جستجوی مقالات مرتبط با کلیدواژه "حفاظت آب و خاک" در نشریات گروه "آب و خاک"

Vegetation is a universal and effective method for water and soil conservation. The significant implications of soil loss necessitate the adoption of appropriate soil conservation practices and soil management solutions according to the regional climate. Investigation of the effects of soil cover on the soil erosion process can provide the information necessary for the success of soil and water conservation practices. In general, vegetation cover can mitigate runoff by increasing water infiltration, enhancing sediment trapping, reducing the kinetic energy of raindrop impact, increasing surface roughness, decreasing flow velocity, and controlling runoff hydraulic properties. The impact of vegetation cover on runoff generation has been studied at different spatial scales, from experimental to watershed scales, and most studies have shown the effectiveness of vegetation cover in reducing surface runoff. In arid regions, it may be difficult and economically infeasible to cover the entire surface area of a soil conservation project with vegetation. Therefore, the question arises as to how much of the soil surface should be covered to have an optimal impact on runoff generation. The main objective of this study was to evaluate the effects of different ratios of alfalfa coverage on runoff generation under simulated rainfall conditions.

A completely randomized design was used with treatments based on the ratio of alfalfa coverage (0, 35, 65, and 90 %) under artificial rainfall conditions. The texture of the studied soil was sandy loam and collected from the surface horizon of farmlands in Kashan. All experimental plots were 2 m long, 0.55 m wide, and 0.35 meters deep with a metal runoff collector. Alfalfa seeds were planted at a spacing of 15×15 cm in the 35 % plot, 10×10 cm in the 65 % plot, and five in 10 cm in the 90 % plot. All plots were subjected to a simulated rainfall with an intensity of 90 mm hr-1 for 70 min. To achieve uniform antecedent moisture conditions, all plots were subjected to a 10-minute long simulated rainfall at an intensity of 90mm h-1 exactly one hour before the experiment.During the experiment, the runoff and sediment samples were gathered using the metal collector (placed at the plot outlet) at 5-minute intervals. In order to investigate the changes in runoff reduction efficiency in different treatments and different testing periods, statistical criteria of runoff reduction efficiency were used. The Kolmogorov–Smirnov, one-way ANOVA, and Duncan’s tests were used for data analysis.

The results indicated that the plant cover treatments were most effective in reducing runoff during the first 15 minutes of the experiments. However, their effectiveness decreased as the experiments progressed due to the soil's inability to pass water at a higher rate once the infiltration reached its final rate. The coverage ratio treatments (0, 35, 65, and 90 %) showed a significant difference in runoff generation (p <0.01). The bare plots had the highest average runoff generation and were classified into a separate group (a). The plots with 35, 65, and 90 % coverage ratios had average runoff rates of 0.329 mm min-1, 0.222 mm min-1, and 0.112 mm min-1, respectively, and were placed in separate groups as well. In the bare soil treatments, the high amount of rainfall drops on the soil surface without vegetation interception exceeded the infiltration rate and subsequently produced runoff. Additionally, soil sealing and crusting processes due to raindrop impacts could reduce infiltration and generate higher runoff. The effectiveness of runoff reduction was also evaluated at 35, 65, and 90 % alfalfa cover. The results showed that 65 and 90 % cover significantly reduced runoff production, but no significant difference was observed between the 35 and 65 % levels.

In this study, we evaluated the influence of alfalfa coverage ratios on runoff generation in experimental conditions subjected to artificial rainfall. We found that higher coverage of alfalfa was associated with a delay and reduction in runoff generation. While all the examined vegetation cover percentages demonstrated an acceptable performance in reducing runoff and sediment. Furthermore, we were able to determine a practical threshold for coverage ratio, which could result in a significant decrease in surface runoff production. We found that a minimum of 65% alfalfa coverage was necessary to achieve this reduction. This threshold could be considered a beneficial criterion for soil and water conservation practices, especially in arid areas where dense vegetation establishment can be difficult and more expensive. This study is also particularly important for dry and semi-arid regions that face challenges of drought and soil erosion. The use of alfalfa as a vegetative cover can help to conserve soil moisture, reduce erosion, and improve water quality in these areas. In addition, vegetation plays a crucial role in soil and water conservation, and alfalfa, being a perennial plant with a deep root system, is a suitable option for erosion and runoff control in various regions, especially in dry and semi-arid areas.

Watershed management practices by biological, biomechanical and mechanical operations are not only trying to solving watershed problems, but also in line with the sustainable development through improving the economic condition and living standards of stakeholders. Therefore, the present study was conducted to impact evaluation of the soil and water conservation practices on the sediment yield of Kan watershed in Tehran province using the data of the period of 1998-2018. The initial results from the practices simulation using the SWAT model showed that there was the large difference between the simulated and observed values, the model was recalibrated and validated after steps performance of the sensitivity analysis with the 2-SUFI algorithm. Based on the obtained results, the coefficient value of explanation in the calibration and validation stage of model obtained equal to 0.74 and 0.86, respectively, and the Nash-Sutcliffe index value was equal to 0.74 and 0.77, respectively, that these values showed the model had the high efficiency for simulation. Then the simulation of watershed management practices investigated on the watershed level and the results indicated if the management practices implement the sediment values will reduce. In such away that the sediment yield in the watershed reduced using practices simulation of terracing, masonry check dams, gabion check dams, loose stone dams, seeding and planting decreased with rates of 44.65, 26.72, 26.70, 8.03, 4.97 and 9.73 percent, respectively.

Soil erosion is one of the most serious environmental issues in the world, causing soil degradation, reduction of land productivity, increasing flood, water pollution and pollutions transportation; it is also a serious threat to sustainable development in the world. Therefore, the soil conservation and the prevention of soil erosion and use of conditioners as the nanoclay can be considered as a solution to improve   land productivity and protect environment. The present study was, therefore, conducted to address the effect of the application of montmorillonite nanoclay with three rates of 0.03, 0.06 and 0.09 t ha-1 on changing runoff and soil loss variables under laboratory conditions. The results showed that the nanoclay with the rate of 0.03 t ha-1 could decrease the runoff coefficient, soil loss and sediment concentration with the rate of 40.65, 88.38 and 82.19 percent, respectively. The average of soil loss in control treatment and conservation treatments of nanoclay with various rates was measured to be 3.76, 0.44, 1.33 and 3.16 g, respectively. Also, the results showed that the most sediment concentration was the control treatment with the rate of 5.84 g l-1 and the conservation treatments with nanoclay in the applied rates was 1.04, 3.47 and 2.96 g l-1, respectively. Also, the results showed that the nanoclay effect was significant on changing the soil loss and sediment concentration at the level of 99 percent. Finally, due to the effect, the use of this conditioner in natural conditions and investigation of the effects on environment and aggregates stability are recommended.

Today, biological methods are considered as one of the effective approaches to control soil erosion at early stages. Biologic management is a scientific and applied approach to manage and control runoff and soil loss. However, there is no practical and specific algorithm for preparing and implementing biological programs for managing or controlling soil erosion in the watershed scale. Therefore, the present study was conducted as a pioneer study to develop a practical framework for the biologic management of soil erosion. In this regard, the erosion status in the watershed was initially considered to identify areas prone to bio-management. Then Ombrothermic and Hythergraph diagrams were prepared and combined with topographic, temperature, precipitation, and evapotranspiration data layers for zoning and obtaining an agroclimatic map. Finally, providing a list of endemic and dominant species of the study area obtained from phytosociological studies and soil characteristics, biologic management of soil erosion for each agroclimatic category was suggested as a final step for the proposed framework. The applicability of the proposed algorithm was evaluated for the Oshnavieh Galazchai Watershed in West Azerbaijan Province, Iran. The results showed that 24 and 76% of the watershed are classified in low and moderate situations in soil erosion, respectively. Based on the agroclimatic map, the suitable species for biological management of soil erosion were identified, and their associated characteristics were extracted. Finally, among the rangeland species in the studied area, Achillea millefolium, Agropyron desertorum, Agropyron tauri, Galium verum, Melica persica kunth, and Stachys inflata benth were suggested for biologic management of soil erosion in almost 64% of Galazchai Watershed. Therefore, the results of the present study could be extended at the country level for the appropriate biologic management of soil erosion.

Soil erosion is of the important global challenges for agricultural and food production. The indiscriminate intervention of man in the nature is of the main reasons for erosion. The success of any conservation program requires an understanding of the various aspects of human behavior. Behaviors are mainly emerge from the people’s knowledge and attitudes. Farmers' attitudes can influence their behavior to adopt conservation practices. Studying the attitude and behavior of farmers towards conservation practices can play a crucial role to help managers and decision makers in understanding the reason for farmers' conservation behavior and to modify and improve it. Several studies have been conducted worldwide on the adoption and application of soil and water conservation methods. Many of them have focused on the purely socioeconomic aspects of the adoption. While the current study examined the attitude of farmers towards conservation practices, access to facilities for and barriers to the application of these practices. The study also examined the perceptual-attitudinal and socioeconomic aspects affecting the implementation of conservation practices. Therefore, the conservation behavior of farmers in Talkhehrood basin in Harris County, East Azarbaijan province has been studied from different aspects.

The aim of this study was to investigate the attitude towards conservation practices and the application of these practices. Survey research method was used in this study. A sample of 220 farmers was selected using Cochran's sampling formula and the necessary data were collected using a face to face interviewing procedure. The random multistage sampling method was used to select the sample farmers. The instrument of the study was a questionnaire. Most sections of the questionnaire was in the form of 5-points Likert items. It was validated by a panel of university staffs and field experts of agricultural and natural resources. A pilot study was conducted using 30 farmers from out of the sample villages for reliability and correction of the questionnaire. The calculated values of Cronbach’s alpha showed that the questionnaire has sufficient reliability.

The results showed that farmers had a positive attitude towards conservation practices. Among the 12 selected conservation practices, compost application, dredging of irrigation canals, weeding and retaining crop residues were at the above-average level. The use of other methods was below the average. Creating windbreaks and flood dam was very weak. Respondents perceived that land fragmentation and lack of financial ability were the most important obstacles to the application of conservation practices. Significant correlations were found between the implementation of most conservation practices. Based on the regression analyses, attitude and access to facilities were the most important perceptual-attitudinal factors, as well as education and farming experiences were the most important socio-economic factors explaining the implementation of conservation methods.

The results showed that while farmers had a relatively positive attitude towards soil and water conservation practices, they implemented low-cost and quick-return practices using available facilities. Due to the lack of financial abilities, the use of practices that required financial investment was not very common among them. Removing barriers and restrictions, providing the necessary facilities and providing educational and extension programs can be effective in promoting the implementation of these practices.

In this study, the effectiveness of wheat straw mulch and wood shred was investigated in order to reducing runoff and sediment yield from unit source micro-catchments. Three micro-catchments (one for control and two others for treatments) were selected with an area of 1/ha for each wich are located in upstream of Gheshlagh Dam in Kurdistan province. After the implementation of treatments (application rate of 3 ton. ha-1), each micro-catchment was equipped with one flume at its outlet to measure the runoff rate and turbidity during storm events across one-year sampling from 2014-2015. The result of RRE and SLRE showed that straw mulch and wood shred have reduced runoff by 24.54 and 13.24 percent, and sediment yield by 58.75 and 44.10 percent in comparison to the untreated micro-catchment, respectively. Wheat straw mulch showed better performance in reducing runoff and sediment than wood shred. This might be due to the twisted fibers of straw mulch, the formation of barrier against the flow, and filtration of sediment particles by straw.

Today, conversion of industrial wastes using methods with the least environmental detrimental effects and profitable application is supposed as a fundamental solution to manage huge quantity of waste material produced in different industries. In this regard, conversion and reuse of hugely and intensive extension of produced dairy factory waste are possible solutions in order to achieve sustainable development. However, the direct or applied application of industrial wastes for soil conservation has not been reported yet. Accordingly, the present study was planned to assess the feasibility of industrial wastes produced biochar in soil erosion control under laboratorial conditions.
In order to conduct the present study, some industrial wastes of the Kaleh Amol Dairy Factory were examined for chemical properties. It was then converted to biochar under temperature of 300 to 350 °C and applied for soil conservation in three levels of 400, 800 and 1200 g m-2 on small experimental plots filled by erosion prone soil of Marzanabad Region in Mazandaran Province, northern Iran. The plots were subjected to rainfall simulation with intensities of 50 and 90 mm h-1 after a span time of 35 days on biochar application in the Rainfall and Erosion Laboratory of Tarbiat Modares University. Study rain were simulated based on intensity-duration-frequency relationships developed for the station at the vicinity of the soil origin. Ultimately, sediment concentrations were measured during simulation and just after commencement of runoff and the soil erosion was consequently calculated.
The results of the present experiments under laboratorial conditions showed that the maximum soil erosion occurred in control plots. So that, the sediment concentrations for treated plots with 400, 800 and 1200 g m-2 of biochar were 47, 52 and 49 % for rain intensity of 50 mm h-1, and 36, 51 and 54 % for rain intensity of 90 mm h-1 of those recorded for control plots at confidence level of 99 %, respectively. The soil erosion rates for the same treatments were also significantly (P The results of this study suggested a positive effect of application of biochar produced from industrial wastes of dairy factory on reduction of sediment concentration and soil erosion. The conversion of aforesaid industrial wastes to biochar is therefore recommended for soil conservation.

The water infiltration into the soil is an effective factor on runoff generation and watershed situation. Although many approaches have been therefore developed to improve infiltration process, but, less attention has been paid to use nano-paticels individually and in combination with organic amendment with the aim of improvement of water infiltration into the soil. The present research has been hence planned to assess the effect of organic vermicompost (V) amendment in 100 g m-2 and silica nanoparticles in 3 levels of 3, 7 and 10 g m-2 individually and in compound on infiltration of a sensitive soil to erosion from Marzanabad-Kandelus at small plots scale under experimental situation. The water infiltration measured under rainfall simulation with intensity of 50 mm h-1 and 50 min duration and different treatments and the statistical analysis was accordingly conducted. The results showed that all treatments except silica nanoparticles level three (NS3), increased the infiltration and decreased runoff volume compared to the control treatment. The water infiltration into soil in the cases of (V), silica nanoparticles (level one( (NS1), silica nanoparticles (level two) (NS2), vermicompost and silica nanoparticles (level one ) (VNS1), vermicompost and silica nanoparticles (level two) (VNS2), vermicompost and silica nanoparticles (level three) (VNS3) increased by 24.79, 30.63 , 10.18, 14.05, 15.09 and 23.30 %, respectively and the (NS3) decreased by 0.24 %. The differences between performance of individually and combined application of vermicompost and silica nanoparticles confirmed the necessity of the correct usage of amendment in soil and water management.

Soil erosion is a global problem that seriously threatening natural resources, human welfare and even life human. Globally, there are many methods for soil conservation including biological, mechanical and bio-mechanical methods, which these methods are expensive and they are not environmental friendly. Mulching is one of the management practices to reduce the impact of raindrops on soil erosion and control surface runoff. From these, organic mulches improve soil texture and infiltration capacity and avoid from environmental pollution. Mulching also decreases crusting of the soil due to rainfall impact also reduces erosion by absorbing the kinetic energy of the raindrops. Wood mulches have been developed from wood manufacturing waste (e.g., wood strands such as Wood Straw, wood shreds or wood chips) made from burned trees or forest thinning operations, and shredded forest floor material from nearby eroded areas. Although these wood-based mulches are unlikely to harbor non-native seeds, their greater density can increase the cost of transportation to the site and aerial application as compared to straw mulch. Laboratory studies established that wood strands have greater resistance to wind displacement as compared to agricultural straw, and both wood strands and wood shreds provide equal or greater protection from erosion as compared to agricultural straw mulch at equal areal coverage rates. Foltz and Wagenbrenner (2010) reported that a 50% cover of wood shred mulch, with small (

Runoff production process is a key hydrological component illustrating watersheds health. Water infiltration in soil is also one of the determinant factors on runoff generation for which many techniques were used to improve it. However, the role of microorganisms for the improvement of water infiltration in soil has been less considered. The present study therefore tried to investigate the effect of artificial soil bacteria population proliferation as a completely biologically and modern technique to improve soil surface properties and increase soil infiltration. To this end, the beneficial bacteria include Bacillus subtilis strain and Azotobacter sp. were isolated and inoculated individually and combined with B4 stimulant nutrient matter to small erosion plots filled by an erosion-prone soil of Marzanabad-Kandelus road neighboring region and left for 60 days. The water infiltration in soil was then measured after rainfall simulation in experimental condition and then the statistical analyses were conducted. The results showed that the inoculation treatments (individually inoculation of Bacillus subtilis strain and Azotobacter sp., individually injection of B4 stimulant nutrient matter and combined inoculation of bacteria and B4 stimulant nutrient matter) improved the water infiltration in soil and reduced volume and consequently coefficient of runoff in 99% of confidence level compared to control. The water infiltration in soil in Bacillus subtilis strain and Azotobacter sp. bacteria inoculation, B4 stimulant nutrient matter and their combined treatments increased about 18, 10 and 21%, respectively. In conclusion, enrichment of soil crust bacteria population through inoculation and simulation techniques was approved in reducing runoff yield. The combined inoculation of Bacillus subtilis strain and Azotobacter sp. bacteria with B4 stimulant nutrient matter had the best performance in increasing water infiltration in study soil.