Slope Classes Research Articles

Economic Evaluation and Performance of a Tree Planting Machine Performing in Two Different Slope Classes and Conditions of Harvesting Slash

In recent years, fully mechanized planters have gained attention in Brazil on flat to steep terrain. A field study was conducted to analyze the potential of a planting machine composed of a hydraulic crawler excavator and a planter unit to perform soil preparation and planting in two slope classes and two conditions of slash presence. The experimental area was divided according to slope – undulating (8% to 20%) and strong undulating (20% to 45%) – and the presence of slash. Slope class did not significantly affect productivity, nor was there a significant interaction effect between the slope and slash factors. The presence of slash proved to be statistically different, with mean productivity of 236 seedlings hour-1 when reloading the carousel in an area without harvesting slash. Tree planting machine utilization was 75.13%, and the mechanical availability was 79.6%. The presence of slash significantly reduced the tree planting machine productivity, including the seedling reloading time, suggesting a newer research line for fasters reloading seedling systems.

Soil Erosion vs. Vineyard Productivity: The Case of the Aglianico del Vulture DOC and DOCG Areas (Southern Italy)

Soil erosion in European Mediterranean vineyards is the main impact factor of uncontrolled solute and nutrient transport, degradation of soil structure, and loss of organic matter, which are key controlling factors in grape productivity and quality. The relationship between soil loss and grape productivity in the Aglianico DOC and DOCG areas of Southern Italy has been studied. Erosion values estimated through the RUSLE model were compared with grape productivity from 2011 to 2019. The obtained results show a negative correlation between the two parameters. The amounts of soil loss for different vineyard slope classes were also considered. The erosion values increase by an order of magnitude moving from the gentle slopes (0–5°) to the steeper ones (>30°), typical of hilly and mountainous areas. The planned shift in the future of vineyards towards these altitudinal bands could prove to be uneconomical if conservative techniques are not carried out.

Agricultural Land Use Planning on Sustained Basis Using Landform and Land Evaluation Approach with Geospatial Analysis (a case study in East Barito District, Central Kalimantan Province)

Spatial planning for agricultural land use is required since the region with its land resource has an opportunity to be opened and cultivated. On the other side, balanced environment should be maintained in order to achieve sustainability for future use. Land resources information can then be used as basic information and prerequisite for analysis and evaluation in planning process. Because of the lack of data, this study was conducted to generate and provide land resource information. Landform approach using raster surface analysis and slope classification derived from digital elevation model (DEM) was then used to determine agricultural land regions. Procedure of land suitability evaluation in addition to geographic information system (GIS) technology were applied to define specific kind of use for lands. In the case of East Barito as study areas, mainly on the basis of landform analysis, the region can be classified into 6 slope classes i.e. <3%; 3-8%; 9-15%; 16-25%; 26-40%; dan >40%. The result of land suitability evaluation integrated into GIS environment establish that arable lands is still available with total area of 226,211 hectare (59.11%) of total study areas. Furthermore, the region can then be delineated for group of commodities involving food crops, estate crops, and forest as well with each total area 62,291 hectares (17.96%), 183,107 hectares (52.78%) and 101,513 hectares (29.26%), respectively. Several restrictive factors that should be considered include slopping lands and peat depth. Any appropriate and specific programs for agricultural development can then be formulated in land use planning process.

Analisis Beberapa Sifat Fisik Tanah Pada Tanaman Kelapa Sawit Di Desa Kuala Behe Kecamatan Kuala Behe Kabupaten Landak

&lt;p&gt;&lt;em&gt;This land suitability evaluation is basically used to determine the level of suitability of a plot of land for a particular use. Kuala Behe Village currently has quite good potential in developing large areas of community oil palm plantations. The aim of this research is to analyze several soil physical properties of oil palm plants in Kuala Behe Village, Kuala Behe District, Landak Regency and provide management recommendations. The method used in this research is land surveying and mapping. The research begins with a preliminary survey of the research location, then continues with making a map of observation points determined based on the distribution of land unit maps obtained from the overlay or overlap of administrative maps, slope class maps and soil type maps with reference to the physiographic survey method. The research location has an area of 120 ha consisting of 6 land units, then continued with carrying out activities in the field (observing the physical properties of the soil and taking soil samples according to the coordinate points that have been obtained). The analysis results showed that the dominant texture was clay with a medium texture class, the effective depth of the soil was included in the deep criteria, had good drainage, very deep sulfidic hazards, light erosion and no threat of flooding. The research location has 2 types of soil, namely Typic Dystrudepts and Fluventic Dystrudepts which are classified into 6 land units, namely land units with a total area of approximately 120 ha. Improvement efforts can be made by constructing drainage channels, constructing contour terraces and planting ground cover plants.&lt;/em&gt;&lt;/p&gt;

Modelling and mapping Soil Organic Carbon in annual cropland under different farm management systems in the Apulia region of Southern Italy

Soil Organic Carbon (SOC) plays a crucial role in many soil functions and ecosystem services. Monitoring its spatial and temporal changes is essential for planning strategies to minimize soil degradation and loss and maintain its quality. Conservation Agriculture (CA) can make a significant contribution to increasing SOC. This article reports on the spatially modeled SOC concentration in the topsoil (0–0.3 m) of the Annual Cropland (ACL) under Conventional Management (CM) and CA in the Apulia region in Italy. To assess the spatial and temporal dynamics of SOC at the regional scale, the “Scorpan-SSPFe” (soil spatial prediction function with spatially autocorrelated errors) approach to predictive modeling and mapping of soil, based on the Geographically Weighted Regression (GWR) model was performed. The method was implemented using a Geographic Information System (GIS) and Google Earth Engine (GEE) environment to calculate the percentage distribution for each SOC level, altitude, and slope class and their combination. 80 environmental variables and 250 soil samples were analyzed to map the SOC in ACL. The SOC values showed an average of 16.68 and 17.73 g/kg for CM and CA respectively. Adequate map accuracy was obtained by GWR, which showed an R2 of 0.71 for CA and R2 of 0.52 for CM The Root Mean Squared Error (RMSE) predictions obtained were better in CA (3.96 g/kg) than CM (5.65 g/kg) with a percentage RMSE difference of 30 %. Predicted SOC obtained by GWR ranged from 4.06 to 35.60 g/kg for CA and from 5.00 to 29.99 g/kg for CM. The proposed method was shown to be promising in predicting SOC in a region of the Mediterranean area and can be used to assess the effect of land use changes, such as the application of CA, on SOC in the whole basin.

ESTIMASI TINGKAT BAHAYA EROSI (TBE) PADA EMPAT TIPE PENGELOLAAN LAHAN DI DESA KARANG SIDEMEN, LOMBOK (Erosion Hazard Level Estimation of Four Land Use Management Types in Karang Sidemen Village, Lombok)

Soil erosion is a significant threat to land sustainability and productivity in mountainous areas. Erosion can affect food security and land vulnerability to climate change. This study was conducted to assess the potential erosion and Erosion Hazard Level (TBE) in four types of land management involving the community in Karang Sidemen Village using the Revised Universal Soil Loss Equation (RUSLE) method. The results showed that for each slope class, the Botanical Forest Park (Tahura) Nuraksa Utilization Zone had the lowest potential erosion value, followed by Community Forest (HKm) and Hortipark Tastura. Forest Areas with Special Purpose (KHDTK) Rarung has the highest potential erosion value in all slope classes. For all slope classes, TBE in the Tahura Nuraksa is considered low-level. Erosion Hazard Levels in Hortipark Tastura, KHDTK Rarung, and HKm are dominated by the moderate category. There were significant high and very high TBE in KHDTK Rarung. Soil erodibility values for all types are low. Potential erosion and TBE in the four management types are strongly influenced by slope and vegetation factors.

Effects of Soil and Water Conservation Practices and Slope Gradient on Selected Soil Physicochemical Properties in Ejersa Watershed, Toke Kutaye District, Ethiopia

This study was conducted to assess the effects of soil and water conservation practices and slope gradients on selected physicochemical properties of soil at Ejersa Watershed based on a total of 18 composite soil samples collected and analyzed using standard laboratory procedures. The values of pH, electrical conductivity, cation exchangeable capacity, organic carbon, organic matter, total nitrogen, and available phosphorus determined in soil samples collected from conserved and nonconserved plots were 6.4 and 6.16, 40.26 mS/m and 15.12 mS/m, 33.51 meq/100 g and 21.56 meq/100 g, 2.66% and 2.24%, 4.58% and 3.86%, 0.24% and 0.15%, and 29.45 ppm and 17.68 ppm, respectively. Soil pH, electrical conductivity, moisture, total nitrogen, and available phosphorus were significantly different ( p &lt; 0.01 ) between treated and untreated plots and among the slope classes. Values of soil organic carbon and organic matter showed significant differences ( p &lt; 0.05 ) between land types but not among the slope classes. Soil cation exchange capacity showed significant difference ( p &lt; 0.05 ) between land types as well as among the slope classes. Relatively, higher values of many of the physicochemical parameters were recorded in samples collected from the treated land and lower slopes which might be attributed to the deposition effects of the conservation practices and decline in the rate of soil erosion.

Modeling Land Use/Land Cover Change in Berau Pantai Forests, Berau Regency, East Kalimantan Province

Land demands increase with the rise of population and regional development. This results in considerable pressure on forest resources which is characterized by an increasing rate of deforestation. To further explore the impact of deforestation and forest management in regional planning process, this study specifically aimed 1) to identify patterns of land use/land cover changes, 2) to analyze driving factors and 3) to model future land use/land cover. This study employed Landsat imageries to construct land use/land cover maps and their variation across time. Driving factors were analyzed using binary logistic regression. Land use prediction was made through Artificial Neural Network approach. Multitemporal analysis indicated that the research area experienced a decreasing trend of natural forest and shrubs, with substantial extension of existing plantation forests, plantations, agricultural lands and settlements. Indicated driving factors included accessibility, slope class, soil type, forest permit, forest function, RTRW and population density. A forecast in 2030 suggested that natural forests and built-up land would increase from current figures.

Analysis of land suitability of clove (Syzygium aromaticum L.) in the humid tropics of South Sulawesi

South Sulawesi is one of largest clove-producing regions in Indonesia. The highest production was obtained in the Luwu, Regency area, but there needs to be data related to the wide distribution of clove development potential, especially in the Bua Ponrang District, the primary producer of clove commodities. Therefore, it is necessary to evaluate the suitability of clove plant land, which can show the area of its development potential in Bua Ponrang District, Luwu Regency. This study aims to analyze the suitability of land in the Bua Ponrang District for cloves, which can become a consideration for agricultural development in Luwu Regency. The method used in this study is a qualitative method with simple limiting factors with soil suitability assesment performed by comparing soil and physical environmental data with the suitability requirements of clove. The sampling method was purposive, conducted for each land unit most representative of the land unit map where clove exists, overlaid with geological maps, slope class maps and land use. The results of the analysis of the actual land suitability class, namely marginally suitable for clove (S3) to the boundary area of 6,222.18 hectares with limiting factors, namely air humidity, drainage, soil depth, total nitrogen (%), base saturation (%), available P (ppm) and slopes (%), which can be increased potential through improvement recommendations such as the addition of organic materials, fertilizers and terracing (conservation). The land suitability class is unsuitable for clove in the 2.570,12 hectares interface with limiting factors for erotion and slope hazard.

Impact of Land Use Change on Land Capability in Katingan Regency, Central Kalimantan, Indonesia

The imbalance between land use and land capability can cause environmental problems in Katingan Regency. This study aims to analyze changes in land use change for the 2015-2021 period, land capability, land cover suitability with land capability in Katingan Regency. This research uses the method of overlaying the 2015 and 2021 land cover maps, analyzing land capability with variables of erosion maps, flood maps, and aridity maps, and analyzing land suitability by overlapping land use maps and land capability maps. The results show that land use change is 67.864 ha with map accuracy KA = 90.6% and OA 81.1%, while the concentration of land use change in Malan Island District with an LQ value of 2.5. Land capability is divided into three with the limiting factors of erosion, flooding, and slope class, namely: class II, III, IV, VI, and VII which are designated as productive paddy fields, dry land agriculture, and agriculture mixed with shrubs. Land use change has an impact on land capability, namely the increase of unsuitable land by 23.050 ha. This research can provide important information for taking policies and strategies for optimizing land use at the site level in Katingan Regency in the future.

Dynamics of soil properties as impacted by contrasting lithology, slope class, and land use types: a case study in semi-arid highlands of northern Ethiopia.

Soil characterization is crucial in creating sustainable platforms for land users to identify areas vulnerable to anthropogenic activities. This study was conducted to investigate the impacts of lithology, slope, and land use on soil properties of a semi-arid highland in northern Ethiopia. Disturbed and undisturbed soil samples collected from 0 to 30 cm depth were analyzed. Most of the assessed physical and biochemical soil properties varied significantly (p < 0.05) with lithology, slope class, and land use type. Shale-originated soils were richer in nutrients than soils of other lithologies. A decrease in slope gradient accounted for an increase in most soil properties, while a reverse trend was observed for sand content, bulk density (BD), water stable aggregates (WSA), mean weight diameter (MWD), structural stability index (SSI), soil organic carbon (SOC), total nitrogen (TN), and available phosphorus (AP). Silt and clay fractions, total porosity, moisture content at field capacity and wilting point, visual evaluation of soil structure, pH, electrical conductivity, calcium carbonate, exchangeable bases, cation exchange capacity, and percent base saturation were found to be higher for cultivated land soils compared to grass land and shrub land soils. Shrub land soils, in contrast, had higher WSA, MWD, SSI, SOC, TN, and AP relative to grass land and cultivated land soils. In summary, slope class and land use type stood out as the major drivers influencing the dynamics and distribution of soil properties other than lithology and their interactions in semi-arid highlands of northern Ethiopia. Thus, from sustainability point of view and in the light of their nutrient retention capability and limitation, more attention should be paid toward ensuring periodic assessment and sustainable management of soils in steep cultivated lands.

ANALISIS KESESUAIAN FUNGSI KAWASAN HUTAN DI DESA MANDALLE KECAMATAN MANDALLE KABUPATEN PANGKAJENE DAN KEPULAUAN

The determination of forest areas in 1982, which is the basis for the function of forest areas, is currently considered to be less relevant, this is due to the large number of activities that are not in accordance with their designation and the presence of a new policy of the Ministry of Agriculture in 2021 where forest areas need to be reviewed using predetermined criteria. This study aims to determine the suitability of function of forest areas in Mandalle Village, which is currently based on the Decree of the Minister of Environment and Forestry number SK.362/MENLHK/SETJEN/PLA.0/5/2019 is a Protected Forest Area(Hutan Lindung). This research method uses the method of scoring forest areas with 3 (three) parameters, namely marbles, soil type and rainfall. From the results of this analysis, it is known that the steep slope class (25-40%) covers an area of 90.64 hectares with a percentage of 35.29% and the smallest the Flat slope class (0-8%) covers an area of 3.69 hectares with a percentage of 1.44%. The average rainfall at the study site was 14.78 mm / day (low) and the soil type of the study site was Podzolic which was categorized as sensitive soil.The results showed that the Protected Forest Area in Mandalle Village Mandalle Subdistrict Pangkajene and Islands Regency an area of ± 70,66 hectares (27,52%) suitable as Protected Forest, an area of ± 157,44 hectares (61,31%) directed as a Fixed Production Forest and an area of ± 28,69 hectares (11,17%) is directed as a Convertible Production Forest.

Land Landscape Analysis Using the Digital Elevation Model (DEM) Method in the Tetempangan Tourism Object, Mandolang District, Minahasa Regency

Abstract. Sandra E. Pakasi*), Vicky Fransiskus Solum ,Tommy D. Sondakh , Wiske Ch. Rotinsulu, Frangky J. Paat , Jooudie N. Luntungan, Diane D. Pioh. Land Landscape Analysis Using the Digital Elevation Model (DEM) Method in the Tetempangan Tourism Object, Mandolang District, Minahasa Regency. Ekoton 5. 36-43. This study aims to determine the state of the landscape in the Bukit Tetempangan Tourism Object, Mandolang District, Minahasa Regency. This study uses the Digital Elevation Model (DEM) method to obtain the state of the landscape, elevation data, and slope in the Tetempangan Tourism Object area. Data collection and processing techniques using the ArcGis 10.3 application. The results obtained in the Bukit Tetempangan Tourism Object Area have 3 slope classes, 0 - 25% (somewhat flat) with an area of 17.8 Ha, 25 - 40% (a bit steep) with an area of 5.33 Ha, and &gt;40% (very steep) with an area of 14.87 ha and a height of 568 meters above sea level (masl). The total altitude data obtained can reach 1986 points. Thus, at this location, there must be a conservation application to prevent erosion and landslides. Keywords: Analysis, Landscapes, Digital Elevation Model

Stemflow infiltration hotspots near-tree stems along a soil depth gradient in a mixed oak–beech forest

In an upland forested micro-catchment during the growing season, we tested soil responses to precipitation events as well as soil water content (SWC). We asked ourselves if what is the difference of SWC response to precipitation events depending on the presence and proximity of a tree? The environmental heterogeneity of the small 7.5-ha headwater area was captured by soil probes at specific locations: (i) probe measurements of SWC at 10-, 30-, 60-, and 100-cm depths; (ii) resolution of near-tree (NT) and between-tree (BT) positions; and (iii) resolution of four slope classes. The results revealed significant differences between the hydrological responses of the soil. NT soils had faster infiltration but were also faster to dry out when compared to BT soils, which were less affected by the presence of trees. Water input threshold values, measured as the precipitation amount needed to cause a significant increase in SWC, were also significantly different, with NT positions always lower than BT positions. Total infiltration of the topmost NT and BT soil layers reached 185 and 156 mm during the study period, corresponding to 43% and 36% of the total 434 mm of precipitation, respectively. Infiltration into the deepest horizon was significantly higher in NT soils, where it reached 114 mm (26%) as opposed to 9 mm (2%) in BT soils, and was indicative of significant vertical hydraulic bypass flow in the proximity of trees. These observations contribute to better understanding the hydrological processes, their nonlinearity, and the expansion of conceptual hydrological models.

Application of Numerical Newton-Raphson Method in Calculation of Emitter Water Discharge of Drip Irrigation System in “Mutis Cemerlang” Coffee Plantation

Based on the slope class, the shape of the area and the elevation of dry land in Nusa Tenggara, agricultural land in Noepesu Village is suitable for planting coffee plants with an agroforestry scheme. To overcome the problem of limited water, drip irrigation system technology can be applied. The use of drip irrigation as an agricultural technology in Noepesu village has been carried out by many farmer groups. Still, the installation process does not consider the pipe specifications (pipe length and pipe diameter) and the condition of agricultural land. This causes the service life of drip irrigation to be not long. If this continues, of course, it will increase system installation costs. To optimize service life, a hydraulics analysis method is needed for drip irrigation pipe network systems that take into account pipe specifications and agricultural land conditions.The hydraulics analysis of the drip irrigation network system determines the emitter’s water flow rate. The emitter flow rate forms a nonlinear equation known as the closed pipe equation. In the process of solving these equations, numerical methods can be used, specifically the Newton-Raphson method. This study focuses on applying the Newton-Raphson method to calculate the amount of water discharge from each emitter of the drip irrigation network system on the farmland of the Mutis Cemerlang Farmer Group in Noepesu Village. The drip irrigation system is designed with 250 nodes, 275 pipes, 26 loops, and 86 outlets divided into two sides, with the left side containing 84 outlets with one emitter and the right side containing 102 outlets with two emitters. The amount of water discharge for each emitter is 0,0008 ml/second≤Q≤2,6 ml/second for the left side and 0,001 ml/second≤Q≤1,1 ml/second for the right side, as determined by simulation calculations utilizing the Newton-Raphson method and Matlab software. The simulation results show that the amount of water discharge at each emitter is ideal in the first iteration because it has a discharge correction value (∆Q)≈0.

MECHANIZED WOOD HARVESTING APTITUDE ZONING

The need to increase forest enterprises productivity has demanded higher levels of mechanization. The objective of this study was to evaluate the suitability of areas in Espírito Santo State to implement mechanized wood harvesting using short log system. To prospect suitable areas for mechanization, algebra map of Eucalyptus edaphoclimatic zoning, land use and occupation, slope, conservation units and their respective buffer zones was performed. Thus, suitability zones were defined based on edaphoclimatic conditions for evaluated species, with temperatures between 19 and 26ºC, water deficit from 30 to 210 mm and annual average rainfall between 900 and 1800 mm defined as suitable. Land use and occupation was classified as fit, fit with type II limitation, fit with type III limitation and unfit. For slope classes, three categories were created: fit (0 - 27º), fit with limitation type I (27.1 - 35º) and unfit (&gt; 35º). Results showed that State has 39.45% of its entire area able to implement mechanized wood harvesting for Eucalyptus and 47.91% is unfit. With results, authors concluded that Northeast micro-region stood out with large areas suitable for Eucalyptus harvest mechanization and employed methodology has potential for use and adaptation in other study areas around world.

Implementation of Unmanned Aerial Vehicle (UAV) for Slope Mapping

This paper discusses the applications of unmanned aerial vehicle (UAV) for slope mapping and its important parameters including perimeter, area and volume of certain selected areas at Perumahan Taman Gambang Damai in Kuantan Pahang. This study also focused on determining the potential slope hazard based on slope angle. Modern UAV able to take high quality image which essential for the effectiveness and nature of normal mapping output such as Digital Elevation Model (DEM) and Digital Orthophoto. This photo captured by the UAV will later transfer to Agisoft to generate full map of study area. With the help of Global Mapper, the measurement (perimeter, area and volume) of selected study areas can be determined easily and considered as the main interest in this study. In addition, another outcome of this study is, this modern method of mapping helps researchers and engineers to study the possibility of slope hazard based on their respective slope angle (according to slope classes). In conclusion, modern technology of UAV proves to be very effective for mapping in geotechnical engineering. Slope mapping help researchers and engineers to obtain slope measurement within short period of time compare to previous traditional method.

Evaluating Productivity of Small-Scale Cable Yarding System Integrated with a Portable Winch

Small-scale forestry operations, which are used in non-industrial and site specific forestry, provide alternative logging methods suitable for precision forestry approach. In this study, a small-scale cable yarding system integrated with a portable winch was considered as alternative timber extraction method compared to a standard tower yarder. It was aimed to evaluate productivity of this yarding method, which was implemented during commercial harvesting activities performed in a 10.74 ha black pine stand located in Bursa province of Turkey. The main factors (i.e. slope, yarding distance, lateral pulling distance, log volume, log length), significantly affecting the productivity, were evaluated based on two slope classes (34–50% and 50–70%) and two yarding distances (100 m and 200 m). The results indicated that the average productivity was 0.95 m3/PMH and 0.90 m3/SMH. It was revealed that the productivity of the small-scale cable yarding decreased as the ground slope and the yarding distance increased. Statistical analysis indicated that there was a significant (p&amp;lt;0.001) relationship between productivity and log volume and length in four applications. On the other hand, it was found that there was a significant (p&amp;lt;0.05) relationship between productivity and lateral pulling distance in only the first application (34–50% slope; 100 m yarding distance). Considering the volume classes of the logs, it was determined that the productivity increased from the low volume class to the high volume class.

Climatic and topographic controls on glacial changes (1973-2020) in Shigar Basin, Central Karakoram, Northern Pakistan.

The Hindukush, Karakorum, and Himalaya (HKH) mountains are often referred to as the "Third Pole" because of high snow, being a major freshwater resource and early indicator of climate change. Therefore, research on the dynamics of glacier changes and their relationship with climate and topographic variability is essential for sustainable water resource management and adaptation strategies in Pakistan. In this contribution, we delineated 187 glaciers and examined these glacier changes in the Shigar Basin from 1973 to 2020 using Corona, Landsat Operational Land Imager/Enhanced Thematic Mapper Plus/Thematic Mapper/Multispectral Scanner System (OLI/ETM/TM/MSS), Alaska Satellite Facility (ASF), and Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) imageries. The total glacier area decreased from 2796.31 ± 132 km2 in 1973 to 2756.27 ± 63 km2 in 2020 at an average rate of - 0.83 ± 0.03 km2yr-1. Specifically, during the period of 1990-2000, these glaciers shrank most heavily at an average rate of - 2.372 ± 0.08 km2yr-1. In contrast, an increased rate of 0.57 ± 0.02 km2yr-1 in total glacier area was observed during the recent decade (2010-2020). Moreover, the glaciers with gentle slopes retreated less heavily than the steep ones. There was reduction in glacier coverage and length for all slope classes, and a small reduction was observed with gentle slopes, while higher losses were observed on steep slope gradients. The transition of glaciers in the Shigar Basin may be attributed by the direct influence of glacier size and topographical characteristics. By comparing with climate records, our findings suggest that the overall reduction in glacier area from 1973 to 2020 was associated with declining precipitation (- 0.78 mmm/year) and rising temperature (0.045°C/year) trends in the region, and glacier advances in recent decade (2010-2020) were likely to be driven by increased winter and autumn precipitation.

Study of soil chemical characteristics on citronella cultivation area in the Gayo Highlands

This research tries to identify the chemical state of the soil in the existing citronella planting area in the Gayo Highlands based on altitude, slope, and soil type. The method used in this research is the descriptive method, with data collected through field surveys and laboratory analysis. Soil samples were taken at each observation point by a purposive sampling method, which was determined based on the components forming a homogeneous land unit consisting of six (6) elevation classes, five (5) slope classes, and five (5) soil types. The results of the analysis showed that the highest value of C-organic was found at location Land Unit 6 (LU6) altitude above 1,200 meters above sea level (m asl), which was 7.29%, and the lowest value was found at location LU1 (200-400 m asl), which was 0.81%. While the highest variation of CEC values was found at locations LU6 and LU3 (600-800 m asl) with a value of 56.40 cmol kg−1, the lowest was found at locations LU1. The citronella cultivation area in the Gayo Highlands was studied based on altitude, slope, and soil type at each observation point. It is still suitable to be developed as a citronella cultivation area where the value of soil chemical characteristics found at each research location is in the low to very high criteria and the pH criteria are in the acid to slightly alkaline criteria.