**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◦1917.9 S–10◦2212.9 S and 123◦2724.0 E–127◦1806.2 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<sup>−</sup><sup>1</sup> (BPS Provinsi NTT 2021).

**Figure 1.** Research location.

#### *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.


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 Opensource 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 managemen<sup>t</sup> (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.
