Demographic data of participants
The study revealed no statistically significant correlation between the farmers’ age and the constituency they belonged to, as indicated by a cross-tabulation analysis (χ
2=4.243; P<0.374). In terms of age distribution among the interviewed farmers, 31.7% were aged 60 years or older, 30.2% fell in the 50-59 age range, 22.2% were in the 40-49 age range, 11.1% were in the 30-39 age range and 4.8% were in the 20-29 age range. While an association was detected among genders, no significant association was identified with household size (Table 1).
The study's results show that most participants were between 40 and 60 years old, which aligns with
Valombola et al., (2021) study. This age range may be due to younger individuals migrating to urban areas for employment opportunities, leaving older people to continue farming in rural regions. It is argued that one of the leading causes of rural young individuals' migration to urban areas is their negative attitudes toward agricultural pursuits. However,
Horn et al., (2015) suggested that youth migration to cities could be reduced if they are motivated to engage in agriculture, where they can produce for income generation.
The study also identified a gender disparity, with fewer men engaging in Bambara groundnut cultivation. This result concurred with
Karunaratne et al., (2015) and
Valombola et al., (2021) findings. This disparity may be due to men prioritizing alternative income-generating activities seen as more profitable or prestigious than Bambara groundnut farming. Traditional gender roles in some societies also assign specific agricultural tasks based on gender, with Bambara groundnut cultivation traditionally associated with women. Addressing this gender gap may require interventions that challenge gender stereotypes, promote gender equality, provide training and resources to enhance men’s agricultural skills and raise awareness about the economic and nutritional benefits of Bambara groundnut cultivation. Involving men in sustainable agriculture is essential for inclusive agricultural development and food security.
Bambara groundnut farming systems
The Bambara groundnut farming systems in the two constituencies of the Kavango East Region are summarized in Table 2. Significant differences were observed in farm sizes between the two constituencies (P = 0.016), with 65.1% of farmers having farm sizes between 2 and 5 hectares, 11.1% with farm sizes larger than 5 hectares and 23.8% with 1 hectare or less. However, no significant differences were found in the area allocated for Bambara groundnut cultivation (P<0.576). Most farmers (77.8%) reported allocating less than 1 hectare for Bambara groundnut cultivation, while 22.2% allocated more than 1 hectare. This study highlighted that farmers in the Kavango region often allocate their cropping areas based on their preferred or most valuable crops. In the case of Bambara groundnut, smaller areas were allocated, indicating that many farmers in the two constituencies prioritize other crops over Bambara groundnut, as larger farming areas are typically dedicated to the most valuable crops
(Horn et al., 2015). Fleissner (2006) found that in the Kavango region, Bambara groundnut was the sixth most important crop, with 67% of farmers involved in its cultivation. Similarly, Bambara groundnut received lower priority in Zimbabwe when allocating land among villages
(Hillocks et al., 2012).
There were also significant differences in annual average yields of Bambara groundnut (P<0.006). Approximately 42.9% of farmers harvested less than 50 kg annually, 33.3% harvested 100 kg or more and 23.8% harvested between 50 and 100 kg. The local farmers in Namibia, especially in the Kavango region, have been cited in
Grönemeyer et al., (2016) as having to deal with low yields and declining soil fertility, which could harm them. The decline in soil fertility could also be attributed to the underprivileged utilization of fertilizer in both constituencies where the study took place. Only 8.7% of farmers in Ndiyona Constituency reported that they use fertilizers in their crop fields while 100% of the farmers in the Mukwe Constituency reported that they do not use any fertilizers in their fields (Table 3). Therefore, measures to restore soil fertility and production in previously degraded fields are essential to ensure food security and increased yield. These measures can include the application of green and farmyard manures, promoting root nodulation for nitrogen fixation through rhizobial inoculants, composting and utilizing crop residues, as well as crop management options such as natural fallow. Other essential cropping practices that could reverse the deterioration in soil health include intercropping, relay cropping, cover crops, crop rotations and dual-purpose legumes. Among these techniques, legumes are widely recognized as soil fertility builders and restorers, owing to their relationship with symbiotic nitrogen fixation
(Musa et al., 2016).
Consequently, microbial inoculants have been used to improve agricultural production, soil health and plant health
(Das et al., 2018; Saad et al., 2020). Many studies have demonstrated that microbial inoculants can significantly boost legume nodulation, nitrogen fixation and grain yield, particularly among subsistence farmers
(Thilakarathna et al., 2019; Ibny et al., 2019; Allito et al., 2021; Gedamu et al., 2021). For instance, a study in the Kavango East Region by
Luchen et al., (2018) demonstrated that cowpeas treated with bio-inoculants yielded higher grain yield than negative control and fertilizer treatments. This shows that bio-inoculants may offer local subsistence farmers a cost-effective and eco-friendly means to enhance Bambara groundnut and other crop yields.
Regarding the purpose of cultivation, 85.7% of farmers in the Kavango East Region grew Bambara groundnut for home consumption, while 14.3% grew it for income generation. This suggests that most farmers primarily cultivate Bambara groundnuts for consumption rather than sale. However, some farmers reported selling their produce or seeds informally at open marketplaces during planting seasons. This study revealed that Bambara groundnut is underutilized and lacks attention in Namibia, unlike other countries where it is used for various purposes
(Temegne et al., 2018).
Farmers in both constituencies considered the preferred seed color when choosing Bambara groundnut varieties and there was a significant difference in seed color preference between the two constituencies (χ
2=18.898; P<0.001). In Ndiyona, the majority favored black-seeded Bambara groundnuts, followed by red-seeded varieties, while in Mukwe, brown-colored seeds were unpopular, with most farmers preferring cream-colored ones. Overall, cream-colored seeds were the most popular (54%), followed by black (20.6%) and chocolate (1.6%). These preferences were similar to those found by
Valombola et al., (2021). However,
Hillocks et al., (2012) reported that red-seeded varieties were more dominant in Zimbabwe than cream-colored ones and commanded a higher market value. Moreover, farmers selected their preferred seed colors based on various characteristics, including early maturation, easy cooking, high yield potential, size (largeness) and other factors such as resistance to wilting, particularly for red-colored Bambara groundnuts. The Chi-square test showed a highly significant association (χ
2 = 27.592; P≤0.000) between seed selection criteria in the two constituencies. According to
Odongo et al., (2023), Bambara phenotypes that are strongly associated with grain yield give breeders alternatives to characteristics selection in Bambara breeding. Farmers explained that specific Bambara groundnut colors, like the red ones, can be bitter, challenging to cook, or hard to crush for relish preparation. According to
Mubaiwa et al., (2017) and
Khan et al., (2021), the hard-to-cook phenomenon is the main issue restricting the use of Bambara groundnut.
Traditional dishes prepared from Bambara groundnut
Bambara groundnut is consumed in various ways at various stages of maturity in the two constituencies in the Kavango East Region (Table 4). After boiling for nearly an hour, newly collected pods are consumed as a snack. Dry Bambara groundnuts are versatile and used in various culinary preparations in Namibia. They can be mashed to create soups or relishes and roasted for snacking. Another popular dish is “mugombakapini,” a stiff porridge blending Mahangu flour with boiled dry Bambara groundnut seeds.
Furthermore, Bambara groundnuts can be roasted, ground into flour and used to prepare “rutura,” an instant porridge. Unfortunately, finding recipes for these essential Namibian dishes is challenging, as much of this culinary knowledge is not well-documented. While the variety of foods prepared in Kavango may be fewer than in other African countries, it is worth noting that similar dishes are prepared in various regions. For instance, Eastern Africa has employed Bambara flour to create thick and thin porridge
(Mubaiwa et al., 2017). In Eastern Nigeria, dry Bambara groundnut seeds are ground into a powder and used to make a delicacy called “okra.” Before cooking, this dish is wrapped in banana leaves and is a staple for many low-socioeconomic families, serving as breakfast, lunch, or dinner by a typical low socioeconomic family
(Obidiebube et al., 2019).
Inputs for Bambara groundnut farming
The Chi-square test revealed a statistically significant association (χ
2 = 3.592; P≤0.058) concerning farmers’ use of fertilizer in the two constituencies. This indicates a difference in the application of fertilizer rates between the two constituencies. Notably, all farmers in the Mukwe constituency reported not using fertilizer in their fields, while 8.7% of farmers in the Ndiyona constituency indicated using fertilizer. Those farmers who reported using fertilizer were identified as participants in the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) programs. They were provided with NPK fertilizer and received training on its proper use, as detailed in Table 5.
The conclusions regarding fertilizer consumption are comparable to those of
Horn et al., (2015), who reported that most farmers cannot access synthetic fertilizers to enhance soil fertility. Furthermore, these fertilizers are believed to increase soil acidity and may result in a high reliance on N fertilizer for crop production (
Lindström and Mousavi, 2020). As a result, more efficient techniques are required. One of the techniques is using rhizobial inoculants to increase leguminous crop production while reducing the need for synthetic nitrogen fertilizer
(Laurette et al., 2015). Rhizobial inoculation is a less expensive and often more successful agricultural strategy for guaranteeing adequate nitrogen supply
(Yakubu et al., 2010). Many strains of
Bradyrhizobiun symbionts were already isolated from Bambara groundnut nodules in Namibia and some were even heat-tolerant (
Grönemeyer and Reinhold-Hurek, 2018).
Bambara groundnut production constraints
The significant production constraints in Bambara groundnut cultivation were identified as high costs and field pests, as indicated in Table 6. In the Mukwe constituency, 62.5% of farmers reported high labor costs as a constraint and 37.5% mentioned high seed costs. In the Ndiyona constituency, 60.9% of farmers cited high labor costs, 30.4% pointed to high seed costs and 8.7% mentioned high fertilizer costs as limitations to Bambara groundnut production. The study’s findings are consistent with previous research, emphasizing that Bambara groundnut production in Kavango Region faces various challenges. Some of the farmers claimed that the reasons for not expanding their production was the lack of necessary harvesting equipment. Some claimed that the cultivation by hand hoeing was limiting their production and urged for government to avail tractors or oxen to them. Where there is no means of labour to land tilling, farmers reserve their energy for cultivating other vital crops like Mahangu instead of Bambara groundnut.
Grönemeyer and Reinhold-Hurek (2018) reported that several factors, such as unpredictable yields, the danger of crop failure and a lack of financial resources, contribute to food insecurity in these rain-fed agriculture systems in the Kavango Region. Equally important, uunpredictable weather, a lack of improved varieties was cited as constraints in Uganda
(Kakeeto et al., 2019). Farmers also need to be provided with the required resources to maximize productivity and use microbial inoculants to boost production or yield. According to
Mfilinge et al., (2014) and
Santos et al., (2019), using appropriate inoculant strains in nitrogen-deficient soils may provide an excellent opportunity for increasing legume growth and development.
There was a statistically significant association between constituencies and field pests (χ
2 = 13.719; P≤0.003), that is, the response to field pests as a contributing factor to yield losses every year was different among the two constituencies (Table 6). Most farmers in both constituencies deal with aphids, known locally as “runwamaghadhi” (Fig 1). In addition, they also reported rodents, termites, ants and cutworms (
Agrotis) as significant pests in their field crops. Similar to this finding,
Mukakalisa (2010) and
Tlankka et al., (2020) found that insect pests such as aphids (
Aphis sp.), leafhoppers (
Hilda patruelis) and bruchids (
Callosobruchus maculatus and C. subinnotatus) limit the output of Bambara groundnuts. Therefore, efficient agriculturally beneficial microbes (microbial inoculants) have the potential to play a role in sustainable crop production due to their immense plant growth promoting attributes, as well as plant protection metabolites (biopesticides)
(Singh et al., 2016; Gedamu et al., 2021). Biopesticides will significantly benefit farmers as they are less expensive and safer than chemical pesticides
(Babalola et al., 2017).
