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The productivity of olive in the northwestern coastal zone of Egypt is significantly constrained by drought and low organic matter in the soil. This study addresses these challenges by exploring the synergistic effects of olive mill wastes (OMW) application and micro-catchment water harvesting techniques on soil properties, runoff, moisture storage, and rainwater harvesting efficiency. Field experiments were conducted over two winter seasons, employing different micro-catchment structures (semi-circular and triangular bunds) and OMW applications. The results revealed that the integration of semi-circular bunds with OMW application (T4) substantially increased rainwater harvesting efficiency by 67.7% and 46.4% in the first and second seasons, respectively. Additionally, T4 and T5 exhibited reduced runoff by 47.8% and 41.3% in the first season and 49.4% and 38.9% in the second season, respectively. T4 significantly enhanced soil organic matter, soil macronutrients (N, P, and K), and micronutrients (Fe, Mn, Zn, and Cu) compared to the control (T1). The study highlights the effectiveness of T4 in improving soil moisture, reducing soil erosion, and enhancing soil fertility. This integrated approach involving OMW application within a semi-circular bund as a water harvesting system proves to be a promising strategy for sustainable olive cultivation in arid conditions. [ABSTRACT FROM AUTHOR]

The Soil and Water Assessment Tool Plus (SWAT+) model depends on the Modified Universal Soil Loss Equation (MUSLE), which in turn depends on the peak runoff rate for the estimation of soil loss from a catchment. The SWAT+ model generates a random number for each day in the process of peak runoff rate estimation from the catchment. On the other hand, the model provides calibration parameters like the peak rate adjustment factor for sediment routing in the tributary channels and main channels. There is uncertainty that how likely the SWAT+ model estimates the actual peak runoff rates. An improved MUSLE does not depend on the peak runoff rate, and, therefore, it minimizes uncertainty related to the peak runoff rate when estimating soil loss from the catchment in the SWAT+ environment. On the other hand, the effect of the topographic factor of the MUSLE or improved MUSLE on soil erosion and sediment transport is not explicitly explained. Therefore, we modify the source code of the SWAT+ model for sediment yield estimation by replacing the improved MUSLE and the best-fitted equations of the topographic factor in the source code. The modified SWAT+ model showed better performance than the original SWAT+ model. [ABSTRACT FROM AUTHOR]

The present comprehensive review delves into the pivotal role of morphometric analysis in watershed management, particularly in prioritizing sub-watersheds (SW) and reservoir catchments. Herein, the authors highlight the critical areas of water spread, soil erosion patterns and aquifer recharge. The study emphasizes the significance of morphometric parameters for effective conservation measures. The review takes a multifaceted approach, analyzing various parameters, exploring mathematical expressions and discussing the tools for sub-watershed (SW) prioritization. The areal, relief and linear parameters play a crucial role in comprehending watershed drainage networks, which in turn impact soil erosion, runoff, flood etc. In view of utility of fundamental Horton's laws, the present study provides a detailed description of each parameter's classification where the range of values and the impact of digital elevation model (DEM) accuracy on morphometric analyses have been discussed. While acknowledging the laborious nature of traditional morphometric analysis, the review also advocates for modern data reduction methods such as principal component analysis (PCA). In the present work, we have described the gaps observed in the sequenced literature reports cited through the content. In addition, the assessing parameter correlations are also acknowledged for emphasizing the ongoing challenges. [ABSTRACT FROM AUTHOR]

Water erosion poses a significant threat to the sustainability of natural resources and hydro-agricultural infrastructure, particularly in the Mediterranean region, including Morocco. The Allal El Fassi watershed faced such challenges and underwent anti-erosion measures between 2008 and 2014. This study aims to evaluate the effectiveness of these measures in mitigating dam siltation within the watershed. The methodologies employed include the utilization of the MUSLE model, optimized with bathymetric surveys of the dam, to estimate the amount of sediment reaching the dam and derive the P-factor associated with the implemented anti-erosion measures. Additionally, the radioisotope technique was utilized to assess erosion rates at managed and unmanaged sites within the watershed. The results obtained using the MUSLE model and bathymetric data revealed a noteworthy reduction in mean annual soil loss within the timeframe of 2002–2010 to 2010–2013, resulting in a 13.9% decrease in sediment reaching the dam. Furthermore, variations in the P-factor of erosion control measures were observed, ranging from 0.31 to 0.52 during the respective periods. Utilizing the radionuclide 7Be, erosion rates ranging from 6.8 to 25.3 t.ha−1 were determined for the studied plots, facilitating the calculation of P-factors for specific erosion control measures. Significantly, gabion check dams displayed a P-factor of 0.47, dry stone barriers had a P-factor of 0.41, fruit trees with basins showed a P-factor of 0.51, and enclosures exhibited a P-factor of 0.67. These findings suggest a causal relationship between the implementation of erosion control measures and the reduction in sedimentation rates at the Allal El Fassi Dam, highlighting the interdependence between the two phenomena. [ABSTRACT FROM AUTHOR]

Sediment fingerprinting is increasingly being used to provide information that can help guide management decisions at the watershed scale. The objectives of this study were to investigate the implications of different sediment fingerprinting sampling designs on characterizing sediment dynamics in the Beheshtabad Watershed in Chaharmahal va Bakhtiari Province, western Iran. First, nitrogen, organic carbon, phosphorus, potassium, calcium, sodium, zinc, manganese, iron, and lime fingerprints were used to discriminate among four potential sediment sources including agricultural topsoil, rangeland, as well as rainfed and urban lands. Then, the suspended sediment was collected from drainage areas at five sites. Nested and local-location fingerprinting sampling designs were employed to evaluate the influence of geomorphic connectivity and land use on apportionment results by using the same source and sediment data set. By averaging all locations using the nested method, agricultural land with an average of 69% had the highest contribution to sedimentation followed by rainfed land with an average of 19.9%, rangeland with an average of 6.8%, and urban lands with an average of 5.99%. Compared to the mean of the total method samples, the local method showed greater soil loss from agricultural lands and lower soil loss from rangeland and rainfed lands. Generally, surface soil in sediments came from agricultural land use. According to the results, total nitrogen, phosphorus, organic carbon, and calcium were the optimum tracers that correctly distinguished source samples. Overall, each of the two fingerprinting sampling designs provided the same information. Thus, the fingerprinting method can determine the sources of sediments. Given the importance of the fingerprinting method, future studies can focus on determining the appropriate combination of tracers and the effect of sediment sampling time. [ABSTRACT FROM AUTHOR]

Soil erosion is considered to be a prominent problem, and its regular spatial assessment in the watershed is required. Thus, for the present study, the Kodar river basin in Chhattisgarh, India, was chosen for the investigation. Three different models, namely Universal Soil Loss Equation (USLE), Revised Universal Soil Loss Equation (RUSLE), and Unit Power-Based Soil Erosion and Deposition (USPED), were chosen by incorporating remote sensing and GIS platforms and their performance were compared. On the basis of area's varied slope and land usage, the erosion rate was calculated. It was noted that a difference of 33,68632 t, −11570.08 t, and 1023.99 t in the sedimentation values of the USLE, RUSLE, and USPED models, respectively were observed. The observed sedimentation data was validated, and the USPED model was found to be the most authentic model among the selected three models. Hence, the present study will be helpful in better understanding of the complex interactions of the variables involved in predicting net erosion of soil. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The spatial differentiation of forest canopy branches and leaves affects rainfall interception. However, the scientific expression of the spatial differentiation of forest canopy branches and leaves has not been clarified, and revealing the effect of spatial differentiation of branches and leaves of the vertical structure of the forest canopy on rainfall interception is difficult. Using the Pinus massoniana planted in Changting County, China, as the research object, this study quantified the spatial differentiation of canopy branches and leaves in a hierarchical manner by combining the unmanned aerial vehicle (UAV) three-dimensional point cloud model with the landscape metrics and further simulated the interception mechanism of Pinus massoniana forest canopy on rainfall of different intensities by constructing the principal component regression model. The results showed that the spatial differentiation of canopy branches and leaves in different strata responds differently to different rainfall intensities. [ABSTRACT FROM AUTHOR]

The selection of promising and appropriate plant species and knowledge of their effects on the soil are essential for mineland rehabilitation success. The present study evaluated the effects of three different plant seed cocktails on fertility, soil cover, and erosion control in two iron waste piles in the Carajás Mineral Province, Eastern Amazon, Brazil. The three different seed cocktails were: commercial (only commercial species); native (only species native of Carajás); mixed (native and commercial species); and a control treatment (without seed application). Additionally, tillers from native grasses from Carajás were planted in one of the waste piles. The cocktails were applied by hydroseeding together with fertilizer, mulch, organic compost, and a tackifier. Analyses were performed at 12 and 24 months after the seeding in the waste piles. In general, all cocktails contributed to vegetation establishment, organic matter accumulation, and increased soil fertility. The commercial cocktail stands out due to its ability to improve soil fertility. Native species showed the best cover performance, and less soil loss, highlighting their use for effective control of soil erosion. Thus, native species have the potential for use in rehabilitation projects involving iron waste piles in the Amazon. This is especially relevant because the use of native plant species is mandatory and a declared rehabilitation target. [ABSTRACT FROM AUTHOR]

The restoration of native vegetation like pines helps mitigate soil erosion, but the effects of pine needle litter on runoff, erosion, and hydrology in karst hillslopes are unclear. This study investigated these factors during the rainy season from June to August 2021 under six treatments (flat, gentle, and steep slopes with and without pine needle coverings). The results showed that pine needle litter significantly increased the soil water content, particularly on steeper slopes, by improving the water-holding capacity. It also substantially reduced runoff (by 23.8%) and soil erosion (by 92.5%). The critical rainfall threshold for generating runoff did not occur in the pine needle covering treatment, whereas it was 19.3 ± 8.8 mm in the bare soil treatment under wet conditions. These findings highlight the efficacy of pine needle cover in reducing runoff and erosion in karst areas, promoting it as a sustainable method for restoring degraded soil. [ABSTRACT FROM AUTHOR]

The agri-food industry, produces organic residues that could be reused as fertilizer, thereby allowing the recycling of nutrients for crops and the replacement of mineral fertilizers. In this context, here we examined the capacity of anaerobic digestates and mixed residues (digestates plus spent mushroom substrates) to supply nutrients to lettuce (Lactuca sativa L.) grown in a greenhouse experiment. Moreover, the potential leaching of nutrients into the soil was evaluated in a column assay. The results obtained from organic residues treatments were then compared to those achieved in soil treated with mineral fertilizer and in untreated soil. Digestates treatments minimized the potential risk of nitrate (NO3−) leaching by allowing the slow release of NO3− maintaining crop yield. Given our observations, this type of organic residues emerges as an alternative to mineral fertilizer. The loss of NO3−-N from the total amount of N applied reached ∼3% in the mixed residues treatments, 36–46% in the digestate treatments, and 68% in the mineral fertilizer treatment. The mixed treatments showed low available N content as a result of immobilization in the soil, which is a limiting factor for crop production. Moreover, the organic residues treatments had no negative effect on lettuce seed germination or plant growth with respect to parameters such as chlorophyll, total polyphenols, and heavy metals in aerial biomass. The findings reported herein contribute to a better understanding of nutrient availability provided by organic residues materials and the capacity of these amendments to replace mineral fertilizers and avoid nutrient loss by leaching. Digestate treatments showed a similar capacity to maintain lettuce production as mineral fertilizer. Mixed treatments did not provide mineral N for the crop by N immobilization in soil. Nitrate loss when organic residues were applied was lower than for the mineral fertilizer treatment. Soil amendment with organic residues has no negative effects on lettuce yield. Digestates emerge as an alternative to mineral fertilizers for lettuce production, reducing soil nutrient loss. [ABSTRACT FROM AUTHOR]

The Himalayan region is the most sensitive due to its fragility, especially in soil erosion; therefore, it is a growing concern for environmentalists and natural resource planners. The study river basin Mandakini is situated in the central part of the Garhwal Himalayan region (Uttarakhand, India), which is highly prone to soil erosion due to various hydro-geomorphological factors. The factors include precipitous slope, geology, rugged terrain, land use and drainage pattern. Therefore, to identify the erosion-prone areas of the study basin, employed watershed prioritization technique using geographical information system and remote sensing integrated with weighted sum analysis (WSA), sediment production rate (SPR) and Technique of Order Preference Similarity to the Ideal Solution with Analytical Hierarchical Process (AHP-TOPSIS) models. It is calculated by taking different parameters indicating linear, landscape, and shape parameters. All the sub-watersheds (SW) of the basin were prioritized in different categories for all models with model performance for the Mandakini river basin in the central Himalaya. The results are showing almost similar results except for high erosion-prone regions. The results of the SPR model indicate that vary large areas (43.47%) of the basin suffering from severe erosion limited in the north-central (WS11, WS12, WS21), eastern (WS2), and southern (WS22 and WS23) parts of the basin among 23 sub-watersheds. The result of model evaluation indicates AHP-TOPSIS is the efficient model in assessing soil erodibility. The study can help to undertake the precise decisions to propose an effective framework for soil erosion control measures and encourage soil conservation priorities of the region. The findings have implications for defining sustainable land resource management and conservation, which are critical to attaining the United Nations' 2030 Agenda for Sustainable Development's societal goals. [ABSTRACT FROM AUTHOR]

The increasing soil erosion (SE) and the associated problems for society, economy, and environment sparked a lot of interest in estimating and mapping SE at different basin scales. The estimation of SE exhibits that SE ranges from 10 to 50 t ha-1 yr-1, with a mean SE of 20 t ha-1 yr-1. The very steep slopes account for 54.21% of total soil loss. The SRB areas where soil loss rates are >10 t ha-1 yr-1 are considered the target areas which account for 27% of the study area and 96% of the soil loss). The high SY is concentrated only in the first-order basins located in a higher slope zone in the northern part of the river. Besides, basin morphometry (basin shape, relative relief) and anthropogenic activities (agricultural land) are retained in the PSLR model as significant factors contributing to SY in the entire river basin. [ABSTRACT FROM AUTHOR]

Soil erosion poses a significant threat to sustainable land management and agricultural productivity. Addressing this issue requires advanced predictive models that can accurately identify areas at risk and inform soil conservation strategies. This study focuses on the development and interpretation of well-optimized deep learning (DL) models to predict soil erosion probability, aiming to enhance decision-making in land management. Utilizing the Revised Universal Soil Loss Equation (RUSLE) in conjunction with ground-truthing, we identified critical erosion-prone areas. To predict soil erosion probability, we employed Bayesian optimization to fine-tune Deep Neural Network (DNN), Convolutional Neural Network (CNN), Fully Connected Neural Network (FCNN), and DNN-CNN hybrid models. These DL models were verified using a set of metrics. SHAP value analysis as a means of explainable artificial intelligence (XAI) was used to interpret these DL models for better decision-making. RUSLE estimations and ground truthing highlight that Soil erosion rates in the northeastern and northwestern regions are nearing the highest observed at 25 tonnes per hectare annually, largely due to steep slopes and limited vegetation. In contrast, the southern and southeastern areas have lower erosion rates, due to denser vegetation and gentler slopes. Deep learning models, optimized using Bayesian methods, demonstrate high performance in spatially modeling soil erosion probability. The DNN model achieved an accuracy of 0.93, a precision of 0.92, and an F1-score of 0.94, identifying 222.73 sq. km as highly susceptible to erosion, which indicates its strong ability to detect true erosion events. The CNN model identified 49.68% of the study area (503.30 sq. km) as high-risk, with an accuracy of 0.90 and a precision of 0.91. The FCNN model showed a balanced risk distribution, indicating 37.04% of the land (375.25 sq. km) as very low risk and 36.43% (369.11 sq. km) as very high risk, with an accuracy of 0.91. The DNN-CNN hybrid model highlighted 41.58% of the area (421.20 sq. km) as high risk, demonstrating its effectiveness in capturing spatial patterns of erosion susceptibility. SHAP value analysis indicates that land use and soil type (LULC and K-factor) are crucial in erosion predictions, with LULC having a significant predictive influence in the DNN model. These insights facilitate the prioritization of soil conservation measures, enabling decision-makers to focus on the most impactful factors for mitigating soil erosion. [ABSTRACT FROM AUTHOR]

In a context of land shortage with high rates of land degradation and soil erosion due to unsustainable agriculture practices in Burundi, vocational agriculture education needs to prioritize competencies that enable graduates to be effective change-agents in addressing sustainable agriculture challenges. This study aimed at identifying context-relevant competencies for change-agents to be able to foster sustainable agriculture. The paper used the Delphi technique to collect data from 28 experts (comprising of 14 teachers and 14 practitioners). The findings identified 11 context-relevant competencies that are considered by experts to be most important for change-agents working on sustainable agriculture. The competence 'facilitator of change' was found to be most relevant and the recommendation is that it should be prioritized in vocational agriculture education curriculum design. Other competencies, such as innovation and creativity, planning, system thinking, domain expertise, continuous learning, interdisciplinarity, and leadership, were also indicated as highly relevant. The competencies stewardship, self-determination and engagement were considered to be comparatively less important, although still relevant. The findings of this study provide insight so that the curricula of vocational agriculture schools can be designed around forming a competence-based education model toward fostering sustainable agriculture. The paper contributes to sustainability competence theory by taking the debate to the domain of vocational agriculture education within the context of Burundi. The study utilized the Delphi process to capture the context-relevance of sustainable agriculture competencies that need to be prioritized in vocational agriculture education in Burundi. [ABSTRACT FROM AUTHOR]

Argentina is a Latin American country which encounters soil degradation problems. The most productive regions have implemented conservative land practices (no-till). However, agricultural frontier has been displaced to marginal lands with arid and semiarid climates, with the consequent disappearance in many areas of native forest and land degradation. In this work, the fallout of gamma-emitting radionuclides, 137Cs and 7Be, was jointly used to assess changes in soil erosion in a recently converted semiarid ecosystem into agricultural land. 137Cs was utilized to estimate the erosion over the past 60 years, whereas 7Be was employed to estimate the erosion after the conversion of the area to cultivated land and soil tillage. For 137Cs the Proportional Model (PM), the Mass Balance Model II (MBMII) and the MODERN model were used, for 7Be the Profile Distribution Model (PDM) and the MODERN model were used. 137Cs indicates mean erosional rates of 8.2, 10.5 and 6.5 Mg ha−1 a−1, using MBMII, PM and MODERN, respectively, and that a soil layer between 0.5 and 0.8 mm was annually lost by erosion. By applying a 7Be tracer, we measured erosion rates of 2.4 and 3.3 Mg ha−1 (with PDM and Modern, respectively), indicating the loss of the upper 0.2 mm of soil. This erosion can be attributed to a few heavy rainfalls that occurred within the past 90 days. The results suggest that current land management practices have led to an increase in soil erosion. This could be attributed to the fact that the soil remains bare after crop harvest, which may compromise its conservation and future productivity. [ABSTRACT FROM AUTHOR]

The use of pesticides in agriculture has raised concerns due to their potential impact on human, animal and ecosystem health. Within a collaborative research framework, a study was co-constructed between researchers and local stakeholders in rural communities of Nan province (Thailand) to assess pesticide exposure levels. A total of 1,023 human serum samples were collected from volunteer participants. The level of exposure to organophosphate compounds showed that 12 (1.1%) and 134 (13%) individuals had hazardous or risky conditions, respectively. Generalized linear modeling revealed that age (older participants), chemical usage (spraying pesticide), habitat landscape characteristics (i.e., villages surrounded by orchard, forest, teak, rubber and rain-fed rice) and soil erosion appeared significant factors to explain the level of exposure. In addition, domestic animals (dogs and cattle) and wildlife (rodents and fishes) living in the vicinity were also assessed for their level of exposure. Applying the One Health principle helps understand pesticide exposure in people, domestic animals and wildlife by linking environmental characteristics at the local scale and thereby developing appropriate policies and regulations to be implemented. [ABSTRACT FROM AUTHOR]

Addition of microsilica improves the mechanical properties of mixtures containing Ca(OH)2 due to the chemical reaction between SiO2 in microsilica and Ca(OH)2 in the composition of prepared mixtures. This study aims to compare the efficiency of different microsilica-based mulches in sand stabilization. Several mixtures were prepared through combining microsilica with clay, lime, gypsum, and cement. Data were analyzed as a factorial experiment based on completely randomized design with treatments including: 1) mulch type: microsilica-clay-lime, microsilica-clay, microsilica-cement, microsilica-lime, microsilica-clay-gypsum, and microsilica-gypsum; 2) thickness: one- and two-layers, and 3) time (7 and 60 days) in 3 replications. Penetration resistance (PR), shear strength (SS), threshold friction velocity (V), and soil loss (SL) were measured. Results revealed that microsilica-clay-lime and microsilica-cement showed the highest PR (6.02 kgcm−2), SS (7.08 and 6.71 Ncm−2, respectively), and V (18.25 and 18.11 ms−1, respectively), and the lowest SL which makes them the most suitable mulches for sand stabilization. [ABSTRACT FROM AUTHOR]

In the present work, four parametric combinations of LS and P factor have been adopted for assessment of RUSLE-based soil erosion in Bamnidhi subbasin of the upper Mahanadi basin. The basin was discretized of the basin into 98 grids where by applying the SEdiment Delivery Distributed (SEDD) model, total sediment yield from the catchment is computed as sum of the yields from each grid. Soil erosion maps generated are classified as low, moderate, and severe concerning soil erosion potential as < 5, 5–30, and > 30 t ha−1 year−1 respectively. It was observed that the percentage disagreement of erosion area for the three classes with 37%, 25% and 12% for combinations 1 and 4, whereas for combinations 2 and 3 the disagreement improves to 44%, 26%, and 18% respectively. Validation of the maps with satellite information-based FCC showed 75% of accuracy to identify points in moderate to severe zone. For development of MLR model to assess soil erosion, the best parameter set has been selected with ${R^2} = 0.75$ R 2 = 0.75 and slope is found to be the most influential factor for soil loss than LULC, rainfall, and soil type. [ABSTRACT FROM AUTHOR]

Morphometric analysis of a drainage basin along with its stream network is indispensable for analysing a river basin's prevailing geomorphology, geo-hydrology, and erosional susceptibility. In this study, an enhanced morphometric evaluation method using Google Earth Engine (GEE) and Principal Component Analysis (PCA) was used to assess and prioritize 12 sub-basins of the Godavari River basin (GRB), India, based on their erosional susceptibility. The findings of erosional susceptibility were validated using the Sediment Yield (SY) model. Our findings highlight that the sub-basins of Indravati, Pranhita, and Manjira, i.e. 42.42% (132707.4 km2) of the entire GRB are at high risk of erosional susceptibility, requiring immediate implementation of soil conservation measures. Our findings also highlight that 52.71% of the GRB is in the mature stage of geological evolution, wherein erosional landform-building processes are still ongoing. Overall, GRB has a relatively low drainage density with dendritic drainage patterns, permeable soils, and elongated sub-basins of enhanced erosional susceptibility. Moreover, the results of the SY model exhibited 90% agreement with the results of the enhanced morphometric analysis. This study presents an efficient framework for enhanced morphometric analysis that can assist policymakers in the demarcation of priority zones for erosional susceptibility. [ABSTRACT FROM AUTHOR]

Currently, there is an abundance of interest in the methods to reduce ammonia (NH3) volatilization and nitrous oxide (N2O) emissions from cultivated soils. Nitrogen use efficiency (NUE) of applied urea is decreased due to gaseous loss, which also lowers soil N (Nitrogen) content. The purpose of this study was to investigate the potential of microbial-based inoculants to decrease NH3 loss and N2O emissions under controlled conditions. Bacillus subtilis ;(UPMB10), and Bacillus tequilensis ;(UPMRB9) in combination with five different nitrogen (N) fertilizer levels 0%, 25%, 50%, 75%, and 100% were used in this study. Results showed that NH3 cumulative volatilization loss was greater in uninoculated soil treated with a full dose of fertilizer-N (507.27 mg/kg) compared with bacterial-inoculated soil (491.20 mg/kg and 500.71 mg/kg for UPMRB9 and UPMB10, respectively). Emission of N2O increased to a greater level (15.11 mg/kg for B0N100) in uninoculated soil compared to inoculated soil (14.65 mg/kg for UPMRB9N100 and 14.93 mg/kg for UPMB10N100-treated soil) and emission of N2O increases as N application increases. Initially, the emission of N2O was greater which decreased from the sixth day until it became zero. In B0N100-treated soil, emissions of N2O increased and after 30 days of incubation, the inoculated soil had a greater N concentration than the uninoculated soil. The total N loss from applied urea was higher in uninoculated soil than in inoculated soil. According to the findings, microbial inoculants have the potential to reduce the loss of N through NH3 volatilization and N2O emissions. [ABSTRACT FROM AUTHOR]

Among the most characteristic offsite effects of soil erosion, reservoir sedimentation is one of the longlasting problems pertaining to storage capacity and dam operations. In this work, sedimentation rates of the Fortezza reservoir in South Tyrol (Italian Alps) are analysed for nine erosive events over 14 months. Sediment rates are calculated through a modified Universal Soil Loss Equation (USLE) combined with a Sediment Delivery Ratio (SDR) module at 2.5 m resolution. The topographic factor is adjusted to the Alpine terrain, and an additional factor is included to consider the nonerodible parts of the basin. The results are validated against a 14-month sediment yield obtained by high-resolution (0.2 m) reservoir bathymetric analyses. The calculated sediment yield has an absolute deviation of 4.8% from the measured one. The results indicate that these methods can be successfully applied for the estimation of reservoir sedimentation rates in the Alps. [ABSTRACT FROM AUTHOR]

Runoff and sediment movement induced by storms have serious economic, environmental, and social impacts around the world. Hydrological models have become useful decision support tools for watershed management. The development of process-based distributed models is complex as it involves a range of disciplines and spans multiple spatial and temporal scales. In this study, a process-based and mesh-distributed model, suitable for both event-based and continuous simulations, is developed. The watershed is conceptualized in three distinct zones: a surface overland region, an unsaturated subsurface zone, and a groundwater zone. Overland flow is governed by the 2D diffusive wave equation with an optional 1D channel network solver; water in the unsaturated zone is modelled through mass conservation and vertical dominance of the processes; and saturated groundwater flow is governed by the 2D Dupuit equation. Soil erosion and transport are governed by the multi-size, non-equilibrium equations incorporating soil entrainment, transport, and deposition. The model is driven by meteorological input, land use and soil type properties. The numerical approach is a generalization of existing models to overcome some current modelling shortcomings. New contributions of the model are highlighted and model verification and validation are reported against benchmark cases. The model is then applied to the Cache Creek watershed in California, USA. Satisfactory agreement with the measured data is obtained with both the runoff flow rate and sediment load. [ABSTRACT FROM AUTHOR]

Soil provides multiple, diverse functions, with these underpinning both planetary and human health. For planetary health, soil contributes to multiple critical processes, including through biomass production, by regulating the carbon pool, providing a habitat for 25% of global biodiversity, cycling the nutrients upon which terrestrial systems depend, and cycling water. Soil also underpins human health; humans use soil to provide 98.8% of our food and sustain our nutrition, regulate pathogens, and supply medicines. However, humans have tended to focus on soil almost solely for producing biomass (food, fiber, and energy) through intensive agriculture, and this narrow focus now causes rapid soil degradation, including through loss of soil organic matter, erosion, and salinization. This degradation directly harms planetary health and reduces the ability of soil to support health of future human generations. We argue that a healthy soil is a soil that is multifunctional and is capable of underpinning human and planetary health. Using this definition, a broad conceptual framework is provided for quantifying soil health, with such an approach enabling a shift in the way that we think about, plan, and manage systems to ensure ongoing planetary and human health. [ABSTRACT FROM AUTHOR]

Theoretical, methodological and applied aspects of assessment of loss and damage to soil resources are considered. As of 24 February 2023 the cost was of the order of $US 34.4 billion but this is provisional and dynamic. Bibliometric analysis suggests inadequate attention to the issue of assessing the impact of wars on soil and land quality and determining loss and damage. This is a first attempt to plug the gap and encourage further work on the methodology, as well as the assessment of just compensation to ensure the restoration of war-damaged soils. [ABSTRACT FROM AUTHOR]

Severe soil erosion can cause both loss of ecosystem services and riverine environmental contaminations. Thus, understanding the spatiotemporal characteristics of soil loss at the watershed scale is critical for sustainable management of land and water resources. The primary objective of this study was to estimate the spatiotemporal variation in water runoff and soil loss in the Tokoro River watershed (TRW), Hokkaido, Japan. Assuming that agricultural land, which becomes bare depending on the season, is the main source of erosion and that large soil losses occur especially during the snowmelt/freeze-thaw period, we quantified and analyzed the mechanism of soil loss using the Soil and Water Assessment Tool 2012 (SWAT2012). Simulation results based on a publicly available dataset showed that croplands were the primary source of stream sediment load, contributing to 86% of the total soil loss. Furthermore, the soil loss rate was high (241.1–270.9 Mg km−2 yr−1) in sub-basins with a higher percentage of cropland, especially sloped croplands. These sub-basins had a higher risk of productivity loss due to intense erosion and river contamination by muddy runoff. Soil loss mainly occurred in early spring (March and April) and late summer (August – October), accounting for 36% and 45% of the annual soil loss, respectively. Vegetation removal by harvest exacerbated soil loss in October. In March, soil drainage was suppressed by frozen soil, resulting in high surface runoff and soil loss. Therefore, surface runoff when the soil was frozen was considered an important driver of soil loss. The estimation error of the stream sediment loads out of the 95% prediction uncertainty accounted for 26% of the total absolute error. This error could be attributed a lack of certainty in the observation data of high stream sediment loads and the model's underestimation of water runoff during intense snowmelt and rainfall events. [ABSTRACT FROM AUTHOR]

Soil erosion, a major factor contributing to land degradation, poses significant environmental challenges across sub-Saharan Africa, including Ethiopia. This study identifies erosion-prone sub-watersheds in southern Ethiopia's middle Omo-Gibe River basin using digital elevation model data, analyzed using a geomorphometric and statistically weighted sum priority approach in a Geographic Information System environment. Additionally, hypsometric analysis, lithology, land use/cover analysis, and field observations were integrated to enhance methodological reliability in assessing soil erosion patterns and subsequent land degradation in the basin. Results highlight sub-watersheds with varying degrees of erosion sensitivity, emphasizing morphometric parameters and landscape characteristics. Furthermore, hypsometric analysis confirms a moderate to high susceptibility of sub-watersheds to soil erosion. Moreover, half of the river basin consists of shrubland, encompassing scrubs, range lands, and small wooded areas. These are less efficient in mitigating erosion compared to forests, especially in the face of significant summer rainfall and ensuing runoff. Statistical prioritization identified 19 sub-watersheds, covering 43% of the basin's total area, as highly prone to soil erosion and land degradation. The study's findings are valuable for Ethiopian watershed management decision-makers, enabling informed resource allocation and targeted interventions to control soil erosion and protect water resources by utilizing the outputs of this study. [ABSTRACT FROM AUTHOR]

Soil erosion exacerbates land degradation, which has a detrimental impact on terrestrial ecosystems all over the world. The purpose of this study is to forecast future soil erosion in the Tumen River Basin (TRB) on the border between China and North Korea under changing land-use and climate conditions from 2030 to 2050 using the revised universal soil loss equation (RUSLE). Precipitation changes during the study period were examined under three shared socioeconomic pathway (SSP) scenarios. Future land use was simulated using a patch-generating land-use simulation (PLUS) model. As the scenario worsens, regions requiring sustained attention in the TRB are expected to rise steadily from 4% (1337 km2) in 2017 to 7.3% (2440 km2) in 2050. Under SSP5-8.5, soil erosion will reach 24.45 t ha-1yr-1 in 2050, which is 6 t ha-1yr-1 more than current soil loss. According to the land cover simulation, 2.7% (~925 km²) of forest area is anticipated to be lost by 2050, with the majority of that area converted to built-up, cropland, and grassland areas increasing by 0.5%, 1.3%, and 0.8%, respectively. This study is expected to enhance the spatial perception of soil erosion at different scales and provide scientific basis for soil and water management. [ABSTRACT FROM AUTHOR]

Soil moisture is an important factor that can be used for referring to flood situations, monitoring drought estimation, and changes in the environment such as storms and soil erosion. The Optical Trapezoid Model (OPTRAM) estimates surface soil moisture using shortwave infrared transformed reflectance (STR) and the Normalised Difference Vegetation Index (NDVI) in trapezoidal space. In this study, Landsat 8 satellite data were acquired for May (2019) and October (2019) and used for analysis in the Narmadapuram district of Madhya Pradesh, India. Validation of the retrieved soil moisture was done using microwave satellite data available on the VEDAS portal. The output maps show that soil moisture values vary from 0.0235 (m3/m3) to 0.162 (m3/m3) for May 2019 and from 0.417 to 0.781 (m3/m3) for October 2019. The data obtained from the VEDAS portal has the average change in soil moisture values in May and October 2019 as 0.04 m3/m3 and 0.55 m3/m3, respectively. The outcome of the study shows that the model has nearly the same accuracy as the VEDAS (Visualisation of Earth Observation Data and Archival System) portal data. [ABSTRACT FROM AUTHOR]

Highland bamboo (Arundinaria alpina, synonym Yushania alpina) is a characteristic and dominant semelparous species in the Afromontane vegetation of Ethiopia. It is utilized for numerous applications. Mass flowering of the species seems to be associated to conversion to other land uses. Objectives of the study were to document a mass flowering event, determine fruiting characteristics, understand the perception of communities, and assess its consequences in Seka-Chekorsa district, western Ethiopia. Focus group discussions and GIS-based assessment were conducted in 13 Peasant Associations (PAs). Our results show that highland bamboo flowering is gregarious and time to seed maturity takes about a year. The extent of mass flowering in each PA ranged from 41-88% of the the bamboo forest. Majority of the respondents (43%) perceived that the bamboo flowering event occurred because of God's wrath, 38% related it to the age of the bamboo plants, and 19% attributed the event to a disease, indicating low awareness regarding the reproduction of the species. Perceived impacts of the mass flowering event were an increased soil erosion, changes in microclimate, reduction in water flow, and negative consequences on farmers' economy. Farmers urgently need training on the management of the species at its reproductive stage. [ABSTRACT FROM AUTHOR]

Soil erosion and sediment deposition in the reservoirs are both consequences of the change in precipitation pattern that has been observed over the past decade. For the purpose of storing water in reservoirs built before the 1980s, the Indian state of Chhattisgarh has a few irrigation projects. As the state has grown, agricultural land has increased while the proportion of forest area has decreased. Due to this development, runoff is introducing more sediment into the reservoirs, resulting in a reduction in intended storage. The effects of sediment deposition in the Kodar reservoir, located in the Mahasamund district of Chhattisgarh State, are evaluated in present study. Prior to five years, the reservoir reported a 30% deficit in actual irrigation. To quantify the sediment load, Remote Sensing (RS), Geographic Information System (GIS), and the Hydrologic Engineering Centre – Hydrologic Modelling System (HEC-HMS) were effectively employed. From 2012 to 2014, the reservoir received an average sediment load of 1.11 million tonnes. In order to preserve soil in the watershed's erosion-prone area, a treatment plan is developed. It includes numerous thematic maps that are overlaid in order to provide preventive measures against reservoir sedimentation and is further proposed in the form of best management practices. [ABSTRACT FROM AUTHOR]

Conserving soil carbon is one of many actions to take in limiting global warming. However, carbon dense peatlands are still being drained or excavated. Infrastructure development is one of the major current threats to boral peatlands in Fennoscandia, but few tools are available for calculations of carbon stocks in peatland areas, necessary for decision makers planning development projects. Thus, we compiled a reference database of key peat characteristics from main boreal peatland types sampled in Norway and tested "best practice" peat depth sampling methods and peat volume interpolations. We implemented our findings in CarbonViewer, a tool and easy-to-use app that reliably calculates carbon stocks of delimited peatlands. Tool and method presented, estimates carbon stocks to assess potential soil carbon loss in planned infrastructure development on peatlands and will give decision makers the necessary knowledge base to limit emissions from soil carbon. [ABSTRACT FROM AUTHOR]

Land degradation is an evident and severe environmental problem in Ethiopia. Since 2003 community-based watershed management has been implemented in the study area to reduce land degradation. This study aimed to investigate to what extent the community-based watershed management is effective in rehabilitating the land. Woody vegetative cover, land use/cover (LULC) change and soil erosion rate were selected variables to examine the effectiveness of the management measures. The LULC and woody vegetative cover spatial datasets were created from Landsat satellite images of 2003 and 2019 using ERDAS IMAGINE 2016® and ArcGIS10.8®. The soil loss rate was modelled using geoinformation techniques combined with the Revised Universal Soil Loss Equation. To assess the perception of farmers involved in the watershed rehabilitation activities, qualitative data were collected through Focus Group Discussions and Key Informant interviews. The results showed that the average annual soil loss rate in the study area was 49.5 tonnes (t)/hectare (ha−1)/year(y−1) in 2003 and 23.8 t ha−1y−1 in 2019, which is a 52% decrease over 16 years. Woody vegetative cover and grassland increased by 11% and 103%, respectively. These figures and respondents' responses, Focus Group Discussants and Key Informants showed that the community-based watershed management measures implemented in the study area were effective for improving vegetation cover and reducing soil loss (reducing land degradation). The sustainability of these achievements is contingent on the availability of a robust local organizational set-up complemented by the provision of natural resources development technologies, capacity building and security of land tenure. In sum, the findings in the study lead to conclude that the active involvement of farmers in land management and security of land tenure are effective approaches to reverse land degradation in the highlands of Ethiopia. [ABSTRACT FROM AUTHOR]

Gully erosion is known to affect soil productivity, and to limit land use in many parts of the world. To assess the susceptibility of soils to gully erosion, the triggering factors must be analyzed. A simulation of gully development over time was implemented in Python – GIS modules based on the topographic characteristics of the study area, soil properties, and measured runoff. The results show that the developed modules allow a successful data preparation, process simulation and spatial visualization of the obtained results in 2D and 3D as well as an analysis of time series of gully evolution. [ABSTRACT FROM AUTHOR]

Rainfall erosivity describes the capability of rainfall to cause soil erosion from a surface during a storm. Currently, the average long-term annual and monthly rainfall erosivity for a location may be obtained from isoerodent maps using a sample of climate stations across the United States (US). However, at the state-scale these measures are sporadic, using rainfall data from an increasingly outdated period, which may not reflect possible changing rainfall erosivity. Focusing on the state of Kentucky, US, we developed rainfall erosivity grids from the state Mesonet system to determine if erosivity has changed spatially and temporally between the original erosivity datasets from the latter twentieth-century and 2011–2020. We further used the Mesonet-derived dataset to develop a GIS-based model to estimate potential soil erosion for croplands during the fallow-season when soil is most prone to erosive storms. Results indicated that monthly erosivity increased across the state between the two periods. Larger increases in erosivity during the latter part of the fallow-season resulted in higher estimated soil erosion from croplands, particularly to the west. These findings may provide guidance in identifying and targeting croplands at greatest potential risk of soil erosion during the fallow-season for additional monitoring, mitigation and management practices. [ABSTRACT FROM AUTHOR]

Retaining walls are a part of the geotechnical construction industry for the support of structures from soil erosion. Granular materials are conventionally used as backfill behind retaining walls. Instead of the conventional compacted granular fill, other industrial by-products are also used nowadays. The utilisation of these industrial by-products for Civil engineering applications helps to build a sustainable environment by reducing the waste depositions. In this paper, an experimental study was conducted to evaluate the properties of coal ash-based Controlled Low Strength Materials (CLSM) for backfill applications. The properties of pond ash-based CLSM mixes were studied to identify the effectiveness in utilising CLSM for backfill applications. Further, numerical analysis using PLAXIS 2D was carried out to evaluate the stresses and displacements developed in retaining walls for different backfilling materials. It was observed that CLSM mixes exhibit the properties required for utilising it as a backfill material. The stresses and deformations developed in situations where CLSM was used were found to be negligible compared to the normal compacted backfill materials. Thus, the studies on CLSM mixes showed that pond ash can be used as a replacement to natural aggregates which can be used as a backfill for retaining wall applications. [ABSTRACT FROM AUTHOR]

Limited access to observe in-situ sediment changes requires viable means for quantifying sediment transport in large rivers for effective management of changes in river channels. This study developed a remote sensing-based framework to identify erosion hotspots by magnifying sediment concentration from Sentinel-2 and Landsat-8/9 multispectral images of the Brahmaputra River and the Indus River. First, uncorrelated independent bands were produced to boost the spectral information using the Principal Component Analysis (PCA). The optimal band composite was then identified by applying the Optimum Index Factor (OIF) on the Principal Components (PCs). This approach determined a 3-PCs composite having the highest variance with the least correlation to highlight active morphological changes during flood times. The results of the study reaffirm the significance of the minor PCs (PC4, PC5 and PC6) to characterize the small variation in the data, whereas the main PCs depict the majority of the brightness values around means. The approach was applied to Sentinel-2 imagery acquired on September 2018 in the Brahmaputra River, and Landsat-8/9 images of 2015 and 2022 in the Indus River during flood time to enhance and identify active riverbank erosion hotspots. Precise and timely monitoring of erosion-prone areas can support the control of riverbank erosion and improve soil conservation practices. [ABSTRACT FROM AUTHOR]

The Daning River Basin is a typical representative of the 'mountain forest' in the Three Gorges Reservoir (TGR) area of the Yangtze River. In recent years, with the completion of the Three Gorges Project, the local vegetation has degraded, soil erosion has become severe, and there is an urgent need to assess the environmental quality. Data were fused using the MODIS Normalized Difference Vegetation Index (NDVI) (250 m) and Landsat NDVI (30 m) through an Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) to obtain ESTARFM NDVI (30 m). This data was then entered into the Carnegie Ames Stanford Approach (CASA) model, along with meteorological and land use data, to calculate vegetation net primary productivity (NPP) and trends in the Daning River Basin. The detection of drivers with a high impact on vegetation NPP was done using a Geodetector. The results show that: (1) In terms of spatial and temporal changes, the annual average NPP of the watershed during the 13 years from 2008 to 2020 generally showed an upward trend, with the average yearly vegetation NPP being 512.33gC·m−2·a−1, exhibiting a low southwest to surrounding increasing trend along the river. (2) The spatial and temporal variation of vegetation NPP is influenced by several factors synergistically, with elevation, temperature, and distance from settlements being the dominant factors. The interaction of these two factors can enhance the explanatory power of vegetation NPP. Through the estimation of vegetation NPP and the analysis of influencing factors in the Daning River Basin, this study can provide a reference for the ecological restoration and management of vegetation NPP in small watersheds under similar environments. [ABSTRACT FROM AUTHOR]

This paper examines the traditional ecological knowledge that existed for generations along the southern coast in Korea with an example from the site of Gungokri. Traditional subsistence along the Korean coast and islands is known as half-farming and half-fishing, Ban-nong ban-eoh in Korean, and we argue that this strategy applies to over 500 years of history at the site. Our data from 150 b.c.–a.d. 400 focuses on archaeobotanical remains recovered from floated sediments, 25 radiocarbon dates, and starch granules extracted from vessels. Our research indicates that Gungokri residents practiced a rotation of crops in both wetlands and uplands to prevent the loss of soil nutrition and erosion from seawater. Furthermore, they diversified food resources by fishing, shellfishing, hunting, and harvesting wild plants from forest edges and wetlands. This type of long-term resilience and ecological flexibility in coastal adaptation was achieved through niche construction of complex seasonal resource management and inheritance of traditional ecological knowledge. [ABSTRACT FROM AUTHOR]

Splitting nitrogen (N) application is beneficial for achieving higher grain yields and N use efficiency (NUE), but the responses of N utilization efficiency of different maize cultivars to top-dressing N fertilizer rates are still unclear. This study investigated the effects of fertilization managements on N uptake and utilization derived from topdressing fertilizers of maize hybrids (Ludan981 and Denghai605) with contrasting NUEs. The N fate derived from topdressing fertilizer was determined using the 15N tracing method. Grain yields, dry matter and N accumulation of both maize hybrids were significantly increased under low N levels but decreased under high N levels. Under N-deficient and excess conditions, Denghai605 had higher NUE than Ludan981. The N rates of topdressing significantly affected N uptake and utilization, but no difference was detected between two maize hybrids, and excessive N use led to higher rates of N loss and residual in soil. The N metabolism enzyme activities did not differ between the two maize hybrids. Our findings suggest optimized N management strategies by adjusting topdressing N application rate and timing are necessary to increase NUE and to minimize environmental costs in maize cropping system. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) has accumulated in New Zealand agricultural systems, predominantly from the application of phosphorus (P) fertiliser to soils. Elevated Cd concentrations in soils are an important issue due to their potential adverse effects on food quality, soil health, land use flexibility, and the environment. This paper reports on our current knowledge of Cd in New Zealand agricultural systems, summarising published and unpublished research that has been undertaken over the last 30 years to better understand, improve, and manage the potential adverse effects of Cd in agricultural soils. We found the research has been wide ranging, investigating factors such as Cd uptake in plants and animals, the rate of Cd inputs, transformation and losses from soils, Cd bioavailability, the development of animal uptake and Cd mass-balance models, as well as identifying and testing strategies and remediation options to manage Cd accumulation in agricultural systems. This research is then placed alongside the policy and regulatory context for managing Cd in agricultural systems in New Zealand, including national Cd management strategies. Finally, key knowledge gaps are presented, along with some potential Cd research directions for the future. [ABSTRACT FROM AUTHOR]

In the cool highlands agricultural area in the Kanto region in Japan, large-scale vegetable cultivation is taking place in sloping fields where Andosols are distributed. In some steeply sloping fields in the area, soil erosion has resulted in the loss of surface soil and its redeposition, causing heterogeneity of soil productivity. In this study, a high-resolution soil map (1 m resolution) was delineated using drone images and machine learning to understand the status of soil productivity in sloping vegetable fields. A digital elevation model (DEM) and orthoimages were created from the analysis of images taken by a drone. Then, 13 topographic index maps, such as slopes, were created from the DEM. The orthoimages were then converted to black and white images to quantify surface soil color. Based on the black and white images and topographic indices of the field, the distribution map of 1) organic carbon content of surface soil and 2) layer thickness of A horizon in the study area were delineated by the Regression-Kriging method. The Empirical Bayesian Kriging method was used to delineate maps of 3) gravel content in the soil profile (0–60 cm) and 4) depth to the gravel layer. Using the 13 topographic index maps and the maps from 1) to 4) as features, a predicted soil map was delineated using the random forest method with eight soil series groups as the map unit. Nine features were selected by the best-predicted model. High-Humic Cumulic Allophanic Andosols and Skeletal Cumulic Allophanic Andosols were generally covered on gentle slopes with low LS-Factor, which was calculated by slope and specific catchment area. Skeletal Low-humic Allophanic Andosols were mainly distributed on steep slopes with high LS-Factor and susceptible to soil erosion. A high-resolution soil map reflecting soil erosion was able to delineate using drone images and machine learning in Andosol's sloping upland field. [ABSTRACT FROM AUTHOR]

Land use is a driver for hydrological and soil erosion responses at the watershed scale. This study aimed to assess the hydrological and soil erosion processes in small watersheds under three different land uses, at three time scales. We investigated four small watersheds in southern Brazil: Agricultural North watershed (ANW), Agricultural South watershed (ASW), Eucalyptus watershed (EW), and Grassland watershed (GW). The SWAT (Soil and Water Assessment Tool) model was used to simulate streamflow (SF) and sediment yield (SY) at monthly, daily and hourly time scales. EW had the lowest SF and SY, whereas ANW showed the highest SY with an increase of 90% and ASW had the highest SF with an increase of 70%. The SWAT model had a satisfactory performance in all time scales and watersheds for SF and SY (NSE and R2 ≥ 0.3 and Pbias ≤ ± 39%). Overall, land use has a major impact on hydrological and soil erosion responses, and the magnitude of these processes depends on the time scale. [ABSTRACT FROM AUTHOR]

Due to climate change's effects, protected areas, particularly national parks, face conservation challenges, negatively impacting tourism. Sustainable tourism requires understanding the climate and conservation challenges in national parks and their implications for tourism. Marakele National Park in South Africa faces climatic and conservation challenges. A purposive and snowball sampling strategy was used to select study participants. An in-depth interview was conducted with the employees of South African National Parks, including top managers, scientists, field, section, honorary rangers, conservationists, and hospitality staff. A perception survey involving 871 tourists was conducted along with field observations, archival data, and an analysis of archival data. The study results indicate that rainfall levels in the national park vary greatly from season to season and are declining. A warm climate and high rainfall were also observed, and increased drought episodes. The observed climatic extremes led to several ecological challenges, including bush thickening and encroachment, intense soil erosion, wetland degradation and an increased frequency of wildfires. The environmental challenges impact the park's aesthetic value, affect tourist comfort and perceptions, and cause employee discomfort. The paper recommends that the park develops anticipatory action plans for the identified climatic and tourist attraction risks. [ABSTRACT FROM AUTHOR]

Low standard of constructed structures, weak land management, unskilled human power, dependency on rain-fed agriculture and natural assets for household farmers' survival make livelihood systems in the study area complex, dynamic and food insecure. The aim of this research paper was to assess and analyze the effect of physical structures on crop yield, annual income and smallholder farmers livelihood based on the data of 2020 and 2021 harvest years. The data was collected from a survey of 262 total household head farmers of which 132 were structureadopters while 130 were nonadopters (nonusers). Household heads were selected using simple random sampling techniques. The statistical data were analyzed using chi-square, t-test and SPSS version 20 software while the economic data were analyzed using econometric models such as propensity score matching, average treatment effect and logistic regression. Focus group discussions, key informant interviews and personal observations were also held to gather qualitative data. The results show that the adoption of physical structures has had a significant and positive impact on smallholder farmers' incomes, crop productivity and livelihoods. Therefore, the adoption of physical structures in Wenago district, southern Ethiopia should be continued and encouraged as much as possible. [ABSTRACT FROM AUTHOR]

Most developing countries and underdeveloped countries suffer from crop shortages due to low yields. One of the main reasons for this potential threat is soil erosion, which is one of the biggest problems in the world today. When sheet erosion removes the top layer, soil fertility deteriorates. In this study, Unit Stream Power based Soil Erosion and Deposition model has been used to determine soil erosion in the Kodar Basin in Chhatisgarh, India. Map of various factors affecting soil erosion were studied and the soil loss due to sheet and rill erosions were evaluated respectively, and it was found that the erosion was mainly caused by rill erosion. For rill erosion high deposition estimated as 3812 ha which is 12.39% of the total area, 2388 ha which is 7.76 % comes under moderate deposition, 6806 ha which is 22.12 % comes under stable, 3585 ha which is 11.65% comes under moderate erosion, 2728 ha which is 8.87 comes under high erosion risk. Various conservative measures were suggested in the watershed for the reduction of soil erosion. [ABSTRACT FROM AUTHOR]

The network of streams continuously changes its location based on time, environmental factors and human interventions. It is very important to study the stream changes in order to provide management solutions for soil conservation. One of the new methods in this regard is to use fractal geometry. The purpose of this study was to investigate the relationship between fractal and morphometric characteristics of the basin and the possibility of fast, low-cost and accurate management of the stream network based on this relationship. For this purpose, using data basic maps, drainage networks map and digital elevation model (10 m) of the ground by ArcGIS 10.7 was prepared. Then applying the rules of the Horton–Strahler river network, fractal dimensions were calculated to examine the relationship between fractal dimensions, and some rivers' geomorphic features were investigated. Finally, by entering the data obtained from the calculations in SPSS 22 and Curve Expert software, the morphometric characteristics of the basin associated with the fractal dimensions were investigated. In the Curve Expert software, the exponential, logarithmic, linear and power models of the dependent variable (fractal dimension) and the independent variable (morphometric characteristics) were investigated and the model that had the higher determination coefficient and was significant in SPSS 22 software for the nonlinear univariate regression was selected and introduced as the appropriate model for the relationship between the two studied variables. Results showed that the fractal dimension of stream branch, the fractal dimension of drainage density and the fractal dimension of total basin area were 1.84, 0.71 and 1.46, respectively. The results also showed that the fractal dimension of watersheds has meaningful relations with factors such as shape form, area, bifurcation ratio and length ratio in the watersheds. Due to the importance of stream characteristics in the management of watersheds in terms of flood, erosion and soil conservation, the fractal models can be used to make quick and accurate decisions about the stream management. [ABSTRACT FROM AUTHOR]

The loss of soil from lands due to erosion has a negative effect on ecosystems and food security. Bacillus due to high catabolic capability is an appropriate candidate for application in biocementation process. The aim of this study is isolate and characterize Bacillus sp. with biocementation capability from various ecosystems. The isolates were separated from 400 samples, and characterized by biochemical and molecular methods include the amplification and sequencing analysis of gyrA and 16S rRNA genes. Growth in presence of urea, in different salinity, pH, and temperature, also scanning electron microscope (SEM), X-ray diffraction (XRD), and wind tunnel analysis were applied to determine biocementation ability. A total number of 195 isolates were recovered from environmental samples, of which 25 isolates (12.82%) were identified as urease-positive Bacillus which belonged to 10 species consisting of Bacillus subtilis five strains (20%), Bacillus vallismortis and Bacillus seohaeanensis four strains (16%) each, Bacillus mobilis, Bacillus pseudofirmus, Bacillus cohnii, Bacillus cereus, Bacillus alkalinitrilicus two strains (8%) each, and Bacillus sphaericus and Bacillus megaterium one strain (4%) each. Moreover, 15 urease-positive isolates (7.7%) belonging to Ralostenia, Actinomycete, and Halomonas genera were identified. Optimum conditions for microbial induced calcite precipitation (MICP) by isolates are 30 °C, pH 9, and 6% salinity. The highest rate of calcium carbonate formation and urease activity recorded in B. subtilis with 24.15 mg/mL of calcium carbonate and 4.40 × 103 unit/L of urease, followed by B. mobilis and B. alkalinitrilicus with 22.85 mg/mL of calcium carbonate and 3.93 × 103 unit/L of urease. After MICP the lowest soil loss ratio at a flow rate of 90 km/h, was observed in B. subtilis 100-fold reduction, followed by B. seohaeanensis, B. cereus, B. vallismortis, with 90, 85, 80-folds reduction, respectively. Results indicate that the diversity of Bacillus sp. offers the potential ability for adaptation to harsh and untapped environments, also showed that the use of MICP on the soil surface can have a very significant role in reducing soil losses due to wind erosion. [ABSTRACT FROM AUTHOR]

The effectiveness of mulching in reducing the risk of erosion has been evaluated in numerous studies. However, its effect on carbon loss has received less attention, despite the potentially negative effects on ecosystem recovery. In this study, the effects of straw helimulching on soil erosion and carbon loss in sediments were investigated after a severe wildfire in NW Spain during the first three years after fire. During the first year after the fire, the accumulated mean sediment yield was 12.4 Mg ha−1 in the control plots and 0.5 Mg ha−1 in the mulched plots. Soil erosion decreased sharply during the second year after the fire and was almost inexistent during the third year after the fire. No differences in carbon concentration were detected between treatments during the period of study. A significantly lower amount of carbon was lost after the mulching treatment due to its effectiveness in reducing sediment erosion. The mulching treatment did not significantly influence the amount of carbon sequestered in the vegetation. Although the application of mulch did not affect carbon fixation in vegetation, its application after fire can be considered a sustainable way of managing forest ecosystems to reduce the impact of fire on carbon emissions. [ABSTRACT FROM AUTHOR]