BALINESE TRADITIONAL AGROFORESTRY AS BASE OF WATERSHED CONSERVATION

. Forests, traditional gardens and green spaces play an important role in regulating the water flow of an area. Along with the high demand for land in Bali for agriculture and tourism, many forest areas have been converted into hotels and settlements. Forest conversion has caused many problems such as erosion, soil fertility decreased, flora fauna extinction, floods, drought, global warming and the disturbing watershed, especially rivers for springs. The purpose of this study is the development of watershed conservation in Bali based on traditional agroforestry. The method that used is vegetation analysis. Calculation of the erosion amount using the USLE formula. Sampling was done by ten plots. The results showed that traditional agroforestry vegetation consisted of vertical and horizontal structures. The characteristic of traditional agroforestry is that dominant plants are distributed irregularly, thus creating a miniature structure like a forest. The vertical structure consists of trees, horizontal structure filled with species of garden plants and agriculture. Trees have roots spread intensively in the soil and reduce nutrient leaching. Land cover by vegetation protects the soil and erosion. The agroforestry has a role as an act of soil and water conservation. Traditional agroforestry land cover has a relatively low C coefficient (0.05-0.25) compared to other lands. The level of erosion hazard is low and moderate. Average erosion value of 55.01 t.ha -1 .yr -1 . This indicates that traditional agroforestry makes the soil have a higher ability to absorb water, thereby reducing surface runoff. Likewise, organic material that improves the water content capacity. In addition, water quality can be improved through the humus filter function. During a long dry season, there is a drought due to low rainfall, but rivers and springs were able to supply water for the peoples daily needs. This condition occurs because of the tree retentions in traditional gardens. Conservation actions need to be taken, namely maintaining trees vegetation, increasing reforestation, bench terraces use, mounds and mulch use. This condition also places traditional agroforestry as a sustainable land management system.


Introduction
Forests, traditional mixed gardens and green open spaces are important in regulating river flows. In accordance with the needs of land in Bali for agriculture and tourism, many forest areas have been converted into hotels and settlements. According to Anputhas et al. (2019), forest land conversion raises many problems such as erosion, decreased soil fertility, flora-fauna extinction, Yuniti et al., JAAST 6(1): 49 -60 (2022) 50 floods, drought, and even global warming thus disturbing river basins, especially rivers for water sources.
The sector of forestry, agriculture and plantation agroforestry activities are already familiar.
Agroforestry is a form of soil and water conservation combining tree crops, or annual crops with other agricultural commodity crops which are planted together or alternately (Gintings, 1982).
Planting trees, which are annual crops, can reduce soil erosion better than agricultural crops, especially seasonal plants. Selected annual plants should be of the type that can provide added value to farmers from fruit and wood products. Besides being able to produce faster and greater profits, agroforestry is also a very good system ecologically, economically and socio-culturally (Kalcic et al., 2015). Knowledge interfacing and sharing towards co-producing collaborative products helps to clarify the performance-based indicators for effective payment for watershed services negotiation between potential sellers and buyers of ecosystem services (Cuvelier & Greenfield, 2016;Leimona et al., 2015). Various agroforestry plant species in Bali, including coffee, Albizia chinensis, and the latest mulberry (Sasmita et al., 2019), shallot (Allium ascalonicum L. especially in Kubu Tambahan Sub-district , petsai (Brassica chinensis L.) evenly in Bali .  (Tika, 2015).
Various regions in Indonesia have traditional agroforestry systems. One of them is in the province of West Java, a traditional agroforestry system that is commonly found in the form of kebun-talun and yard (Karyati et al., 2017). In Bali, traditional agroforestry known as abian, kebon and telajakan are familiar to people who live in rural areas. . Abian is a dry land/field that is located far from the residential area ( Figure 2). Kebon is a garden which is located not far from a residential area ( Figure 2). Telajakan is part of the green open land around the settlement located on the main road or village road in front, beside or behind the yard of the house, including the road itself, sewer and drainage, yard and others ( Figure 1). All three are related to the Tri Hita Karana concept in Balinese Hindu beliefs (Kaler, 1983). Tri Hita Karana namely three harmonious relationships between humans with God, man with man, and humans with the environment described with the Parahyangan, Pawongan, and Palemahan (Windia, 2005). Tri Hita Karana concept lowered the Tri Mandala concept consists of: the main mandala as Parahyangan or holy place, Madya Mandala in the form of yards including buildings place to live and natah, meanwhile despicable mandala in the form of a backyard (teba) and the front yard (telajakan). Traditional Balinese landscaping uses Tri Mandala concept (Dewi, 2018).
Until now the land use system of abian, kebon and telajakan has an important role as a source of fulfilling community needs. The benefits of abian, kebon and telajakan are as a source of daily food needs, a source of income and other environmental service benefits. Abian, kebon and telajakan as a traditional agroforestry system in Bali have not received the attention and recognition of various parties both the government and local government agencies, agriculture, forestry in the development and use of land in their area. This study aims to evaluate the value and benefits of traditional dry land use (abian, kebon and telajakan) in the Bali area.

Methods
The study was conducted in 5 districts with 5 points and 10 research plots ( Erosion prediction on land can be calculated using the model that Wischmeier & Smith (1978) developed by Arsyad (2012) with the formula A = R x K x LS x C x P. Rain erosivity factor is calculated using rainfall data in the last 10 years. Rain erosion in the study area was predicted using the formula proposed by (Arsyad, 2012) as follows EI = 2.21 R 1.36 , with EI = erosivity index, R = monthly rainfall (cm).

Rainfall in the Last Ten Years (Rf)
Most of the Balinese people are planted as small farmers with traditional farming patterns.
The Balinese style of agricultural production is strongly influenced by climate change, especially natural cycles and rainfall. Therefore, the transition of seasons is one indicator that can be used to detect the dry season or the rainy season earlier, so that agricultural planning, especially the planting period and commodity types, can be arranged according to actual climatic conditions.
Climate is closely related to human activities, plays an essential role in economic development. It has even become an essential factor in the aspect of prosperity because increasing human needs will increase industrial activity, forest clearing, agricultural businesses, and households that release greenhouse gases. Bali is generally a tropical region, which is influenced by seasonal winds. There is a dry and rainy season interspersed with a transition season. From June to September, wind currents originate from Australia and contain little moisture, resulting in a dry season. While in December to March, wind currents provide a lot of water vapor from Asia and the Pacific Ocean, resulting in the rainy season.
The increase in average air temperatures, rising sea surface temperatures, changes in patterns and rainfall, shifts at the beginning of the dry season, or the rainy season are a series of impacts from global warming or climate change. There are two consequences of increasing temperature/temperature, namely a change in pressure, where air circulation causes wind speeds to be firmer, and there is evaporation, where water vapor accumulates above, causing a wet atmosphere, so the intensity of rainfall increases.
According to the Meteorological, Climatological, and Geophysical Agency (BMKG) Bali Region, as presented in Table 2, that when viewed from rainfall in each region of Bali, recorded the highest average rainfall occurred in January, reaching 371.10 mm. Conversely, the lowest rainfall occurred in August, reaching 36.62 mm. Source: Rainfall Observation Laboratories in Bali (data processed)

Rain Erosion Index (EI)
The Rain Erosivity Index (EI) is obtained using equations developed by (Arsyad, 2012). So the R-value obtained for the last 10 years is 1370.90 t.ha -1 .yr -1 and can be seen in Table 3. Source: research data processed The erosivity value can be an indicator of the occurrence of high surface runoff in the watershed area of Bali when it rains. This surface flow carries soil particles that result from damage to soil aggregates due to strong pressure rain because of the kinetic energy of the rain. According to Asdak (2018), if the amount and intensity of rain is high then the potential for surface runoff and erosion will also be high. Erosivity is affected by the fall of raindrops directly on the ground and partly because of the flow of water above ground level.   (2017) The use of forestry land in Bali is in accordance with its function. According to its function, forests are divided into protected forests, production forests, nature reserves, tourist parks, and tourism forests presented in Table 4.
Local wisdom in Bali like telajakan play a role in maintaining environmental balance. Water infiltration land is still maintained by telajakan. It is formed, which also functions as a water catchment area. Groundwater reserves are still available with the help of telajakan as water absorption into the ground during the rainy season . During 2017, visits to these tourist forest locations were more dominated by foreign visitors who reached 164,337 people (67.80 %) compared to 78,031 domestic visitors (32.20%).

Soil Erosion Rate (A)
Land use in the watershed area of Bali generally consists of four types, namely forests, mixed gardens, dry fields, and rice fields. Types of mixed garden land use as traditional agroforestry at 10 observation points on land with a slope of 0-25% obtained the average erosion of each type of land use is presented in Table 5.
Based on the classification of surface erosion in Table 5  Source: research data processed

Traditional Agroforestry (TA)
Although the definition of a traditional garden is a plot of land on which there are stands of trees and types of cultivated plants (Herri et al., 1985), in reality, it also includes areas around which no trees grow. Thus it can be said that what is meant by traditional gardens is to cover the whole land as a whole (with trees and not trees), which is owned by someone either in the vicinity of the residence (Home gardens) or state forest land (Forests gardens). The area of traditional gardens in Bali varies greatly, from the smallest less than 0.5 ha to as large as 5.0 ha and there are even some that are wider. The distance to the garden has generally located some distance between 1 to 5 km from the settlement and can be reached on foot.  The distinctive feature of traditional gardens as a model of traditional agroforestry was dominant plants are distributed irregularly, thus creating miniature structures such as natural forests. The spatial structure of mixed gardens consists of horizontal and vertical structures. The horizontal structure of the garden is related to the number of trees in one land, in terms of stand density and canopy cover level. As we get closer to settlements, there is a tendency for vegetation to decrease regarding the types of cultivation and the number of tree populations in the stand. The vegetation stratification of traditional agroforestry in Bali based on the vertical structure is presented in Table 6.
In general, large trees with a diameter of more than 100 cm are not found in traditional gardens owned by individuals, the number of trees is relatively evenly distributed throughout the diameter class. This is because the age of traditional gardens is relatively young. Because of that, the trees that grow in traditional gardens belonging to the community besides being of medium diameter, are generally also species that have been cultivated. In addition, to stand density and canopy cover in traditional gardens, there are several forms of plant stand layout. There are three types of traditional gardens in Pinge Tabanan Village, namely stands in a hilly area, stands on the edge of a river and stands near a settlement. Different layouts have specific purposes and objectives including to shorten the road to the work area in the fields and fields, close to finding water sources, as well as functioning to protect against erosion and landslides.

Conclusion
The characteristic of traditional agroforestry is that dominant plants are scattered irregularly, thus creating miniature structures like natural forests. The structure of vegetation is filled with types of trees, and types of food plants. The relationship between rainfall and water storage function determines the flow of river water in an area. Land cover by vegetation protects the soil from erosion. The role of traditional agroforestry in Bali as an act of soil and water conservation has a relatively low C coefficient (0.05-0.25). The level of erosion hazard is low and moderate.
The average erosion value of 55.01 t.ha -1 .yr -1 indicates that traditional agroforestry makes the soil have a higher ability to absorb water, thereby reducing surface runoff. Low erosion occurs because people plant and maintain trees in the traditional garden area. Conservation actions maintain tree vegetation, increase reforestation, use of bench terraces, ridges and use of mulch as one of the watershed conservation efforts. Traditional agroforestry as a sustainable land management system indicates that watershed conservation activities are going well.