bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploration of student’s understanding of distance and displacement concept
Authors: Jufriadi A , Kusairi S , Sutopo S 
Published: April 2021

Abstract
This study aims to explore students’ understanding of the kinematics, especially in the concepts of distance and displacement. This survey research involved 21 first-year physics students that registered in the odd semester of the 2019-2020 Physics Education Program at Universitas Kanjuruhan Malang. Justification of students’ understanding of kinematics concept is done by analyzing their responses to multiple choice questions, evaluating their arguments in answering the test items, and also through a series of individual interviews. With a mixed-method approach, the data are analyzed quantitatively and simultaneously as well as qualitatively. The result shows that about 42,8% of new students 2019-2020 understanding of displacement and distance concept, and the other have shallow understandings and even misconceptions. Exploration of understanding the concepts of distance and displacement can be used as reference material and consideration for educators to develop appropriate, measurable, and efficient learning strategies.
Feature extraction of noise signal in motorcycle by Fast Fourier Transform
Authors: Delina M , Nurhusni P A 
Published: April 2021

Abstract
This research aimed to study the feature of noise signal from various exhausts in motorcycles by the Fast Fourier Transform (FFT). The noise signal was examined into three different features; energy, entropy, and zero-crossing rate. The energy and entropy defined the noise came from an exhaust or non-exhaust, while the zero-crossing rate distinguished normal and racing-exhaust. The results showed that the energy of an exhaust noise was always in the range of 2.4 to 2.8 joule. The entropy of exhausts racing was observed in the range of 0.00 to 0.05 joule. When the acceleration pedal was on, the entropy was become higher. The zero-crossing rate of racing exhaust was in the range of 0.00 to 0.05, the non-racing exhaust was in the range 0.05 to 0.1.
Band gap energy calculation of theaflavin and Cyanidin-3-Glucoside molecules as active material in Dye Sensitized Solar Cells using Density Functional Theory (DFT)
Authors: Rizqillah G , Muttaqien I , Perkasa Y S , Sanjaya M , Ramdhani R , Aliah H , Pitriana P 
Published: April 2021

Abstract
Dye-Sensitized Solar Cell (DSSC) is one of photovoltaic (PV) cell which converts solar energy into electrical energy, by using dye as its active material. In this study, total energy and bandgap energy of natural dyes such as theaflavin and cyanidin-3-glucoside (C3G) molecules were calculated using density functional theory (DFT) method via quantum espresso software. Optimization of some calculation parameters such as cutoff energy, pseudopotential and k-point have been done to ensure minimum total energy of dyes molecule. Based on the result, the total and bandgap energy of theaflavin is 10172.80 eV and 1.96 eV, while the total and bandgap energy of the C3G molecule is 8442.26 eV and 1.73 eV. From these results, further investigation is necessary to the opportunities of the two dyes as DSSC sensitizers.
Changes in soil respiration after application of in situ soil amendment and phosphate fertilizer under soybean cultivation at Ultisol South Lampung, Indonesia
Authors: Yusnaini S , Niswati A , Aini S N , Arif M A S , Dewi R P , Rivaie A A 
Published: April 2021

AbstractSeveral inputs are needed to increase the production of soybean in Ultisol. The Application of organic soil amendment will increase carbon, nutrients, and water stored in the soil. Besides, the soil structure becomes stable so that plants will be more tolerant of climate change. The higher organic C in the soil, the more fertile soils, the plants grow healthier and fertile, and then the emission of CO2gas into the air can be suppressed. Therefore, this study aims to determine soil respiration (CO2) due to the application ofin situsoil amendment and phosphate fertilizer. This research was conducted at the research station of BPTP Natar, South Lampung, from July to November 2019, arranged with random complete block design in two factorials. The first factor is the source of phosphate fertilizer is without P fertilizer, TSP fertilizer 200 kg ha-1, and rock phosphate 5 tons ha-1, and the second factor is the application of soilin situamendments.i.e.: without the soil amendment, rice husk biochar 5 tons ha-1(B1), organonitrofos compost 10 tons ha-1, and cow dung manure 10 tons ha-1. All experimental units were fertilized with urea at a dose of 50 kg ha-1and KCl at a dose of 200 kg ha-1. The result showed that the highest soil respiration was obtained in the plot treated with rock phosphate and cow dung manure at the single factor. The combination of rock phosphate and cow dung manure resulted in the highest of soil respiration.
The effect of silicate fertilizer on the root development of rice and its tolerance to salinity stress
Authors: Rachmawati D , Ramadhani A N , Fatikhasari Z 
Published: April 2021

Abstract
The problem of salinity stress in agricultural land is increasing rapidly, mainly due to climate change. Salinity in the soil has a detrimental effect on the root growth of rice and reduces the ability of the plant to absorb water and other nutrients from the soil resulting in stunted growth. The application of silicate fertilizers is an effort to reduce the negative effects of salinity stress. Absorption of beneficial element silicon (Si) by rice plants can reduce salinity stress. The objective of this research is to analyze the effect of calcium silicate on rice root growth and its tolerance to salinity stress. This research was conducted with the addition of silicate fertilizer consisting of three levels of CaSiO3 (0 mM, 2 mM, 4 mM) in red rice (Oryza sativa L. ‘Sembada Merah’) under salinity stress treatment at the level of 0 dS m-1(control), 3 dS m-1 (low), 7 dS m-1 (moderate) and 10 dS m-1 (high). The treatment with a salinity level of 10 dS m-1 reduced root length, fresh and dry weight of the root. The addition of calcium silicate in salinity stress conditions was able to improve the root anatomical characteristics of rice ‘Sembada Merah’ by increasing the epidermis thickness, cortex thickness, stele diameter and root diameter. Silicate fertilizer is indicated to play a role in increasing suberin and lignin to form apoplast defenses in order to prevent the entry of Na+ ions into the stele.
Assessing major drivers of crop shifting from rice to horticultural production: a case of Landono sub-regency in Southeast Sulawesi
Authors: Saediman H , Indarsyih Y , Abdullah S , Fyka S A , Mboe I S 
Published: April 2021

Abstract
Climate change can have adverse impact on rice as it depends much on precipitation and temperature. In recent years, due partly to climate change, rice farming becomes riskier to failure and less competitive than other crops, so many farmers have left rice farming. This study aimed to determine the major drivers responsible for crop shifting from rice to horticultural production. The study was conducted in Abenggi village of South Konawe Regency in Southeast Sulawesi. Interview and Focus Group Discussions (FGC) were used to collect data and information. Data were analyzed using pairwise comparison method. Study results indicated that the pull factors were more dominant than the push factors. Five most important crop shifting drivers were high farm returns, lower risk of failure, high market demand from horticultural production, and high risk of failure and inadequate water supply from rice farming. Horticulture farming provides more benefits than rice farming in income generation and local economic growth, but abandoning rice fields might compromise food security promotion efforts in the long run. The government and all stakeholders should understand all these drivers to adopt integrated policies and programs in pursuing development objectives of food security promotion, poverty alleviation, and rural development to achieve sustainable development
The fluctuation of rice production of tidal swampland on climate change condition (Case of South Kalimantan Province in Indonesia)
Authors: Khairullah I , Alwi M , Annisa W , Mawardi  
Published: April 2021

Abstract
Indonesia has a wet tropical climate which is part of its territory crossed by the equator. The rice planting period in Indonesia follows the climatic conditions generally divided into two planting seasons, namely the rainy season from October to March and the dry season from April to September. Almost every 3 to 5 years extreme climate changes occur namely El-Nino and La-Nina which have an impact on rice production. Nationally, the extreme climate phenomenon above showed the effect on rice production. El-Nino during the year 1970–2010 was reported to cause a decrease in rice production around -4.08%, while La-Nina in the same period caused an increase in production by about 1.78%. However, the two extreme climatic conditions had reduced rice productivity by -0.50% and -0.65%, respectively. Most of the tidal swamplands have long been cleared and used for the cultivation of lowland rice. In an effort to optimize tidal swampland as a source of rice production in the future, several strategic actions are needed. The purpose of this paper is to uncover the effects of extreme climate change (El-Nino and La-Nina) on rice production and productivity in tidal swamplands and strategic efforts to overcome the decline in rice production due to the extreme climate changes.
Thermal comfort assessment over the past two decades in different landscape areas within Palembang City
Authors: Rusdayanti N , Karuniasa M , Nasrullah N 
Published: April 2021

Abstract
Urbanization has an impact on changing landscapes to built-up land so that it triggers changes in microclimate conditions and potentially disrupts the thermal comfort of urban communities. For two decades, the condition of air temperature and thermal comfort at two locations (Sukarami and Sako) in Palembang city with different landscape changes have been assessed in this study. The variations of air temperature over the past two decades were reported. The Temperature Humidity Index (THI) was an indicator for assessing thermal comfort and its values are categorized as comfortable, quite comfortable, and uncomfortable. The results showed that the air temperature in Sako increased by about two times greater than the increase at Sukarami which was 1.1 °C and 0.5 °C. This study clearly reveals that thermal comfort conditions have worsened in the last two decades. During 1999, the THI values were dominated by quite comfortable categories at both locations. After two decades, in 2019, the percentage of days in the quite comfortable category of both locations decreased by almost 60% at Sukarami and more than 80% at Sako. The main factor this difference occurs is the landscape changes with depletion of vegetation area at both locations.
The evaluate soil quality of mangrove forest in Merauke, Papua
Authors: Sumani  , Supriyadi  , Masiyah S , Aryani W 
Published: April 2021

Abstract
Mangroves are very important to reduce climate change impact since they have been the indispensably portion of the environment serving different functions such as coastline assurance, obstructing salt water interruption, aquaculture, fodder for post, kindling, charcoal generation and moderating botanical and faunal species. Knowledge of soil quality is important for appropriate decision making regarding sustainable land use systems mangrove forest. Soil quality management helps to maintain biological productivity; air and water quality; and human habitation and health. The objective was to evaluate and identify an effective SQ indicator dataset from different mangrove forest types in the Payum beach Merauke area, the soil quality index are computed for basic of framework soil management system. The study was carried out from November 2019 to May 2020. This research use descriptive exploratory research method through field survey. Precise inspecting with three trancec each measuring 5 m2 were built up in both plots. The total of 9 soil samples consisting of 3 trancec type were collected from layer surface 0 to 15 cm, for evaluated quantify soil nutrient reserve and soil quality index (SQI). Soil samples were the analyzed for physical, chemical and biology indicators were used standart laboratory method. The results showed that for mangrove forest has the lowest to medium soil quality index (0.34-0.38) so natural forest has the medium soil quality index (0.39). Soil organic carbon and available phosphorus play major roles in making significant differences in the SQI among the different mangrove forest.
Secondary metabolites of turmeric and ginger on various altitudes and soil characteristics
Authors: Setyawati A , Komariah  , Pujiasmanto B , Fatawi A , Batubara I 
Published: April 2021

Abstract
Turmeric (Curcuma longa) and ginger (Zingiber officinale) are included in important spice commodities in Indonesia. The altitude and the environmental condition have an impact on the secondary metabolite content in the medicinal plants. Moreover, the current situation of climate change also affecting on the local environmental condition which is impacting on the secondary metabolite production. This research aims for determining the effects of altitude and soil characteristics on secondary metabolites. The research method was surveyed, then purposive sampling on farmlands with different altitude and soil characteristics at Karanganyar District, Indonesia. The variables observed were altitude, climate, soil characteristics (soil pH, Cation Exchange Capacity, Organic Matter, texture, Nitrogen, Phosphorus and Potassium), and secondary metabolites of turmeric and ginger (curcuminoid, gingerol, shogaol). The results indicated that the secondary metabolite of turmeric affected by altitude, soil pH, soil texture sand and soil available phosphorus. On the other hand, the secondary metabolites of ginger are affected by altitude, soil pH, soil organic matter, soil texture (silt and sand), and soil phosphorus. Turmeric and ginger in the highlands were produced more secondary metabolites compared with in lowlands.
Organic vegetable farming system enhancing soil carbon sequestration in Bali, Indonesia
Authors: Sardiana I K 
Published: April 2021

Abstract
Climate change as an implication of global warming due to the influence of increasing concentrations of greenhouse gases in the atmosphere has become an important issue in recent decades. Organic farming plays an important role in mitigating climate change by reducing atmospheric greenhouse gas emissions through increased soil carbon sequestration. This study was designed to compare soil carbon sequestration levels between conventional and organic vegetable farming fields in Bali, Indonesia. Soil samples were taken from organic fields and conventional fields in pairs. Variables of soil organic carbon, soil labile carbon, and soil bulk density are measured. Vegetable yields were estimated by fresh weights from a quadrant of 45 plants (1.12 m2) in each farming system, which is then converted to the fresh weight per hectare. The results from soil analysis indicate that organic farming leads to soil with significantly higher soil carbon storage capacity than conventional farming. The labile C fraction shows a more significant increase compared to total C. Organic farming can increase by 1.13 tons C per hectare per year compared with the conventional farming system. The use of manure compost as an alternative in vegetable fields of Bali has resulted in increased soil organic carbon storage and gross benefits for farming. Although more research is needed on the actual emissions of CO2 gas from organic and conventional farming, this research can be used as an early indication that organic vegetable farming system can increase the mitigation of global warming, and build sustainable agriculture in Bali, Indonesia.
Land suitability evaluation for sorghum (Sorghum bicolor L.) at Gunungkidul, Yogyakarta, Indonesia
Authors: Komariah  , Ariyanto D P , Rachmawati V A 
Published: April 2021

Abstract
Gunungkidul, Yogyakarta is a dry area with limited water availability for farming. To support food security problems that may be resulted by climate change impact in the future, various possible commodities with the low water requirement, including sorghum, should be evaluated. This study aims to evaluate the land suitability of Gunungkidul in Yogyakarta, Indonesia for sorghum (Sorghum bicolor L.). This research was conducted in Purwodadi Village, Tepus District, Gunungkidul in Yogyakarta with purposive sampling and survey method at four land units. The results showed that the area was classified as marginally suitable (S3) due to the slope of more than 20% which is prone to erosion hazard, and not suitable (N) because of the loamy sand soil texture which may inhibit the root growth. However, constructing terraces and adding soil ameliorant such as organic fertilizer for rather long period are potential to increase the status to moderately suitable (S2) and S3, respectively. Overall, the sorghum farming at the area is feasible since the revenue cost ratio (R/C ratio) was bigger than 1 (1.46).
Climate change adaptation strategies in the highland by vegetable farmers
Authors: Hermawan A , Ambarsari I , Sarjana  , Kusumasari A C , Oktaningrum G N 
Published: April 2021

Abstract
The Highland of Magelang Regency has a strategic role as a vegetable production center in Central Java. Farmers in the highlands of Magelang cultivate various types of vegetables. Since highland vegetable farming hugely depends on rainfall as a primary water source, climate change remarkably affects farming. Vegetable farmers often encounter problems due to climate changes in drought and highly intense rainfall, which caused crop damage. Since specific studies on vegetable farmers’ adaptation strategies to cope with climate changes and their economic effects are still limited, this research aimed to study the phenomenon. The observation was performed by interviewing all members (20 farmers) of the Mutiara Organic farmers group in Sumberejo Village, Ngablak Sub-Regency, Magelang Regency, conducting field observation and soil analysis in September-November 2018. The results showed that farmers developed several adaptation strategies to deal with climate change, namely applying multiple cropping systems, developing organic agriculture, growing vegetables under plastic shelters, and expanding a vegetable nursery as an alternative source of income. Farmers cultivated extra crops in the wet season due to abundant water availability. Organic vegetable farming, which began in 2013, from the higher value of the benefit-cost ratio, was more profitable than non-organic farming. Besides, organic farming’s land quality was also better based on organic carbon (C-organic), Nitrogen (N), Cation Exchange Capacity (CEC), and other nutrients. Therefore this study recommended to develop organic vegetable farming on a broader scale and seriously support farmers’ vegetable nursery business, since it was profitable, contributed significant income for farmers, and strategic for vegetable farming industries development.
Factors influencing the adoption of integrated crop-livestock to support land conservation of organic agriculture in Mojosongo area, Karanganyar, Indonesia
Authors: Purnomo S H , Sari A I , Emawati S , Rahayu E T 
Published: April 2021

Abstract
The current climate change must be anticipated with various efforts in order to preserve nature, especially agricultural land. One effort to preserve sustainability is to apply organic agriculture that brings together crops-livestock. This study aims to determine the influence of four factors (farmer attitude, knowledge and skills, infrastructure, and government support) on the adoption of an integrated crop-livestock system. The basic method in this research is the survey research method. The research sample was determined by convenience sampling consisting of 40 farmers. Data collection techniques were carried out through interviews, observation and questionnaires. The variables used on the adoption of integrated crop-livestock were attitude (X1), knowledge (X2), infrastructure (X3) and government support (X4). Data analysis involved validity analysis, reliability analysis and multiple linear regression analysis. Validity and reliability tests showed the results were valid, with the value of r statistic > 0.5 and the reliability value of α > 0.6. Multiple linear regression analysis showed that all variables had positive values with regression equation Y = 1.102 + 0.374X1 + 0.153X2 + 0.108X3 + 0.145X4 + e and showed the coefficient of determination (R2) of 0.719. F test showed F-statistic > F-table (9.455 > 2.53) at significance level P < 0.05. T-test showed that t-statistic values of X1, X2, X3, and X4 were 2.435, 0.138, 0.478 and 1.209, respectively, while the t-table value was 2.030. Simultaneously, adoption factors (X1, X2, X3, and X4) affected significantly the adoption of integrated crop-livestock (Y), while partially only the X1 variable affected significantly the adoption (Y), and X2, X3, and X4 variables did not affect significantly.
Effect of organic fertilizers on CH4 and N2O production from organic paddy field
Authors: Anshori A , Sunarminto B H , Haryono E , Pramono A , Mujiyo  
Published: April 2021

Abstract
Organic fertilizer potentially results in healthy soils and sustainable agriculture. Organic fertilizer is a nutrients source in organic farming. Organic fertilizer application affects CH4 and N2O production. CH4 and N2O production affect increasing greenhouse gas emission concentration, global warming and further climate change. This study aimed to determine organic fertilizers effect on CH4 and N2O production from organic paddy fields. Five types of organic fertilizer namely mixed compost (MC), cow manure (CM), cow manure compost (CMC), straw compost (SC) and solid biogas waste (SBW) were added to paddy soil and determined CH4 and N2O production. The result showed that CH4 and N2O production were affected by organic fertilizer addition. CH4 production was 109.52 mg kg soil-1 day-1 and N2O production was 1.70 mg kg soil-1 day-1. The lowest production of both gasses was in SBW treatment. CH4 production was 177.21 mg kg soil-1 day-1 and N2O production was 2.80 mg kg soil-1 day-1. The highest was in soil with cow manure (CM) treatment. CH4 and N2O production correlated positively with organic carbon and Carbon and Nitrogen ratio (C/N) of organic fertilizers (p < 0.05). Application of solid biogas waste (SBW) with drainage treatment on 10th day and composting are the best effort to mitigate CH4 and N2O production.
Does soil type hold a role in the dynamic of carbon dioxide (CO2) emission from paddy rice fields?
Authors: Ariani M , Hanudin E , Haryono E 
Published: April 2021

Abstract
Soil holds a vital role in forming greenhouse gas (GHG) emission from paddy rice fields. There are three main GHG from paddy rice, namely Methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). This research aimed solely to explore the dynamic of CO2 emission from paddy rice with different soil types, namely sandy loam and clay soil. In each site, two-factor treatments were applied. There was water regime namely 1) continuously flooded, and 2) alternate wetting-drying (AWD) as the first factor and organic matter application namely 1) without organic matter (OM), 2) bio-compost 5 t ha-1, and 3) bio-compost 10 t ha-1. Carbon dioxide flux in sandy loam soil ranged between -11.50 to -0.47 mg CO2 m-2 d-1 under continuously flooded conditions and -7.64 to 3.03 mg CO2 m-2 d-1 alternate wetting-drying conditions. The clay soil was lower, ranging between -7.43 to 0.51 mg CO2 m-2 d-1 under continuously flooded conditions and -5.54 to 0.47 mg CO2 m-2 d-1 under alternate wetting-drying conditions. Clay soil tended to emit less CO2 emission than sandy soil. The result showed that soil physical characteristic plays an important role in controlling CO2 from paddy rice.