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 15 / 20 These practices become now an integral part of the farm practices in some parts of the study area, yet others have to adopt them. This is common in the Rift Valley of the current study area where climate change and variability are mani- fested through frequent droughts and floods, erratic rainfall and fluctuating mean temperatures [36]. So, crop intensifica- tion in those areas was less likely practiced. Legume production and potential in the region Legumes are the key component of Ethiopia’s smallholder agricultural systems [37]. They are easily adapted farms and used as feed for livestock or as food for humans in a variety of processed forms [38]. These crops are commonly known as “poor man’s meat” because they are crucial to the diets of millions of people in developing countries [39]. Grain legumes are among of the most significant commodities in the study region, after cereals making smallholder farmers to produce diverse of them. More than a dozen different legume species have been growing in some parts of the study area. For instance, in Gamo zone, people adopted growing faba beans, field peas, cowpeas, mung beans, common beans, groundnuts, pigeon pea, etc., making the area one of the potential legumes growing sites. The legumes contribute to smallholder farmers’ income as a more valuable crop than cereals, and to diet as a cost- effective source of protein, accounting for around 15% of protein intake and the land coverage increases in all agro-

ecology regions [44]. They are common in areas where carbohydrates reach root crops such as cassava, enset, taro, etc. grow and where agroforestry farming practices are common. Southern Ethiopia region is known for agroforestry farming where those legumes become the most important sources of protein for the communities. Studies show that through- out the 1990s and 2010s, there was an increase in the production of legumes, and the export values climbed [42]. The National Statistical Agency reported the area under cultivation and production for the top 10 edible legume crops. In terms of the proportion of the national area production, faba bean (4%), common bean (2.4%), chickpea (1.7%), and field pea (1.69%) are among the major legume crops [11]. Actually, the common bean is one of the Ethiopia’s most extensively produced legume crop. It is a valuable source of food, revenue, soil fertility management, medicinal, fodder, and honeybee feed [43]. Their leftovers are used for cattle food and bedding, as well as mulching, fire, and roofing [46]. Its key production areas today include Ethiopia’s central, eastern, and southern regions [44]. It thrives in a wide range of environmental circumstances, including well-watered and drought- prone locations between 1000 and 2200 meters above sea level [45]. Smallholder farmers use conventional agronomic approaches to produce common bean crops. It is grown in home gardens and fields throughout its range. It is usually grown for household consumption or sale in local markets, and it has served as a small export crop for over 40 years [43].

Legume cultivation across all agro-climatic zones within the region is quite remarkable. Soybean, cowpea, mung bean, and groundnut are examples of crops that thrive in lowland areas, while other legumes grow in mid-altitude and high- altitude regions. Of particular significance is the widespread growth of common beans across various agro-ecologies, proving to be invaluable to farmers [37]. With a short maturation period of three months, these crops offer a means to escape drought and food starvation times. The potential of short-season grain legumes in addressing community chal- lenges associated with climate variability is substantial, contributing to the development of more robust and productive agricultural systems. Often serving as emergency sustenance for vulnerable HHs, legumes encounter various obstacles in their production [38]. In general, legumes are the most vital component of the farming systems in the region next to cereals (for example, common bean is the second and third most priority crop for the HHs) but no inputs are used for their cultivation. Collec- tively, their overall productivity is low, needing interventions for improving. The recent development of massive rhizobia inoculant applications against the grain legumes in central parts of Ethiopia has revealed significant improvement of their productivity (www.N2Africa.com). Seeing their potential in the region, escaping environmental risks, growing in different agro-ecologies and recent inoculant application developments that confirmed the improvement of the legume productivity,