Soil Degradation Research Articles

A ecological study of galamsey activities in Ghana and their physiological toxicity

Background: Small-Scale Small-Scale Gold Mining (ASGM), locally known as "galamsey," has emerged as a pervasive issue in Ghana characterized with environmental degradation, land and water resource depletion, health hazards for miners, social and economic impacts. This comprehensive review explores the ecological and health effects of galamsey operations across different regions of the country. Methods: The study employs a systematic analysis method to examine the available literature from 2000 to 2023. Various academic databases, including PubMed, Google Scholar, JSTOR, and relevant government publications, were searched to gather relevant information. Findings: The review reveals that galamsey has had significant ecological consequences, including deforestation, habitat destruction, water pollution, and soil degradation, which have adversely affected Ghana's natural beauty. These environmental challenges pose a threat to local ecosystems and resources, particularly in the Ashanti, Western, and Central regions of Ghana. Moreover, the study highlights the physiological health issues faced by galamsey miners, such as accidents, physical strain, mental strain, kidney problems, respiratory disorders, and metabolic diseases. The presence of elevated levels of mercury, cyanide, arsenic, and cadmium in both the environment and the human body are directly linked to ASGM in Ghana. About seventy percent (70%) of the houses in ASGM community relied on surface water, and all of the homes utilized the fields or bush as their main toilet. Conclusion: Implementing remote sensing, geospatial technologies, promoting clean mining technologies, integrating environmental conservation, occupational safety and public health awareness are key technical and innovative measures to mitigate galamsey in Ghana. Novelty/Originality of this article: This study proposes an integrated approach to address the impacts of galamsey, combining remote sensing and geospatial technologies with public health and environmental conservation programs. The model can provide a comprehensive understanding of the spatial and temporal impacts of ASGM and enable more targeted interventions.

Intelligent Farming Systems in Future Using Machine Learning: A Focus on India

Abstract: The integration of machine learning (ML) into Indian agriculture holds transformative potential for addressing critical challenges such as climate variability, water scarcity, soil degradation, and market fluctuations. This paper explores the current state of ML applications in Indian agriculture, highlighting successful case studies and initiatives led by government, private sector, and academic institutions. It discusses the technological integration of ML with the Internet of Things (IoT), remote sensing, and blockchain to enhance precision farming practices. Key barriers to widespread adoption, including data quality, infrastructure, and farmer awareness, are identified, along with strategies to overcome them. Future directions emphasize the importance of robust data infrastructure, localized ML models, collaborative research, sustainable practices, and supportive policy frameworks. By leveraging ML, Indian agriculture can achieve significant improvements in productivity, sustainability, and profitability.

Comparing the financial benefits of different grain production systems in South Africa’s summer rainfall region

There is growing evidence that soil degradation, among other factors, has led to both the decline and constraint of agriculture in southern Africa. Conservation and regenerative agriculture (CA/RA) have been proposed as a grain crop production system that could slow down, halt or even reverse some of these disturbing trends. But the question remains whether it is financially viable. We sought to find an answer to this question by comparing the financial returns of a CA/RA system over a 20-year period to its alternatives, namely conventional tillage (CT) and no-tillage (NT) production systems. The cumulative free cash flow (CFCF) of the average between the realistic and conservative CA/RA scenarios in year 20 is considerably higher than that of the other systems under investigation. The CFCF for CA/RA in year 20 in Mpumalanga is estimated to be R86 million, compared to -ZAR51 million for CT and about ZAR4 million for NT. That is a net difference between ZAR137 million (compared to CT) and ZAR82 million (compared to NT). In the Maluti area, the CFCF for the CA/RA production system is estimated at ZAR26 million, compared to -ZAR66 million for CT and -ZAR19 million for NT. In the North-West production area, the CFCF for the CA/RA production system is estimated at ZAR35 million, compared to -ZAR9 million for CT and about ZAR21 million for NT. The differences between the CFCF of the CA/RA system and the other systems represent the financial opportunity cost of not converting to the CA/RA system.

Prescribed fire and grass mulch impact on selected soil properties and amelioration potentials of amendments under an agricultural field in Ile-Ife, Nigeria

Prescribed fire (slash and burn) tends to impede the sustainable functionality of soil in agricultural systems. However, the use of amendment has a potential to reverse these negative effects. Prescribed fire is still used by farmers in Nigeria for land preparation before planting. This has continued to increase soil degradation in Nigeria with no agronomic activities that could ameliorate this effect in view. This study therefore examined the influence of prescribed fire and grass mulch on selected soil physical properties and organic carbon immediately after burning, and the potential of amendment to improve the soil properties negatively affected by fire. The prescribed fire treatments consisted of 200 °C and 500 °C fire intensities using Megathyrsus maximus (a large perennial bunch of grass that is dominant in the study area) as the fuel and also served as the grass mulch. Cured poultry manure at 7.5 t ha−1 was combined with urea at 40 kg N ha−1 and applied as a combined amendment while a single dose of urea was applied at 80 kg N ha−1 as an inorganic amendment. The experiment was carried out across three cropping seasons on maize (Zea mays L.) in 2019 and 2020. Soil water repellency (SWR), bulk density (Db), soil unsaturated hydraulic conductivity (Kunsat), water stable aggregates (WSA), soil strength (SS), and soil organic carbon (SOC) were determined immediately after burning and three months after amendments were applied. Data obtained were subjected to analysis of variance and means separated using the Duncan multiple range test at p≤0.05. Results showed that prescribed fires increased SWR by an average of 50.1 and 62.7 % for 200 °C and 500 °C intensities, respectively compared with the control. Three months later, the SWR was reduced by 25.9 % and 62.3 % for 200 °C and 500 °C, respectively when no amendment was added. Notably, the addition of sole urea and cured poultry manure + urea reduced the SWR by 50 % and 48.5 %, respectively in the 200 °C intensity, and 62.2 % and 62.7 % in the 500 °C intensity, respectively. Also, Kunsat was reduced by an average of 49.6 and 62.2 % by 200 °C and 500 °C intensities, respectively just after burning. However, it was not improved three months after the prescribed fires despite the applied amendments. The prescribed fire of 200 °C and grass mulch had no significant influence on OC just after the fire. Also, amendments did not significantly improve OC three months after prescribed fire. Therefore, the non-improvement of other soil properties, after the applied amendments, showed that further study is required to determine the required rate of the applied amendments that will significantly improve other soil properties negatively affected by prescribed fire in agricultural soils.

Water, Sanitation, Waste Management, and Professional Activities in Relation to Diseases with Neighboring Citizens of Congo Rivers in the Brazzaville Agglomeration (Republic of Congo)

Situated on the right bank of the Pool Malébo, in the Congo River basin, the city of Brazzaville is rich in potential water resources. These resources are polluted by human practices that deteriorate the quality of the soil and, consequently, the quality of the water. The aim of this study is therefore to inventory the activities carried out by the population around watercourses, to investigate waste management and to assess the impact on water and soil quality. The survey sample was selected on the basis of impacted zones located between 250 m and 750 m around watercourses. The aim of this study is therefore to inventory the activities carried out by the population around watercourses, to investigate waste management and to assess the impact on water and soil quality. The survey form was drawn up using Sphinx Plus2-Edition Lexica-V5 software. The survey data was entered into the same software, then transferred to Excel to generate the graphical. 880 people were surveyed, the most dominant age group was 25-48 years old, i.e. a rate of 66%. The most dominant gender was female, with a rate of 54%. The average age of the respondents was lower secondary school, and they were generally employed in the private sector. Commercial activities (restaurants/bars, pharmacies, grocery stores/ butchers, markets, etc.) are the most common economic activity, with a rate of around 70%; 59% of these activities are located close to or very close to the watercourse (750-1000 m). The activities that contribute to soil degradation, and consequently water degradation, in the city of Brazzaville are: 59% the dumping of household waste and/or wastewater on the ground and 32% uncontrolled urbanization. The study shows that soil and water pollution in Brazzaville is caused by poor management of household waste and uncontrolled urbanization.

Anaerobic hydrocarbon biodegradation by alkylotrophic methanogens in deep oil reservoirs.

Methanogenic biodegradation of crude oil is a common process in subsurface biodegraded oil reservoirs. This process was previously assigned to syntrophy of hydrocarbon-degrading bacteria, and methanogenic archaea. Recent studies showed that archaea of the Candidatus Methanoliparum named as alkylotrophic methanogens coupled hydrocarbon degradation and methane production in a single archaeon. To assess geochemical role of Ca. Methanoliparum, we analyzed the chemical, and microbial composition, and metabolites of 209 samples from 15 subsurface oil reservoirs across China. Gas chromatography-mass spectrometry analysis revealed that 92% of the tested samples were substantially degraded. Molecular analysis showed that 85% of the tested samples contained Ca. Methanoliparum, and 52% of the tested samples harbored multiple alkyl-coenzyme M derivatives, the intercellular metabolites of alkylotrophic archaea. According to metagenomic, and metatranscriptomic analysis, Ca. Methanoliparum dominates hydrocarbon degradation in biodegraded samples from the Changqing (CQ), Jiangsu (JS), and Shengli (SL) oilfields, and it is persistently present as shown in a 15-year long sampling effort at the SL oilfield. Together, these findings demonstrate that Ca. Methanoliparum is a widely distributed oil degrader in reservoirs of China, suggesting that alkylotrophic methanogenesis by archaea plays a key role in the alteration of oil reservoirs, thereby expanding our understanding of biogeochemical process in deep biosphere.

Impact of moisture on the degradation and priming effects of poly(lactic acid) microplastic

AbstractThe degradation of biodegradable microplastics (MPs) can either stimulate or inhibit the decomposition of soil organic carbon (SOC), but the factors influencing these phenomena remain unclear. In this study, we used the 13C natural abundance to differentiate between carbon dioxide (CO2) arising from the mineralization of SOC and poly(lactic acid) (PLA) MP under varying soil water holding capacity (WHC) in alkaline and acidic soils. We also quantified the incorporation of soil‐ or PLA‐derived carbon (C) into phospholipid fatty acid (PLFA)‐distinguishable microbial groups. An increase in soil moisture did not significantly affect PLA MP degradation in alkaline soil, but significantly increased PLA degradability in acidic soil. In particular, the percentages of PLA‐derived C incorporated into PLFA‐distinguishable gram‐negative and gram‐positive bacteria were 14%–63% and 5%–33%, respectively, in all the treatments. The presence of PLA MP induced positive priming effects from 0 to 20 d in all the treatments but subsequently induced negative priming effects under some conditions. The total priming effects induced by PLA MP were significantly greater in alkaline soil with ≥70% WHC (37–43 mg C kg−1 soil) than in this soil with 50% WHC (8.6 mg C kg−1 soil). The total priming effect was 72–78 mg C kg−1 soil in acidic soil with ≤70% WHC, but a negative priming effect was observed in this soil with 90% WHC (−56 mg C kg−1 soil). In alkaline soil, the dissolved organic carbon content was positively correlated with the priming effect, but a negative relationship was observed between the priming effect and the amount of soil‐derived C incorporated into gram‐negative bacteria and fungi. In acidic soil, a positive correlation was found between the priming effect and the soil nitrate content. In summary, our findings indicate that 0.4%–2.8% of PLA MP was degraded in soils after 2 months, and that the intensity and direction of the priming effect induced by PLA MP are regulated by soil moisture and pH, but further exploration is needed to elucidate the microbial mechanisms underlying these effects.

Factors governing the dynamics of soil organic carbon and nitrogen in wetlands undergoing management changes in a semi-arid region

Soil organic carbon and nitrogen play pivotal roles as indicators of soil quality and ecological functioning in wetlands. The escalating impact of human activities and climate change has led to a severe degradation of wetland soils, particularly in semi-arid regions. However, an understanding of the factors governing the dynamics of total soil organic carbon (TSOC) and total soil nitrogen (TSN) in semi-arid areas remains elusive, impeding a comprehensive understanding of wetland ecological functions. The present study investigated variations in TSOC and TSN content as well as vegetation and soil physicochemical properties under five different land management practices (mowed wetlands, mowed and slightly grazed wetlands, moderately grazed wetlands, heavily grazed wetlands, and natural wetlands unaffected by human interference) in the semi-arid Songnen Plain region of China. The results revealed significant decreases in TSOC and TSN content within managed wetlands compared to natural wetlands. Moreover, positive correlations were observed between pairs of SOC-TN or their storage values for SOC (TSOC)-TN (TSN). Furthermore, TSOC and TSN exhibited significant positive associations with aboveground and belowground biomass levels, stem C:N, stem C:P, soil C:P, and soil N:P. Additionally, redundancy analysis indicated that species diversity accounted for 37.4% of the variations in TSOC-TSN while belowground biomass accounted for 8.5% of the variations. Furthermore, nutrient content within stems (particularly N content and C:P) contributed to a 37.2% variation in TSOC and TSN whereas root nutrient content (especially N:P, C:N, and C:P) contributed to a 15.3% variation. Soil C:P, C:N, and total phosphorous (TP) content accounted for 65.7%, 9.6%, and 7.5% of variations of TSOC and TSN, respectively. Besides, variation partitioning analysis revealed that plant community characteristics, community nutrient content, and soil physicochemical properties collectively influenced the dynamics of TSOC and TSN. Among these factors, soil physicochemical properties emerged as the primary drivers of carbon and nitrogen dynamics in degraded wetlands in semi-arid regions. The impact on TSN was more pronounced than that of TSOC. This study provides valuable insights for understanding the processes and mechanisms underlying carbon and nitrogen accumulation in degraded wetlands, facilitating the development of regionally adaptive management plans under different management practices.

Mechanical Behavior of Frozen Soil Subjected to Freeze–Thaw Cycle Under Cyclic Impact Load and Passive Confining Pressure

In this study, the effects of freeze–thaw cycles and cyclic impacts on frozen soil were systematically investigated. With an increase in the number of freeze–thaw cycles, the peak stress of frozen soil decreased until a stable state was achieved. Moreover, subjecting frozen soil to an increased number of cyclic impacts led to notable alterations in mechanical characteristics, including peak stress, critical strain and dynamic elasticity modulus. Both the freeze–thaw cycles and cyclic impacts were identified as primary damage mechanisms in understanding frozen soil degradation processes. Damage resulting from these impacts conformed to the Weibull distribution pattern. Damages induced by freeze–thaw cycles, individual impacts and cyclic impacts were integrated into the Zhu–Wang–Tang viscoelastic model (ZWT model). Relying on principles of elastic mechanics, the role of confining pressure on frozen soil was examined and subsequently integrated into an improved ZWT model. To evaluate the model’s effectiveness, its predictions were compared with experimental results.

USING THE GEOSPATIAL MULTI-CRITERIA DECISION ANALYSIS MODEL AND METHODS FOR SOIL DEGRADATION RISK MAPPING

Modern methods of spatial analysis and modeling are increasingly being combined with decision-making methods and fuzzy set theory. The latter are actively integrated into the environment of Geographic Information Systems (GIS), such as well-known ones like ArcGIS or QGIS, in the form of separate tools, plugins, or Python scripts. Decision-making methods allow structuring the problem in geographical space, as well as taking into account the knowledge and judgments of experts and the preferences of the decision-maker in determining the priorities of alternative solutions. This paper provides a description of a geospatial multi-criteria decision analysis model, which allows addressing a wide range of ecological and socio-economic issues. An example of applying this model to map soil degradation risk in Ukraine is presented in the paper. According to the object-spatial approach, the properties of a territory are determined as the result of the action (impact) of a set of objects (processes) belonging to this territory. The territory is represented as a two-dimensional discrete grid, each point of which (local area) is an alternative. The set of local areas of the territory constitutes the set of alternatives. The representation of the territory model as a system of objects and relationships between them allows justifying the choice of a set of criteria (factors) for assessing soil degradation risk. Each criterion is a separate raster layer of the map. To build a hierarchical decision-making structure and calculate the importance coefficients of the criteria, the Analytic Hierarchy Process (AHP) method is used. To account for uncertainty in assessments and judgments of experts at the stages of standardization of alternative attributes by different criteria and aggregation of their assessments, expert membership functions for fuzzy sets and fuzzy quantifiers are applied. The particular feature of the proposed multi-criteria decision analysis model is its low computational complexity and ease of integration into the GIS environment.

Investigation of transformer oil aging using no-core optical fiber (NCF) sensor

Abstract Transformer oil plays a crucial role in insulation and cooling within high-voltage transformers, but it degrades over time. This research proposes a durable sensor capable of detecting the refractive index (RI) of transformer oil when it exceeds the RI of the sensor structure, known as high refractive index (HRI) sensing. The study utilizes a no-core optical fiber (NCF) to monitor the quality of transformer oil. In this setup, single mode fiber (SMF) is employed as both the input and output of the NCF, forming an SMF-NCF-SMF (SNS) sensor. To date, to the use of an NCF in the SMF-NCF-SMF scheme has not been reported for high RI fiber sensing and transformer oil degradation detection. Additionally, this study provides an analysis of the influence of different diameters and lengths of NCF on the sensor’s sensitivity. The HRI sensing performance of the sensor was evaluated both numerically and experimentally by observing power spectrum changes due to leaky modes interference in response to varying transformer oil RI values from 1.4600 RIU to 1.5500 RIU. The NCF, with a geometry of 1 cm in length and 100 µm in diameter, demonstrated remarkable sensitivity, achieving up to 88.285 dBm/RIU for HRI values within the specified range. The sensor effectively discerned various aging levels of transformer oil in power transformer applications. Additionally, since the NCF structure is entirely composed of silica-based materials, it exhibited significant temperature resistance. These characteristics make the SNS structure well-suited for reliable deployment in challenging thermal environments.

Determination of oil quality during crispy pork rind frying: near infrared spectra and color values as predictors

This study provides a comprehensive analysis of oil degradation during the frying of various semi-finished pork rinds, including high-fat (HF), non-fat (NF), streaky (SK), and thin (TN) types. By quantitatively assessing parameters such as peroxide, acid, anisidine, and Totox values, we sought to elucidate the complex interactions and effects on oil quality during the frying process. The oil samples underwent evaluation utilizing a near-infrared (NIR) spectrometer and the color variations in the frying oil during the process. The resulting data highlighted significant correlations between color parameters and oil quality. The NIR models exhibited an impressive and robust predictive proficiency with high correlation coefficients values (R > 0.9 for all measured parameters) and low root mean square errors of cross-validation (RMSECVs). They promise rapid, non-destructive, and accurate evaluation of oil quality during frying processes. Additionally, the study identified oil color as a viable, low-cost alternative for predicting oil quality parameters where sophisticated spectroscopic equipment is unavailable.

Thermodynamic insights into the degradation of oil well cement by CO2 under geologic sequestration conditions

Geological carbon storage (GCS) is an effective way to reduce CO2 emissions into the atmosphere. The degradation of oil well cement by CO2 poses a risk to the feasibility of GCS. It is critical to understand how the oil well cement degrades. The previous research is mainly experimental. The objective of this paper is to investigate the degradation of the oil well cement by thermodynamic theory in terms of the chemical reaction of individual phase and the phase evolution of the cement-CO2-water system. The results show that hydration products have different degradation resistance. The order of degradation resistance from best to worst is revealed. The thermodynamic equilibrium of the chemical reactions of degradation is affected by temperature and pressure. The higher the temperature and pressure, the less likely a chemical reaction will occur. Temperature tends to affect more than pressure does. The hydration product of the oil well cement is determined by thermodynamic modeling. The hydration products consist of calcium silicate hydrate solid solution (CSHQ), Si-hydrogarnet solid solution (Si-HG), ettringite solid solution (Ettri), portlandite (CH), and OH-hydrotalcite (OH-HT). The hydration products begin to degrade in the following order: CH, CSHQ, Si-HG, Ettri, and OH-HT. The results can be used to improve the degradation resistance of the oil well cement and research new type of degradation resistant cement. The thermodynamic theory is an effective way to investigate the degradation of the oil well cement by CO2 under geologic sequestration conditions.

Possibility of brewery wastes application to soil as an organic improver of biological and chemical properties

Soil degradation, marked by declining organic matter, threatens global food security. The impact of brewer's spent yeast (BSY) on clay and sand was analysed at varying application rates to assess its effectiveness in improving soil quality. A randomized complete block design with three replicates was employed. One kilogram of soil were mixed with BSY at application rates of 2 t/ha and 5 t/ha. The samples were incubated at 26 °C for 5 months with daily watering. We analysed pH, total nitrogen, organic carbon, total phosphorus, and electrical conductivity (EC); microbial activity (total heterotrophic bacteria, actinobacteria, and fungi) and soil enzyme activity (dehydrogenase, catalase, protease). BSY application improved soil quality, particularly in clay. Clay showed increased in pH, EC, N and C. BSY significantly boosted microbial populations (bacteria, fungi) in clay with a lesser effect in sand. Enzyme activity and a fertility index also improved in BSY-treated clay, while sand displayed increased activity of a different enzyme. Results suggest BSY holds promise as an organic fertilizer, especially for clay soils. Further research is needed to optimize application, understand long-term effects, and evaluate economic feasibility and social acceptance. This study contributes to the search for sustainable, local solutions to improve soil health and agricultural practices.

Analyzing the impacts of watershed management interventions and scenarios on soil erosion reduction using InVEST model in Yezat watershed, North West Ethiopia

ABSTRACT Land degradation is a serious problem for Ethiopia's productive capacity for land resources. To reverse these environmental dynamics, slow down soil degradation, and raise smallholder farmers’ agricultural yields, watershed management interventions have been implemented in Ethiopia since the 1980s. Thus, this study was aimed at assessing the effects of watershed management interventions on soil erosion reduction by using the InVEST model in the Yezat watershed, north-west Ethiopia. The modified ecosystem services valuation model (InVEST) was employed to evaluate soil loss reduction in response to watershed management interventions. Different watershed management intervention scenarios (baseline scenarios, afforestation scenarios, soil/stone bund scenarios, and integrated scenarios) were also applied to evaluate the effectiveness of watershed management interventions on soil loss reduction. The result of the study indicated that a high amount of mean annual soil loss (111 tons ha− 1 year−1) was observed in 2000 in the study area due to the expansion of cultivated land and built-up area at the expense of forest, shrubland, and grassland. However, the mean annual soil loss decreased from 111 tons per year in 2000 to 79 tons per year in 2021 in the study area due to different watershed management interventions. Additionally, at the baseline scenario, the estimated mean annual soil loss of the watershed was 111 tons ha-1 yr-1. Conversely, it was reduced to 49.3 ton ha-1 yr-1 in the reforestation scenario, 16.49 ton ha-1 yr-1 in the soil bund scenario, and 8.26 ton ha-1 yr-1 in the integrated scenario. The watershed covered by the very severe soil erosion severity class was reduced in all watershed management intervention scenarios. Among others, the highest soil erosion reduction was observed in the integrated (bio-physical) scenarios of watershed management interventions. Therefore, watershed management interventions and scenarios were the best mechanisms for soil loss reduction.

农业车辆作业后不同深度的土壤应力分析

In modern agriculture, with the development and widespread use of agricultural mechanization, mechanical compaction of soils has become a growing problem, resulting in soil degradation in the field. Based on the Boussinesq solution, the soil stress formula for the circular load area is derived, and MATLAB is used to simulate the stress-strain relationship of the soil at different depths. The results show that under the same load conditions, as the soil depth increases, the soil stress gradually decreases, with the most significant stress change occurring at 0.2 m depth. Soil compression experiments conducted using a consolidation instrument revealed that the soil void ratio dropped rapidly under loading of 50-200 kPa, and the decline slowed after 400 kPa. When the soil void ratio decreases to 0.2-0.4, the soil stress changes tend to stabilize. Comparison between the theoretical formula and the compression experimental data indicates that the soil stress gradually decreases as the thickness of the soil layer increases and the pressure load increases, verifying the linear relationship predicted by the theoretical formula.

‘Propagandists for the Soil’: Gender, Erosion and the Murray Valley in the Mid-Twentieth Century

This article studies the contributions of a trio of settler Australian women to a wider conversation about soil and water conservation in the Australian Alps in the mid-twentieth century. The women discussed here began their interventions during the war years and continued their efforts into the immediate postwar decade. Their education and labour as well as, to varying degrees, their family’s affluence and esteem, and wartime afforded these women new opportunities to engage directly with the challenges of soil degradation and to share the insights they drew from these firsthand experiences. Focusing on the contributions of Jocelyn Henderson, Maisie Fawcett and Elyne Mitchell, this article argues that soil conservation in 1940s and 1950s southeastern Australia was a profoundly gendered project that only gained legitimacy and authority as its importance became recognised by state governments.

Effect of Soil Tillage Systems and Crop Seasonality on the Sediment Geochemical Properties Transferred into a Headwater: A Case of Study in Tobacco Plantation

ABSTRACT The global impacts of agricultural land conversion on soil erosion and pollution, particularly in tobacco cultivation areas, are well-recognized as significant contributors to soil degradation. These areas are identified as hotspots for environmental concerns due to practices that lead to increased erosion and pollution. From this perspective, this case of study explores fine sediment samples from two areas with tobacco cultivation under different tillage systems and seasonal variations, transport into a headwater, and evaluates, on a local scale: (1) the impact of tillage systems on the geochemical signature of sediments; (2) if whether crop seasonality affects these sediment geochemical signatures. The Conventional Ridge Tillage (CRT) system involves extensive soil exposure and machinery for soil management, while the Mulch Ridge Tillage (MRT) system prioritizes soil conservation and relies on herbicides for weed control. The analytical methodology used to assess the sample element characteristics was Energy Dispersive X-ray Fluorescence (EDXRF). It was applied on the twenty fine sediments (ten of harvest and ten of inter-harvest season of tobacco) to quantitatively assess their inorganic composition. Additionally, Pearson correlation analysis, Hierarchical Cluster Analysis (HCA), and Principal Component Analysis (PCA) were applied on the EDXRF data to highlight the similarities and, thus, providing information to assess the complex data clustering patterns. As a result, the sediment compositions from the two studied soil systems are not similar. The PCA showed that the CRT sediments are characterized by the P, S, K, Ca, and Mn content, presenting a geochemical signature related to manure and fertilizer compared to the MRT, which is correlated with Al, Ti, Fe, Cu, and Zn contents, exhibiting a geochemical signature characterized by the natural soil composition. Therefore, the sediment geochemical signatures might be affected by two phases in the study area: a) tillage system characteristics and b) seasonal soil erosion. These findings underscore the importance of managing soil nutrients to mitigate soil pollution and nutrient exportation to aquatic systems. Moreover, the results emphasize the recommendations for sustainable agricultural practices in tobacco-growing areas to protect environmental quality.

Participatory Assessment of Agriculture Land and Vegetation Associated Issues and Possible Interventions in Gurage Zone, Ethiopia

Land degradation and depletion of natural forests made agriculture unsustainable and threaten communities and ecosystems as a whole. The objective of this participatory assessment was to identify researchable issues related to agricultural land and vegetation cover in Gurage zone. Accordingly, seven representative districts were selected and from each district two representative kebeles were purposively selected. Focus Group Discussion with farmers, development agents and subject matter specialists and direct observation were important primary sources of information. The survey result depicts in the Gurage zone land degradation, undulating steep slope topography, small and overwhelmed land tenure, inappropriate land use system, cultural landscape mismanagement, deforestation of indigenous trees and expansion of eucalyptus tree, and decreasing enset production are the major identified problems associated with land use and vegetation cover of the study area. In the mixed farming system, enset is produced as a homestead farm and its coverage is decreasing due to disease, lack of processing machines, and shortage of organic matter. Due to the expansion of eucalyptus and land use change, the majority of native trees are disappearing or decreasing in area coverage. Therefore, enset and eucalyptus require suitable policy attention. In the mountainous areas of Gurage; limited land availability, soil degradation, shortage of appropriate farm technologies, water scarcity, lack of knowledge for alpine agriculture and inconvenient topography for mechanized farming machines issues threaten agriculture of area. Despite the fact that there are few attempts to control land degradation; the issue still needs much attention. Appropriate agricultural technologies and knowledge suited for mountain agriculture, dense populations, enset-based farming systems, and small land tenure are important priority research focus areas for future research.

Anthropogenic restoration exhibits more complex and stable microbial co-occurrence patterns than natural restoration in rubber plantations

Forest restoration is an effective method for restoring degraded soil ecosystems (e.g., converting primary tropical forests into rubber monoculture plantations; RM). The effects of forest restoration on microbial community diversity and composition have been extensively studied. However, how rubber plantation-based forest restoration reshapes soil microbial communities, networks, and inner assembly mechanisms remains unclear. Here, we explored the effects of jungle rubber mixed (JRM; secondary succession and natural restoration of RM) plantation and introduction of rainforest species (AR; anthropogenic restoration established by mimicking the understory and overstory tree species of native rainforests) to RM stands on soil physico-chemical properties and microbial communities. We found that converting tropical rainforest (RF) to RM decreased soil fertility and simplified microbial composition and co-occurrence patterns, whereas the conversion of RM to JRM and AR exhibited opposite results. These changes were significantly correlated with pH, soil moisture content (SMC), and soil nutrients, suggesting that vegetation restoration can provide a favorable soil microenvironment that promotes the development of soil microorganisms. The complexity and stability of the bacterial-fungal cross-kingdom, bacterial, and fungal networks increased with JRM and AR. Bacterial community assembly was primarily governed by stochastic (78.79 %) and deterministic (59.09 %) processes in JRM and AR, respectively, whereas stochastic processes (limited dispersion) predominantly shaped fungal assembly across all forest stands. AR has more significant benefits than JRM, such as a relatively slower and natural vegetation succession with more nutritive soil conditions, microbial diversity, and complex and stable microbial networks. These results highlight the importance of sustainable forest management to restore soil biodiversity and ecosystem functions after extensive soil degradation and suggest that anthropogenic restoration can more effectively improve soil quality and microbial communities than natural restoration in degraded rubber plantations.