The Development of Indigofera spp. as a Source of Natural Dyes to Increase Community Incomes on Timor Island, Indonesia

Abstract

A strategy that has the potential to contribute to the achievement of the targets established under SDG 8 (“Decent Work and Economic Growth”) involves the development of sustainable tourism to create productive job and livelihood opportunities and to promote local culture and products. In the province of East Nusa Tenggara (NTT), Indonesia, ikat weaving is an integral part of the cultural heritage of the region, with ikat characterized by unique design motives and the use of natural dyes. Unfortunately, in some areas, the use of natural dyes is diminishing as a result of competition with synthetic dyes and the limited availability of raw materials, particularly for the production of blue dye. The development of Indigofera spp. to produce natural, plant-based blue dye has significant potential to contribute to community incomes and employment. This study outlines a strategy for developing the use of Indigofera spp. as a natural dye and describes its potential for contributing to community incomes, especially on Timor Island, NTT. The study shows that weavers currently use indigo plants that grow naturally in gardens and yards. Although the community has a tradition of using these plants, informed by local wisdom, to develop the cultivation and processing of this plant through the application of the appropriate techniques, including innovative approaches to producing indigo paste, could enable the development of Indigofera spp. cultivation on a larger scale. The study shows that the availability of suitable land is high (±370 thousand ha), with 80% of the suitable land being categorized as critical. The study proposes a development based on the analysis of strengths, weaknesses, opportunities, and threats to assess the manner in which these opportunities could be leveraged with the support and participation of local communities and other stakeholders by leveraging the culture and wisdom of the community regarding the use of Indigofera spp.

1. Introduction

The province of East Nusa Tenggara (hereinafter referred to as NTT) has been in the top three poorest provinces in Indonesia (Beneditus Dalupe 2020; Wiryanta 2007). The livelihoods of the people of NTT still depend on natural resources, 48,7% obtained from agriculture, forestry, and fisheries, while 34% from the service sector. Likewise, on Timor Island, 40.35% of the people depend on natural resources for their livelihoods in agriculture, forestry, and fisheries (BPS Provinsi NTT 2021). However, NTT has creative economic potential through the culture-based tourism industry. With the increasing importance of achieving the Sustainable Development Goals (SDGs) in various situations, tourism can play an important role in achieving goal number 8 of the 17 SDGs (UNWTO and UNDP 2017; Dahles et al. 2020; Scheyvens and Hughes 2019; Westoby et al. 2021).

Tourism, if implemented sustainably, seeks to balance the three pillars, namely economy, society, and the environment (Saarinen 2018; Sharpley 2020; Westoby et al. 2021). Although not always evenly distributed, tourism can increase income for many local people (Nugroho and Numata 2020). The expansion of cultural tourism towards intangible cultural heritage and contemporary culture has created more attention for the increased integration between tourism and the creative economy (Richards 2018).

The famous cultural product of the NTT community is ikat weaving (Amaral and Ikat 2019; Bessie et al. 2021; Dioh 2020; Luik et al. 2021; Wangge 2021), which is a hereditary culture from the ancestors of the NTT people with diverse geometric patterns (Windiyarti 2006; Hartono 2010; Tas’au 2016). The making of ikat is considered as a woman’s activity; a tradition passed down from mothers to their daughters (Sulaiman and Anita 2020). Ikat is family property that has a high value as a symbol of social, religious, cultural, and economic status (Elvida 2015; Wangge 2021).

Ikat reflects the identity of the different ethnic groups in NTT, with each group having a different style (Susilawati 2010), such as representations of animals (Sumba Island), leaves (Rote Island), silk and embroidery weaving (Timor Island), and warp ikat weaving (Alor Islands) (Salma et al. 2018; Sulayman et al. 2017), also colors that differ widely from those found elsewhere in the archipelago (Dioh 2020) due to the use of natural dyes in its production (Ledoh et al. 2021; Murniati and Takandjandji 2015; Nomleni et al. 2019; Sabuna and Nomleni 2020).

Colored dyes are produced from colored plants (flowers, fruit, seeds, leaves, wood, bark, roots, and other parts), animals (insects that produce red and purple colors), and minerals (metals, metal salts, and oxides, red ocher) (Elsahida et al. 2019). Indigofera tinctoria L. is one of the plants used as a black and blue dye for yarn for making ikat by the community of NTT (Setiawan and Suwarningdyah 2014).

Indigofera species comprise mainly herbs, perennial or annual, shrubs or small-sized trees, distributed in forests, savannas, and disturbed areas (Marquiafável et al. 2009; Gerometta et al. 2020). The lifespan of Indigofera tinctoria L. as a dye producer is 2–3 years (Kurniawan 2020; Ariyanti and Asbur 2018), whereas if it only functions as a land cover it is 1.5–2 years (Kurniawan 2020).

The genus Indigofera, the third-largest in the family Fabaceae, consists of almost 800 species (Prabhu and Bhute 2015; Schrire 2013). However, tropical and subtropical zones are areas in the world where indigo natural plant dyes are widely found (Su et al. 2008; Prabhu and Bhute 2015). The distribution of this species is in Africa and Madagascar, the Sino-Himalayan region, Australia, and Central and South America (Schrire 2013), and a small portion can be found in temperate areas of East Asia (Ponmari et al. 2014).

Several species in the genus Indigofera are known to produce economically valuable indigo dye (Schrire 2013), such as I. tinctoria L. and I. suffruticosa (Marquiafável et al. 2009). This species is also an important prairie legume (Schrire 2013), with many benefits, such as an ornamental plant, soil cover, shade plant, green humus cover, and erosion control (Marquiafável et al. 2009). They are also used for their medicinal properties (Prakash et al. 2007; Renukadevi and Sultana 2011; Santos et al. 2015; Vieira et al. 2007).

Indigo has been used as a natural textile dye since before synthetic dyes were invented. Indigo extraction from Indigofera plants (I. tinctoria L.) started in India, Egypt, and China and then spread to other tropical countries, including Indonesia, while indigo in sThuringia (Europe) came from the woad plant (Isatis tinctoria L.). Indigo extracted from I. tinctoria L. has a better level of color quality than indigo extracted from Isatis tinctoria L., so the European textile industry began to import indigo from India and Indonesia (Głowacki et al. 2012). The development of natural dyes fluctuated with the fame of Indigofera in Indonesia, which was recorded in 1918–1925. The highest export value occurred in 1921, reaching 69,777 kg dry weight (Heyne 1987).

Natural indigo dye is slowly being replaced by synthetic indigo, and in 1913, the indigo dye used for textile purposes was derived from synthetic indigo (Séquin-Prey 1981; Głowacki et al. 2012). At present, an increasingly large proportion of weavers use synthetic blue dyes, as these dyes are relatively low cost, durable, and readily available, thus resulting in increased efficiency in the manufacturing process (Haji 2010; Indraningsih and Darsih 2013). The use of natural dyes is generally considered less practical, given that the quality of the product is uneven and that the dyes cannot be stored for long periods of time (Samadara 2018). Along with increasing public awareness of the dangers posed by using synthetic dyes, people are returning to using natural dyes that are more environmentally friendly (Angelini et al. 1997; Muzzazinah 2019).

In Indonesia, indigo paste production fluctuates from year to year. Thus far, domestic needs of indigo paste have not been optimally met because there is no industry specifically producing it. Furthermore, the production of indigo paste has only been supplied by household-scale producers in which the raw materials rely on wild or uncultivated plants (Kurniawan 2020).

While 18 species of Indigofera spp. are found throughout Indonesia, only six species can be used to produce natural dyes (Muzzazinah 2016). Several of these species, including I. suffruticosa Mill. and I. tinctoria L., are distributed across the Island of Timor in NTT (Agustarini et al. 2021). The morphology of Indigofera, which grows in the NTT region with its dry area, produces different colors than the same type that grows in Java and Madura (Muzzazinah et al. 2018).

The climate and land of NTT are dry, and most land is not very fertile. The grassland is mainly suitable for animal husbandry and dryland farming (Kwong and Ronnås 2011). This contributes to low economic growth and a limited role in adding gross value (Saragih 2007). The agricultural activities in NTT need to be more market-focused agribusiness. Based on the market potency of indigo as natural dyes, I. tinctoria L. and I. suffruticosa as agricultural commodities could be developed to support cultural tourism.

This paper shows the result of a series of activities conducted on Timor Island on (i) the evaluation of the use of natural dyes on Timor Island; (ii) the identification of best practice cultivation techniques for Indigofera spp.; (iii) socializing the leaf-processing technologies that enable the production of indigo paste for use as dyes; (iv) land suitability analysis for the cultivation of Indigofera spp.; and (v) economic analysis to determine the viability of the cultivation and utilization of Indigofera spp. as a raw material for the production of natural dye. It is hoped that this study will enable the identification of optimal strategies for the development of Indigofera spp. to produce natural dyes on a wide scale and thereby facilitate the achievement of targets established under SDG 8.

2. Methodology

2.1. Research Locations

The research was conducted in an area of Timor Island, Indonesia, that has a long community tradition of weaving, as shown in Figure 1. Timor is the largest island in NTT (>30% of NTT area), covering an area of ±2.9 million ha, with this divided into Indonesian territory (±50%) and the independent nation of Timor Leste (±50%). The research focused only on the part of the island that is Indonesian territory. Geographically, it is located at coordinates 8°19′17.9″ S–10°22′12.9″ S and 123°27′24.0″ E–127°18′06.2″ E. The research was conducted over the period from March 2019 to August 2021.

Timor Island lies at an altitude of 14–1480 m above sea level, with a land slope of about 16%. The soil predominantly consists of inceptisol, which is formed from limestone (sedimentary rock). The air temperature on Timor Island ranges from 24.4 to 33.0 °C, with air humidity levels ranging from 77% to 79% (BPS Provinsi NTT 2021). According to the Schmidt-Ferguson climate classification system, Timor Island can be categorized either as moderately dry or dry (E and F), with relatively long dry seasons (Andrianyta and Hermawan 2017). On average, 6 to 7 months of the year can be categorized as wet, while 5 to 6 months can be categorized as dry. The number of rainy days ranges from 91 to 92, with the amount of annual rainfall ranging from 1211 to 1242 mm year⁻¹ (BPS Provinsi NTT 2021).

2.2. Research Methods

2.2.1. Evaluation of Community Cultivation and Utilization of Indigofera spp.

An evaluation of community cultivation of Indigofera spp. was conducted first through a survey of the literature, followed by interviews with members of weaving communities and other stakeholders. Community data was collected in three villages in the district of Timor Tengah Selatan (TTS) on Timor Island, these being Fatumnasi, Bosen, and Oel Ekam. The informants were selected using purposive sampling techniques (Rai and Thapa 2015) according to the research objectives. In-depth interviews were conducted on 3 farmer groups, each consisting of 25 people. The purpose of gauging their knowledge regarding Indigofera spp. and other dyes used, their history of using Indigofera spp., the manner in which they produced and utilized natural dyes, the extent to which they had received training or other support from related institutions, and the degree to which they were interested in cultivating Indigofera spp. to make indigo paste. These interviews were conducted on July 2019.

2.2.2. Techniques for the Cultivation of Indigofera spp.

After the evaluation, the patterns of the community utilization of Indigofera spp. were compared with the techniques for its cultivation. The cultivation techniques were examined by observing demonstration plots established by farmer groups in the village of Bosen (North Mollo subdistrict, TTS). The plots were located on a relatively flat area, at an altitude of 600–900 m asl, with a slope of 3–8%. With regards to climatic conditions, the demonstration plots received an average annual rainfall of 1000–1500 mm, with an average temperature of ±21–24 °C, and a maximum temperature of ±27–30 °C. The experimental cultivation techniques conducted on these demonstration plots included three main stages, these being: (i) germination, (ii) seeding, and (iii) planting.

(i)

Germination: The germination technique applied for the cultivation of I. tinctoria L. involved an experiment that utilized a Completely Randomized Design with two different types of treatment, involving seed scarification and planting media, respectively. The seed scarification treatments involved soaking the seeds in cold water for 24 h; soaking them in pure coconut water (100%) for 30 min; or without scarification treatment (control). In terms of planting media, three different treatments were applied, with the seeds sown in a planting medium consisting of: soil; sand; and a mixture of sandy soil (1:1). Thus, the experiment involved nine treatment combinations, with each treatment combination being repeated three times and with each replication consisting of 50 seeds, so the total number of seeds used for all the treatment combinations was 1350 seeds. The parameter observed was the percentage of seeds that germinated.

(ii)

Seedling: The experiment was conducted in I. tinctoria L. nurseries using a Divided Plot Design, with shade level treatment as the main plot and nursery media as a subplot. Three different shade levels were investigated (0%, 50%, and 70%), with four different types of media, these being soil; soil mixed media + cocopeat (1:1); soil mixed media + rice husk charcoal (1:2); and mixed media soil + cocopeat + rice husk charcoal (1:2:2). At each shade level, the different media treatments were repeated six times, with 15 seedlings in each case, with the total number of units at 90 seedlings. The parameters measured were: seedling height and diameter; number of stalks; number of leaves; survival rate; dry weight; Top:Root (TR) ratio; and Seed Quality Index (SQI).

(iii)

Planting: The I. suffruticosa Mill. were planted on an area with a slope gradient of about 15%. The field experiment was conducted using a split-plot design, with spacing as the main plot and with the application of manure as the subplot. The main plot consisted of three different spacings between plants, these being 50 × 50 cm; 75 × 75 cm; and 100 × 100 cm. In the subplot involving the application of manure, three different levels were applied: no fertilizer (control), 100, 150, and 200 g per tree. Each fertilization treatment was repeated three times, with 16 seedlings in each case. The parameters that were observed included the survival rate, plant height, and the diameter and number of branches.

2.2.3. Techniques for Processing Indigofera Leaves to Produce Indigo Paste

The processing of Indigofera leaves to produce indigo paste begins with harvesting the leaves. Harvesting takes place 4–5 months after planting when the tree is producing mature brown fruits and bluish green leaves. The best time to conduct the harvesting process, which commences with pruning the leaves at the lower section of the plant (10–15 cm from the bottom), is in the morning or late afternoon. An evaluation was also conducted to compare the community’s utilization of Indigofera with the application of leaf processing to produce indigo paste.

The processing of Indigofera leaves to produce natural dyes takes place in three stages, these being: the fermentation process; the oxidation or stirring process; and the indigo paste precipitation process. The fermentation process involves soaking the fresh leaves of the Indigofera plant in water, with the soaking time depending on the treatment. The oxidation process involves stirring and aerating the water in which the leaves of Indigofera were soaked, with the addition of some slaked lime (Ca(OH)₂), by gradually drawing the solution into the air to facilitate the oxidation process, at which point the color of the foam solution turns blue. The indigo paste precipitation process involves storing the indigo solution at room temperature for 24 h so that the indigo paste settles. Thus, the processing of Indigofera leaves involves the production of a paste by soaking the leaves and adding slaked lime.

2.2.4. Potential Cultivation Area of Indigofera spp. on the Island of Timor Island, Indonesia

An assessment of the suitability and availability of land for cultivation of Indigofera spp. was conducted through an analysis facilitated by the geographic information system (GIS), with the analysis utilizing an Analytical Hierarchy Process (AHP) facilitated by Open-source sofware QGIS Desktop version 3.14 and Superdecision version 2.10, free educational software by The Creative Decisions Foundation(Pittsburgh, PA, US). The weight of the criteria was determined on the basis of the AHP, with this weight then being applied to a weighted overlay in the GIS model. This multi-criteria method has been widely used to assess the suitability of land for the production of agricultural commodities (Kumar and Jhariya 2015; Mighty 2015; Widiatmaka 2016).

The land suitability criteria that were applied was consistent with the criteria developed by Indonesia’s Ministry of Agriculture in 2011, according to the biophysical characteristics of the demonstration plots. Three different land suitability parameters were applied, these being parameters related to: soil (Texture, pH, CEC, C-org); topography (slope class and elevation class); and climate parameters (rainfall, average temperature, and maximum temperature). Data related to the soil parameter were based on the Digital Soil Map of The World (Food and Agriculture Organization of the United Nations 2003), with data related to elevation and slope processed on the basis of SRTM imagery with 90 m spatial resolution: http://srtm.csi.cgiar.org/ (accessed on 28 September 2021); data related to climate were based on world climate data: https://www.worldclim.org/ (accessed on 28 September 2021); and data related to administrative boundaries were based on Global administrative area: https://gadm.org/ (accessed on 28 September 2021). Data related to land cover, critical land, and land function status were based on the MoEF-Indonesia map product. Land function status related to the status of the land is in forest land/forest state or outside (Other Use Area (Areal Penggunaan Lain, APL)). The Indonesian Ministry of Environment and Forestry (MoEF) applies Consensus-Based Forest Land-Use Planning (Tata Guna Hutan Kesepakatan; TGHK) to establish the forest estate and designate its use. The TGHK mapping program classified forest land (kawasan hutan) by functions: (1) protection forest; (2) conservation forest; (3) limited production forest; (4) production forest for commercial logging; and (5) conversion forest for conversion of degraded production forest to agriculture or other uses. The area outside the forest land is then referred to as APL, where this area is intended for cultivation activities, settlements, and other activities; they are public lands that are not designated as Forest Area (Brockhaus et al. 2012). Critical land referred to in this paper refers to a map of critical land created by MoEF, Indonesia. Critical land is the land inside and outside forest areas that have been degraded, resulting in the loss or reduction of ecological function to the specified or expected limit. Its determination is based on the criteria of land cover, slope, hazard level of erosion, productivity, and management (Ministry of Environment and Forestry 2013; Ministry of Environment and Forestry 2018). This is shown in Figure S1 (Steps for Indigofera Land Suitability—Land Availability Analysis).

2.2.5. Economic Analysis of Indigofera Development

Indigofera is cultivated through intercropping systems. To determine the added value derived from Indigofera in terms of contributions to community incomes, the analysis only takes into account the economic value of the Indigofera. The economic analysis included a feasibility analysis for the exploitation of indigo paste, a sensitivity analysis, and the calculation of the economic and social potential to be derived from the development of Indigofera spp.

Feasibility Analysis

The scope of the financial feasibility analysis for the commercial production of indigo paste covers all processes, from the cultivation of Indigofera leaves to the treatment of these leaves to produce indigo paste. In this analysis, the cost assessment covers only the operational costs, both fixed costs and variable costs, without any investment costs. Paste-making activities are carried out on a household scale so that it does not require infrastructure facilities that are categorized as investment costs, such as building houses or making soaking tubs.

The wages in the cost assessment is based on the local community wage standard, IDR 65,000 per labor day. This daily wages rate does not differ between woman and man, and type of work. The nature of Indigofera development on Timor Island is a home industry, and the labor was unpaid as they are family members. Wage value is used for analysis purposes only.

Income assessment is carried out by measuring the productivity of Indigofera per ha, then processed into a paste by calculating the yield based on research results of (Agustarini et al. 2021). The analysis of the price of the final product was based on an investigation of the selling price for indigo paste ins the marketplace (Shopee n.d.).

A number of different criteria are commonly used to assess business feasibility, including the following: Net Present Value (NPV), Internal Rate of Return (IRR), Net Benefit Cost Ratio (Net B/C Ratio), and Pay Back Period (PBP) (Nurmalina et al. 2018).

• Net Present Value (NPV)

$$\mathrm{NPV}={{\displaystyle \sum }}_{\mathrm{t}=0}^{\mathrm{n}}\frac{\mathrm{Bt}-\mathrm{Ct}}{{\left(1+\mathrm{i}\right)}^{\mathrm{t}}}$$

(1)

Notes:

• NPV = Net Present Value (IDR)
• Bt and Ct are the benefits and cost, t is the year in a series ranging from 1 to n, and i is the discount rate.

• Internal Rate of Return (IRR)

$$\mathrm{IRR}={\mathrm{i}}_1+\frac{{\mathrm{NPV}}_1}{{\mathrm{NPV}}_1-{\mathrm{NPV}}_2}\times \left({\mathrm{i}}_1-{\mathrm{i}}_2\right)$$

(2)

Notes:

• IRR = Internal Rate of Return
• i₁ = interest rate that results in a positive NPV
• i₂ = interest rate that results in a negative NPV
• NPV₁ = positive NPV
• NPV₂ = negative NPV

• Net Benefit Cost Ratio (Net B/C Ratio)

$$\mathrm{Net}\frac{\mathrm{B}}{\mathrm{C}}=\frac{{{\displaystyle \sum }}_{\mathrm{t}=1}^{\mathrm{n}}\frac{\mathrm{Bt}-\mathrm{Ct}}{{\left(1+\mathrm{i}\right)}^{\mathrm{t}}}}{{{\displaystyle \sum }}_{\mathrm{t}=1}^{\mathrm{n}}\frac{\mathrm{Bt}-\mathrm{Ct}}{{\left(1+\mathrm{i}\right)}^{\mathrm{t}}}},\frac{\mathrm{Bt}-\mathrm{Ct}>0}{\mathrm{Bt}-\mathrm{Ct}<0\mathrm{s}}$$

(3)

Notes:

• Net B/C = Net Benefit Cost Ratio
• Bt and Ct are the benefits and cost, t is the year in a series ranging from 1 to n, and i is the discount rate.

Pay Back Period refers to the period or time (years) that it takes for the investment to yield a positive return, indicated when the NPV value becomes positive. A business may be deemed financially feasible if NPV > 1, BCR > 1, and the IRR analytic interest rate and PBP are in the business cycle (Tiwa 2016).

Sensitivity Analysis

A risk model sensitivity analysis can be used to identify the most significant risk factors and to assist in developing priorities for risk mitigation (Frey and Patil 2002). According to (Kumar and Parikh 2001), climatic conditions greatly impact agricultural yields. Climatic anomalies, including those associated with La Nina and El Nino, can affect agricultural productivity. This is one of the factors that need to be considered in conducting a sensitivity analysis. Production costs and changes in the level of productivity of Indigofera spp. are parameters that are determined by prevailing conditions.

The Potential Economic and Social Value of the Development of Indigofera

Economic value is determined on the basis of the net profit value per hectare multiplied by the size of the area deemed to be most suitable (S1) for Indigofera cultivation, with three development target scenarios: 100% planted area (scenario 1); 50% planted area (scenario 2); and 25% planted area (scenario 3). Social value is determined on the basis of the rate of labor absorption associated with the development of Indigofera spp.

$$\mathrm{potential}\mathrm{income}=\mathrm{net}\mathrm{profit}\mathrm{value}\times \mathrm{land}\mathrm{deemed}\mathrm{suitable}\mathrm{for}\mathrm{the}\mathrm{cultivation}\mathrm{of} Indigofera \mathrm{spp}.$$

(4)

2.2.6. Development Strategy for the Sustainable Utilization of Indigofera to Produce Natural Dye

Analysis of the strategy for the development of Indigofera was conducted through the application of a SWOT-AHP analysis to the descriptive data. This method has previously been used to formulate agricultural and manufacturing product development strategies for a number of commodities (Ali et al. 2021; Santos et al. 2019; Görener et al. 2012; Kazemi et al. 2018).

The analysis is conducted through the systematic identification of both internal factors, including strengths and weaknesses, and external factors, including opportunities and threats. The SWOT analysis is conducted in a number of stages, including: compiling the Internal Strategic Factors Analysis Summary (IFAS) and External Strategic Factors Analysis Summary (EFAS); analyzing the Internal Factor Evaluation (IFE) Matrix and External Factor Evaluation (EFE) Matrix; and analyzing the Strategy Matrix. Factor weights were determined on the basis of pairwise comparisons between factors using the Analytical Hierarchy Process (AHP). AHP is a mathematical method for multi-criteria decision making developed by (Saaty 2008).

3. Results and Discussion

3.1. Evaluation of the Cultivation and Utilization of Indigofera spp.

Plant materials used for the production of colored dyes, especially I. tinctoria L. and Morinda citrifolia L., are collected from nature directly, either by the artisans themselves or by professional collectors (Setiawan and Suwarningdyah 2014). The collection of these plants is informed by different bodies of local wisdom. In Atambua, weavers believe that there is a strong spiritual dimension to the relationship between humans and nature so that they only collect enough plant materials to meet the needs of the producing household income (Siombo 2019). In general, weavers use naturally-growing Indigofera spp. grown in their gardens without any intensive cultivations to meet the production needs of the dye’s raw materials (Seran and Hana 2018; Agustarini et al. 2021; Murniati and Takandjandji 2015).

Based on information from weavers in the research location, there are two species of Indigofera spp. in the region, these being I. suffruticosa Mill. and I. tinctoria L. (Agustarini et al. 2021). They explained that the species of Indigofera used produces a particular type of fruit (I. suffruticosa Mill.), as this type is more commonly found in gardens than I. tinctoria L. Users of Indigofera as a natural dye on Timor Island are weavers who are still on a household scale, so they only rely on plants that exist in nature. However, if in the future the industry becomes more developed to support cultural tourism, it is necessary to use cultivation.

The results of interviews with respondents indicate that the community is more familiar with Indigofera for use to produce black dye rather than blue, a finding supported by two other studies (Ledoh et al. 2021; Nomleni et al. 2019). The black color is obtained by mixing clay with Indigofera spp. and applying it to the thread. In this area, a synthetic dye is used for blue. Regarding the composition of the raw materials, they produce the dyes based on their needs and their available equipment. Usually, natural dyes are applied directly to the yarn after they are produced, without any attempts to store them.

The people of Timor Island, NTT, rely mainly on farming or animal husbandry for their livelihood. However, ikat weaving is another livelihood that is no less important. The activity of making ikat has been integrated with the daily activities of the community, especially the women (Buni et al. 2021). In the past, weaving was an activity for leisure time. Nowadays, along with the development of cultural tourism, ikat weaving has became a profitable source of income (Samadara 2018).

Women are more dominant in the activity of making ikat, which can be seen from the composition of weaver respondents, with a composition of 65% of women and 35% of men (

Table 1. Respondent information in three (3) research locations.

Farmers Group	Location	Gender Proportion of Group Members (%)
		Woman	Man
Eno Saenman	Fatumnasi	68.4	31.6
Pahlawan	Bosen	47.1	52.9
Paloilmonit	Oel Ekam	75.0	25.0
Average		65.5	34.5

). This is supported by the myth that developed in the community, especially in terms of processing Indigofera as a paste. There is a strict taboo forbidding men from being directly involved in producing dye from Indigofera, with a belief that those who violate that taboo will be cursed with infertility (personal communication with Marthen Tualaka, member of Farmer Group in Bosen Village, North Mollo, TTS District on 28 March 2019). Therefore, women dominate the process of manufacturing natural dyes from Indigofera, whereas men are more involved in the cultivation of Indigofera.

The main job of the head of the family is generally as a farmer whose sources of income are very small and also depend on the seasons. In general, the role of the women economically adds to the family’s income. However, based on the study of (Buni et al. 2021) in Sumba shows that the contribution of women’s income to the weaving business and animal rearing is household income is very large, equal to 88%.

Training on the use of Indigofera as a natural blue dye is still rarely done. Thread of Life, a social enterprise that promotes the community-scale production of textiles using traditional materials and techniques as a means of achieving poverty alleviation, has made efforts to introduce the use of Indigofera in producing natural blue dye. In 2016, the organization conducted training programs and other forms of assistance to enable local communities to produce indigo paste from Indigofera with this training. It is expected that there will be an uptake in the use of Indigofera to produce good-quality and highly durable blue dye. Thread of Life could also play a role in facilitating access to markets for the indigo paste and the ikat that is produced by the community using natural dyes.

The community has responded to these initiatives positively, being open to receiving information and guidance and expressing enthusiasm for cultivating Indigofera spp. and the manufacturing of indigo paste. However, ongoing training and assistance will be needed to enable the community to produce indigo paste that meets market requirements. It is expected that these investments in community capacity building will produce positive impacts and benefits for all stakeholders involved in the cultivation and utilization of Indigofera spp. and for communities more generally.

3.2. Techniques for the Cultivation of Indigofera spp.

The system used to cultivate Indigofera spp. was similar to one applied in the Philippines (Mann and Garrity 1994). Indigofera spp. is never cultivated in monoculture systems but is always intercropped with other food-producing and/or commercial crops, including maize, green beans, and tobacco. It has been suggested that the cultivation of Indigofera spp. in multi-crop systems would reduce the need for chemical fertilizers (Garrity et al. 1994). Given that Indigofera spp. is a type of legume, intercropping with this plant could play a positive role in the nitrogen fixation process (Nezomba et al. 2008).

These techniques for the cultivation of Indigofera spp. could be adjusted to meet the needs of members of local communities on Timor Island on the basis of considerations related to the availability of land and applied where intercropping systems are in place for the cultivation of seasonal crops (maize), with the spacing between the plants adjusted in accordance with the conditions required for this system. In general, farmers on Timor Island plant maize with a distance between plants of 75 × 75 cm, although on dry land, the optimal spacing for maize is 100 × 50 cm (Arifin and Tafakresnanto 2019). For the cultivation of Indigofera spp., distances between plants of 100 × 100 cm are applied, intercropped with maize (with a spacing of 100 × 50 cm) (Figure 2).

The techniques applied by the community for the cultivation of Indigofera spp. cultivation technique involved a number of stages, from germination to seeding and planting in the field. At each of these stages, the results of the research were applied, with the following identified as the best practice techniques for cultivation:

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Germination. Indigofera seeds are characterized by external dormancy, as is the case with other types of legumes. Thus, they need to be subjected to a process of scarification to overcome this dormancy, with scarification achieved through immersion (Luna et al. 2009). The results of the research demonstrate that the combination of scarification and sowing media had no significant effect on the germination of I. tinctoria L. The treatment that had the greatest impact on germination was the sowing media. The three treatments that have the greatest impact on the germination of the I. tinctoria L. were without scarification (control), soaking in cold water for 24 h, and soaking in pure coconut water (100%) for 30 min. These treatments resulted in the highest germination rates in sand media, at 73.33%, 77.33%, and 88.00%, respectively (Table S1). By contrast, seeds sown on soil media and on a mixture of soil and sand produced a germination rate below 50%. This indicates that sand is a suitable medium for sowing I. tinctoria L. seeds. Even though the sand medium is poor in nutrients, according to (Wiryanta 2007), sand contains a number of minerals essential for the plants’ growth. In addition, the porosity of the sand media enables imbibition and adequate aeration, enabling the seeds to germinate rapidly.

▪

Seedling. Based on experience on Timor Island, planting Indigofera directly from seeds in the field without going through a nursery will cause delays in leaf harvesting. Planting using seedlings will harvest at the age of 4 months while using direct seedings when the plant is one year old. The successful growth of the plants is heavily dependent on the quality of the seeds, with the quality of the seeds being determined by the media used in the nursery. Therefore, mixed media with a sufficient level of nutrients and porosity results in the production of high–quality seeds. In addition, according to (Fredrick et al. 2020; Onyekwelu et al. 2012; Veloso et al. 2017), light intensity is another environmental factor that affects the survival and growth rates of seedlings with each plant species requiring a different light intensity for growth. Research shows that I. tinctoria L. seedlings planted in a mixed media consisting of soil, cocopeat, and rice husk charcoal (1:2:2) and placed in an unshaded location (0%) had the highest TR ratio and SQI, namely 5.53 and 0.0030, respectively (Table S2).

The high TR ratio indicates that the media used is relatively fertile and that sufficient water is available (Orpa et al. 2019). According to (Rivai et al. 2015), rice husk charcoal has good aeration and drainage properties but low water holding capacity, while coco peat has both high porosity and water holding capacity. Mixing these two media with soil produces an ideal medium for the growth of I. tinctoria L. seedlings, particularly in an unshaded location (0% shade). By contrast, I. tinctoria L. seedlings planted in a mixture of soil and rice husk charcoal (1:2) and placed in 50% shade resulted in a seed quality index of 0.0030, but with a lower shoot to root ratio value (4.72). According to (Orpa et al. 2019), the low value of the root to shoot ratio indicates that the rate of the growth of shoots is lower than that for roots. This indicates that the level of nutrients contained in the mixed soil and rice husk charcoal media is lower than in the mixed soil, cocopeat, and rice husk charcoal media so that plants concentrate on forming roots to optimize nutrient absorption. Both types of media and shade treatment combinations also produced a relatively high biomass compared to other treatments, at 0.0768 and 0.0798 g, respectively. According to (Orpa et al. 2019), the increase in biomass indicates that photosynthesis is proceeding well, thereby resulting in increased plant growth. This is presumably due to an improvement to the growth media resulting from the addition of rice compost charcoal and/or cocopeat, with an increased soil nutrient content and improved aeration and drainage. However, both types of media require different light intensities to promote optimal seedling growth.

At three weeks of age, the I. tinctoria L. seedlings did not meet the criteria for transferring seedlings to the field, with the quality index value of the seeds failing to reach 0.09 (Bogidarwanti and Darwo 2016), with a minimum SQI value of 0.09 required to ensure a high survival rate. According to (Ariyanti and Asbur 2018), I. tinctoria L. seedlings are ready to be planted in the field at the age of 4–6 weeks, while I. suffruticosa Mill. seedlings are ready at around the age of 6–8 weeks or when the minimum seedling height is 30 cm. The use of ready-to-plant seeds may result in seedlings that are able to compete with those growing in a natural environment, where environmental factors cannot be fully controlled.

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Planting. The viability of I. suffruticosa Mill. plants up to the age of 4 months stood at 100% for all spacings, with the results of the research showing that the spacing treatment and the application of fertilizers did not significantly affect the growth of Indigofera spp. at 4 months of age. However, I. suffruticosa Mill. planted at a spacing of 100 × 100 cm showed better growth than the plants spaced at 75 × 75 cm and 50 × 50 cm. The average increase in height, diameter, and branch of I. suffruticosa Mill. planted at a spacing of 100 × 100 cm stood at 25.87 cm, 3.26 mm, and 6.44, respectively (Table S3). According to (Li et al. 2019), plant spacing has an effect on the final yield of a range of different types of plants. Likewise, (Azam-Ali and Squire 2002) reported that plant density depends on the soil, climate, and the type of plant grown. In extreme conditions, with poor soil and in semi-arid areas without irrigation, planting is best conducted at low density to avoid the growth of weak, weedy plants. Not only do these extreme conditions result in low yields; they also create ideal conditions for pests and diseases. With the different fertilizer treatments, the results of the analysis show that fertilizer dose sizes did not result in a significant difference in growth rates but that the application of fertilizer (100, 150, and 200 g per plant) resulted in better growth in diameter and number of branches than in the case of plants planted without fertilizer (0 g plant⁻¹). Similarly, the results of a study conducted by (Setiono and Azwarta 2020) show that the application of cow manure had a significant effect on plant height, stem diameter, number of leaves, and net weight of cobs per plant in maize, with the best results produced with 600 g of fertilizer per plant. This indicates that the soil at the study site required the addition of the appropriate amount of nutrients to facilitate growth, with the application of manure as a basic fertilizer at the beginning of the planting process adding macronutrients and some micronutrients required for plant growth, as well as improving soil structure, aggregating water holding capacity, and increasing soil permeability and the exchange of cations. Found in the study (Nyakpa et al. 2008) manure, as an organic fertilizer, plays an important role in the growth of plants due to its positive effects on the physical and chemical properties of the media. Manure can increase the media’s capacity to absorb water and improve the living conditions of the microorganisms in the media, stimulating granulation and enabling available nutrient ions to trigger cell wall growth, resulting in increases to the size of the stem diameter.

The results of the research showed that the most significant factor in the cultivation of Indigofera in TTS is planting time, with the planting time having a strong effect on the leaf production of Indigofera. According to (Ariyanti and Asbur 2018), the optimal time to plant Indigofera is at the beginning of the rainy season. Therefore, the recommended time to plant Indigofera on Timor Island is in November, which receives high rainfall.

Planting at this time results in optimal growth and high leaf production. By the time of the arrival of the dry season, the plants have adapted to the environment, so there is no need for watering. However, in cases where the dry season occurs earlier than forecast, watering may be required. Under normal conditions, Indigofera leaves can be harvested four months after planting.

Indigofera plants are productive for about 2–4 years, depending on the species and growing location. For example, the life cycle of Indigofera tinctoria L. on Java Island is 2–3 years (Kurniawan 2020; Ariyanti and Asbur 2018). The development cycle for the cultivation of Indigofera spp. described above throughout the four stages (germination, seedling, planting and harvesting) is very different from the cycle traditionally applied by the community (Figure 3A). The community only harvests Indigofera spp. plants found in nature, usually once a year, following the commencement of the rainy season (Figure 3B).

The initial planting of Indigofera is conducted at the beginning of the rainy season (around November) and preceded by germination and seedling (1.5–2 months before). The cultivation of Indigofera tinctoria L. on Java Island, harvesting is carried out when the plants are 4–5 months old. The next harvest is carried out 3–4 months after the first harvest or it can be harvested 3 times a year, with the life span of the plant as a dye producer being 2–3 years (Kurniawan 2020; Ariyanti and Asbur 2018). Furthermore, (Ariyanti and Asbur 2018) say that Indigofera tinctoria L. grows optimally in areas with rainfall below 1750 mm year⁻¹ accompanied by a hot and humid climate. The dry condition of Timor Island (rainfall 1211–1242 mm year⁻¹) makes the frequency of harvesting not as often as in Java, a maximum of 2 times a year. Harvesting on Timor Island is conducted 4 months after planting when the plants are in full bloom, and the leaves are colored bluish green (community experience). Harvesting is conducted in the morning at 4–6 am (Ariyanti and Asbur 2018), with the process involving pruning at the bottom (1 m from the bottom) (Muzzazinah et al. 2021).

The initial harvesting takes place in March and a secondary harvest takes place in July. Likewise, maize, which is a staple crop, is planted in November and harvested in April, with the full cycle taking a year. Following the second harvest in July, the dry season arrives, during which period the plants will experience a decrease in growth. However, with the return of the rainy season, the growth of the Indigofera increases, enabling harvesting to take place in around March of the following year. Figure 3 depicts the annual production cycle.

3.3. Processing Indigofera Leaves to Produce Indigo Paste

After harvesting, the leaves of the Indigofera are immediately separated from the twigs, after which they are processed. This must be undertaken immediately to obtain a high yield of indigo dye. According to (Ariyanti and Asbur 2018), semi-dried or dry leaves will produce only a low yield because the β-glucosidae enzyme is more active in fresh leaves than in semi-dried or dry leaves. Indigofera leaves extract contains indican glucoside, which can be hydrolyzed to glucose and indoxyl. Indoxyl itself is a colorless indigo precursor that, in alkaline conditions, is easily oxidized, resulting in the production of blue indigo pigment.

The production of indigo paste from Indigofera leaves involves three processes these being fermentation to release the indigo precursors, removal of the leaves and oxidation of the liquor as a result of aerating under alkaline conditions caused by the addition of slaked lime (Ca(OH)₂), and the precipitation of the indigo dye with the slaked lime. Following these processes, the precipitate is used to produce a paste that is ready for use (Figure 4).

There are a number of differences between the indigo paste processing technique and the community utilization process. More details can be seen in

Table 2. Differences between the indigo paste processing technique and the community utilization process.

Components	Community Utilization Process	The Indigo Paste Processing Technique
Raw materials	Indigo leaves	Indigo leaves
Additional materials	Clay + lime (CaO)	Lime (CaO)
Volume and composition	Depending on needs and available equipment usually 1:10	Lime (CaO) equivalent to 2% of raw materials
Process	- Indigofera spp. leaves are pounded + water, boiled, then filtered - thread soaked in black clay + lime (CaO) - removed and placed in a different container - Indigofera spp. solution is poured over the clay-covered thread - allowed to sit overnight - dried and then washed to remove clay - placed in the sun until fully dry - black thread is produced	- fermentation to release the indigo precursors - removal of the leaves and oxidation of the liquor as a result of aerating under alkaline conditions caused by the addition of slaked lime (Ca(OH)2) and the precipitation of the indigo dye with the slaked lime - stirred or crushed for 30–60 min and then left for 24 h - the water is filtered until the indigo paste precipitate is obtained
Processing time	4–6 days	3 days
Final product	Solution	Paste
Viability period	Discarded immediately after being used to die the thread (±48 h)	Can be stored for a year or more
Color produced	Black	Blue Indigo

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3.4. Potential Cultivation Area of Indigofera spp. on Timor Island, Indonesia

Indigofera spp. plants have a high level of adaptability, often growing in the wild in all types of soil, with high levels of tolerance to drought, flooding, and high salinity (Campos et al. 2018). Many are found growing in coastal regions in soil with clay-sand soil characteristics and with a pH ranging from 6 to 7. It grows well in locations with an average temperature of 22–28 °C and with a maximum temperature of 32 °C (Bobojonov et al. 2012). For the cultivation of plants, altitude is the first criterion that must be considered out of a number of topographical parameters. Altitude parameters are closely related to temperature parameters, with a relationship between altitude, temperature, and rainfall (Sagredo et al. 2014). I. suffruticosa Mill. can be found at altitudes of 1–1800 m asl, while I. tinctoria at 0–800 m asl. Both species grow in areas where the air temperature ranges between 21 and 34 °C. Generally, it is recommended that agricultural activities take place in flat areas to minimize soil erosion, in areas with soil of good quality (Kumar and Jhariya 2015). Due to impacts on environmental sustainability, cultivation on steep slopes is not recommended (Malley et al. 2006). Based on these considerations, the areas with the highest suitability scores are those with slopes of 0–3%. Climatic parameters are a critically important factor for plant growth, affecting a wide range of physiological processes (Gruda 2005). Both rainfall and temperature affect plant growth in high-land areas, as shown by a number of studies (Motsa et al. 2015; Naughton et al. 2015). Air temperatures have an impact on chemical reactions and the physical properties of plants, with effects both at the cellular level and at the plant level (Gruda 2005). On Timor Island, temperatures range from between 12.2 and 27.6 °C, with a maximum temperature of 33.5 °C.

The weight of the criteria generated from the AHP is presented in

Table 3. Weight of criteria resulting from pairwise comparison.

Criteria	Text.	Ph	CEC	Corg	Alt	Slope	RF	Temp.	MaxTemp	Weight
Text.	1	2	5	4	1/5	3	1/4	1/3	1/2	0.069304429
Ph	1/2	1	4	3	1/5	2	1/5	1/4	1/3	0.049803415
CEC	1/5	1/4	1	1/2	1/9	1/3	1/8	1/7	1/6	0.017784182
Corg	1/4	1/3	2	1	1/8	1/2	1/7	1/6	1/5	0.024925978
Alt	5	6	9	8	1	7	2	3	4	0.306953228
Slope	1/3	1/2	3	2	1/7	1	1/6	1/5	1/4	0.034439834
RF	4	5	8	7	1/2	6	1	2	3	0.22058476
Temp.	3	4	7	6	1/3	5	1/2	1	2	0.15394614
MaxTemp	2	3	6	5	1/4	4	1/3	1/2	1	0.122258035

Notes: Text: texture, CEC = cation exchange capacity, Corg = C organic, Alt = altitude, RF = rainfall, Temp. = temperature, MaxTemp = maximum temperature.

. The results showed that the consistency ratio (Cr) stood at 0.03. This value is still below the maximum threshold (Cr) of 0.1. This shows that the results are valid, in accordance with the threshold recommended by (Saaty 2008).

The results show that topographic and climatic conditions have a higher weight than soil quality. These results indicate that soil quality is not a limiting factor for the successful cultivation of Indigofera spp. Soil on Timor Island has specific characteristics, as follows: dominated by medium soil texture (±85% of the area); ±47% of the area has soil conditions with pH 7.1, CEC 10.4, and Corg 0.97. A study by (Suriadi et al. 2021) found that soil pH on Timor Island is neutral to alkaline. Although the soil is alluvium, the surrounding parent material is made entirely of limestone. Soil derived from limestone parent material has a shallow solum of <50 cm, with most of it lithic. The soil also has very low organic carbon content. In terms of topographic conditions, the largest proportion of the land has a slope of <8% (±53% of the area), at an altitude of <600 m above sea level (±77% of the area). In terms of climatic conditions, the largest proportion of the land has an annual rainfall of 1000–1500 mm (±84% of the area), with an average temperature of 24 °C (±69%) and a maximum temperature of 30 °C (±48%). Timor Island is characterized by a dry climate (Suriadi et al. 2021).

The results of the land suitability analysis for Indigofera spp. on Timor Island are presented in Figure 5. Land that is not suitable for the cultivation of Indigofera spp. plants covers an area of less than ±1% of the total area of the island. The unsuitable land is mainly located around mountain peaks, characterized by a combination of physical properties that do not permit crop cultivation, including steeper slopes and very low temperatures. This land is generally not cultivated, with the land cover consisting of forests. Thus, almost 99 percent of the land on Timor Island is suitable for the cultivation of indigo plants. The degree of suitability varies, however, from very suitable (S1) to marginally suitable (S3), with the greatest proportion of the land falling into the very suitable (S1) category, with land in this category covering a total area of ±1.3 million ha.

To determine the suitability of land for the cultivation of Indigofera spp., a land availability analysis was conducted, based on considerations related to land cover and land-use conditions. Of the Indonesian territory on the Island of Timor that consists of agricultural land, 453,931 ha has suitable land conditions for indigo cultivation. However, the development of land for this purpose is directed at land not covered by forest and/or that has been used for plantations or other agricultural uses. Thus, 369,836 ha of the Indonesian territories of Timor Island are available for the cultivation of Indigo, with most of this land consisting of abandoned land, mostly either open land or covered with shrubs and grasslands (Figure 6).

In Indonesia, measures to develop the cultivation of Indigofera spp. could also play a role in accelerating land rehabilitation, considering that a large proportion of the suitable areas consist of critical land (±80%), with more than 60% of this area located outside forest areas (Other Use Area (Areal Penggunaan Lain, APL)). Measures to accelerate land rehabilitation initiatives are important, particularly in the context of the threat of deforestation in the tropical mountain forests of Timor (Pujiono et al. 2019). The most suitable land in critical APL areas could be prioritized for the development of Indigofera spp. (±163 thousand ha). The distribution of the area based on the level of criticality of the land and land function status is presented in

Table 4. Area available for the cultivation of indigo cultivation based on land function status and land criticality for the prioritization of rehabilitation efforts.

Category		Land Use Function (ha)
Suitability	Criticality	Protection	Production	Conservation	APL
S1	Moderately Critical	34,599	41,749	201	140,556
S1	Critical	14,363	8038	179	22,297
S1	Very Critical	667	40	—	171
S2	Moderately Critical	10,143	720	805	12,969
S2	Critical	3342	34	177	2304
S2	Very Critical	161	—	—	117
S3	Moderately Critical	281	—	490	16
S3	Critical	43	—	33	—
Total		63,599	50,581	1885	178,429

Remark: S1 = suitable, S2 = moderately suitable, S3= marginally suitable.

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3.5. Economic Analysis of the Cultivation of Indigofera spp.

3.5.1. Feasibility Analysis

A business feasibility assessment was conducted to determine the feasibility of the development of Indigofera spp., including cultivation activities and the production of indigo paste. Indigofera spp. cultivation activities includes nursery, nursery maintenance, planting preparation, planting, and plant maintenance. The production of indigo paste activities includes harvesting and processing the paste.

Cost

The cost of activities associated with the cultivation of Indigofera spp. and the processing of leaves to produce indigo paste were assessed. The following

Table 5. Types of expenditure involved in the cultivation of Indigofera spp. and the production of indigo paste in 2021.

Type of Expenditure	Units Required	Units	Total Expenditure (IDR)
a. Fixed operating costs
Purchase of paranets	7	m	210,000
Purchase of tarpaulins	175	m	1,050,000
Purchase of dippers	56	fruit	560,000
Purchase of filtering cloth	56	m	1,120,000
b. Variable Operating Costs			-
Purchase of polybags	40	Kg	1,800,000
Purchase of manure for the nursery	100	Kg	2,500,000
Purchase of manure for planting	200	Kg	5,000,000
Purchase of water for production of paste	28,000	Liter	14,000,000
Purchase of quicklime	56	Kg	2,800,000
Wages for filling polybags and sowing	50	labor day	3,250,000
Nursery maintenance fees	5	labor day	325,000
Wages for digging holes	50	labor day	3,250,000
Wages for planting	20	labor day	1,300,000
Wages for maintenance work	730	labor day	47,450,000
Wages for harvesting and processing leaves	56	labor day	3,640,000
Wages for paste production	112	labor day	7,280,000
Total			95,535,000

contains a list of the type of expenditures involved and their magnitude:

Income

Income calculation begins with Indigofera productivity, with total production calculated based on Indigofera leaf productivity per unit area. In 1 ha with a spacing of 100 × 100 cm, there will be 10,000 plants. Each individual plant produces an average of 35 g of Indigofera leaves per harvest. Harvesting on Timor Island can be done twice a year. Therefore, in 1 year, the production of Indigofera leaves is 700 kg ha⁻¹. Based on the productive age of the plant, the Indigofera cultivation cycle is 4 years. Thus, the productivity and total production of Indigofera leaves in one business cycle for 4 years is 2800 kg ha⁻¹.

The next step in the income calculation process is to calculate the yield of paste. Based on the results of the study, it was found that when 300 g of Indigofera leaves were added to 6 g of lime (2%) and 3 l of water, this yielded 177 g of paste (Agustarini et al. 2021). The calculation of paste yields based on the research activities is presented in

Table 6. Indigo paste production from 1 hectare of Indigofera plant.

Indigo Paste Yield in 1 Year	Value	Units
Paste yield per kg (1000 g) of Indigofera leaves	390	g
Productivity of Indigofera leaves per ha per harvest	350	kg
Paste yielded in a single harvest per hectare	136.50	kg
Paste yielded per year per hectare	273	kg

.

The productivity of paste yields per hectare per year is 273 kg (Table 6). The price of indigo paste is relatively inelastic due to both the supply and demand for indigo paste being relatively stable. Thus far, there has been no substitution of natural blue dye apart from Indigofera, and production competition is still limited. There is no large industry that produces an indigo paste that will potentially monopolize the market price. The price used for income analysis was the price of indigo paste in 2021, based on the selling price of indigo paste in the market place (IDR 110,000 kg⁻¹, or USD 7.75). Therefore, the income derived from producing indigo paste is IDR 30,030,000 ha⁻¹year⁻¹ (or USD 2117) and income during the cultivation cycle is IDR 120,120,000 ha⁻¹ (or USD 8469).

Results of the Financial Analysis

In conducting a financial feasibility analysis, it is necessary to consider changes in the value of currency over time. The cash flow on which the calculation of the investment eligibility criteria is based runs over a fairly long period of time (4 years). A calculation of the changes in the value of money over this period is calculated by including discounts in the analysis. Discounts are needed to convert the expected future flow of resources into an estimated present value (Riyanto 2018). The results of the financial analysis for the production of indigo paste are presented in

Table 7. The results of the financial analysis into the production of indigo paste with a factor discount of 8% over a 4-year business cycle.

Investment Parameters	Value
NPV	IDR 18,526,006 or USD 1306.145
BCR	1.23
IRR	126%
BEP	Second year

, based on an assumption of a discount factor of 8%, based on the Bank Rakyat Indonesia credit interest rate in 2021. This follows (Nurmalina et al. 2018), who state that one of the factors for determining the discount rate is loan interest rates.

The results of the analysis demonstrate the feasibility of indigo paste production. This is shown by the values of the investment parameters, with the NPV showing a positive value, with the BCR above 1, with the IRR above the discount rate, and the BEP within the period of the business cycle. The analysis shows that the production of indigo paste has the potential to yield profits of IDR 4631,501.50 ha⁻¹ year⁻¹, or USD 326,536 (exchange rate: USD 1 = IDR 14,183.73).

El Nino events impacted Timor Island in 2006–2007 (Kieft and Soekarjo 2007), with further impacts from La Nina in 2009 (Kota and Adiningtyas 2010), with these climatic anomalies having a severe impact on Timor’s agricultural sector and on community welfare. The results of research related to the cultivation of Indigofera spp. show that climatic conditions are one of the most important factors for the cultivation of this plant, with significant implications for productivity. Thus, it can be concluded that the climatic anomalies associated with El Nino and La Nina would impact the productivity of agricultural crops.

With El Nino conditions resulting in extreme dry seasons, when these conditions occur, it is essential to water plants so that they do not die. To determine the impact of this on the cultivation of Indigofera spp., a sensitivity analysis was conducted, taking into account factors including decreased productivity and the increased production costs resulting from the need for watering.

The analysis involved two scenarios for decreased productivity, with the first assuming a 10% decrease (a reduction in income of IDR 3,003,000 year⁻¹ or USD 211.72 year⁻¹) and with the second assuming a 20% decrease (a reduction in income of IDR 6,006,000 year⁻¹ or USD 423.44 year⁻¹). The two scenarios involving increased production costs are respectively based on the need for watering activities with an intensity of 1 month in 1 year (resulting in an additional cost of IDR 3,741,497 year⁻¹ or USD 263.79 year⁻¹) and on an intensity of 2 months in 1 year (resulting in an additional cost of IDR 7,482,993 year⁻¹ or USD 527.58 year⁻¹), as shown in

Table 8. Results of sensitivity analysis for the decreased leaf production of Indigofera spp.

Investment Parameters	Productivity from Indigofera spp.
	Decline of 10%	Decline of 20%
NPV	IDR 8,581,689 or USD 605.0375	IDR −1,364,628 or USD −96.21
BCR	1.11	0.98
IRR	51%	0.02
BEP	Third year	Not achieved

.

The results of the sensitivity analysis for the decreased leaf production of Indigofera show that the production of Indigofera paste would remain feasible if the production of Indigofera leaves decreased by a figure not exceeding 10%. However, if the decrease is greater than 10%, then the production of indigo paste is not feasible. Sensitivity analysis is conducted if there is an increase in costs due to watering activities. It is carried out in 2 scenarios, namely 1 and 2 months of watering in a 1 year planting period (

Table 9. Results of sensitivity analysis to the increase in costs due to watering activities.

Investment Parameters	Period for Which Watering Is Required in One Year
	1 Month	2 Months
NPV	IDR 6,135,695 or USD 432.5868	IDR −6,256,616 or USD −441.1122
BCR	1.07	0.94
IRR	38%	−19%
BEP	Third year	Not achieved

).

The results of this sensitivity analysis indicate that indigo paste production activities remain feasible if watering is required for a maximum of 1 month in 1 year. However, when watering is required for longer periods than this, indigo production becomes unfeasible.

3.5.2. Potential Economic and Social Value to Be Derived from the Development of Indigofera spp.

The potential economic value of Indigofera development is from the indigo paste selling activities in which its raw material is harvested from Indigofera potential cultivation areas. Based on the results of the various analyses, a number of findings related to the development of Indigofera on Timor Island were obtained, including the following: the potential area to be prioritized for development covers ± 163 thousand ha; I. suffruticosa Mill. can generate production yields of 700 kg ha⁻¹; resulting in yields of indigo paste of 273 kg ha⁻¹, with the potential to generate profits of IDR 4,631,501.50 ha⁻¹ year⁻¹ or USD 326.54 (exchange rate: 14,183.73). The potential economic value to be derived from the development of Indigofera on Timor Island is distinguished based on three plantings scenarios: 100% targeted area development with intercropping (scenario 1); 50% targeted area development with intercropping (scenario 2); and 25% targeted area development with intercropping (scenario 3). A comprehensive outline of the potential economic and social value to be derived from the development of Indigofera can be seen in

Table 10. Potential economic and social value to be derived from the development of Indigofera.

Parameter	Scenario 1 (100% Target Area)	Scenario 2 (50% Target Area)	Scenario 3 (25% Target Area)
Area (Ha)	163,000	81,500	40,750
Potential supply of raw leaves (tons year−1)	114,100	57,050	28,525
Potential supply of indigo paste for dye (tons year−1)	44.5	22.25	11.12
Economic potential	IDR 754,934,744,500 or USD 53,225.40	IDR 377,467,372,250 or USD 26,612.70	IDR 188,733,686,125 or USD 13,306.35
Potential social impact in terms of employment (labor day)—per year	42,054,000	21,027,000	10,513,500

.

The potential social impact to be derived from the development of Indigofera takes the form of employment, given that the processes involved are labor-intensive. This potential is demonstrated in Figure 7, which shows that wages account for the largest proportion of the operational costs associated with the development of Indigofera (70%). The wage component for 4 years of Indigofera production cycle absorbs 1023 labor day (years 1: 348 labor day, years 2–4: 225 labor day) consists of the cultivation of Indigofera and the producing of indigo paste. In the first year, we need more labor for the cultivation activities. In the second to fourth year we only have maintenance and indigo paste production. In the cultivation of Indigofera, the wage component reaches 84% of the total cost of wages, while the proportion of the manufacture of indigo paste reaches 16%. Thus, this sector is suitable to be developed as it is able to absorb many workers in the rural sector.

Ikat weaving also has economic potential as a tourist attraction. Weaving from this region has significant aesthetic value and plays a major role in establishing cultural identity (Susanti 2021). Thus, it has the potential to act as a form of cultural tourist attraction that could create value for NTT as a market for tourists.

As shown by a study conducted by (Muda and Suwito 2019), ikat weaving could drive increased tourist visits to the region, with significant potential economic benefits for the community. The development of weaving crafts has the potential to generate significant employment and to reduce the unemployment rate. Thus, this innovation has the potential to generate strong positive social value (Salma et al. 2018). There is good potential to develop the ikat weaving business, given that most craft people work individually, with very few working together in groups (Muda and Suwito 2019). Weaving has strong market potential due to its recognition as an environmentally friendly art product by upper-middle consumers. According to (Samadara 2018), both national and international tourists prefer to buy ikat from Sumba with natural dye compared to synthetic dyes.

Together with increasing public awareness of the negative effects of synthetic colors on health and the environment, the market for natural dyes has good prospects (Salma et al. 2018). Therefore, ikat weaving can be regarded as a form of cultural heritage that could be developed through a community empowerment approach to generate significant positive economic and social benefits for members of communities in rural areas.

3.6. Development Strategy the Sustainable Use of Indigofera Leaves to Produce Natural Dyes

A development strategy for the sustainable use of Indigofera leaves to produce natural dye was formulated through a quantitative SWOT analysis. A quantitative SWOT analysis may be used to conduct an evaluation according to specific desired parameters and to develop management strategies (White et al. 2015). The main advantage of the SWOT approach is to show current and possible future constraints related to implementing a proposed initiative (Johnson et al. 1989). The SWOT analysis approach is an effective technique to formulate strategies (Hill and Westbrook 1997) because it categorizes factors related to the proposed initiative as either internal (strengths, weaknesses) or external (opportunities, threats) (Shrestha et al. 2004). Therefore, the approach can provide insights into how to transform threats into opportunities and offset weaknesses into strengths (Wang 2010; Liu 2013).

The SWOT diagram for the development of the use of Indigofera leaves as a natural dye in a sustainable manner on Timor Island, Indonesia, was constructed according to interviews with experts. Strengths and weaknesses are categorized as internal factors, and opportunities and threats are categorized as external factors (

Table 11. Diagram of the SWOT analysis for the sustainable development of Indigofera to produce natural dyes.

Internal factor	Strength	Weakness
	Communities in the region are accustomed to agricultural cultivation activities	Community members do not yet cultivate Indigofera, but gather it from the wild
	Indigofera grows naturally on Timor Island	Communities are not yet familiar with techniques for cultivating Indigofera
	High potential Indigofera that grows naturally and can be collected by members of the community	The process of producing natural dye from Indigofera is more complicated than the process of producing other types of natural dyes
	Strong willingness of community members to participate in cultivating Indigofera, which is usually conducted through collective cooperation	Communities are not yet familiar with the processes for producing indigo paste of sufficient quality to compete with other products
	Wide availability of land suitable for the cultivation of Indigofera	Low general levels of education may constrain the transfer of knowledge related to the cultivation and processing techniques
	Communities have a strong cultural tradition of weaving using natural dyes
	The use of Indigofera is a natural dye is widely accepted as part of local cultural traditions, preceding the use of synthetic dyes
External factor	Opportunity	Threat
	Increased farmer incomes from the production of indigo paste from Indigofera leaves	Unpredictable climatic conditions due to global climate change
	Increased weaver incomes from the sale of cloth using natural dyes	The presence of synthetic dyes that makes weaving more efficient
	Indigofera can be intercropped with food crops without negative impact on the growth of any of the crops involved	Paste production is inefficient and manufacturing costs are high due to increased paste production not balanced by the availability of raw materials
	Indigofera has good potential for use to rehabilitate critical land
	There are good prospective markets for indigo paste
	The technology required for the production of indigo paste is available
	Trend back to nature
	Increased awareness of the need for environmental and occupational safety
	Limited availability of plants that produce natural blue dye

).

The determination of weights in the SWOT-AHP model is based on the results of comparisons between SWOT components using pairwise comparisons. The results of the analysis show that the value of the consistency ratio (Cr) is 0.03 for external factors and 0.04 for internal factors. This value is still below the maximum allowable Cr of 0.1, following the recommendations of (Saaty 2008). The results of the SWOT-AHP analysis show that the coordinate value for the internal factors stands at 2.10, while the external factor stands at 2.32 (Tables S5 and S6). Based on the position and action evaluation matrix strategy, there are four quadrant strategies: aggressive, competitive, defensive, and conservative (David et al. 2019).

These results indicate that the strategy for the production of Indigofera spp. on Timor Island lies in quadrant I, indicating that the strategy should be implemented aggressively. An aggressive strategy’s leverage is the existing strengths and opportunities, rather than using defensive options to minimize weaknesses and threats (Rauch 2007).

Local wisdom relates not only to providing livelihoods and sustaining the lives of local communities but as also as a means to strengthen ecological sustainability and to leverage the community’s unique resources to stimulate the sustainability of local wisdom itself (Lake et al. 2018). The strategy for the development of Indigofera spp. on Timor Island involves leveraging the community’s culture and wisdom related to the use of this plant acquired over generations, as a result of which it has developed the appropriate cultivation techniques, which consist of knowledge of the right time for planting, following good cultivation practices, and using appropriate planting materials. This provides a strong basis for leveraging the development of indigo paste in suitable areas to capture significant economic and social opportunities.

Based on the SWOT-AHP analysis, it would be possible for the regional government of NTT to formulate a number of strategies for the development of Indigofera spp. on Timor Island, including the introduction of Indigofera spp. as an agro-industry commodity and its use for the rehabilitation of critical lands. These strategies could be implemented by developing partnerships with the private sector to increase the potential sale of indigo paste, to expand markets, and to increase community capacity is to cultivate and process the plant. A number of stakeholders and actors could be involved in this initiative, including women’s farmer groups, Dewan Kerajinan Nasional Daerah/Dekranasda (the Regional National Crafts Council), the Industry and Trade Office, the Women’s Empowerment Service, the Agriculture and Plantation Service extension agencies, and private companies. Support for women’s capacity building in terms of education is needed for the regeneration or further development needs. This is reinforced by (Chisamya et al. 2012), which states that by being educated, girls experienced a transformation of the inequitable gender relations they faced in society. Related to agriculture, although in Indonesia it is dominated by men, women appear to have equal access to productive resources, such as land and inputs, and greater control over household income than men (Akter et al. 2017). Funding and financing for these strategies could be sourced from related agencies, grant funds, business service agency (Badan Layanan Umum, BLU), and mutual cooperation funds managed by farmer groups.

Thus far, neither the NTT provincial government nor district governments have promulgated regulations related to the preservation of ikat or the use of natural dyes. Regional regulations could play a significant role in supporting strategies to develop the commodity, to create predictability and legal certainty, and to demonstrate a clear commitment to the development of cultural industries in NTT (Setiawan and Suwarningdyah 2014). In addition, local regulations related to weaving and tourism could play a strong role in facilitating the achievement of SDG 8 targets.

4. Conclusions

The people of Timor Island are familiar with a range of plants that can be used to produce natural dyes, one of which is Indigofera spp. (I. tinctoria L. and I. suffruticosa Mill.), which is generally used to produce a black dye for ikat fabrics made by the community.

The cultivation of Indigofera is conducted in three stages: germination, seeding, and planting. Sowing media plays an important role in increasing the germination rate, with the best sowing media for the germination of I. tinctoria L. being sand media. At the seedling stage of I. tinctoria L, a mixed media consisting of soil, cocopeat, and rice husk charcoal (1:2:2) and placed in an unshaded area (0%) and mixed media consisting of soil and rice husk charcoal (1:2) and placed in 50% shade resulted in the highest biomass and the best quality index. At the planting stage of I. suffruticosa Mill., a spacing of 100 × 100 cm resulted in the best increases in height, diameter, and number of branches, while the use of fertilizer (100, 150, and 200 g plantings) resulted in better growth than without the use of fertilizer. Providing 100 g of fertilizer per plant results in the best results in terms of height, diameter, and number of branches.

Indigo paste is produced by adding quicklime CaO equivalent to 2% of the weight of the leaves and water equivalent to 10 times the weight of the leaves. This technique is more time-efficient and results in the production of a higher quality paste with a longer shelf life than through the techniques currently applied by the community.

The potential area suitable for the development of Indigofera spp. on Timor Island covers ±163,000 ha. The results of the financial feasibility analysis showed that the processing of Indigofera spp. to produce indigo paste is feasible. The results of the sensitivity analysis show that the tolerable decrease in production levels is only 10%, with a maximum of one month of watering in a year for the production of indigo paste to remain feasible. The total potential supply of raw materials to produce indigo paste from Timor Island stands at 11–44 tons/year, with the economic potential standing at USD 13–53 million/year. The cultivation and processing activities are labor-intensive, requiring a workforce of 1032 person/ha during the Indigofera spp. production cycle (4 years).

Strategies to develop the cultivation and processing of Indigofera spp. on Timor Island could be conducted aggressively by leveraging the identified strengths related to the cultivation of Indigofera spp. In particular, this would involve deleveraging local wisdom and cultural traditions related to the use of Indigofera spp. over generations by applying the appropriate cultivation techniques, together with innovations in the indigo paste production process and the development of suitable areas to capture economic opportunities.