Introduction

Indigenous knowledge systems (IKSs) can be understood as the knowledge that is reflected in the philosophies, skills and understandings developed through historical interactions between people and the physical environments that they have lived in. This knowledge has been passed down over generations and is thus deeply ingrained within the culture and natural heritage of particular communities and or societies.

IKS thus forms the basis of the local knowledge that many rural and indigenous people use in their daily lives, and which often influences their decision-making. Admire and Tinashe [2] reported that the development of IKS within the context of livelihoods and natural resources has supported the survival of the indigenous people who have created these systems. Jiri et al. [26] noted that IKS is preserved within communities’ memories and actions and is often represented through storytelling, music, mythology, idiomatic expressions, festivals, cultural norms, convictions, ceremonies, social regulations, local languages, farming methods, plant species and even in the domestication of animals.

Across the globe, IKS has been used by communities to assist them in achieving food security. The Food and Agricultural Organisation (FAO) always define ‘food security’ as the availability of culturally acceptable and nutritionally adequate food of quality and variety [20]. Subsistence farmers in rural communities are constantly grappling with the negative effects of climate change on their ability to achieve food security. In their drive to achieve food security, many subsistence farmers are increasingly relying on various IKS to achieve their goals. These systems vary from the indigenous knowledge used by local communities in response to early warnings signs of negative weather conditions; the anticipated impact of changes in the wind direction; the crescent moon’s form; seed selection and the behaviour of specific animals [24, 38]. According to Berkes [8], some forms of IKS can provide reliable forecasts of rainfall probability and other weather variables from which farmers may then organize their farming activities to minimize their risk and maximize their crop productivity. While IKS is increasingly documented as a possible solution to providing food security in rural communities, it must be applied more systematically if it is to effectively boost agriculture productivity. For this reason, the use of IKS is increasingly being included in the development agendas that are related to the efforts of rural subsistence farmers. There is some evidence that nations in the Global South, frequently implement indigenous knowledge-based tactics when establishing their food security plans [50].

In South Africa, the Household Food Insecurity Access Scale (HFIAS) [52] highlighted the challenge of food insecurity in the country and noted that in 2016 the percentage of households with insufficient or lack of access to adequate food declined from 23.9% in 2010 to 22.3%. However, on a provincial scale, the HFIAS [52] measured the food insecurity of indigenous households in villages in the Limpopo Province and it established that the majority of households (80%) could not access sufficient food, and this negatively influenced food security levels in the province. Kome et al. [35] reported that generally, the significance and value of IKS practices in subsistence farming are limited or lacking on a national level in South Africa and more in favour of more western and scientific modes of crop production, and this has negatively impacted on the value of indigenous farming and the resultant food security in the country in general and specifically in the Limpopo Province.

While there is limited documented research on the use of indigenous knowledge systems in enhancing food security and increasing agricultural productivity in the rural communities of Southern Africa, there is some research that has been conducted in South Africa and Limpopo Province in particular. While Kamwendo and Kamwendo [30] reported that albeit limited there were limited studies that had examined the extent to which indigenous knowledge systems can contribute to the achievement of food security in Limpopo Province. One such study includes the work of [42] established that communities in the Sekhukhune district in the Limpopo Province successfully depended on indigenous techniques to preserve and process crops and in this way, IKS had indeed contributed positively to food and nutrition security. Further, Jiri et al. [27] reported that although IKS practices among local farmers could contribute to the improvement of food security and better livelihoods, IKS had been marginalized in favour of more Western knowledge and applications in many communities in the province.

In various interactions with the local farmers in Limpopo Province, the researchers of this paper established that these farmers strongly believe in the social-cultural knowledge of their ancestors, especially within the context of dealing with extreme weather conditions and food security. Previous research testing is often limited to more conventional expertise that has been used to mitigate adverse weather events, and this has been performed at national or multi-regional levels of rural farming systems in South Africa. The challenge with these studies is that they are widely aggregated and are often too generalized and confined to be of use and direct value to a rural subsistence farmer who needs highly localized information on the risks of climate change in the immediate geographical location of their farmlands. This challenge extends to the provision of localized weather forecasts by the South Africa Weather Service (SAWS) and the distribution of related resources that contain information on the mitigation of climate change is very limited among rural farmers in South Africa [56]. It is thus the contention of the researchers of this paper that there is a strong argument for prioritizing indigenous resilience as a root for localized indigenous knowledge coping strategies that would result in better food products that will enhance the food security of rural households.

According to Maponya and Mpandeli [40], Mpandeli et al. [44] and Kom et al. [35] report that in Limpopo Province, rural subsistence farmers often have indigenous knowledge related to weather prediction going back many generations, and thus, they have managed to develop effective coping strategies and adaptive strategies to ensure successful crop production in adverse conditions. Such knowledge is pivotal in updating rural and national adaptation responses, as scientific coping and adaptation strategies most frequently practice top–bottom methodologies which do not mirror grassroots authenticities. This is aligned with the sentiments of [21] that highlight the danger that is associated with the failure of building on and further developing IKS is related to the risk of poor coping, maladaptation and inappropriate responses to climate stocks among rural farmers.

Using a case study approach, this paper aims to investigate the role of IKS in achieving sustainable food security among local farmers in five villages (Vondo, Phiphidi, Tshiondo, Levubu and Tshakuma) located in the Vhembe District in the Limpopo Province of South Africa. Further, this paper seeks to inform district and national policymakers on how rural farmers could employ indigenous knowledge practices to combat climate change and at the same time enhance the food security of the households in these villages. It is hoped that this paper will contribute to the documentation of valuable indigenous adaptation and storage techniques and the implementation and interaction with IKS that could positively contribute to food security in the villages in the Vhembe district.

Materials and Methods

Profile of the Study Area

Vhembe district is in the far north part of Limpopo province, South Africa [37]. The study villages are located within the four municipalities of the district, as indicated in Fig. 1. Due to its geographic location within the country, this district is particularly vulnerable to both physical and climate-related risks. It is bordered in the North-east by the sovereign states of Botswana and Zimbabwe in the North and the dedicated region of the South African, Kruger National Park in the East. The climatic conditions are generally warm and humid, receiving the bulk of its annual rainfall in November through to March in line with the Inter Tropical Convergence Zone (ITCZ) as it moves Southward over Southern Africa [9]. These climatic conditions have influenced indigenous agriculture practices and food security, as crop production is highly dependent on climatic variables [31]. The annual minimum temperatures vary from 6 to 17 °C during winter, whereas in summer, the maximum temperature varies between 34 and 38 °C [1]. Most indigenous farming activities in the province depend also on climatic conditions, with some small-scale furrow-irrigated cultivation. However, changes in rainfall and temperature patterns have greater negative impacts on crop productivity and hence food insecurity within the villages.

Fig. 1
figure 1

Location of the study sites [34]

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Population and Economic Activity

According to the 2011 Census survey, Vhembe district municipality has a total population of 1,294,722 people, with a density of 50.6 people per square kilometre. The population of Vhembe increased by 41,979 persons between 2001 and 2007, and by 54,687 between the 2007 Community Survey and the 2011 Census. According to the VDM's integrated development from 2012/13 to 2016/17, the population is mostly made up of 44.4% females, 41.6% males and 16% under the age of 20 [52]. The population in the district is made up of the majority of black Africans (1,375,053), followed by 11,170 white people and 2689 people of other races.

The entire area of the district is 2,140,708 hectares, of which 247,757 are cultivable land. Large-scale commercial farming and indigenous farming (subsistence farming) are the two main types of agriculture practised in the district. About 70% of the arable land is owned by white farmers who practised commercial agriculture, and just 30% is owned by a few indigenous farmers, most of whom are black [55]. The majority of households in the municipality produce their food through crop and livestock farming, but these sectors' viability has declined over time. In the past, households produced their livestock including cattle, sheep, goats, pigs and chickens, as well as food-related crops like maize, sorghum, groundnuts and tropical fruits. In recent years, most farmers currently struggled to generate enough food to feed their households, so they increasingly rely on food products purchased. The study seeks to enhance food security in the Vhembe district of South Africa through the use of indigenous knowledge systems.

Economically, the district generated 17.71% of the R 358 billion GDP of the Limpopo Province in 2018, up from 17.09% in 2008, with a GDP of R 63.4 billion [52]. South Africa's GDP in 2018 was R4.87 trillion, and the district contributed 1.30% to that figure. The sector with the biggest share of the district's overall GVA (Gross Value Added) in 2019 was community services, accounting for 33% of it. Following the trade (18%) and finance (17%) sectors, the finance sector makes up the second-largest portion of the GVA at 18%. Agriculture and manufacturing make up the two economic sectors that contribute the least, each accounting for 3% of the GVA overall. The trading sector, where around 40,500 people were employed in 2018, saw the biggest growth in the number of jobs in the informal economy in 2018.

Study Population and Sampling Method

The population unit of the study is made up of subsistence farmers from five villages (Vondo, Phiphidi, Tshiondo, Levubu and Tshakuma) within the Vhembe district in Limpopo province. A total of 200 subsistence farmers from the five villages were chosen using a purposeful sampling technique. A further breakdown of the sample reflects 40 households per village (so a survey of 40 households was conducted per village). The sample size was used to indicate the more accurate the average values will be. Before choosing the respondents of the study, some consultation was done with key informants, such as agricultural extension agents, local leaders and local indigenous knowledge holders and practitioners. Key informants were chosen because they could offer in-depth and pertinent knowledge regarding indigenous foods and IKS as well as their role in ensuring household food security. All participants who took part in the study did so voluntarily, and they were made aware that they may opt out at any time.

The subsistence households were used as a representative unit of the investigation. The selection of households was based on their ability to provide thorough and pertinent details concerning indigenous food preservation and indigenous knowledge systems, as well as their role in promoting food security to the community. A snowball sampling technique was used to choose households for the study. With the help of this technique, it was feasible to find the other households by starting with one that employed indigenous knowledge to forecast weather events and enhance food preservation. The initial households in their village were identified with the assistance of the traditional leaders. When the data were saturated or did not change while being gathered, the sample size was determined. There were 200 households surveyed in all (40 households in every village). Five villages were chosen methodically. According to the houses we visited, these are communities where small-scale agriculture is flourishing and the people can apply their traditional knowledge to improve food security and forecast weather patterns. The villages were also selected by employing a grid that was completed beforehand with input from stakeholders for the selection of study villages engaged with IK and food security in the Vhembe district and these are accessible villages as well.

Data Collection Methods

The data for this study were collected using participatory rural appraisal (PRA) and rapid rural appraisal (RRA) methodologies. Participatory rural appraisal (PRA) is a method of learning about rural life and circumstances from the perspective of local communities [14]. Rapid rural appraisal (RRA), on the other hand, entails learning quickly and directly from indigenous people, as well as gathering information for the sake of analysis. Both PRA and RRA were applied in this research as they complimented each other in obtaining pertinent information on farming projects in the five villages and how indigenous farmers use IKS in their farming activities that contribute to local food security. In addition, the following dedicated research tools were used to collect data through focus group discussions (question guidelines); household interviews (semi-structured questionnaire) and stakeholder interviews (semi-structured interviews). During focus group discussions, the researcher introduced pertinent themes that guided the ensuing discussion that was recorded audibly. The time spent in each village to gather information was 3 days, and this included collecting data from focus group discussions (six to 10 participants in each) and one-on-one interviews with local farmers. At all times during the data collection process and infused into all data collection tools, it was the assumption that indigenous knowledge and food security challenges can only be articulated by the local farmers in each village. Data of a more qualitative nature were collected in each village until a point of saturation was reached. When conducting research on climate change and food security collaboratively with local households, quantitative analysis was employed as a supplementary to a qualitative method. This is because traditional research methodologies' use of qualitative methodology models has some limitations [23, 29].

Data Analysis

The researchers employed key subsistence farmers’ semi-structured interviews, questionnaires and focus group discussions; these provided qualitative data, which were coded with STATA version 8. The SPSS (Statistical Package for the Social Sciences) software Version 12.0 was used to analyse quantifiable data from the questionnaire and frequency and percentage; graphs were produced using descriptive and inferential statistics [36]. The study also used thematic content analysis to analyse the data, which entailed reviewing field notes, listening to transcribing and translating recorded material from focus group discussions and individual interviews. Quantitative data were collected via questionnaire and analysed to get information regarding the number of household farmers that employ indigenous knowledge to enhance food security. Furthermore, semi-structured interviews were conducted using a detailed theme guide with questions that aid the probe for more information in the research group. Respondents were asked questions on indigenous knowledge of food consumption to ensure food security and their indigenous knowledge systems about sustainable food production within Vondo, Phiphidi, Tshiondo, Levubu and Tshakhuma villages.

Ethical Protocols

The researchers and field assistants obtained informed consent from the participants before the commencement of data collection. In addition, the researchers had to obtain permission from the relevant local authorities and traditional chiefs of the respective villages to gain access to the villages and to undertake the research.

Results and Discussion

Demographic Profile of Households’ Head

To understand the basic socioeconomic status of the households that formed part of the sample for this research, it was important to examine the demographic profiles of the respondents. The information used was collected from the head of the household and the analysis included aspects related to gender, age group, material status and household size.

A total of 200 subsistence farmers' households were administered in all five villages, that is 40 sample sizes from each village. The result of the study revealed that 80 households are headed by males which make up 44.44%, while the remaining 120 respondents were females and consisted of 66.66%, the latter thus reflecting the majority. This analysis is typical of the circumstances within the South African rural environment, where semi-migration is a dominant phenomenon as the economically active male member of the rural household works (and lives) in larger urban areas but retains their continued connection with their households in the rural area. In the sample for this study, the economically active male members of the households sampled for this research worked in larger cities in the Gauteng Province such as Pretoria and Johannesburg. Significantly, females in many rural households in the Limpopo Province are the custodians of the traditional understanding of IKS [35]. Thus, the large percentage of female-headed households in the sample for this research is significant due to their understanding of indigenous knowledge and how they use this knowledge to sustain livelihoods, and the preservation of cultural continuity and community. It is also significant that most respondents of the sample were female, as rural women in Africa are typically considered to be the key producers of indigenous food crops and the preservation thereof for their households. Culturally based the findings indicate that women headed most households and are majority of farmers in each of the study sites. The survey reported that elderly members more to be female, given that they are considered custodian. So, their involvement in farming operations and their exposure to IKS for food storage and preservation is the reasons behind this. However, households led by male farmers, usually relocate or travel in search of employment to neighbouring cities such as Makhado. These findings are similar to that in Limpopo province of South Africa by [34]. Further, elderly farmers are among the most important sources for the dissemination of information since they are the guardians of indigenous knowledge [45]. They are essential to curriculum design, programme implementation and instructional planning in culturally responsive efforts like the Alaska Rural Systemic Initiative. Several literatures stated that the value placed on indigenous women and elders by indigenous communities does not lessen the difficulties or enhance the living circumstances of these individuals [50, 53]. In addition to being the primary caregivers, they also serve as the guardians of biological diversity, culture and traditional knowledge [23, 29]. According to Hart and Mouton [23], Kelumikiza [29] and Magni [39], younger generations suffer from this since it reduces their social capital and may consequently make it harder for them to respond to ecological and socioeconomic difficulties.

An analysis of the size of the households is important for research that is related to sustainable livelihoods, as the size of a household has a significant impact on the levels of food security in the household. According to the Living Conditions Survey of Households 2014/2015 undertaken by Statistics South Africa [52], the average household size in South Africa was 3.3 members. Table 1 reflects the household size of the sample surveyed. Just under 49% of the households in the survey comprised between 1 and 3 members, while over 51% of those surveyed exceeded four household members while 20% of these represented households of seven or more members. As such, the average household size for those included in the sample marginally exceeds the 2017 South African average. Qualitative responses to household size during the data collection process revealed that many respondents believed the positive result of larger households was that this would allow for more labour and this would result in higher agricultural production, with the added advantage that some members could be diverted to labour-related to more off-farm activities. This qualitative assessment is aligned with similar research undertaken by [7] among small-scale rural farmers in the Central Ethiopia.

Table 1 Household size of the 200 respondents from Vondo, Phiphidi, Tshiondo, Levubu and Tshakhuma Villages, Vhembe District, Limpopo Province, South Africa
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In the research of [36, 53] undertaken in the Limpopo and Eastern Cape Provinces, it was established that gerontology is crucial to understanding the role IKS can play in crop production and the resultant impact on levels of household food security. In their findings, they identify elderly female members of a community to be more likely to possess the appropriate IKS for the production, processing and storage of food as they are widely considered to be the main custodians of IKS. Aligned with the work of other researchers, an analysis of the age groups of the respondents for this research is significant as it is generally the older members of a community who have the best knowledge and practical experience in the application of IKS in food production. Table 2 reflects the breakdown of the age groups of the household heads that formed part of the survey.

Table 2 Age groups of the 200 respondents from Vondo, Phiphidi, Tshiondo, Levubu and Tshakhuma Villages, Vhembe District, Limpopo Province, South Africa
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The sample included the heads of households that were 24 years and older. The age group that represented the highest number of participants were aged from 46 to 55 years. The 65 years and older group represented a 9% portion of the sample, and they were purposively selected based on the notion, the elder members of the community are the custodians of IKS and would thus be able to transfer skills to the younger members of the community. During the focus group discussions, the responses from the older representatives of the sample provided the basis of the information documented in this paper that related to IKS that is practised and could be practised in the villages to mitigate climate change and thus improve food security.

Using Indigenous Knowledge to Manage Soil

One of the major challenges facing the indigenous community was food security which can be ascribed to poor soil fertility. Respondents reported various indicators that they widely employed to recognize soil fertility and thus determine crop yield. During field surveys and semi-structured interviews, farmers reported that yellowing of leaves, stunted growth of crops in the study areas and the spread of disease and pest outbreaks or proliferation during crop growing seasons were associated with poor soil fertility and not because of climate change events, such as rainfall variability. Three significant methods of improving soil fertility were identified by the respondents, namely the addition of manure, crop rotations and mixed and intercropping farming.

The findings of the study indicated that most of the farmers used manure as part of an organic fertilization process to improve crop yield. Manure from their livestock is important in maintaining and improving soil fertility among indigenous farmers and the sample villagers. Very little reliance is placed on the use of inorganic fertilisers, probably due to economic factors. The respondents in the study areas reported that they used animal manure to increase plant nutrients as most farmers both practice crop and animal husbandry micro-scale farming. During the interviews, farmers indicated that using manure was an old and tested system that is used to improve soil fertility and thus increase crop production. An estimated 25% of local farmers reported that the main reason that they do not apply manure is to improve soil fertility as this practice encouraged the growth of weeds, increased the number of pests and resulted in the occurrence of new plant diseases. It was reported that some of the locals would combine various decomposed organic materials when composting the animal manure as they believed that this practice would eliminate weed seeds and discourage pests from crops grown in the manure. Within the villages, it was noted that many farmers would plant crops at new old cattle kraal sites. These findings are aligned with the research of [33] who documented that the IKS related to the use of cattle kraals and manure is critical in improving livestock productivity and food security in the Maasai community in Kenya. Respondents shared their understanding that planting corps near former cattle kraals would yield a comparatively higher crop yield when compared to crops grown elsewhere. The custodians of IKS in the villages shared those years after the cattle kraal had been relocated and/or abandoned, former cattle kraal grounds are widely maintained and utilized in growing crops. During the focus group discussions, local farmers shared their knowledge on how they determine the quality of manure. The most significant of these indications included the manure colour, the moisture levels, the texture, the existence (or absence) of mounds and the amount of decomposed organic crop residues they contain. Respondents reported that manure was once thought to be of high quality if it was dark, moist, fine and free of sand, a few mounds and crop residues.

The results further revealed that farmers used kraal as manure (from poultry and cattle) to improve and maintain soil fertility, as well as to retain soil moisture and reduce plant pest outbreaks. The IKS shared concerning the use of manure includes that when the first summer rains are forecast, farmers apply the manure compost on their plots, and the rain helps the manure permeate the soil. Once the first rain has fallen the farmers would use hoes or domestic animals (donkeys) to mix the manure into the soil. Participants in the study area reported that this method of soil fertility generally improves topsoil humidity. In Levubu, Tshiondo and Tshakuma local farmers recognize that if weeds are allowed to grow, this should be a positive occurrence as the weeds protect the soil and prevent it from overheating or drying out. In addition, weeds provide natural and positive competition, that not only simulates crop production, but they also reduce runoff and soil erosion during the rainy season. The participants also reported that a mulching method can be used to maintain and improve soil moisture. That waste and previous harvest residue from the maize stalks, tomatoes and dried beans is good soil fertilisers. The study revealed that after harvest, the crops' waste and residue are tilled with the soil to increase the moisture and fertility of the soil. Bruschi et al. [10] cited that the use of traditional plants and local farm waste materials in rural communities of Mozambique enhances and replenishes depleted soil nutrients. During interview sessions, local farmers reported that one of the oldest practices used to improve soil fertility and better crop productivity was fallowing. The findings show that exhausted farms are left fallow for about three to six seasons. The farmers said that this practice enhances the soil recovery process in terms of the levels of fertility. During the fallowing practice, domestic animals such as cattle, sheep and goats are driven in the uncultivated plot to browse course grass and their droppings help add to the recovery of the soil fertility.

Crop rotation was indicated as one of the methods used by local farmers for generations to ensure successful crop production and a variety of food that is needed as a component of food security. Most of the subsistence farmers in the study areas used a crop rotation farming system of growing different crops on the same piece of plot such that no land or plot has the same crop in succeeding years within the same parcel of land. It is a method intended to maintain the soil's capacity for production, lessen parasites and diseases, use fewer chemicals and control nutrient needs, all of which contribute to maximizing yield. Crop rotation is a technique that improves soil structure boosts a farm's capacity to store carbon and increases farm yield and food security. The findings also revealed that as local farmers choose crop rotation strategy carefully, it may be possible to maintain long-term soil fertility, eliminate the exchange between crop viability and ecological impacts and disrupt the weed and disease cycle process through intrinsic nutrient recycling. The findings of the study concur with that of [28] stated that the supply of food security is increased by the crop rotation system.

Indigenous multiple cropping systems were also used to improve soil fertility among the local farmers. The findings revealed that participants sow different seeds randomly and simultaneously by hand in the same plot. The growth of all crops simultaneously on the same farm is maximized by this technique. Cropping systems can reuse their own stored micronutrients via interplanting. When comparing this technique to mono-cropping techniques that employ the same degree of management, output per unit area is higher than the former. To increase the likelihood of producing numerous crops, farmers combine a range of plants with varied growth tendencies in the same plot or their backyard gardens.

Additionally, local farmers' ability to produce enough food depends also on their ability to manage and control weeds, which compete with crops for nutrients and sunshine and consequently lower agricultural production. Root and tuber crop yields are severely threatened by weeds because they grow slowly at first and are therefore weak weed competitors. Numerous traditional and non-traditional weed control techniques are employed by farmers in the research area. The study exposed the local weed control techniques employed by subsistence farmers in the study region. To manage weeds, most farmers use manual hoes, livestock traction and manure techniques. About 100% of respondents employed the hand-hoe weeding technique in their backyard gardens, as did most area farmers. Additionally, findings indicate that almost half of the farmers employ draft animals using plough oxen for weeding or farm preparation.

During focus group discussions, most farmers in Vondo, Phiphidi and Tshiondo villages reported that a mixed crop technique was adopted, to adapt to the changing climate and to improve crop yield. The results show that 75% of the respondents in the five villages carry out this farming approach, and this involves crops being grown at the same time on the same piece of a plot by farmers in an attempt to decrease the depletion of soil nutrients and retain soil moisture. In the villages, local farmers reported that mixed cropping of cowpeas, Bambara groundnuts and maize is important for the soil's health since the mixture has a considerable capacity to fix nitrogen in the ground; these crops are referred to as “green manure” as they boost soil fertility. The following reflects the conversation of several elderly respondents from Tshakuma, Levuba and Phiphidi:

Mixed crop farming approach supports them in the monitoring of pests, as they destroyed some crops flowers and leaves. The pulses of many other crops among the main crop, therefore increasing the chance of insects encountering bad stimuli, confuse them with taste and bad smell which makes it difficult for the insects to identify the chosen crop to prey on still the crop grows to maturity with limited damage from insects.

Additionally, participants reported that they practice this style of farming to ensure better crop production and as a backup should some crops not produce or fail. Large plot sizes are needed with this type of farming system to accommodate several crops. Following the farmers' preferences as well as farm locations, it was seen during the field survey that most of the farmland in the study sites was farmed with a variety of crops. It was also noted that several crops grown in Tshiondo, Vondo and Phiphidi, including beans, tomatoes and okra, were naturally drought-resistant.

Findings on the multi-cropping and mixed cropping methods applied in the sample villages are consistent with empirical data of the research of [39] reported that the cultivating of crops and trees on the same plot reduces the risk of excessive evapotranspiration during intense heat waves. Farmers in Vondo and Phiphidi employed this method because the area is semi-arid. These findings are consistent with the research of [29, 34] that showed that growing maize plants alongside leguminous crops like beans and groundnuts reduces soil degradation and adds nitrogen to the soil. Further, it was revealed by farmers that mixed cropping is preferable to mono-cropping as a method of farming. Hart and Mouton [23] revealed similar results, stating that mono-cropping is a poor method of cultivating the same or similar crops on the same plot year after year leading to pests and disease outbreaks and concentrating nutrient uptake from the same soil depth, leading to nutrient depletion.

Indigenous Methods of Processing and Post-harvest Storage of Food

Due to inadequate preservation and processing facilities, a significant amount of food is wasted or lost after post-harvest. Numerous techniques are employed by local farmers in the study areas to guarantee prolonged crops after harvest. Storage facilities are utilized to reduce insect buildup and better safeguard stored products from moisture, precipitation and domestic animals. Table 3 reflects the variety of traditional food processing and post-harvest storage methods in the five villages in the study. Rural households rely on preserved foods as their source of food amidst periodic food shortages until the start of the harvesting season. While a variety of traditional preservation and storage techniques exist in the villages, respondents reported that the persistence of customs and beliefs accompanied by a lack of adaptability and openness to necessity is one of these issues in applying IKS.

Table 3 Indigenous food preservation and post-harvest storage methods are used in the Vhembe district
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The results revealed common methods employed by the local farmers regarding food preservation and storage during the season of abundant harvest and lack. During semi-structured interviews, the sun-drying method was the indigenous method used by 87.8% of the respondents in the preservation of food, such as meat, fish, fruits, vegetables and maize. Respondents reported that in times of shortage, processing a variety of food through traditional preservation methods and technology is critical as it increases their household access to a variety of food. By stabilizing food supplies outside of the villages and the season of production, they help improve food security. Caballoero-Serrano [13] reported that the use of IKS in food processing and preservation also encourages a wide variety of diets and provides individuals with access to a greater variety of products, which allows them to ingest more vitamins minerals and other nutrients than they otherwise would. This indigenous technique of drying foodstuff can take the form of frequent sun-drying, which entails spreading the fruit or vegetable on bare ground or the roofs of houses. Foods like maize, peeled cassava, peeled yams, veggies, etc. may all be sun-dried to preserve them for a long period without going bad. The findings also revealed that pounding using local mortar was a major practice used by indigenous people to preserve food. An estimate of 137 households (76.1%) employed the local mortar for pounding foodstuff such as maize, dry vegetables, peanuts and sweet potatoes to be preserved and used later during food shortages. These findings are in line with previous studies conducted in Africa by [15, 23, 47] who reported that pounding maize is locally done using stone grinders (outdated method), local mortar and wooden pestle and increasingly by the power-driven hammer mill. Therefore, local farmers have used this process for grinding food stuff and to prepare for food security in the near future.

Additionally, sacks, tanks and basins were identified as additional methods that were used for the storage of seeds and crops after harvesting and threshing, which represented about 124 households (68.9%). These methods prevent crops from being attacked by weevils and the harvests remain fresh until they are all consumed in the future. The participants said one of the most common preservation practices used was hanging the maize cons from the house roof. The findings indicated that seeds are mixed with wood ash from special plants and stored in tanks and basins or locally made clay pots. This method could preserve seeds to last for more seasons. The data acquired during the questionnaire show that 77.2% of farmers used a mixture of red chilli pepper (Capsicum annum) is used to preserve harvested maize and cowpea in storage.

The local communities reported that they have used maize cribs for centuries to preserve and store crops for future use. This post-harvest storage equipment is constructed in a homestand using hardwood and corrugated zine(iron) for protection from extreme weather conditions and pests. A total of 91.3% of the indigenous farmers dried and stored maize in this maize crib. Most of the farmers reported that the maize crib is a sufficient process and post-harvest storage system, and it protects crops and seeds from weevils and animals.

The high summer temperature witnessed in the Vhembe district is a major challenge to the local farmers. Adeola et al. [1] indicated that the maximum summer temperature varies between 34 °C and more than 40 °C, so farmers have developed other indigenous methods. for crop storage which is burying under moistened soil. The findings indicated that indigenous farmers also used moistened soil or cool tanks to keep farm produce from their home gardens. An estimated 48.9% of farmers preserved their crops in moistened soil and harvested only when they needed to cook. Further, farmers store crops by burying them under moistened soil until the summer season (high temperature) is over. Farmers in Vondo, Phiphidi, Tshiondo, Levubu and Tshakuma villages experience extensive heatwaves in summer; thus, households that store their crops in cool tanks or moistened soil in summer mentioned that they had to cover them with tree leaves and irrigate for water to infiltrate into the soil during the day when temperatures are very high,

Indigenous Knowledge of Weather Forecast

Climate and weather forecast help farmers be more productive, which in turn encourages household food security. Farmers were able to predict the imminent arrival of rain due to indigenous weather forecasting techniques. The findings of the study revealed that a total of 115 respondents representing 57.5% of the sample disagreed with the assertion that local farmers use traditional knowledge to anticipate the weather, on the other hand, 42.5% of respondents agreed with using traditional forecasting techniques. According to the study, although indigenous practices had a favourable effect on crop production, most of them were ultimately lost. Therefore, using particularistic traditional knowledge on weather forecasting is based on empirical information that affects cosmological beliefs, and it is useful in modern studies.

Regardless of whether indigenous practices are fading away, traditional weather forecasting still provides communities with reasonable projections on weather conditions that reduce food shortages, hunger and climate change. Indigenous farmers are thus vested in ensuring rural livelihoods. As a result of climate change and commerce of first-rain uncertainty, most of the decisions made by Vhembe district local farmers are grounded on individual experience. The findings of the study gathered during semi-structured interviews and questionnaires showed that most respondents within the study area used indigenous knowledge to forecast the quality of the planting season to make informed farming decisions and manage crops during extreme climate events. Hence, elderly farmers believe in the idea of using indigenous methods (birds, sun, clouds and wind) to predict the weather, despite their diminishing use. The findings are in line with [35] study on the use of IK indicators by farmers for adaptation to changes in climate in rural South Africa. Their findings showed that farmers used traditional means of weather prediction because modernized weather forecasts do not always provide reliable estimations of the weather. To forecast weather patterns, farmers employed animals, insects and wind direction. Anju and Bonny [6] also discovered that farmers of Wayanad in India employed traditional techniques to forecast the weather using signs such as birds, vegetation and astronomy. Farmers in Levubu also said that swarms of dragonflies that migrate east from August to November were clear warning signs of the rainy period. Therefore, in the absence of conventional weather forecasting, farmers in the Vhembe district can decode weather signals from the behaviours of specific flowering plants and animals. Similar findings by [26] conducted in South Africa reported that star movement from west to east at night under a clear sky predicts impending rain for a few days.

Additionally, during semi-structured interview sessions, the study revealed that plant phenology is commonly employed by local communities in the district in rainy season forecasting. The early flowering of certain trees from September to November has been identified to be one of the signals of a good rainfall season. The findings of the study showed that crop cultivation was associated with wind movement, migratory and mating trends of both domestic and wild animals and the position of the moon. The colour of the horizon at sunrise and sunset and appearances of rare animals and bird breeding patterns in river valleys were used in drought and flood prediction as were the flowering patterns of certain plant species. Empirical studies indicated that traditional knowledge alerted local communities of possible disasters such as delays in the start of rains, untimely or excessive rains and spells of too-high or too-low temperatures [16, 18, 29]. Forecasts provided farmers with guidelines for seasonal planning in terms of timing for planting, choice of crops suited to projected conditions and the likely impacts of weather on farming operations in general. In South America, Mexican farmers base their predictions of seasonal rainfall on observations of natural occurrences, such as the appearance of birds, animal mating and plant flowering, while cultural and ceremonial experts base their forecasts on oracles, hallucinations or dreams [4, 5]. The study recommends the acknowledgement and utilization of existing traditional knowledge systems in weather forecasting in readiness for the coming agricultural season that is for planning crop farming and the general development of communal areas in sustainable food security.

Advantages of Indigenous and Western Scientific Knowledge

For centuries, indigenous farmers have used their traditional knowledge to adapt to changing environmental conditions [25]. Thus, indigenous understanding has shown to be an invaluable resource for ensuring food security and adapting to climate change for the traditional farmer. The study conducted by Kom et al. [35] emphasizes the distinctiveness of indigenous knowledge systems and ideas as compared to scientific knowledge, which is mainly applied by commercial farmers, it is very different.

The knowledge of indigenous people has been used for generations; the locals stressed. The following generation of farmers in the family or household is verbally taught. Because of this, people greatly trusted it and believed that its source was trustworthy. It was therefore utilized more frequently than scientific information or meteorological forecasts. The seasonal changes and their occurrences can be accurately predicted by the farmers in the area but within a limited time frame. They achieve this by spotting clues in the natural world. For instance, the arrival of summer is signalled by the peach tree's blossoming and the first rains in October. Because they have been applying the same indigenous knowledge for centuries, farmers are therefore able to recognize these symptoms well in advance. Based on the weather they anticipate, they then make plans for the welfare of their cattle or crops. Using traditional knowledge does not cost money or electricity. Thus, this is beneficial to rural areas like Vondo, Phiphidi, Tshiondo, Levubu and Tshakuma with limited electricity and high load-shedding. The people believe that this is particularly significant because there are no outside influences hindering the use of indigenous knowledge. The barriers faced by scientific modes of knowledge transmission and applications have no bearing on the transfer of indigenous knowledge. Although data from science may benefit farmers in Vondo, Phiphidi, Tshiondo, Levubu and Tshakuma, they hardly employed it due to a lack of (understanding) application. Scientific knowledge: According to Sraku-Lartey et al. [51], it is composed of organized, well-documented knowledge that is methodically delivered through lectures or courses. It is grounded in factual knowledge and free of sentiment and social attachment. The information gathered by the nearby farmers indicates that scientific knowledge is more trustworthy and applicable. Additionally, the daily weather report is clear and accurate.

Bvenura and Sivakumar [12] cited that rural households have traditionally depended on indigenous knowledge to provide food security. Local farmers can recognize many edible natural fruits, vegetables and roots, for example. They also know which crops to grow when and how to plant them, as well as when and how to harvest and preserve food to guarantee food security. Farmers in rural areas can also adopt methods of agriculture like mixed farming, intercropping and rain harvest for irrigation. Rankoana [48, 49] and Kom et al. [35] claim that even before conventional agriculture was introduced, agriculture based on IK ensured the production of a range of foods by employing mixed farming system.

The practice of scientific modern farming necessitates the ideal combination of water, chemical inputs and sophisticated farm equipment (tractors, harvesters and threshers) with enhanced seed production. Without access to contemporary scientific knowledge, finance or external inputs, indigenous farmers cultivate their own crops based on their understanding of seasonal variations and environmental conditions [41].

The daily highest and lowest temperatures are highlighted in scientific weather information that is broadcast on radio and television. The anticipated percentage of rain is very important to the locals. Scientific knowledge can be easily obtained by the limited percentage of farmers who have access to the internet and technical equipment. Because scientific methods and applications are so inventive and sophisticated, they help local farms by offering chemical pest control options. There is no help for the farmers with pest management from indigenous knowledge. Precise and detailed information is given. It illustrates the various best practices for planting and harvesting.

Limitations of Indigenous Knowledge Systems Practices

Recognizing the magnitude and approach of adaptation decision-making exposes the disparate objectives of climate change adaptation that exist. These objectives will vary across different study areas, throughout communities, and, most importantly, across generations. In the context of IKS, there exist some potential challenges or limitations associated with relying solely on indigenous practices for food security and climate change adaptation. However, this section will briefly examine the challenges encountered by local farmers as they depend mainly on their traditional knowledge as an approach to adaptation to climate change and food security. The idea behind the paper is integrating indigenous knowledge into interventions related to climate change and food insecurity which could result in the creation of practical, affordable, sustainable and appropriate indigenous adaptation techniques [56]. The limitations of adaptation to climate change and food security, as techniques employed by indigenous knowledge, can only be comprehended in their contextual framework.

Local farmers acknowledged during focus group discussions that information gathered through indigenous knowledge is less predictable and untrustworthy in the district as predicting climate change for about two to five planting seasons is a challenge. Therefore, there is no assurance that predictions will come to pass or provide the desired outcomes. Traditional know-how offers limited solutions to mitigate the effects of climate change and food security. Indigenous knowledge has reportedly become less dependable and predictable in recent years [3]. It does not offer long-term solutions and techniques that farmers may apply to future challenges regarding food security. Some farmers believed that indigenous knowledge was unable to anticipate seasonal rainfall, even though many of the farmers in the area could utilize it to predict seasonal changes and rainfall activities during the season. As a result, they are unable to make informed judgments about food security and effectively adjust to climate change. Additionally, soil-related problems cannot be predicted or identified using indigenous knowledge. The indigenous farmers in Vhembe district are unable to identify pests and diseases, nor can they estimate the fertility of the soil. Because of all these elements, scientific information is now more reliable.

Also, elderly farmers living in the villages where the IK is utilized keep the majority of the information in their thoughts. Information is communicated and transferred through a variety of routes; it is not physically recorded or archived [3]. Examples of these include personal observations of the surroundings, social, religious or adaptation methods, food gatherings, storytelling between children and elders and the gathering of records in the form of drawings and photographs [56].

IK is site-specific, hence, to create localized policies and interventions; it is imperative to evaluate IK relevant to a local community. To optimize integration for end users, it is necessary to analyse its procedures, methods and results. Current indigenous knowledge needs to be improved by scientific information. By doing this, a forum for debate and discussion may be established where households can exchange knowledge about climate change. The significance of indigenous knowledge practices in efforts to adapt to climate change is revealed by some results. Farmers in the area have reported and experienced changes such as decreased precipitation, early cessation of rainfall, higher temperatures, more frequent droughts and shorter growing seasons, but their understanding of climate variability and change is inadequate. According to Olatokun and Ayandile [46], they cited that collaboration on information that is pertinent for successful adaptation action at the local level is being developed through collaboration between people with indigenous knowledge and scientific research. By doing this, a forum for debate and discussion may be established where residents can exchange knowledge about climate change and food security.

Conclusions

Indigenous households have been forced by vulnerability and lack of access to meteorological data to develop indigenous knowledge to forecast climate events and improve food security. Therefore, this study demonstrated how indigenous farmers play an essential role in food security, thanks to the indigenous knowledge systems employed on their farms for better crop preservation and post-harvest storage. Demographics and socioeconomic factors like gender, the age of the head of a household and the size of the household contribute to the ability of a household to apply IKS and the number of people available to undertake important farming and non-farming activities. Further, findings indicated IKS related to the preservation of soil fertility and soil moisture, crop rotation, mixed cropping, post-harvest storage and processing, and the ability of local farmers to make the application more traditional methods of weather prediction all contribute to enhancing food security in adverse conditions related to climate change.

Additionally, know-how on food security among indigenous people is low. From the above observations, this study proposes that using indigenous knowledge alone will not solve crop output shocks or food security issues. This acknowledgement has not, however, minimized the contribution made by contemporary scientific understanding. It is crucial to understand that the two complement one another in terms of their strengths and shortcomings. Thus, promoting a more symbiotic merge of contemporary systems with IKS will in this way provide for more efficient and sustainable food production within the Vhembe district.

A more active participation strategy aimed at fostering productive cooperation between farmers, scientists and other stakeholders is required. This will present an opportunity to assess farmers' traditional wisdom in the preparation for its later fusion with scientific understanding. For further research on sustainable soil management, it will be important to assess the material quality characteristics of soil health indicator plants grown by farmers as well as the corresponding soil health status of the sample locations.

The findings of the research identified that there is a need for policy changes in the South African agricultural sector. Indigenous knowledge of farming techniques has been disregarded. This study has demonstrated how indigenous knowledge practices support household food security by making it easier to get the resources needed to produce and preserve food for future consumption. However, to see the village shift from basic subsistence to self-sustaining food security, agricultural production must be raised because traditional farming methods have been considered as SDG 2 can be minimized.