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 2 / 20 conditions, the proliferation of pests and diseases, as well as erratic rainfall patterns [1]. The consequences of climate variability resulting a shortage of food, water deficit, outbreaks of infectious disease of both human and animal diseases, and losses of biodiversity which result in a loss in endemic and adaptive food sources [2]. The region’s overreliance on rain-fed agriculture, climatic changes such as irregular and unreliable rainfall patterns, and rapidly growing populations [3] pose significant con- cerns to food supply [4]. To cope with the impacts of climate change, there is a rising interest in the significant restructuring of agricultural systems throughout Africa that enhances farmers’ resilience to climate change [5,6]. Agriculture is an important sector in Ethiopia’s economy, with a significant con- tribution to the GDP (32.6%), and export share (77%), and 72.7% of the working population is dependent on it [7,8]. Small-scale farmers, who own less than 2 hect- ares of land [7] make up 80% of the population in the country and play a significant role in agriculture. These farmers utilize subsistence farming methods and produce more than 95% of the country’s crops [8]. The main crops produced by those farmers include cereals, legumes (pulses), oilseeds, vegetables, root crops, fruits, and cash crops like coffee and khat, with suboptimal yields [6]. To reduce vulnerability of smallholder farmers, agricultural intensification is needed

to increase the productivity of fragmented plots, maintaining ecological function and increase resilience to shocks [9]. The cultivation of legumes is pivotal in the pursuit of sustainability owing to their capability to assimilate atmospheric N2 through sym- biotic relationships with rhizobia; they furnish organic resources and can mitigate other limitations by enhancing soil fertility [10]. The relation among legumes, sus- tainable intensification, and the improvement of farmers’ livelihoods is extensively documented. Moreover, legumes provide organic inputs that positively influence the chemical, physical, and biological properties of soil, thereby enhancing agricultural productivity [9]. Grain legumes constitute a significant category of staple food crops in Ethiopia, ranking second to cereals, and account for 10% and 87% of the overall annual grain output within the nation, respectively [11]. A comprehensive analysis reveals that legumes constitute 12.90% of the total national agricultural land dedicated to farmlands [9]. More than twelve distinct legu- minous species are cultivated within the country [14]. Among these, four predominant legume species include faba bean (Vicia faba L.) (30%), common bean (Phaseolus vulgaris L.) (19%) chickpea (Cicer arietinum L.) (12%) and field peas (Pisum sativum L.) (14%) [8]. Smallholder farmers have derived significant advantages from legumes as sources of food, specifically excellent sources of proteins for poor farmers [12] and animal fodder [13], as well as tools for soil nutrient enhancement. Both herbaceous

and tree legumes possess the capacity to rejuvenate soil fertility in degraded land- scapes and mitigate the processes of land degradation [14]. Despite the country’s potential for growing the legumes many Ethiopian soils lack essential nutrients such as nitrogen, phosphorous and potassium which are crop yield limiting factors [15]. Among these soil nutrients, nitrogen (N) is an essential macronutrient for plants, and its availability highly influences the plant productivity [16], needing frequent replenishment. Consequently, prompt resolutions to the issues and reproduction in any medium, provided the original author and source are credited. Data availability statement: All relevant data are within the paper and its Supporting Information files. Funding: The research was funded by the Fund for Innovation and Development (FID) and focused on the adoption of Rhizobium Inoculant Technology (ARIT) at Arab Minch University, Ethiopia. Competing interests: The authors have declared that no competing interests exist.