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Evaluation of Andisol Soil Physicochemical Properties and Their Relationship to Potato (Solanum tuberosum L.) Production in Karo Regency
No full textAndisol soils, which dominate the Karo Regency, have low nutrient availability and a high capacity for phosphate fixation, and these conditions often cause crops to experience nutrient deficiencies that ultimately reduce productivity. Potato production in the region varies widely because the characteristics of Andisol soils, elevations, and cropping patterns applied by farmers in each land mapping unit differ considerably. These variations lead to inconsistent crop responses to nutrients, pH, soil texture, and land management, resulting in the absence of site-specific cultivation recommendations. Therefore, this study is needed to clarify how soil characteristics and cropping patterns influence potato productivity so that more effective and sustainable land-management strategies can be developed.
This study aimed to characterize the variation in physicochemical soil properties across different Land Mapping Units (SPL) in Karo Regency and to identify the soil factors that most strongly influenced potato production. The study also assessed the effects of several cropping patterns on changes in soil properties and potato yield. Ultimately, the research sought to determine the optimal combination of soil characteristics and cropping patterns to support productive and sustainable management of Andisol soils. The study was carried out across multiple SPLs in Karo Regency, which exhibit substantial agroecological diversity, including elevations ranging from 1,000 to 1,600 m above sea level, slopes of 2–35%, soil textures from sandy to predominantly silty, and cropping systems such as rotation without mulch, rotation with mulch, intercropping, monoculture, and mulched monoculture on sloping land.
This research was conducted in Karo Regency and focused on land characteristics across various elevations and slope gradients for potato cultivation, based on the established Land Mapping Units. The study consisted of two main parts. n the first part, the researcher examined the soil characteristics of potato cultivation areas through the stages of preparation, data collection, and data analysis. The researcher collected primary and secondary physical data and obtained soil samples from each land unit for analysis at the Soil Laboratory of PT Socfindo. The soil characteristics were analyzed by comparing the physical environmental conditions with the growth requirements of potatoes, based on land suitability criteria and cropping patterns, to evaluate land quality and characteristics. In the second part, the researcher analyzed the influence of soil characteristics and cropping patterns on potato (Solanum tuberosum L.) production on Andisol soils in Karo Regency. This study was conducted from February to June 2023 on several potato fields representing different cropping systems, including monoculture (with and without mulch), intercropping with vegetables, and crop rotation (with and without mulch). In this stage, the researcher collected soil samples for physical and chemical analysis, while yield data were obtained from farmers’ fields.
The results of the first research phase showed that the physicochemical properties of the soil in each Land Map Unit (SPL) in Karo Regency varied considerably. Andisol soils across all units exhibited moderately acidic to acidic pH values, ranging from 4.63 to 4.99 (H₂O), with high to very high organic carbon contents of 3.31–7.18%. The capacity of cation exchange was classified as very high, ranging from 28.03 to 43.19 me/100 g. The most notable variation among land units was observed in Bray II-P, which ranged from 90.97 to 231.09 mg/kg, and in base saturation, which ranged from 5.44% to 11.51%. In addition, the exchangeable cations Ca-dd and Mg-dd differed significantly, with Ca-dd ranging from 0.37 to 2.29 me/100 g and Mg-dd from 0.38 to 1.39 me/100 g. These differences reflected variations in topography, soil texture, and nutrient leaching intensity across the SPLs. Potato yields in all SPLs ranged from 17.33 to 24.67 t/ha, with the highest yield recorded in SPL 1, which had high soil moisture, Bray II-P of 204.44 mg/kg, base saturation of 11.51%, and Ca-dd of 2.29 me/100 g. Conversely, the lowest yield was found in SPL 4, characterized by Bray II-P of 182.68 mg/kg, low base saturation (5.44%), and very low Ca-dd (0.52 me/100 g). Overall, the findings indicated that potato production was strongly influenced by Bray II-P, Ca-dd, Mg-dd, base saturation, soil texture, and cation exchange capacity. Land units with higher Bray II-P, adequate Ca-dd, and relatively stable sandy textures produced higher yields than units with overly sandy textures and low base saturation.
The second phase of the study analyzed various cropping patterns, including rotation without mulch, rotation with mulch, monoculture, intercropping, and rotation–mulch systems that influenced soil conditions and crop yields. The results showed that the use of mulch consistently increased soil moisture, maintained the stability of Bray II-P, and improved soil structure, particularly on sloping land. The rotation–mulch pattern produced the highest yields in almost all land units because it was able to reduce the loss of silt and organic matter due to erosion, especially on slopes ≥20%. Rotation without mulch improved Ca and Mg during the early vegetative stage, but a decline in base saturation at harvest resulted in suboptimal tuber formation. Monoculture produced the lowest yields because it caused rapid soil compaction, decreased organic matter, and reduced nutrient uptake efficiency. Intercropping generated better yields, although its effectiveness depended strongly on the type of companion crop and the degree of shading.
The integrated results of both studies showed that potato production in Karo Regency was determined by a combination of factors: elevation, silty soil texture, high organic carbon content, a balanced Ca–Mg ratio, a pH approaching neutral, high Bray II-P levels, and the use of rotation–mulch cropping patterns. Accordingly, soil management strategies for mountainous Andisols needed to focus on increasing soil pH, strengthening the Ca–Mg balance, implementing soil conservation measures on sloping land, and applying mulch to maintain water stability and prevent soil structure degradation.129 PagesDisertasi Dokto
Artificial Immune System Controlled Adaptive Multi-Agent Classification and Segmentation Network (AISAM-CSNet) Model for Convolutional Neural Network Optimization in Image Classification and Segmentation
No full textAutomatic and precise image classification and segmentation remain significant challenges in various modern computer vision (CV) applications. To enhance visual analysis capabilities, CV needs to be combined with Machine Learning (ML) or Deep Learning (DL), which in many cases have been proven to surpass human performance. However, CV often encounters obstacles such as low image quality, complex object image background, variations in viewing angles, and color similarities between object parts, which lead to intra-class variations. Traditional ML approaches still require complex manual feature engineering and heavily depend on human expertise, while DL requires large datasets to be effective. When data is limited, DL models often suffer from overfitting or underfitting. Determining hyperparameters becomes crucial yet difficult to perform manually due to the complexity of DL architectures. These conditions cause many conventional algorithms to fail in producing optimal segmentation and classification results. To address these problems, this study introduces AISAM-CSNet (Artificial Immune System-Controlled Adaptive Multi-agen Classification and Segmentation Network), a multitask deep learning model designed to perform adaptive image classification and segmentation. This model integrates an adaptive multi-agent approach, Reinforcement Learning (RL) control, and Artificial Immune System (AIS) optimization to improve efficiency and accuracy. Each CNN layer acts as an agent optimized through locally rewarded RL, while hyperparameter adjustment is performed globally using AIS. As a case study, AISAM-CSNet uses strawberry and pineapple images to detect defective areas and classify postharvest quality, which until now has been assessed manually and subjectively. Evaluation results show that AISAM-CSNet outperforms various baseline classification models such as VGG16, RestNet50, and EfficientNet-B0 with an average accuracy of 92.6%. For segmentation, AISAM-CSNet also outperforms the UNet and DeepLab V3 baselines with an IoU of 84.4%. Based on the Multi-task Performance Efficiency (MPE) evaluation, AISAM-CSNet is able to maintain a balance between the number of parameters and multitask performance. Compared to the heaviest baseline (ResNet50 + DeepLabV3+), AISAM-CSNet, with approximately 42.1 million parameters, is proven to be 1.58× more efficient while achieving higher performance. The model also demonstrates a competitive parameter–performance ratio, where the increase in parameters is proportional to the multitasking advantages that baseline models do not possess. These findings support the development of sustainable smart agriculture technologies based on computer vision and evolutionary optimization.176 PagesDisertasi Dokto
Differences in the number of Staphylococcus aureus Bacteria In Throat Swabs of Active Smokers and Non-Smokers in Selayang Village Medan Selayang District
No full textStaphylococcus aureus is a gram-positive bacterium, facultative anaerobic, producing yellow pigment in cocci form, with a diameter of 0.5-1.5 μm, arranged like grapes, catalase positive and found singly or in pairs. This bacterium can cause infections in the oral cavity with characteristic signs such as inflammation, necrosis, and abscess formation. Staphylococcus aureus also has the ability to form biofilms on tooth surfaces, making it difficult to kill with standard antibiotics. This results in chronic infections such as endocarditis, osteomyelitis, and the formation of pus pockets or abscesses. Staphylococcus aureus can spread through the blood vessels, causing abscesses in the lungs and bones. People who smoke cigarettes regularly exhale smoke and affect others, especially those aged 10-18 years, increasing from 7.2% to 9.1%. Active smokers are exposed to more genotoxic substances than passive smokers. In several studies, active smokers with throat swabs can be isolated from Staphylococcus aureus bacteria. Purpose of the study to determine the number of Staphylococcus aureus bacterial colonies and the difference in the number of Staphylococcus aureus bacterial colonies in throat swabs of active and non-smokers in Selayang Village, Medan Selayang District. Method this study used descriptive observational research with a cross-sectional approach, presented in tabular form and analyzed. Results of the study showed that there are 100% of 10 Staphylococcus aureus bacteria in active smokers, the average number of colonies is 120 with the highest number of colonies PA2 183 colonies and the lowest PA3 with 69 colonies and in non-smokers 60% with an average number of colonies of 25 colonies in non-smokers the highest number of colonies is NP1 with 48 colonies and the lowest is NP9 with 14 colonies. Other bacteria that could be isolated were Streptococcus sp., Klebsiella pneumoniae, Staphylococcus warneri, Kocuria kristinae, Staphylococcus hominis and Staphylococcus lentus. Conclusion is that there is a difference in the number of Staphylococcus aureus bacterial colonies in active smokers and non-smokers.91 PagesSkripsi Sarjan
The Role of Communication in the Work Activities of Employees in the Assistant Inspectorate Section of the North Sumatra Inspectorate Office
No full textIn an organization, communication plays an important role as a driving force that connects people, teams, and ideas to achieve common goals. However, based on observations at the North Sumatra Provincial Inspectorate, specifically in the Assistant Inspectorate for Region One, various communication problems were found, such as miscommunication between employees, weak horizontal communication, and a lack of motivation among employees to implement good communi-cation. This study aims to determine the role of communication in the work activities of employees in the Assistant Inspectorate for Region One of the North Sumatra Provincial Inspectorate. This study uses a qualitative descriptive approach. Data were collected through three main techniques: direct observation, interviews with employees of the Assistant Inspectorate for Region One, and internal documentation of the institution. The communication methods used are still ineffective, causing disruption to work activities, which often arises from the lack of reciprocity in the reception of messages by employees, high levels of egoism, and the existence of a dominant perspective in creating good communication, while communication plays a very important role in employee work activities. Communication plays a very important role in the work activities of employees at the Regional Assistant Inspectorate. However, this role has not been carried out effectively and optimally due to obstacles such as a weak understanding of effective communication among human resources and a lack of skills in carrying out effective communication. Therefore, it is necessary to conduct open dialogue, effective conflict resolution, and training for employees on good communication.95 PagesKertas Karya Diplom
Evaluation of Rice Plant Diversity (Oryza sativa L.) F2 Results of Mercury-Tolerant Parent Crossbreeding
No full textThis study aims to evaluate the genetic diversity of F2 generation rice plants(Oryza sativa L.) resulting from the crossbreeding of five parents, namely IF-16,IR-64, Inpari-32, Cakra Buana, and Siganteng. The study was conducted at theExperimental Field of the Faculty of Agriculture, University of North Sumatra,fromJune to September 2025. The research material consisted of 10 F2 families andtheir reciprocals, each of which was planted with 65 plants. The parametersobserved included plant length, number of tillers, number of productive tillers, ageat panicle emergence, panicle length, harvest age, percentage of filled grains,percentage of empty grains, and grain yield per hill. The results showed highgenetic diversity in the agronomic traits observed. Heritability values varied fromlow to moderate to high. Several traits, such as the number of productive tillers andpercentage of filled grains, showed high heritability values, indicating a dominantgenetic role. Distribution analysis based on skewness and kurtosis values showedthat some traits were controlled by additive genes, while others were influenced byepistatic genes with polygenic inheritance patterns. The IF-16 x Cakra Buanagenotype was identified as having the highest grain yield, while the Inpari-32 xCakra Buana genotype had the lowest yield. Thus,the F2 population resulting fromthe cross between mercury-tolerant parents has the potential to be a geneticresource that can be utilized in rice breeding programs to produce superiorvarieties that are adaptive to environmental stresses and have high productivity.56 PagesSkripsi Sarjan
Empirical Model Of Temperature And Cutting Parameters Correlation In Hard Turning Of AISI 4340 Steel With The Response Surface Methodology
No full textHis study aims to develop an empirical model describing the correlation between cutting parameters—spindle speed (n), feed rate (f), depth of cut (a), and main cutting angle (Kr)—and cutting temperature in the hard turning process of AISI 4340 steel using coated carbide tools. The experimental work was carried out on a conventional lathe using a Response Surface Methodology (RSM) approach with a Central Composite Design. Cutting temperature, measured using a non-contact infrared thermometer, served as the response variable, while statistical analysis including regression and ANOVA was performed to evaluate the influence of each cutting parameter.The experimental results show that the cutting temperature ranges from 90 to 160 °C, with spindle speed identified as the most significant factor affecting temperature rise. In contrast, feed rate, depth of cut, and cutting angle exhibit relatively minor effects. The developed empirical model produced an R-sq value of 51.08%, while the adjusted R-sq and predicted R-sq were 8.28% and 0%, respectively, indicating that the model has limited predictive capability. Additionally, theoretical temperature estimation using the Cook method was performed and compared with the experimental results. Overall, both trends show similar patterns despite deviations observed at several data points.This study provides insight into the influence of cutting parameters on cutting temperature and presents an empirical model that may serve as an initial reference for optimizing hard turning processes with respect to heat control and energy efficiency.87 PagesSkripsi Sarjan
Association of National Early Warning Score 2 with Short-Term Mortality among Neurocritical Patients at Adam Malik Hospital Medan
No full textBackground: Neurocritical patients are at high risk of early clinical deterioration and short-term mortality due to acute neurological injury accompanied by systemic physiological disturbances. Early assessment of disease severity is essential for identifying patients at increased risk of mortality. The National Early Warning Score 2 (NEWS2) is a physiological scoring system designed to detect clinical deterioration; however, its association with short-term mortality in neurocritical patients requires further evaluation.
Objective: To determine the association between National Early Warning Score 2 (NEWS2) and short-term mortality in neurocritical patients admitted to the intensive care unit of Adam Malik General Hospital, Medan.
Method: This was a prospective cohort study involving 62 neurocritical patients admitted to the ICU. NEWS2 was calculated using physiological parameters recorded within the first 24 hours of intensive care unit admission. The outcome was 14- day mortality. Bivariate analysis was performed to assess the association between NEWS2 and mortality. Receiver operating characteristic (ROC) analysis was used as an additional method to evaluate the strength of the association and to identify the optimal cutoff value.
Result: The 14-day mortality rate was 64.5%, with a median NEWS2 score of 7 (range 2–14). A NEWS2 score >6 was significantly associated with increased 14- day mortality (RR 1.710; 95% CI: 1.109–2.638; p = 0.007). ROC analysis yielded an area under the curve (AUC) of 0.768, with a sensitivity of 67.5% and specificity of 68.2% at the cutoff >6.
Conclusion: A significant association between NEWS2 score and short-term mortality was observed in neurocritical patients. Higher NEWS2 scores were associated with an increased risk of short-term mortality, supporting the role of NEWS2 as a clinical risk stratification tool in the ICU.134 PagesTesis Magiste
Evaluation of Physiological Characters and Yield of F2 Rice (Oryza sativa L.) Derived from Crosses of Mercury
No full textMercury (Hg) contamination in agricultural land is a major constraint in rice
cultivation as it negatively affects plant physiological performance and yield. This
study aimed to evaluate the physiological characteristics and yield of F2 rice (Oryza
sativa L.) derived from crosses of mercury-tolerant parental lines. The research was
conducted at the Experimental Field of the Faculty of Agriculture, Universitas
Sumatera Utara, Medan, in April 2025. The plant materials consisted of ten F2
genotypes along with their reciprocal crosses derived from five rice varieties,
namely IF-16, IR-64, Inpari-32, Cakrabuana, and Siganteng. The planting medium
was topsoil treated with 15 ppm mercury to simulate heavy metal stress conditions.
Observed parameters included chlorophyll content, stomatal density, leaf area,
fresh and dry weight of shoots and roots, and yield per plant. The results showed
significant differences among several genotypes and their reciprocals in most
physiological and yield parameters under mercury stress. Certain cross
combinations exhibited better physiological performance and higher yield,
indicating the inheritance of mercury tolerance traits from the parental lines.
Therefore, F2 rice genotypes derived from mercury-tolerant parents have potential
as selection materials in breeding programs aimed at developing mercury-tolerant
rice varieties.72 PagesSkripsi Sarjan
Analysis Of The Distribution Of Curly Chili Commodity (Capsicum Annuum L.) Di Kabupaten Karo Provinsi Sumatera Utara
No full textThis research aims to analyze the base areas and the distribution characteristics of curly chili (Capsicum annuum L.) commodities in Kabupaten Karo based on the principles of localization and specialization. The methods used in this study are Location Quotient (LQ), Localization Index (LI), and Specialization Index (SI). The data used are secondary data on curly chili production per kecamatan from 2019 to 2024.
The results of the LQ analysis show that kecamatan such as Kutabuluh, Laubaleng, Mardingding, Tiganderket, and Payung consistently serve as production base areas for curly chili, indicated by LQ values greater than 1. A shifting trend in base areas is also seen from the increasing LQ values in Naman Teran and Kabanjahe in recent years. LI analysis shows that kecamatan such as Merek, Dolat Rayat, and Tiganderket have high production concentration, while kecamatan like Merdeka, Simpang Empat, and Kabanjahe have negative LI values, indicating a low concentration or specialization in this commodity. Meanwhile, SI analysis shows that Kutabuluh, Laubaleng, and Tiganderket have high specialization levels in curly chili production. Conversely, areas such as Merdeka, Simpang Empat, and Kabanjahe show negative SI values in almost every year, indicating low production contribution. Overall, this study provides a comprehensive spatial and temporal overview of the base areas, concentration, and specialization of curly chili in Kabupaten Karo, which can serve as a foundation for sustainable commodity development planning.
Keywords: Cabai keriting, Location Quotient (LQ), Localization Index (LI), Specialization Index (SI), Kabupaten Karo.76 PagesSkripsi Sarjan
The Role Of Parents Towards School Dropouts In Lawe Desky Village Babul Makmur Subdistrict Southeast Aceh District
No full textThis study aims to examine the role of parents in the educational lives of school dropout children in Lawe Desky village, Babul Makmur Sub-district, Aceh Tenggara Regency. The number of school dropouts in this villige is relatively high compared to neighboring villige and has contributed to the emergence of risky social behavior among children. This research employs a qualitative approach using a case study method. The informants consist of school dropout childen, parents, teachers, village officials, and school reprensentatives. Data were collected through in-depth interviews, observation, and documentation, and analyzed using the Miles and Huberman model, including data reduction, data disply, and conclision drawing. The findings indicate that parents‟ roles in supporting children‟s education have not been optimally fulfilled. Parents tend to provide limited attention, supervision, and learning motivation. Education is often viewed as a secondary need, particularly under economic constraintas. Additionally, parents‟ low education as a fundamental right of children. Poor communication and lack of parental guidance result in decreased motivation to attend school, leading children to drop out. The study concludes that weak parental involvement is a key factor contributing to school dropout cases in Lawe Desky Village. Therefore, increased parental awareness, active involvement, and support from government and social institutions are necessary to reduce school dropout rates.126 PagesSkripsi Sarjan