The transition of small-scale coffee farming systems and new pathways for coffee production: A case study in the central highlands of Vietnam

The dynamics of agriculture in general and coffee farming systems need to be investigated to derive insights for policies and interventions to promote sustainable agriculture. Through a systematic approach, including historical and adaptive ones, the study aims to probe the spatial-temporal transition of coffee farming systems. We found evidence for the diverse adaptive capacity of the coffee farming systems in Dak Lak province in their response to various factors. Moreover, an economic comparison was made between coffee farming systems, including mono-coffee farms and coffee-based intercropped ones. The study showed that coffee-based intercropped farms yield higher returns than mono-cropping ones by productivity enhancement, land equity ratio, and gross margin. These findings provided empirical evidence to design appropriate policies for the sustainable development of coffee farming


Introduction
estimated that 84 per cent of farms are small (less than 2 ha), with around 570 million small farms globally. Smallholders face growing pressure on their livelihood, low prices in the world market and climate changes (FAO, 2018). Therefore, new pathways for sustainable agricultural development to obtain the target of global development policies are essential, especially in regions of limited farming land. For instance, agroforestry and diversification are strategies to mitigate risks and improve benefits (Lin, 2010;Niether et al., 2020;Byrareddy et al., 2021;Ricciardi et al., 2021).
Vietnam benefits from good climatic conditions to cultivate tropical perennial crops. During the last decade, the development of these crops dramatically accelerated, and Vietnam is presently the world's second-largest coffee producer (ICO, 2019). Coffee production in the central highlands accounts for ninety-seven per cent of Vietnam's coffee beans. Although perennial crops contribute to the socioeconomic development of Vietnam, considerable crop losses are mainly due to climate change, such as drought. For instance, in 2017, agricultural production from 152,000 ha was affected with direct losses of VND 6,004 billion (US$ 269 million) (Grosjean et al., 2016;World Bank, 2017).
According to Vietnam's guidelines, agricultural development needs to generate "more from less." Put differently; farming is oriented to create more economic value for farmers. Still, it uses fewer natural resources, human capital, and a smaller amount of harmful intermediate inputs to minimise the negative impact on the environment. Further growth must rely principally on increased efficiency, diversification, and innovation to take advantage of value addition. The Vietnamese Ministry of Agriculture and Rural Development (MARD) addresses economic efficiency while concerned with sustainability and environmental conservation. Eventually, in recent years, the national and local governments have contributed to the success of perennial crop sectors by implementing various policies that are considered to improve farmers' technical, economic, and environmental efficiency (Ho et al., 2021).
The coffee farming systems have considerably and successfully evolved in Dak Lak province over the years. Specifically, coffee has become an important income-generated crop for provincial farmers. Unfortunately, coffee production faces declining yields, high costs, low profits, and pests and diseases. Mono-coffee farming systems are highly susceptible to increasing temperatures and frequent droughts (Pham et al., 2020). In response, monocultures of coffee have been substituted with crop-diversified systems, where coffee is grown in a mixture with fruit, other perennial crops, or annual crops. The intercropping approach between coffee and other cash crops mostly appeals because it can deal with environmental and socio-economic problems, such as water loss reduction and coffee price volatility (Priess et al., 2007;Lin, 2010). For instance, the coffee intercropped with pepper system has more economic return than monocultures and is considered a new pathway for coffee production (Ho et al., 2017;Thuy et al., 2019a).
This study focused on the transition of coffee farming systems in the research site and conducted an economic comparison of these systems. Additionally, we seek alternative pathways for coffee farming systems in the province.

Study area
Coffee and other cash crops are widely grown in Dak Lak province. However, to ensure the province's representativeness in the coffee farming system, we chose three districts Cu M'gar, Cu Kuin and Buon Ma Thuot city, to conduct our survey (Fig. 1).

Data inventory
Qualitative and quantitative data collected from primary and secondary sources were used in this study. We applied the participatory methods and household surveys using a semi-structured questionnaire to collect the primary data regarding 32 mono-coffee and 30 coffee-pepper intercropping farms. We selected the secondary data from official sources, including publications by the General Statistics Office (GSO), the Dak Lak Statistics Office (DSO), historical books, maps, project reports, and annual reports in local departments.  Because farming systems, in transition, vary in adaptation approaches, we identified the periods of coffee farms based on types of activities reconstructing the coffee crop system. In contrast, changes in these activities connect with socioeconomic and political transformation. We followed Barral et al. (2012), Diepart and Allaverdian (2018), and Byrareddy et al. (2021) to use chronological, historical, and timeline event methods in spatial and temporal assessments. Moreover, the region can be divided into three zones through map-based visualisation and transect walks. The zone includes areas highly favourable for coffee farms with high fertility capacity (Zone 1-dark orange and orange sites), places that are moderately suitable for coffee growing (Zone 2-light orange sites) and locations that are unfavourable for coffee farms (Zone 3-purple sites). In each zone, we clarified the types of coffee farming systems.

Gross margin analysis
For each farming type, the gross margin of a given surveyed farm was calculated as follows FAO (2016).
Where Y i is the coffee and pepper production outputs (i = 1,2) of the farm, and P i is the farm-gate prices of coffee and pepper. The cost of production denoted by C is related to inputs (e.g., herbicides, fertilisers, pesticides, compost, hired labour, or energy).

Land equivalent ratio (LER)
LER is land productivity that compares the yields obtained by intercropping two or more crops and those obtained by growing one crop as pure systems. In this paper, we compared the yields of MCF and CPI (coffee agroforestry) to calculate LER.
The formula is LER = Σ (Y pi /Y mi ), with Y p being the yield of each crop (coffee and pepper) in the coffee agroforestry system. Y m is the yield of coffee in the coffee monoculture (Utomo et al., 2016). Following Mead and Willey (1980), LER is more than 1.0, indicating mixed systems are advantageous, whereas LER less than 1.0 shows the disadvantage of the hybrid system. The ratio is calculated to find the partial LER for each crop. Then the partial LERs are summed to give the total LER for the coffee and pepper intercropping. In a sense, the LER shows the intercrop interference levels in the coffee and pepper cropping system.

Results and discussion
The transitions in coffee farming systems in the study region Firstly, coffee farming systems in Dak Lak have undergone rapid development for decades (Phan et al., 2022). As a result, the dynamics and practices must be adjusted to suit agroecological and socioeconomic transformation. The transformation story of coffee farming systems can vary in system type, production location, farm size, and government support across space and in time.
Mainly, coffee farming systems were often large-scale and heavily dependent on natural resources such as favourable soils in the early development stage (Duong, 2016;Thuy, 2016). In other words, coffee monocultures were dominant before reunification in 1975. For instance, coffee areas, including companies and households, accounted 1,928 ha, while rubber area was only 135 ha (Duong, 2016). Coffee plantations were principally concentrated in the high-fertility region (Zone 1). Coffee underwent a quick expansion while other crops remained unchanged. During the colonial era, coffee crops were planted in Zone 1. In this period, the moderate soil fertility region (Zone 2) was only for growing annual crops such as maise, beans, and rice for food subsistence. Meanwhile, fallow and forest land covered a large area in the unsuitable region (Zone 3) (Duong, 2016;Thuy, 2016, Minot, 1998Doutriaux et al., 2008;DSO, 1986).

Prospects and new pathways to coffee farming systems
Although some studies showed that certified coffee farms have a better performance than noncertified farms (Ho et al., 2018;Hung Anh et al., 2019), the area and number of households under certified coffee production showed a declining trend in most cases (Table 2). Ho et al. (2018) showed that sustainability-certified coffee production does not help increase farmers' economic benefits or reduce negative environmental impacts.

Fig. 2. A chronological diagram of the local transect of the coffee farming systems in Dak Lak province (Source: Author's elaboration)
So it indicates a declining preference for coffee production under accredited schemes. As certificated production is not a favourable option for coffee growers, coffee-based intercropping is another direction for farmers, widely observed in the research site, dominated 19.3 per cent (with CBIS 39,100 ha). However, coffee and pepper intercropping held the leading position in CBIS, about 20,000 ha (Fig. 3).
Unlike annual crops, new pathways for coffee production should be built through gradual transformation. The authorities should carry out a master plan concerning coffee cultivation zones to reduce coffee's physical expansion and enhance cost-efficient production. In Zone 1 and Zone 2, the production of speciality coffee beans should be encouraged to increase competitiveness for more value addition (Dak Lak Provincial People's Committee, 2019b). In Zone 3 (soil of unsuitable or low fertility), there should be encouragement and enhancement measures to rejuvenate old coffee farms or transfer them to other crops. To facilitate this policy, the local government should expand access to financial services at a low-interest rate. Besides government involvement, it is essential to enlarge the role and participation of social organisations such as women, youth, and farmers' unions to create diverse credit sources. In addition, sustainability-certified coffee should be re-evaluated based on economic and environmental aspects.  Coffee growers are encouraged to employ a suitable certification in suitable locations to reduce ecological impacts, decrease production costs (e.g., irrigation costs), and improve households' income from by-products (timber, fruit) (Ho et al., 2018;Jezeer et al., 2018). Additionally, coffee farms should produce under agroforestry systems rationale because of the utility in providing ecosystem services, mainly when producing certified coffee (Pico-Mendoza et al., 2020). The government should pay more attention to quality certification for farms rather than quantity certification. Finally, coffee tourism could provide a potential additional market segment to maintain stability or improve livelihood and rural development in difficult economic situations.
For coffee-based intercropping, it is recommended that farmers and local authorities pay more attention to intercropped systems, especially coffee-based ones. Farmers should be encouraged to learn modern practices in contemporary production and management. They will reap benefits in saving costs, reducing environmental impacts, and identifying and treating pests and diseases. Consequently, in the coming years, farmers need to consider technical advice, optimised density and manage costs to boost crop productivity, increase the land utilisation ratio and enhance the benefits for second crops. In other words, farmers' perceptions and knowledge concerning the role of intercropping on farms need to be reinforced in future. Table 3 shows that CPI seems to be higher productivity than MCF. For instance, when CPI reached 2.3 tons of coffee and 1.8 tons of pepper per ha, MCF only obtained 2.1 tons of coffee per ha. It is the reason for the farmers to intercrop their coffee with pepper. However, CPI tends to have higher costs (C) than MCF, especially hired labour costs (VND 12 million in CPI compared with 3 VND million in MCF) (Table 3 and Fig. 6A). It could create some difficulties for no-financial assets or limited-financial households. Therefore, to reduce this cost (labour demands), the level of management of the plantation on CPI is always considered a future benefit for farmers. In addition, a loan with a low-interest rate from institutions such as banks  or agricultural insurance could be managed by the Vietnamese government to deposit it. CPI had more economic contribution than MCF concerning gross output (GO) and gross margin (GM) to farmers (Table 3 and Fig. 6 B, C). For instance, the GM of CPI had VND 102 million while MCF only had VND 43.4 million per ha. It will be offered to households having long-term credit. Additionally, previous studies supported that agroforestry creates more benefits than monocultures (Pham et al., 2018;Niether et al., 2020;Byrareddy et al., 2021;D'haeze, 2020). Thus, coffee agroforestry should be encouraged. In addition, it also suggested that farmers should be provided with market information, technical training, and management knowledge.

Land productivity for coffee cultivation
The land equity ratio (LER) of CPI was more significant than one, indicating that the CPI system was superior to the coffee monoculture. In the CPI model, the highest value of LER is 1.88 implies the area of MCF must increase by 88% to have an equivalent output of the CPI model (Table 4). Thus, CPI is a suitable option for farmers of limited land.

Conclusion
The study highlights the transition of smallscaled coffee farming systems during spatialtemporal scale and new pathways for coffee production. Coffee systems have been well adapted and transformed from monocultures to others, where coffee and pepper intercropping systems (CPI) have recently become typical in the research site. Moreover, this study compared the economic contribution between MCF and CPI. In detail, CPI creates higher productivity, LER, and GM than MCF. In other words, CPI seems like a high-inputhigh-output system, and farmers have been incentivised to gradually transit to CPI in recent years. However, some constraints, such as knowledge and loan constricting CPI expansion, should be considered. Therefore, farmers need to be supported by local authorities and institutions so that CPI can be an agroecological pathway for a coffee farming system in the province.  (2019)