortages and a lack of legume seeds. SIMLESA participants lead in crop rotations, with a 63% higher adoption rate, and show the highest crop diversity, with a 99% increase in farmers growing three crops and a 74% increase in those growing four crops compared to non-SIMLESA farmers. The SDI values were 0.39 for non-SIMLESA, 0.48 for SIMLESA neighbors, and 0.57 for SIMLESA participants. Access to NGO inputs, larger farm sizes, and participation in research programs were positively associated with diversification, while food insufficiency was negatively associated with its adoption. The study highlights the importance of integrating participatory research methods to promote development initiatives effectively.

The agronomic effectiveness of biofertilizers is influenced by strain origin, genetic identity, crop genotype, soil type, and environmental conditions. For best results, both the plant and rhizobia strain must be adapted to the common harsh soil conditions in the tropics. While plant varieties have changed over the years, complementary research on new strains effectiveness under varying soil fertility conditions has lagged in southern Africa. Seven field experiments were established in the main soybean-producing areas of Zimbabwe in the north, central, and north–east regions to evaluate agronomic benefits of new rhizobia strains against the current exotic commercial strain (MAR1491). One site was irrigated (site 3), and the other six sites were rainfed (sites 1, 2, 4, 5, 6, and 7). While trends in inoculation response varied from site to site due to site conditions, inoculation with the strains NAZ15, NAZ25, and NAK128 consistently yielded high grain yields, which were similar to the current commercial strain MAR1491 and to application of mineral fertilizer (51.75 and 100 kg N ha⁻¹). Grain yield levels were generally below 2 t ha⁻¹ for sites 2, 3, and 5 and above 2 t ha⁻¹ for sites 1, 4, and 6, while for the irrigated site 3, they ranged upwards of 3 t ha⁻¹. When irrigated, all strains except NAK9 performed similarly in terms of grain yields and aboveground N uptake. Further testing on the inclusion of the indigenous strains NAZ15, NAZ25, and NAK128 in multi-strain commercial inoculant production targeting application in regions and soils where they excel beyond the current exotic strain MAR1491 is recommended.

Agronomic effectiveness of biofertilizers is influenced by strain origin, genetic identity, crop genotype, soil type and environmental conditions. For best results both the plant and rhizobia strain must be adapted to the common harsh soil conditions. While plant varieties have changed over the years, complementary research on new strains effectiveness under varying soil fertility conditions has lagged in southern Africa. Seven field experiments were established in the main soybean producing areas of Zimbabwe in the north, central and north-east regions to evaluate agronomic benefits of new rhizobia strains against the current exotic commercial strain (MAR 1491). One site was irrigated (site 3) and the other six sites were rainfed (site 1, 2, 4, 5, 6, and 7). While trends in inoculation response varied from site to site due to site conditions, inoculation with the strains NAZ15, NAZ 25, and NAK128 consistently yielded high grain yields which were similar to the current commercial strain MAR 1491 and to application of mineral fertilizer (51.75 and 100 kg N ha-1). Grain yield levels were generally below 2 t ha-1 for site 2, 3, and 5, above 2t ha-1 for sites 1, 4, and 6, while for the irrigated site 3 they ranged upwards of 3 t ha-1. When irrigated all strains except NAK9 performed similarly in terms of grain yields and aboveground N uptake. We recommend further testing on the inclusion of the indigenous strains NAZ15, NAZ 25 and NAK128 in multi-strain commercial inoculant production targeting application in regions and soils where they excel beyond the current exotic strain MAR 1491.

Smallholder farming systems in sub-Saharan Africa are highly heterogeneous, resulting in differences in farmers’ capacities, priorities, and responses to sustainable intensification (SI) innovations. This study assessed farmers’ perceptions of six SI innovations and evaluated their suitability across four farm typologies in the Mtunthama Extension Planning Area, Central Malawi. A mixed-methods participatory approach involving focus group discussions and farmer-led innovation ranking was used across 44 trial farmers. Qualitative data were analysed using thematic content analysis, while preference rankings were converted into weighted standardised scores for comparison across farm types. Kruskal–Wallis tests were applied to assess whether maize grain yield differed significantly across farm typologies by treatment. Farmers generally perceived SI innovations positively, identifying improved yields, soil fertility, food security, dietary diversity, and climate resilience as major benefits. Labour requirements, input constraints, management complexity, and limited training were identified as key barriers. Innovation preferences differed across farm typologies, reflecting variations in household resource endowment and livelihood strategies. Although conventional ridging with continuous sole maize received the highest proportion of first-choice rankings, conservation agriculture incorporating legumes, particularly maize-cowpea double-row strip cropping, achieved the highest overall preference scores across farm types. Yield analysis revealed significant differences across farm typologies for CA Maize-Lablab Rotation (H = 9.823, p = 0.020) and Conventional Maize (H = 12.834, p = 0.005), with resource-constrained farmers consistently recording lower yields. Field days attended by 253 independent observers confirmed community-level preference for cowpea-based CA innovations, with maize-cowpea strip cropping receiving the highest vote share at both sites. Post-project follow-up revealed that 68 out of 253 field day observers (26.9%) independently adopted cowpea-based conservation agriculture in the following season, of whom 58.8% were women. Adoption was driven by the early maturity of the cowpea variety under climate variability and access to a ready vendor market. These findings demonstrate that integrating farm typology analysis with participatory innovation assessment and post-project tracking improves the targeting of SI interventions and supports the design of context-specific innovation packages more likely to achieve sustained adoption than blanket technology recommendations.