Soil Conservation Techniques Research Articles

Drivers and Consequences of Land Degradation on Livestock Productivity in Sub-Saharan Africa: A Systematic Literature Review

Land degradation is a major threat to sub-Saharan Africa rangelands, which are crucial for livestock farming and the livelihood of millions of people in the region. This systematic review aims to provide a comprehensive understanding of the causes and effects of land degradation, as well as to evaluate the effectiveness of different mitigation strategies. Following the PRISMA guidelines, we identified, screened, and analyzed 25 peer-reviewed articles published before 30 June 2024 using Scopus. The review highlights key factors that drive land degradation, such as soil erosion, drought, deforestation, and climate change, as well as socio-economic factors like poverty, land tenure issues, population pressure, and economic instability. These factors have serious implications, as land degradation can lead to poor quality of forage, an increased incidence of diseases, higher mortality rates among livestock, and a significant decline in livestock productivity. The socio-economic consequences of this degradation are significant, leading to reduced household income, increased poverty, and heightened food insecurity. Furthermore, the review assesses various mitigation strategies and concludes that practices such as rotational grazing and soil conservation techniques demonstrate high effectiveness, while agroforestry practices show only moderate success. An integrated approach that combines environmental, economic, and policy measures is crucial to addressing the complex challenge of land degradation in sub-Saharan Africa. Strengthening land tenure, improving economic stability, and promoting sustainable agricultural practices are essential steps toward improving the health of rangelands, increasing livestock productivity, and supporting the resilience and well-being of rural communities.

Modeling Ecosystem Regulation Services and Performing Cost–Benefit Analysis for Climate Change Mitigation through Nature-Based Solutions Using InVEST Models

Climate change and land degradation menace ecosystem sustainability. This study assessed the effectiveness of integrating nature-based solutions (NBSs); soil and water conservation techniques, agroforestry, and reforestation, to mitigate these impacts. Focusing on carbon storage and sediment retention at the watershed level (Sidi Barrak), the InVEST model quantified changes from 1990 to 2050 under the Business as Usual (BAU) and management scenarios. The results showed a significant decrease in sediment retention and carbon storage from 19.25 to 15.5 t ha−1year−1 and from 1.72 to 1.61 t ha−1year−1, respectively, between 1990 and 2021. By 2050, BAU scenario projections demonstrate a 28% decrease in sediment retention and a 16% drop in carbon storage under Representative Concentration Pathways (RCP) 4.5. The Management scenarios indicate substantial improvements, with carbon storage increasing by 77% and sediment retention by 87% when all strategies were combined. The economic valuation, performed through the application of the cost–benefit analysis, shows positive net benefit values (NPVs) for the different NBS management scenarios. The combined management scenario, which includes soil and water conservation techniques, agroforestry, and reforestation under the same scenario, presents the highest total NPV with 11.4 M€ (2%, 2050), an average of 130 €/ha (2%, 2050), and an opportunity cost of 1.7 M€ compared to BAU. Such results may orient decision-making by providing solid arguments toward ecosystem resilience and climate change mitigation.

Sustainable integration of rubber plantations within agroforestry systems in China: current research and future directions

The integration of rubber plantations with agroforestry systems, or the under-forest economy, represents a pivotal shift towards sustainable agriculture in China. This paper reviews the latest research on agroforestry practices and innovations within China's rubber plantation under-forest economy, with a focus on the balance between economic productivity and environmental sustainability. We explore the adoption of diverse agroforestry models that incorporate rubber trees with other valuable plant species, aiming to enhance ecosystem services, biodiversity, and farmers' livelihoods. The review highlights significant advancements in sustainable management practices, including species selection, planting designs, and soil and water conservation techniques that contribute to the resilience of these systems against environmental stresses. Economic analyses underscore the potential for rubber agroforestry systems to improve income diversification and stability for rural communities while also navigating market challenges. Environmental assessments reveal the positive impacts of these practices on carbon sequestration, biodiversity preservation, and soil health, positioning rubber agroforestry as a beneficial strategy for mitigating climate change effects. However, the review also identifies challenges, including the need for supportive policy frameworks, access to knowledge and technology for smallholders, and further research on long-term sustainability outcomes. Future directions for research are proposed, emphasizing the integration of ecological, economic, and social dimensions to fully realize the potential of the rubber under-forest economy in China.

Determination of C-factor for conventional cultivation and soil conservation technique used in hop gardens

Abstract The research presented in the article was focused on determining the C-factor for hops for conventional cultivation (CT) and soil conservation technique, which is based on the presence of cover crops (CC) in the inter-rows. The values of the soil loss ratio, which are the basis for the calculation of the C-factor, are also presented. The research activities were carried out between 2016 and 2023 and a field rainfall simulator was used for the measurements. Rainfall simulations were conducted at three developmental stages of CC. The results show a high C-factor value for CT (0.73), which indicates insufficient erosion control efficiency. In contrast, a C-factor of 0.16 was determined for the cover crop technique. This means that cover crops in the inter-rows of hop gardens can effectively reduce the risk of water erosion. The values reported in the article can be used as input parameters in various erosion models and equations to refine the subsequent calculation.

The Impact of Climate Change on Food Security and Natural Resource Management in Smallholder Crop Farming Systems at Mthonjaneni Local Municipality, Kwazulu-Natal, South Africa

This study assessed the impact of climate change on food security and natural resource management on crop farming systems. Forty-five respondents were interviewed using an open-ended, and structured questionnaire. The open-ended questions allowed respondents to share their thoughts and experiences in their own words, while the structured questions helped to ensure that all respondents were asked the same questions and that the data collected was consistent. The results of this study showed that smallholder farmers perceived an increase in hot days (51.1%), a decrease in rainfall (51.1%), and a decrease in flood occurrence (71.1%). In addition, 95.2% of the respondents indicated that climatic conditions have influenced their farming systems. Natural resource changes noticed by farmers because of climate change include reduced grazing feedlot for livestock farmers (85%), reduced herbaceous cover (80%), decline in volume of water (57.8%), and increased tree damage and land degradation (11.1%). Increased soil erosion (6.7%) and increased bush encroachment (2.2%) were some of the natural resource challenges facing smallholder farmers. Some signs of climate change experienced by farmers included increases in crop pests (71%) and crop disease (8,9%). The adaptation strategies applied included the following: use of water harvesting, use of little soil disturbance techniques, adjusted fertiliser use, application of different planting dates techniques, use of different crop varieties, use of drought tolerant seeds, applied crop diversification, use of techniques that shortened growth length, planting new trees and avoiding planting on sloppy areas, and applied soil conservation techniques. Agriculture extension advisors should address vulnerable systems, including agricultural water and natural resources. In addition, it is important for agriculture extension advisors to strengthen the link between climate change adaptation and key climate change policy processesto improve their effectiveness and ability to deal with the effects of climate change. This will help overcome shortcomings along the food value chain and ensure food security.

Paisaje Agrario: Producción Agrícola Familiar en la Campaña Dange-Quitexe 2019-2022

Family farming in Angola has pre-colonial historical roots. It faced challenges during the colonial period and the war of independence, but after 1975, the government promoted it as essential for economic development. Despite the obstacles, the province of Uíge plays a crucial role in food security and rural development, receiving investment for strengthening and sustainable growth. The aim of the research was to analyse the influence of agricultural practices on food availability in the region and to represent the temporal evolution of land use and land cover in the agricultural production of families in the municipality of Dange-Quitexe. The methodology used was a temporal land use study, involving the collection of data on traditional agricultural practices, analysing soil conditions, defining sustainability goals and implementing management practices such as crop rotation, intercropping, water management and soil conservation techniques. The results of this study offered a deeper understanding of family farming over the two agricultural seasons, and provided valuable information to guide future actions and initiatives in the area of agriculture and regional development, land use revealed significant improvements in productivity and resilience, the implementation of sustainable practices, such as crop rotation, intercropping and water management, resulted in healthier harvests and more stable yields over time, in addition, it presented the level of production for food security in the municipality of Dange-Quitexe-Uíge in the 2019-2022 agricultural seasons.

Investigation of the discharge performance in infiltration wells based on several soil subgrade models

Heavy precipitation would result in hydrometeorological disasters such as landslides and floods. In general, disasters cause hazardous situations and property loss. Infiltration wells are water and soil conservation techniques that can reduce surface runoff and increase infiltration to mitigate the effects of hydrometeorological disasters. However, evaluations of geotechnical properties have not yet jointly or actively considered these environmental developments. This paper aims to analyse the wide range of soil types against several diameters and depths of the holes. The variation in soil varied from type 1 to 6, containing different properties and consistencies. The holes diameter used are 0.4m, 0.5m, 0.6m, 0.7m, and 0.8m, associated with several depths; 0.5m, 0.75m, 1m, 1.25, and 1.5m. The analysis was conducted with Geostudio SEEP-W in different model variations to obtain the well’s discharge value. The result shows that all the depth depicts similar behaviour of the discharge well. The sand model has the highest value of all categories, with the second place being the sand-clay layer model. In contrast, the clay simulation generates the lowest value of this research. This output offers a strong recommendation between infiltration well structure and soil parameters, which show sand is the most required property to increase the performance of hole infiltration.

Estimation of Water Yield and Soil Erosion in Samanalawewa Watershed in Sri Lanka using GIS-based InVEST Model

Ecosystem services (ES) are a group of tasks performed by the earth's ecosystems that are required to support life and offer benefits to humanity. Thus, this study explores two of the water-related ecosystem services, water yield, and soil retention that were distributed in the Samanalawewa Watershed (SW) and its eight sub-watersheds in Sri Lanka, over 20 years (2000-2020) with five- year time intervals. Soil and water conservation and water yield play an important role in ecosystem management. Hydrological balance is a crucial component of the hydrological ecosystem services. Assessing water yield and soil erosion are pivotal for watershed management. Thus, this study estimated and mapped the water yield and soil erosion, using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST 3.9.2) Annual Water Yield (AWY) and Sediment Delivery Ratio (SDR) model respectively. According to the obtained results, in 2000, 2005, 2010, 2015 and 2020, the estimated mean annual water yield was 2.62x105, 2.6x105, 3.5x105, 3.58x105 and 2.75x105 m3 ha-1year-1, respectively. Furthermore, the estimated mean annual soil erosion rates for the above- mentioned years were 53.2, 52.9, 69.7, 87.7 and 70.2 t ha-1 year-1. The estimated soil loss values of the SW are 10 to 18 times greater than the soil erosion tolerance (5 t ha-1 year-1) in Sri Lanka. The results show that the years 2015 and 2005 have the highest and the lowest water yield and total soil loss values, respectively. The upper part of the watershed has relatively moderate water yield and soil loss values than the lower part. These findings would be beneficial in developing watershed management strategies and in the implementation of suitable soil and water conservation techniques within the watershed. 
 Keywords: Ecosystem services, InVEST, Samanalawewa watershed, Soil erosion, Water yield

CLIMATE-SMART RICE PRODUCTION: A REVIEW

‌Rice is one of the world's most important crops and the primary source of nutrition for the world's more than half population. Currently, the world rice production is 495.78 million tons, while it will increase to 525 tons in 2050, which is not sufficient for the world's increasing population. At the same time, various climatic factors affect rice production, such as air temperature, atmospheric CO2, light, water, and soil nutrients. For instance, high temperature was the main climate factor that caused yield variation by affecting the rice maturity periods, spikelet fertility, and spikelet number. Thus, it is an urgent need to improve rice production and reduce the negative effects of climate change on rice production. In order to solve above-mentioned problem, one of the most important options is using climate-smart practices, which are planting improved rice varieties, soil and water conservation techniques, and adjusting planting and harvesting dates. The importance of adapting climate smart practices is an increase in rice yield by 15.87%. Climate-smart rice production and climate-smart practices in rice needs still to be investigated widely. The review objective is to describe climate-smart practices in rice cultivation, in order to mitigate the negative effects of climate change on rice production.

Woody species alongside earth contour bunds enhance the soil water‐infiltration capacity in the Sahel, West Africa

AbstractLand degradation, including the loss of tree, forest and vegetation cover, and its related loss of water availability are the main constraints affecting the rainfed agricultural systems in West African Sahel and dry savanna. Therefore, farmers are implementing various soil and water conservation techniques such as zaï pits, half‐moons, contour stone and earth bunds to improve crop production through reduced erosion and enhanced water retention. This study explores the effect of woody and herbaceous vegetation established along earth contour bunds on soil infiltration capacity in southern Mali. The soil infiltration measurements were carried out from September to December 2019 using single ring infiltrometers up‐slope and down‐slope of the bunds built on contour lines in 2015 and 2016 with four types of vegetation: (1) natural annual herbaceous vegetation; (2) planted Andropogon gayanus (perennial grass); (3) planted Gliricidia sepium (woody species) and (4) planted Acacia colei (woody species). The field‐saturated hydraulic conductivity (Kfs) was estimated from the infiltration data and subjected to statistical analysis to compare the effect of the four types of vegetation on soil infiltration capacity. The results revealed significant differences in infiltration rate and Kfs between the four vegetation types. The highest infiltration rate and Kfs were observed for earth contour bunds reinforced with woody species G. sepium (299.5 ± 0.6; 45.3 ± 1.4 mm h−1), followed by A. colei (232.2 ± 2; 38.2 ± 1.6 mm h−1). These were followed by the grass A. gayanus (189.4 ± 2.5; 33.0 ± 1.7 mm h−1) and natural annual herbaceous vegetation (132 ± 2.3; 20.7 ± 1.9 mm h−1). In addition, soil water‐infiltration rate and Kfs were higher for down‐slope compared to up‐slope areas for the two woody species. In practice, it is appropriate for farmers to reinforce contour bunds with woody species and perennial herbs given the beneficial effect on soil water infiltration and retention capacity and the expected socio‐economic benefit they can get from them.

Participatory Demonstration of Pennisetum pedicelluatum and Elephant grass (Pennisetum purpureum) Strip as Biological Soil and Water Conservation Measures for Erosion Control

On three beneficiary farmer fields, prescaling up and participatory demonstration of biological soil conservation techniques using Desho (Pennisetum pedicelluatum) and Elephant grass (Pennisetum purpureum) were carried out in 2019/2020 in comparison with control (no grass) activities. Assessing the role of biological conservation techniques in reducing soil erosion and farmers' opinions of these techniques was the primary goal. A total of 132 m2 demonstration plots were used to collect and analyze the experimental data. Elephant grasses (134 tons/ha) and desho (61.1 tons/ha) differed significantly (P < 0.05) in the second year. Elephant grass provided an average soil loss of 6.6 tons/ha/yr-1, desho grass produced an average of 10.9 tons/ha/yr-1, and control provided an average of 13.4 tons/ha/yr.The elephant grass plots showed the least amount of nutrient loss, while the control plots showed the greatest amount.When compared to Desho grass, elephant grass has a higher potential to control soil loss due to its robust root system and to rebound quickly, even in the event of a severe drought.Furthermore, because elephant grass grows quickly and has the largest freshweight biomass of any grass, farmers gave it more consideration in their assessments of grass strips than they did Desho grass.In order to improve acceptability and spread of the technology in dry land areas with a 5% slope for managing soil and nutrient losses, it is best to scale up elephant grass on a bigger scale. The highest nutrient loss was observed on the control plots and the least on the elephant grass plots. Based on the study results, elephant grass has a high potential to control soil loss through a strong root system and recovery immediately, even under severe drought conditions, compared with Desho grass. Additionally, farmers' evaluations of grass strips showed a higher attention to elephant grass than Desho grass due to the fast-growing nature of the grass and their highest fresh-weight biomass. Finally, it is better to scale up elephant grass on a larger scale to enhance acceptance and diffusion of the technology in dry land areas on a slope of 5% for controlling soil and nutrient losses.
 Keywords: Biological soil and water conservation, Desho grass, soil and nutrient loss

Probing Farmers’ Awareness about Climate Change and Adaptation in Karkihalli Village, Koppala District, Karnataka

Study conducted in Karkihalli village, Karnataka, India, aimed to assess the impact of climate change on agriculture and livestock, as well as the adaptation and mitigation strategies employed by farmers. Through interviews with ten farmers, it was found that a majority of farmers were aware of climate change and had observed various climate-related changes over the past two decades. These changes included rising temperatures, decreased rainfall, prolonged droughts and increased occurrences of heat waves, among others. The impact of climate change on agriculture was evident in the form of water scarcity, declining water quality and increased susceptibility of crops and livestock to pest and disease attacks. Farmers noted specific challenges such as new diseases affecting crops, such as fall armyworm and wilt disease, which led to significant crop losses. Erratic monsoon patterns and hailstorms further exacerbated the situation, resulting in reduced agricultural yields and earnings. The deteriorating quality of food due to chemical farming practices was observed to have adverse effects on human health, with changes in food consumption habits contributing to an increase in diseases. Moreover, livestock diseases were more prevalent in recent years, likely linked to climate-related shifts. Farmers identified various drivers for climate change adaptation, including a lack of information and knowledge about climate change, accessibility to credit facilities and the outbreak of new diseases or food scarcity. While many lacked knowledge about climate change mitigation strategies, they had adopted practices like crop rotation, improved seeds and soil conservation technique.

Nitrogen Use Efficiency Using the 15N Dilution Technique for Wheat Yield under Conservation Agriculture and Nitrogen Fertilizer

Conservation agriculture (CA), which could contribute to sustainable agriculture, maintains or improves soil nitrogen fertility by eliminating tillage (no-tillage). Quantitative assessment of soil constituents is enhanced by stable isotope techniques such as 15N, which are used to better understand nitrogen dynamics. This study was therefore carried out to assess the impact of tillage type and fertilizer application on soil and plant nitrogen fractionation. The trial consisted of two tillage types: no-tillage (NT) and conventional tillage (CT). Three nitrogen doses (82, 115, and 149 kg ha−1) were applied. The experimental design was a randomized complete block with three replications. The Louiza variety of durum wheat was used in this study. Soil nitrogen sequestration was assessed using the stable nitrogen isotope (15N) method. The statistical analysis (ANOVA) showed that, overall, there was no significant difference between tillage types and nitrogen doses for grain and straw yields and grain total nitrogen. In contrast, the effect of both factors and their interaction were significant for straw total nitrogen. There was no difference between tillage types for grain nitrogen use efficiency (NUE), even though NT was superior to CT by 3.5%, but nitrogen doses had a significant effect and a significant interaction with tillage type. When comparing nitrogen doses for each tillage type separately, results showed that the average NUE for grain was 20.5, 8.4, and 16.5%, respectively, for the three nitrogen doses for CT compared with 26.8, 19.0, and 30.6% for NT, indicating clearly the better performance of NT compared to CT. Regarding straw, the NUE is 3.2, 3.5, and 5.4% for CT compared with 3.4, 4.9, and 9.2% for NT. NUE in grain and straw under no-tillage was higher than under conventional tillage in all three nitrogen doses. These results show that soil conservation techniques such as no-tillage and the integrated application of nitrogen fertilizer can be good strategies for reducing soil nitrogen losses.

Design of soil and water conservation techniques to minimize soil erosion on degraded land in Samarinda Tenggarong Axis Road

Soil conservation activities are aimed at tackling land degradation, especially soil erosion, which occurs rapidly. If there is human intervention, land will become more sensitive to the influence of water (rainfall) and gravitational forces. This study aimed to identify the types of erosion that occur on degraded land and design appropriate soil and water conservation techniques based on vegetative and physically degraded land conditions on the Samarinda-Tenggarong Axis road. The results of the documentation collected from each research site identified the type of erosion, and designed soil and water conservation techniques. This research is focused on the design referring to Permenhut P.04/Menhut-11/2011 and UU RI/37/2014. The results of this study showed that location 1 of the recommended technique is the vegetative technique and the manufacture of Water Sewerage, location 2 is the bench terrace technique, location 3 is the retaining wall technique, location 4 is the individual terrace technique, location 5 is the stone terrace/wall technique, location 6 is the stone terrace/wall technique, and location 7 is the garden terrace technique. The design of the soil and water conservation techniques recommended in this study is expected to have a positive effect on minimizing soil erosion on degraded land.

Knowledge and Practice of Sustainable Land Management of Coffee Agroforestry in Community Forest Areas, West Lampung Regency

This study aims to identify knowledge and practices of sustainable land management in coffee agroforestry in community forest areas. The research was conducted from November to December 2021 in a community forest area in Air Hitam District, West Lampung Regency. The respondents are 40 coffee farmers who cultivate coffee in the community forest area. The study used the Knowledge, Attitude, and practice framework to identify knowledge and practices of sustainable land management in coffee agroforestry and analyzed using a qualitative descriptive approach. The study results show that coffee farmers’ knowledge of sustainable land management is in the fairly high category. Farmers understand that sustainable land management supports forest sustainability and increases coffee productivity. Sustainable land management practices that coffee farmers have implemented include the use of organic fertilizers from livestock, the use of coffee shells as natural compost, planting shade trees to prevent erosion and increase soil fertility, and soil conservation techniques using the Rorak method (making holes for water absorption, accommodate soil sediments and sources of organic matter). The practice of sustainable land management by coffee farmers is in line with the objectives of social forestry, namely the use of forests to improve welfare without neglecting forest sustainability.

Numerical Quantification of Surface Runoff and Soil Erosion using PCRaster

Surface runoff and soil erosion of the Upper Lagawe River Sub-watershed, Ifugao Province, Philippines were quantified using Geographic Information Systems (GIS)-based numerical simulation. PCRaster software was used as a framework for the model. Manning’s and Rose, and Freebairn’s Equations were utilized to compute surface runoff velocity and sediment mass. Analysis and comparison of the measured and predicted streamflow yielded a mean Nash and Sutcliffe Efficiency Index of 0.70, a mean percent bias of -8.38%, and a mean root mean square error (RMSE) of 0.16. Based on the model, super typhoon Lando (international name: Koppu) generated an estimated surface runoff volume of 186000 m3 and an estimated sediment mass of 36587 kg for the entire sub-watershed. The mass of eroded sediments equated to 18.6 kg/ha of erosion rate just for the said super typhoon. Stable ecosystems, such as the Upper Lagawe River Sub-watershed, where forest vegetation is intact and farmers practice soil conservation techniques are still vulnerable to the effects of extreme rainstorm events, can generate voluminous surface runoff and eroded sediments.

Erosion patterns, drainage dynamics, and their environmental implications: a case study of the hammamet basin using advanced geospatial and morphometric analysis

AbstractUnderstanding erosion patterns and drainage conditions is crucial for optimizing agricultural productivity and for addressing the challenges of wastewater treatment. To achieve this, we employed a comprehensive approach, combining the morphometric method with weighted sum and Geospatial techniques. Utilizing a 30-m-wide Digital Elevation Model (DEM), specifically the Aster DEM, and leveraging ArcGIS software, we meticulously delineated drainage systems and watershed boundaries. Through the application of standard formulas, we calculated areal, linear, and relief parameters to effectively rank and prioritize the sub-watersheds. Our examination led to the calculation of a composite factor, determined through an assessment of 18 morphometric criteria employing a weighted summation approach for each subcatchment. The outcomes of our research unveiled a wide range of compound factor values, spanning from − 0.128 to 9.28. This study underscores the pivotal role of the minimal compound factor value in determining the sustainability of sub-watersheds. As a practical illustration, we found that Basin 3 exhibited superior sustainability when compared to Basin 4, primarily attributable to soil erosion issues in the latter. Sub-watersheds were additionally grouped into classes according to their composite factor values, commonly characterized as highly favorable, favorable, intermediate, or unfavorable, providing insights into their vulnerability to erosion. Moreover, our research pinpointed Basin 4 and Basin 7 as highly vulner able to soil erosion, with a combined area of 294.9 km2. The implications for wastewater treatment are significant in these areas, as proper water and soil conservation techniques are imperative not only for the sustainable management of these lands but also for mitigating the environmental impact of the wastewater treatment process.

Assessing sustainable management practices of expert-introduced physical soil and water conservation measures

Soil erosion is a significant environmental and socio-economic concern. Soil and water conservation methods, guided by experts, have been developed and implemented through various channels such as government initiatives, non-governmental organizations (NGOs), and public campaigns. These efforts aim to mitigate the adverse effects of erosion. The effective maintenance of soil and water conservation measures by farmers is of paramount importance in ensuring the sustainable utilization of such measures over an extended period of time. The objective of this study was to evaluate the attitude of farmers and their implementation of sustainable management techniques regarding physical soil and water conservation measures provided by experts. Field data were obtained through the process of conducting interviews with a total of 92 households residing within a watershed that is predominantly engaged in agricultural activities. To enhance and organize home responses, the research team included key informant interviews and focus group discussions. The results of the study indicated that a significant majority of farmers (97.8%) held the perception that soil erosion was a prevailing issue. The causes of erosion were identified as frequently cultivation (21.3%), inadequate implementation of physical soil and water conservation practices (19.6%), excessive precipitation (17.9%), degradation of conservation structures (16.7%), unregulated grazing (15.3%), and deforestation (9.2%). Indigenous conservation strategies, such as the utilization of traditional diversion ditches, as well as the adoption of introduced soil and water conservation techniques like Fanya juu and soil bunds, were employed with the aim of mitigating the adverse effects of erosion. While a majority of farmers, specifically 65.2%, have adopted the improved conservation measures on their agricultural land, it is noteworthy that a significant proportion, approximately 79.3%, have not adequately maintained or repaired these imposed conservation measures. The majority of the cropland has seen substantial damage to the designed measures as a result of inadequate upkeep. The scarcity of labor and insufficient knowledge and skills provide significant constraints for farmers in effectively implementing designed conservation measures. Nevertheless, it seems that farmers are not inclined to invest their labor and financial resources in order to maintain the introduced structures, as they are mostly established through public campaigns or government/NGO incentives. Hence, it is imperative for the government and non-governmental organizations (NGOs) to allocate resources towards the promotion of awareness, policy execution, and other pertinent matters that support the long-term viability of the introduced conservation measures.

Evaluating the impact of ponds on flood and drought mitigation in the Bagmati River Basin, Nepal

Abstract This study investigates the effectiveness of ponds as a nature-based solution (NBS) to concurrently ameliorate flood and drought impacts, emphasizing the need for an integrated response to multi-extreme hydrological events. We incorporate ponds into agricultural landscapes in the Bagmati River Basin of Nepal and assess their performance using the Soil and Water Assessment Tool (SWAT+). Six different scenarios are thoroughly explored to see how these interventions affect the main components of the water balance, such as surface run-off, lateral flow, percolation, and evapotranspiration. The spatial efficiency of the ponds, particularly in their immediate surroundings and downstream areas, has been proven to be a crucial factor in their overall efficacy in attenuating extremes, which increases with the size of the intervention area. Although the effects of ponds on floods and droughts are minor, they could be significantly magnified by a synergistic use of other NBS tactics, such as conservation tillage or soil conservation techniques. Future studies should establish the most appropriate sites and volumes for these interventions, as well as further investigate the possible advantages of several NBS, to optimize flood and drought management in the Bagmati River Basin and other similarly susceptible places.

Assessment of short- to medium-term impacts of bench terrace construction on soil water repellency in north-central Portugal

Agrarian terraces are surely recognized as a traditional soil and water conservation technique, however the use of these methods in forestry are poorly studied, especially the hydrological impacts of bench terracing for forest plantations. The employment of heavy machinery in forests have been described to increase soil bulk density and compaction which might reduce soil water infiltration capacity, and thus, increase runoff generation. However, in the case of terraces, the flattening of the terrain may increase the infiltration and re-infiltration of runoff due to consecutive slope discontinuity. The present study assesses the short to medium-term impacts of bench terrace construction on soil water repellency and soil water infiltration in eucalypt forest plantations. A chrono-sequence approach was used to analyse a time series of sites terraced at different periods with neighbouring mature long-undisturbed sites. Therefore, Methanol droplet test was employed in-situ in four different periods of time-since-terracing (0, 5, 10 and 17 years after terracing). Three pairs of nearby terraced and non-terraced eucalypt plantations were studied for each period, counting a total of 24 study sites. Our results revealed clear differences in SWR between terraced and non-terraced eucalypt plantations, with all non-terraced sites showing extreme SWR values while at the terraced sites highly variable values were found. In addition, the median SWR increase with time elapsed since terrace construction, i.e. from very wettable immediately and 5 years after terracing, and increase to strong and moderate water repellent at 10 and 17 years following terracing. The infiltration variables were observed inversely correlated with SWR following terrace construction and were watched to decrease with time-since-terracing. The litter and the Oh humified layer were found positively correlated to the SWR as well as the stone and bulk density variables, while the percentage of organic matter and the soil moisture content in the soil were poorly correlated.