Legume integration in smallholder farming systems for food security and resilience to climate change

PLOS One | https://doi.org/10.1371/journal.pone.0327727 August 13, 2025 16 / 20 we suggest that smallholder farmers need sustainable intensification of the legumes for resilience to climate change and food security in Southern Ethiopia. Legumes as an alternative crop for the copping plan The legume sector in Ethiopia has the potential to be a key accelerator of agricultural development and growth. It can potentially contribute to a valuable role not only in boosting export incomes but also in enhancing the rural economy, improving food/nutrition diversity, enhancing soil fertility, and livestock productivity, reducing global warming and creating more sustainable and climate-resilient food systems due to its ability to fix atmospheric nitrogen through biological nitro- gen fixation [39]. Despite legume crops encompassing both edible and fodder crops, and a potential diverse crop portfolio in Ethiopia, the national statistical agency [7] highlights the area under cultivation and production only for the major 10 edible legume crops. So, the national area and total production coverage for major legume crops (faba bean, field pea, chickpea, lentil, grass pea, soya bean, fenugreek, mung bean and lupine) in 2021 were 12.9% and 9.4%, respectively. In terms of the proportion of the national area production, faba bean (4%), common bean (2.4%), chickpea (1.7%) and field peas (1.69%) are among the major legume crops [7]. To increase productivity per plot of land and overcome the

ever-increasing price of chemical fertilizer, biofertilizer technology has been gaining attention among agronomists and soil scientists because of its considerable benefits, especially in sustainable agriculture [40]. The country has identified a tremendous potential in biofertilizers to increase the productivity of soils [41]. Even though the country has started to expand the research on biofertilizers, to identify and isolate, more strains of beneficial microbes [40] and a few private companies started to produce and distribute to the farmers, it is limited to the central part of the country. In the study region, the agricultural experts and development agents (DAs) have information about biofertilizers, but the target farmers did not have information about it. This tells us a considerable number of farmers receive or do not at all receive agricultural innovations. Agricultural intensification has been characterized as ‘increasing average labor or capital inputs on a smallholding, either cultivated land alone or cultivated and grazing land, to enhance the value of output per hectare’ [38], one of such intensification is use of inoculants, which is absent in the current study area. Fertilizers, improved seeds, agrochemicals, and agricultural gear are among the measures used to intensify land use [39]. Ethiopia has a long history of agricultural intensification through the adoption of technologies that either save labor (the ox-plough), preserve natural resources (various land structures, such as terracing and the use of tree crops to pre-

serve soil integrity), or maximize value per hectare [40]. However, a very rapid population increase offers the demand for intensification, while market access gives the opportunity [41]. Fertilizers are one of the key productivity-enhancing inputs widely promoted by the extension system in Ethiopia to increase yields by addressing the productivity losses caused by declining soil fertility [38]. Fertilizer intensification has been considered a key game changer in Ethiopia’s agriculture transformation agenda, and as a result, fertilizer imports have more than doubled over the last two decades [42]. From June 2022 to January 2023, the Ethiopian Ministry of Agriculture (MoA) claimed that more than 15 million quintals of fertilizer were given for a single cropping season, accounting for around 83 percent of the total need. Fertilizer costs, fertilizer prices are still prohibitively expensive for most farmers with poor household incomes because worldwide fertilizer prices are high due to the indirect effects of conflicts, retail fertilizer prices have doubled to 1,400 USD/MT [43]. Farmers and development agents confirm it that when landholding declines, so does per capita legume production. The farmers replied that when they face a short- age of land, they prioritize their main stable cereals and tuber crops (S7 Fig). Continuous cereal-based mono-cropping practices, soil fertility depletion and erosion problems, limited improvement and farmers’ preferred legume varieties, lack of/limited access to quality seeds and no/or minimal uses of inputs in legume

production, limited promotion of appropriate legume technologies, wrong farmers’ perceptions for legumes input uses are the most important constraints of legume intensification in the country [44]. In addition, problems of institutional setup, limited availability of value-adding processing machines for legume products, policy, and strategy gaps on legume-based