Water and Soil Sciences

Temperature can have a significant effect on the conductivity and TDS (total dissolved solids) of water. In general, as the temperature of water increases, its conductivity also increases. This is because at higher temperatures, water molecules move more quickly and are able to carry more charged ions, which increases the overall conductivity. The effect of temperature on TDS is a bit more complex. TDS refers to the amount of dissolved solids in water, including minerals, salts, and other substances. As water temperature increases, the solubility of certain substances can change, which can impact the TDS measurement. For example, some salts become less soluble at higher temperatures, which can result in a decrease in TDS. However, other substances may become more soluble, which could increase the TDS measurement. i.e. it's important to take into account the effect of temperature when measuring conductivity and TDS in water to ensure accurate results.

Rhizobacteria are promising as biotechnological methods to improve soil fertility and legume production under field conditions. A field experiment, organized in a randomized complete block design with three replications, was conducted to evaluate the effects of inoculation with plant growth-promoting rhizobacteria (PGPR) in combination with Rhizobium on nodulation, growth, yield components, nutrient and protein content of common bean (Phaseolus vulgaris cv. Nebraska) as a model legume plant. The effect of co-inoculation of Rhizobium and PGPR on soil microbial activity and availability of soil N, P, and Fe was also investigated. Three PGPR strains (Micrococcus agilis KMe7, Serratia marcescens BM1 and Pseudomonas fluorescens TW2) were selected based on their ability to produce indole acetic acid and siderophores as well solubilization of inorganic phosphate. Generally, the results obtained from this study indicated that the co-inoculation of Rhizobium with each of the three tested PGPR significantly increased (P <0.05) the nodulation (nodule number and nodule dry weight), root and shoot dry weight as compared to Rhizobiuminoculated alone and uninoculated control plants at 70 days after sowing. The uptake of N, P, K, and Fe in shoot tissues increased significantly in the co-inoculation treatment and plant growth was enhanced as compared with the single inoculation treatment and uninoculated control. Co-inoculation with Rhizobium and PGPR significantly increased soil dehydrogenase activity compared with single inoculation. Additionally, co-inoculation of Rhizobium and PGPR also had a positive effect on the composition of the rhizosphere microbial populations and significantly increased populations of bacteria, phosphate solubilizing bacteria and siderophores producing bacteria as compared with individual inoculation. The results show that the dual inoculation of PGPR and Rhizobium significantly increased common bean yield and yield components (pods per plant, seeds per pod, and 100-seed weight as well as straw, seed, and biological yields) compared with single inoculation and uninoculated control. Results showed that the best coinoculation treatment was Rhizobium + Pseudomonas fluorescens with relative increase of seed, straw, and biological yield reaching 19.6, 35.4 and 22.2%, respectively, over the Rhizobium alone treatment. Finally, co-inoculation significantly increased the percentage of protein in common bean seeds as compared with single inoculation or uninoculated control. These results indicate that co-inoculation with PGPR and Rhizobium had a positive effect on common bean nodulation, growth, soil nutrients status, nutrients uptake, and yield. The present study concluded that PGPR can be used to promote legume plants in Egypt and to increase soil fertility when it is inoculated with symbiotic N 2 -fixing bacteria.

The EPICSEAR model is a newly developed version of the EPIC model for simulating crop production and nutrient uptake on highly wheatered, acidic soils. It has been used to simulate soil water dynamics and biomass production of a Maize/Cowpea intercrop with and without fertilization on an Alumi-Haplic Acrisol with high aluminium saturation. The simulation results were used to appreciate the effect of fertilization on water use efficiency in rainfed agriculture on similar sites. The simulation results where checked against soil water and biomass measurements of a field trial in the semiarid Northeast of Brazil. The field had been previously used for Maize/Cowpea mixed cropping and the effect of complete fertilization (C) on soil water changes, nutrient uptake and biomass development was tested in a randomized complete block design with four repetitions against the control treatment (CR) without fertilizer application. Depending on the parametrization of soil hydrological properties, the average total dry matter production of both treatments (C and CR) was reasonably well represented by the model. The absolute soil water content was better represented when field capacity and wilting point were calculated from pedotransferfunctions other than the EPIC defaults. The coefficients of transpiration in the treatment with complete fertilization were ranged on average between 576 and 653 l kg -1 dry matter depending on the calculation method for crop transpiration, whereas those in the control were between 1265 and 1528 l kg -1 . The results demonstrate the extremely high coefficients of transpiration of a maize/cowpea intercrop under semi-arid tropical conditions and the increase of efficiency of transpiration by more than 100% when mineral fertilizer is applied. Crop production in the semiarid Northeast of Brazil is characterized by water scarcity, which becomes most evident during drought years which are mostly related to the El-Nino phenomenon. Hence, the efficient use of water (irrigation or precipitation) is of major importance. Fertilizer trials in temperate regions have demonstrated, that the coefficient of transpiration of wheat and rye are strongly increased through the application of mineral fertilizers (N, P, K, Ca) with or without farmyard manure under different soil conditions (Klapp 1962, Schulze und Schulze-Gehmen 1957. In semiarid West Africa, water use efficiency of millet had been doupled through fertilizer application . Therefore, fertilizer trials were conducted in the state of Piauí (NE Brazil) on a typically light-textured plateau soil (Alumi-Haplic Acrisol (FAO 1988), Latossolo Amarelo Alico (EMBRAPA 1981)) with low soil nutrient availability in order to study the effect of the application of N, P, K and lime on biomass production and efficiency of water use by maize and cowpea. The field experiment was a randomized complete block design with four repetitions. Five fertilizer treatments were tested: (1) Complete fertilization (N, P, K) with lime (Complete), (2) Complete without nitrogen, (3) Complete without phosphorous, (4) Complete without potassium,

Intermetallic correlation and the ameliorative effects of metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) were determined in water and sediments in the Gwebi River, a major tributary to Lake Manyame, which is a source of potable water to the City of Harare. Water and sediment were sampled at four selected sites in the wet (December-March) and dry (April-November) seasons and metal concentrations were analysed by flame atomic absorption spectroscopy (FAAS). Significantly high concentrations of zinc and copper were observed in water in both the wet and dry season. Concentrations of chromium, copper, zinc iron and nickel in water in both the wet and dry seasons surpassed World Health Organization (WHO) thresholds. The significant difference (ANOVA, p < 0.05) in seasonal/temporal variation in metal concentrations in water indicate different pollutant sources within the catchment of the river. Ameliorative effects of metals were also observed seasonally in the Gwebi River, with Fe and Zn playing a prominent role in both sediment and water phases.

Filter is one of the main components of embankment dams. By a simple but effective performance, filter protects the dam against erosion and soil scouring in impervious core caused by leakage (piping) and makes it safe. Interaction between filter and erodible base soil is a complex phenomenon which is dependent upon several factors, and has challenged researchers for better understanding the filtration system behavior. Therefore, more investigations in this field are needed. Identification of dispersive soil filtration is of great importance because of high erodibility potential of these soils. In this study, in order to evaluate dispersive soil filtration a device is designed and made by the authors for filter testing. This device can measure the hydraulic gradient in flow path by using a controlled flow head. By performing filter tests on dispersive and non-dispersive soil samples, the effect of uniformity coefficient and effective pore size of the filter on critical hydraulic gradient has been studied. The critical hydraulic gradient varies with the change in filter uniformity coefficient, and by increasing the effective pore size of the filter, critical hydraulic gradient is decreased.

Recently the stepped spillways have been used as an appropriate solution for energy dissipation. In the present study, Siahbisheh dam spillway is simulated by using Computational Fluid Dynamic (CFD), in which the Mixture method and Reynolds Stresses Model (RSM) turbulence model is used. In the first modeling series the over all steppes slope is constant. The number of the steps is increased to 80, in which the step height and length is decreased to 0.51 and 1.53 m, respectively. In another case, by reducing the number of the steps to 30, steps height and length increased to 1.36 and 3.9 m, respectively. In the next modeling series, the steppes slope was changed. By reducing the number of the steps in to 30, spillway slope increased to 33 0 and the height of the steps increased to 1.36 (step length was 2.1 m). Then by increasing the number of the steps to 80, spillway slope decreased to about 14 0 and the height of the steps decreased to 0.51m (step length was 2.1 m). Results analysis and comparison of the increasing the energy dissipation to 60 steppes case shows that by decreasing the number of the steppes into 30, the energy dissipation decreases. This trend is expected to continue by increasing the steppes number into 80, but it is not. It seems that there is no fixed pattern between the number of the steppes and energy dissipation percentage. It can be said the increasing the number of the steppes and decreasing the slope up to a certain value increases the energy dissipation, and this number would be optimal under certain conditions. Finally it seems that the effect of the slope is considerable, so that the case in which larger number of steppes with a mild slope is closer to the optimum condition of maximum energy dissipation.

Recently the stepped spillways have been used as an appropriate solution for energy dissipation. In the present study, Siahbisheh dam spillway is simulated by using Computational Fluid Dynamic (CFD), in which the Mixture method and Reynolds Stresses Model (RSM) turbulence model is used. In the first modeling series the over all steppes slope is constant. The number of the steps is increased to 80, in which the step height and length is decreased to 0.51 and 1.53 m, respectively. In another case, by reducing the number of the steps to 30, steps height and length increased to 1.36 and 3.9 m, respectively. In the next modeling series, the steppes slope was changed. By reducing the number of the steps in to 30, spillway slope increased to 330 and the height of the steps increased to 1.36 (step length was 2.1 m). Then by increasing the number of the steps to 80, spillway slope decreased to about 140and the height of the steps decreased to 0.51m (step length was 2.1 m). Results analysis a...

Analysis of non-laminar flows in coarse alluvial beds has a wide range of applications in various civil engineering, oil and gas, and geology problems. Darcy equation is not valid to analyze transient and turbulent flows, so non-linear equations should be applied. Non-linear equations are classified into power and binomial equations. Binomial equation is more accurate in a wide range of velocity changes in comparison to power equation and its validity has been verified by dimensional analysis and Navier-Stokes equations. But since velocity changes are rather limited in engineering problems, power equation would be accurate enough. Non-Darcy flow analysis for the cases in which streamlines are almost parallel has been investigated by numerous investigators in pressured and free surface conditions. Radial flows are accompanied by streamlines contraction. Contracted streamlines in free-surface radial flows result in flow inflation, i.e. flow depth through the path increases significant...

Filter is one of the main components of embankment dams. By a simple but effective performance, filter protects the dam against erosion and soil scouring in impervious core caused by leakage (piping) and makes it safe. Interaction between filter and erodible base soil is a complex phenomenon which is dependent upon several factors, and has challenged researchers for better understanding the filtration system behavior. Therefore, more investigations in this field are needed. Identification of dispersive soil filtration is of great importance because of high erodibility potential of these soils. In this study, in order to evaluate dispersive soil filtration a device is designed and made by the authors for filter testing. This device can measure the hydraulic gradient in flow path by using a controlled flow head. By performing filter tests on dispersive and non-dispersive soil samples, the effect of uniformity coefficient and effective pore size of the filter on critical hydraulic grad...

According to the former researcher's presented relations for flow through rock-fill porous media, the effects of physical characteristics was not studied separately. Hence, due to the application of these relations, physical characteristics of porous materials effect must be investigated separately. In various constructed physical models of porous media, the effect of several variables such as unified coefficient of materials, kind of materials, material gradation and material figures on the parameters such as void ratio, raggedness and specified surface area of materials have been studied. These parameters have a significant effect on the flow discharge coefficient through rock-fill porous materials. In the defined research during this paper, using artificial unique spherical materials with diameters of 10, 37 and 75 mm with the same configuration, the effect of parameters including specified area of rock-fill materials, figure of rock-fill materials and the size of rock-fill materials on the hydraulic characteristics of discharge flow through rock-fill porous media in rock-fill dam models with inbuilt spillway and spillways on the upstream face, have been studied. Also, using the data of these experiments in combination with the data of experiments of the former researches on the natural rock-fill materials, dimensionless relations of Bazargan have been investigated. Finally, using statistical multi variable analysis, a dimensionless relation with maximum correlation coefficient and acceptable accuracy based on the physical characteristics has been presented.

Isolasi adalah mengambil mikroorganisme yang terdapat di alam dan menumbuhkannya dalam suatu medium buatan. Prinsip dari isolasi mikroba adalah memisahkan satu jenis mikroba dengan mikroba lainnya yang berasal dari campuran bermacam-macam mikroba. Hal ini dapat dilakukan dengan menumbuhkannya dalam media padat sel-sel mikroba akan membentuk suatu koloni sel yang tetap pada tempatnya. Isolasi bakteri atau biakan yang terdiri dari satu jenis mikroorganisme (bakteri) dikenal sebagai biakan murni atau biakan aksenik (Suharti, 2020) Biakan yang berisi lebih dari satu macam mikroorganisme (bakteri) dikenal sebagai biakan campuran, jika hanya terdiri dari dua jenis mikroorganisme, yang dengan sengaja dipelihara satu sama lain dalam asosiasi, dikenal sebagai biakan duajenis Persyaratan utama bagi isolasi dan kultivasi fage adalah harus adanya kondisi optimum untuk pertumbuhan organisme inangnya. Sumber bakteriofage yang paling baik dan paling utama adalah habitat inang. Sebagai contoh fage koli yang di jumpai di dalam pencernaan dapat diisolasi dari limbah atau pupuk kandang. Hal ini dilakukan dengan sentifugasi atau filtrasi bahan sumbrnya dan penambahan kloroform untuk membunuh sel-sel bakterinya (Adams, 2019). Bakteri di alam umumnya tumbuh dalam populasi yang terdiri dari berbagai spesies. Oleh karena itu, untuk mendapatkan biakan murni, sumber bakteri harus diperlakukan dengan pengenceran agar didapat hanya sekitar 100-200 bakteri yang ditransfer ke medium, sehingga dapat tumbuh menjadi koloni yang berasal dari bakteri tunggal (Lina, 2022). Isolasi harus memperhatikan beberapa hal penting, yaitu sifat spesies mikroba yang akan diisolasi, tempat hidup atau asal mikroba,medium untuk pertumbuhan yang sesuai, cara menanam mikroba tersebut, cara inkubasi mikroba, cara menguji bahwa mikroba yang diisolasi telah berupa biakan murni dan sesuai dengan yang dimaksud, dan cara memelihara agar mikroba yang telah diisolasi tetap merupakan biakan murni (Ismiati, 2020). Karakterisasi morfologi bakteri dapat berupa pengamatan makroskopik dan pengamatan mikroskopik. Pengamatan makroskopik dapat dilakukan pada medium NA miring dan medium NA dalam cawan petri berupa bentuk morfologinya. Bentuk pertumbuhan goresan garis tunggal di atas permukaan agar dikelompokkan menjadi echinulate (bersambungan, seperti benang, dengan tepian tidak beraturan), filiform (bersambungan, seperti benang, dengan tepian halus), effuse (pertumbuhan tipis dan menyebar), beaded (pertumbuhan koloni terpisah), spreading (pertumbuhan tebal dan menyebar), plumose (pertumbuhan seperti pohon), dan rhizoid (pertumbuhan seperti akar) (Mirta, 2022).

Control of the high velosity and kinetic energy of the flow at downstream of the hydraulic structures in order to prevent the erosion of the channel bed is one of the most important concerns of hydraulic engineers. For this reason, energy dissipation structures are used.The sudden symmetrical expanding channel is an energy-dissipation structure that requires minimal tailwater depth for the formation of hydraulic jumps. Rough beds are important for reducing stilling basin dimensions and the effect of the roughness elements impact the hydraulic jump. The effect of bat-shaped elements in a sudden expansion channel have been investigated here. The experiments were performed in a rectangular channel with symmetric expansion ratios of 0.67, 0.5, and 0.33, and a Froude number that ranged from 4.6 to 11.3. The results show that the shear stress in a rough bed of a sudden expansion channel was more than 12 times greater than the shear stress in a smooth prismatic channel. Also, the secondary...

investigación que tiene como meta medir las cantidades de lluvia que interceptan cuatro contrastantes comunidades forestales, en las cuencas hidrológico-forestales del Río Amajac y Río Texcoco, en los estados de Hidalgo y México, respectivamente. Se establecieron cuatro módulos de investigación con una superficie de 1.0 ha, el primero, en matorral inerme espinoso a una altitud de 1 920 msnm y tres más en bosques de alta montaña, ubicados en un rango de altitud de 2 850 a 3 650 msnm. En cada parcela, se realizaron mediciones dendrométricas de cada árbol a partir de 7.5 cm de diámetro normal. Durante los periodos de lluvia de los años 2007, 2009, 2010 y 2011, se realizaron mediciones de precipitación, determinándose cantidades de precipitación total y su distribución dentro de cada periodo de lluvia. Para las mediciones de precipitación total, se emplearon dos pluviómetros ubicados fuera de cada parcela. Para las mediciones de interceptación, se utilizaron en promedio 70 pluviómetros de lectura directa distribuidos aleatoriamente bajo dosel. Las mediciones de precipitación-interceptación se registraron por evento de lluvia. Las cantidades de lluvia interceptadas por el dosel de copas del arbolado se expresaron como porcentajes para cada uno de los cuatro grupos estudiados: Matorral (18.6 %), oyamel (26.1 %), encino (21.7 %) y pino (19.2 %). Se generaron los modelos estadísticos no lineales de la relación: precipitación total (mm) -lluvia interceptada (%), para cada tipo de bosque.

In the present paper we investigated macrophyte community structure in 60 natural and impacted stream and river sites distributed throughout the Walloon river network. The objectives were to describe the distribution of macrophyte assemblages in relation to physico-chemical parameters of their environment and to assess the variability in ecological metrics within these watercourses. Two-way clustering allowed us to simultaneously assign sample units and species to groups by performing two separate cluster analyses. Indicator species analysis allowed us to assess the degree to which a species indicated a group, based on its constancy and distribution of abundance. Six end-groups were identified as a result of using twoway clustering and indicator species analysis techniques. Hygroamblystegium fluviatile, Chiloscyphus polyanthos and Lemanea fluviatilis were found to characterize acidic and low impacted streams and rivers (G1), while Ranunculus fluitans was found in all low impacted large streams (G2). Potamogeton pectinatus, proved to be more common in eutrophicated waters in the calcareous areas particularly in the ʺLoess low plateauxʺ region (G6). Cinclidotus riparius, Fissidens crassipes and Pellia endiviifolia, appeared in rivers situated in the Condroz region (G4), which was characterized by a high concentration of nitrogen.

Sudden pipe expansions have been known as efficient hydraulic energy dissipaters for a long time. The complex phenomenon of flow separation and velocity discontinuity at the interface of incoming jet and the recirculation flow, results in intensive shear and tensile rupture of the fluid and the associated destructive phenomenon of cavitation. This paper focuses on aeration in sudden pipe expansion as a remedy to recover the effects of cavitation. The experimental setup consists of a sudden pipe expansion with an expansion to inflow diameter ratio of 3.675. Variation of air content ratio with respect to the Reynolds number and effect of air entrainment on time averaged velocity and pressure distribution is investigated. Finally a combination of sudden pipe expansion and aeration is recommended for energy dissipation at bottom outlets and tunnel spillways.

In this paper twelve different empirical resistance coefficients expressed in terms of Manning's roughness are used apiece in seventeen known compositing methods. The data obtained from ten different cross-sections of the Sefidrood River, Iran, are used for the evaluation of the empirical formulas. The present case-study is selected from a reach with gravel bed topology. Then no remarkable bed form exists. Comparison of the calculated discharges and resistance coefficients with measurements shows that the Keulegan formula used simultaneously with the Brownlie formula in different compositing methods results in highly over estimated discharges, while the Meyer-Peter & Muller, Marion, Chien-Mai formulas in conjunction with the total force approach match best with the measurements. Also comparison of the calculated discharges from empirical formulas in individual sections reveals that Chien-Mai and Subramanya formulas have the least discrepancies from measurements.

Soil salinization is a critical global issue that undermines agricultural productivity, threatens food security, and compromises the sustainability of farming systems. In the coastal region of Navotas, Balayan, Batangas, Philippines, the increasing salinization of irrigated rice farmlands due to saline-sodic soils has become a pressing concern. The understanding of farmers' perceptions regarding the risks associated with soil salinity, as well as their insights into the causes, consequences, and coping mechanisms, remains inadequately explored. This gap in knowledge may hinder the development of effective countermeasures and appropriate policy interventions. In this study, farmers' perceptions of saline-sodic soils were assessed through Key Informant Interviews (KIIs) and Focus Group Discussions (FGDs), which were analysed using thematic analysis and Causal Loop Diagrams (CLDs). Saltwater intrusion was consistently identified as the primary cause of soil salinization, with subsequent reductions in rice yields ranging from 60% to 100%, depending on the growth stage of the crop. The most vulnerable periods were identified as June to August, particularly during the vegetative and flowering stages of rice. Farmers reported coping strategies such as irrigation with freshwater and the cultivation of salt-tolerant rice varieties; however, challenges related to delayed access to freshwater and seeds were frequently mentioned. The expansion of saline-sodic areas was identified as the most significant threat to rice production, with the condition of saline-sodic soils in lowland rice paddies increasingly viewed as a worsening problem. These findings underscore the severe impact of saline-sodic soils on both agricultural productivity and farmers' livelihoods, providing valuable insights that can inform the development of tailored management strategies and mitigation measures.

Tanah memiliki sifat kimia, fisika, dan juga biologi. Masing-masing sifat tanah tersebut dipengaruhi oleh berbagai macam faktor seperti vegetasi, mikroorganisme, suhu, pH, iklim, dan kelembaban. Pada sifat biologi, tanah memiliki kemampuan dalam respirasi. Kemampuan ini dipengaruhi oleh mikroorganisme yang hidup dan memiliki peranan penting dalam ekosistem tanah. Tujuan artikel ini dibuat adalah untuk mengetahui pengaruh mikroorganisme terhadap kemampuan lau respirasi dari tanah. Metode yang digunakan pada artikel ini adalah dengan menggunakan metode kualitatif. Berdasarkan pencarian yang sudah dilakukan, mikroorganisme dan laju respirasi tanah saling mempengaruhi satu sama lain. Mikroorganisme dipengaruhi oleh iklim yang terdapat pada lingkungan tersebut. Banyaknya mikroorganisme yang terdapat pada tanah akan meningkatkan kesuburan dari tanah. Terdapat upaya pengendalian populasi mikroorganisme yaitu dengan pengolahan tanah yang baik serta penambahan biochar sebagai penambah bahan organik dalam tanah.

Sustainable land management is a great challenge for land users and other stakeholders around the world. Disturbance of dryland ecosystems can quickly lead to severe land degradation and thus desertification. This study evaluated the management methods that have been adopted for the semi-arid slopes in the Southern Al Jabal al Akhdar, and their effects, by measuring some field and laboratory indicators, the soil fertility status, and some physical and chemical properties of the bare and cultivated areas. The results indicated that there are relative differences in some soil quality-related parameters when cultivated and bare lands are compared. Higher CEC values, as well as a significant increase in soil content of organic matter and total nitrogen, were recorded within the cultivated land compared to the bare land. The study showed that the applied land management practices have improved some soil properties that are directly related to the production function and quality, as a result, more fertile and productive areas were available within these semi-arid cultivated lands. Considering the output of the present research, it can put forward some recommendations to be used for strengthening sustainable land management practice and to relieve the negative impact of land degradation and soil fertility deterioration. This recommendation could include adapting the recent agricultural technology, establishing sustainable land management practices, efficient use of both organic and chemical fertilizers. In addition, more research for soil fertility management practices will be essential for the success of future soil conservation plans within these fragile areas. .

In this research, the numerical method of computational fluid dynamics and dimensionless parameter of Froude number have been applied to determine the flow regime over ogee spillways. Froude number is a dimensionless dynamic parameter calculated using the square root of the ratio of inertia force and gravitational force. Considering that the study of the regimes of flow over hydraulic structures especially spillways is of great importance, and as the most applied spillway is ogee one, therefore it is required to study such structures. To study the sensitivity of the dimensionless parameters of Froude number and velocity using in the proper calculation of the profile of the flow over ogee spillway the software of fluent computational fluid dynamics software has been used. Based on Gauss-Seidel convergence condition applied for the convergence and control of equations, the step time of 0.01 second, quad pave meshing and RNG k-İ turbulence model have been used. The results of this research shows that the decrease of reference design head by 10, 20, and 30 percent leads to the decrease of reference average Froude number and reference average velocity of the flow over ogee spillway by 7.

Plant-derived biopolymers, also known as natural polymers, have been extensively studied for sustainable and eco-friendly technologies. This research paper explores the extraction, characterization, and application of biopolymer carrageenan in screen-printed conductive ink formulation. Carrageenan was extracted from red algae (Rhodophysea). Conductive inks fabricated from graphite as a conductive agent and carrageenan with carboxymethyl cellulose as adhesives. The use of carrageenan enhances the conductivity of the produced ink with respect to carboxymethyl cellulose. The high conductivity of carrageenan based conductive ink is due to the amorphous structure of carrageenan and the presence of sulfate groups in its chain structure.

Ugep is famous for its annual 'New Yam Festival' which gives the people the opportunity to showcase their cultural heritage and agricultural produce. As the farmers attempt to meet-up with this annual-ritual, they continuously cultivate the soil resulting in soil nutrient exhaustion. This study characterized the major soil units in Ugep and focused on the fertility capability classification (FCC) as well as land suitability evaluation for cassava production. With the aid of the geology-and topo-maps, two profile pits were sunk in the soils over alluvium (AL), sandstone (ST) and dolerite (DO) resulting in six profiles. The results present loam, sandy loam and clay loam textures in the surface soils, while bulk density was < 1.8 Mgm-3 and organic carbon, available P and total N recorded 2.0-37.3 g/kg, 1.25-36.12 mg/kg and 0.1-2.1 g/kg, respectively. Exchangeable bases were comparatively higher in DO, with a rating of high for exchangeable Ca 2+ and Mg 2+ , while exchangeable acidity was due to H +. FCC indicated L (loam-surface and subsurface) in AL with limitations due to low K reserve (k), CEC (e), organic carbon (m) and gleying. DO qualified as LC (Loam-surface and clay-subsurface) with limitations of high gravel (r) as well as k, e and m, while ST qualified as SL (sand-surface and loam-subsurface) and L (loam-surface and subsurface) with limitations of k, e and m. By the parametric approach, current and potential aggregate suitability of moderately or highly suitable for ST had less limitations than marginally suitable classifications of AL for cassava production.

La intercepción de lluvia, es el proceso por el cual el agua de lluvia, modifica su trayectoria al ser interceptada por el dosel de los árboles, ejerciendo de esta manera, una marcada influencia en el patrón de la lluvia que alcanza a llegar al piso forestal. Una vez interceptada, el agua es retenida por las hojas y ramas de los árboles, incluso por plantas epifitas, pudiendo a partir de este momento, continuar su trayectoria, por una o más de estas tres vías: evaporarse, gotear desde la copa, o fluir por las ramas hasta la base del fuste (García, 2006). Los estudios de intercepción constituyen una de las formas que permiten identificar cómo es que las condiciones actuales en la cobertura arbórea, o las modificaciones a esta condición estructural, afectan el balance hidrológico de un área arbolada, ya sea por la aplicación de técnicas silvícolas o por perturbaciones naturales. Para el caso de México, esta área de investigación ha sido poco explorada en particular en el ámbito de la ecología. El objetivo del presente trabajo es cuantificar la intercepción de lluvia y su variabilidad, medida bajo dosel en rodales cuya vegetación dominante es Acacia farnesiana y Juniperus flaccida. En una zona forestal del municipio de Atotonilco el Grande, Hidalgo, se estableció un módulo de investigación de 0.64 ha, en donde se colocaron 60 pluviómetros bajo el dosel de un bosque representativo de la zona, conformado

Rainfall partitioning by vegetation plays an important role affecting the water balance at local scale due to the control that vegetation canopies exert by modifying both evaporation and the redistribution of precipitation in different fractions of throughfall, stemflow and interception loss. These fractions have been evaluated during three years in an evergreen oak coppice in the eastern Algeria using specific collection devices. The results revealed that the mean rate of throughfall was 66.30% of the open field precipitation (gross rainfall). Stemflow represented on average a very small fraction (7.13% of open field precipitation), whereas the interception loss was relatively high (26.46% of the open field precipitation). The use of linear regressions showed strong correlations between open field precipitation and different fractions of water (stemflow, throughfall and interception loss) at the studied station.

Formation of hydraulic jump is necessary for dissipation of the excess kinetic energy downstream of spillways and gates. Hydraulic jump stilling basins of sudden expansion are one of the energy dissipater structures which are used where the available tail water depth is less than the required sequent depths. In the present study to further reduce the hydraulic jump sequent depths ratio, a roughened bed type of stilling basins of sudden expansion is experi- mentally investigated. Four different expansion ratios of 0.33, 0.5, 0.67 and 1 were studied under wide range of flow conditions, Froude numbers between 2 and 10. Results of the present study show that sequent depths ratio is 16-20 percent lower and the jump efficiency can increase 20 percent in comparison to the classical jump.

Global warming is due to the increasing of greenhouse gases (GHG) concentration in the atmosphere. There are a lot of informations on CO2 fluxes from peat land, but those from soil mineral is very limited. The purposes of this study are to measure and compare CO2 flux of Andosol used for tea plantation and bare land, and to compare CO2 flux from mineral soils and peat soils. The method used for gas sampling is the closed chamber method and Infra- Red Gas Analyzer (IRGA) was used to measured CO2 concentration. The results showed that CO2 flux in the land used two lands on Andosol is about of 1,00 to 8,00 g C-CO2 m-2 day-1. Daily mean of CO2 fluxes were obtained from 25 weeks are 2,01 g C-CO2 m-2 day-1 (bare land) and 2,81 g C-CO2 m-2 day-1 (tea plantation). Mean daily CO2 flux of tea plantation was a higher than that of CO2 flux from bare land. These results are resembled by the data of microbial populations in the soil of tea plantation that was higher than that of the bare land. Th...

Antioquia (Colombia), fueron medidos los flujos de escorrentía superficial (ES) por un periodo de tiempo de 16 meses. Se implementaron parcelas cerradas de escorrentía superficial de 10 m de largo x 2 m de ancho, tanques colectores y sistemas de registro volumétrico. Los flujos fueron de 23,19 mm año-1 (1,07 % de la precipitación) para la cobertura de roble; 35,13 mm año-1 (1,61 % de la precipitación) para la cobertura de pino pátula y 230,64 mm año-1 (11,05 % de la precipitación) para la cobertura de ciprés. Mediante análisis de componentes principales (ACP) se identificaron las relaciones existentes entre las variables hidrológicas y los flujos de ES, y por medio de análisis de regresión lineal múltiple se ajustaron modelos para los flujos de ES por cobertura en función de la precipitación, la precipitación en el bosque y la intensidad de lluvia promedio, variables que mostraron alta relación con la ES según el ACP.

Designing and optimizing the dimensions of drainage systems is very important for keeping the downstream shells dry and preventing the increase of pore water pressure in the body of earth dams. By optimizing the drainage dimensions, the minimum factor of safety, and consequently the construction costs, can be reduced. The purpose of this research was to optimize the size of horizontal drainage that is affected by some important parameters of the dam. In this study, a homogeneous earth dam was modeled using the Geostudio software. The minimum factor of safety was obtained by changing drainage dimensions, materials, and the slope of the dam body. A two-layer neural network was used to predict the least factor of safety resulted from different scenarios created in the software. By training the neural network based on the data obtained from homogeneous dams, the minimum factor of safety for drainage optimization was extracted. For optimal, an Mfile was fitted to the trained neural netwo...

Bulk density is a fundamental soil property that is difficult to determine for gravelly to extreme!y gravelly soils because results vary significantly with sample volume. For such coarse soils, the representative volume (for whole-soil bulk density) should be large, but guidelines for selecting an appropriate sample volume do not exist. We evaluate the representative volume for a soil with abundant rock fragments, by comparing measured properties of sarnplcs ranging in volume from 0.03 to 410 liters, For whole-soil bulk density determination, the representative volume is 4 liters or larger for a soil horizon containing 34?40 gravel (by volume) and is between 5 and 50 liters for a soil horizon containing 54V0 gravel. Intactsarnplcs of that size are prohibitively large, so an alternative approach is dcvclopcd that starts with measurement of fine-earth bulk density. For fineearth bulk density, the sample volume needed for representative results is between 0.2 liters and 1 liter for gravelly to extremely gravelly soils. The alternative approach reliably synthesizes whole-soil bulk density using 1) fine-earth bulk density from modest sized samples, 2) mass size-distribution from large (>40 kg) representative disturbed samples, and 3) rock fragment bulk densities. The mass and volume of rock fragments that "should be" in a sample are added to the mass and volume used to calculate fine-earth bulk density. 'I'he method allows integration of lateral variability in the soil without the consequence of averaging properties over a large depth range.

The integration between geomorphology and topography has been widely used in soil sciences, with topographic and geomorphologic features information being derived from digital elevation models (DEMs) that derived from photogrammetry and satellite images to calculate topographic attributes such as digital elevation, slope gradient and aspect were produced manually and applied to investigate spatial variability in soil characteristics and to produce soil maps. The current study aims to reveal the effect of the topography factor and geomorphologic features on the soil characteristics western of Bahr Yusef area, Minya Governorate. The study was based on taking 11 soil profiles (27 samples) which were distributed over four geomorphologic units: upper, back, toe slopes, and the flood plain. The four physiographic units were extracted and identified based on topographic attributes and Landsat 8 satellite image processing (radiometric enhancement and an atmospheric correction, replace bad value and classification), in addition, the vegetation cover density was determined by Normalized Difference Vegetation Index (NDVI) which was determined using OLI sensor and calculate the confusion matrix to validate the results of NDVI. Some soil morphological and Physico-chemical characteristics such as soil profile thickness (depth), soil particles distribution especially that related to clay content, electrical conductivity (EC), organic matter (O.M), gypsum and calcium carbonate content and exchangeable sodium percentage (ESP) were determined according to references which mentioned in materials and methods section. The geostatistical methods were used to study the correlation between the topographic attributes (slope position, slope, aspect) and geomorphologic units in and spatial distribution of soil in the study area. The results of the study revealed that the soil characteristics, whether physical or chemical were affected by geomorphologic feature and the topography factor, where the AUCES

The integration between geomorphology and topography has been widely used in soil sciences, with topographic and geomorphologic features information being derived from digital elevation models (DEMs) that derived from photogrammetry and satellite images to calculate topographic attributes such as digital elevation, slope gradient and aspect were produced manually and applied to investigate spatial variability in soil characteristics and to produce soil maps. The current study aims to reveal the effect of the topography factor and geomorphologic features on the soil characteristics western of Bahr Yusef area, Minya Governorate. The study was based on taking 11 soil profiles (27 samples) which were distributed over four geomorphologic units: upper, back, toe slopes, and the flood plain. The four physiographic units were extracted and identified based on topographic attributes and Landsat 8 satellite image processing (radiometric enhancement and an atmospheric correction, replace bad v...

La Selva Baja Caducifolia se desarrolla en áreas semiáridas con déficit de agua y es la cubierta vegetal con la mayor extensión a nivel mundial y nacional con 42% y 60% de cobertura, respectivamente. Una de las zonas que mejor representan éste biosistema en México es la Región Mixteca. La cobertura arbórea de esta selva, por la intercepción de las gotas de lluvia del dosel, impacta el escurrimiento y la erosión hídrica. Con el propósito de conocer el efecto del dosel en la intercepción de la lluvia, se midió el f lujo caulinar, el f lujo de dosel y la lámina interceptada por el follaje. Estas mediciones se usaron para establecer relaciones matemáticas, utilizando regresión lineal múltiple, que permitieron calcular sus magnitudes; a través de valores conocidos de lámina de lluvia, por evento, y geometría del dosel. Las mediciones se realizaron durante 2013, en 21 árboles (9 especies) predominantes de la Selva Baja Caducifolia, para 350 eventos de lluvia ocurrido...

DHI-Mike Software is one of best softwares describing water wave diffraction in onshore/offshore concepts. Diffraction happens due to obstacles along wave direction and has an important role in designing structures. The scope of this study is to show the relation between Porosity Coefficient and its effects on Diffraction Coefficient (C d) by means of a suitable and verified numerical model. Porosity Coefficient is one of the breakwaters&#39; characteristics that describe the reflection quantity of the wave that influences on Diffraction Coefficient. This parameter determines the quantity of obstacles porosity and helps in implementing the sensitivity analysis. A calibrated Model helps as a suitable background to examine different Porosity Coefficients. Reputed &quot;Wave Diffraction Diagrams&quot; has been used for model calibration and will be discussed in detail in an appropriate section. It has been concluded that by increasing the Porosity Coefficient, wave height and Diffracti...

Clay core rock-fill (CCR) dams are chosen dam construction model due to their low cost and rapid construction advantages. The stability of dam embankment and analyzing their earthquake resistance is of great concern to geotechnical engineers. Here, we analyze static and dynamic degrading behavior of a clay core rock-fill (CCR) dam through using the finite element method. The static part of the analysis considers the stage construction, reservoir impoundment and total displacements while, the dynamic part considers the seismic response of the dam under a real earthquake data which the data corresponds to typical measures of a peak ground acceleration (PGA). The static state analyses show a gradual increase in the magnitude of vertical displacements during the impounding stage where the hydrostatic force acts on the surface of the dam body and causes additional force on the clay core section. When the dam is subjected to real earthquake data which had a 0.4 g PGA, we observe larger di...

Clay core rockfill (CCR) dams are commonly used and the chosen model dam construction due to their low cost and rapid construction advantages; moreover playing a key role in national water and power management systems. In terms of large water reservoir impoundment behind a high dam, they include a risk to the public, in case of an earthquake, especially for urban areas. Therefore, the stability of dam embankment and analysing seismic safety is of great concern to geotechnical engineers. In fact, these analyses are complex issues which concern both elastic and dynamic effects on the influence of the seismic response to real earthquake records. The objective of this study is to evaluate the three dimensional static and dynamic degrading behaviour of a CCR dam through using the finite difference method. The static part of the analysis considers the layered construction, reservoir impoundment and vertical displacements whereas, the dynamic part considers the response of the dam to a rea...

Intermetallic correlation and the ameliorative effects of metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) were determined in water and sediments in the Gwebi River, a major tributary to Lake Manyame, which is a source of potable water to the City of Harare. Water and sediment were sampled at four selected sites in the wet (December-March) and dry (April-November) seasons and metal concentrations were analysed by flame atomic absorption spectroscopy (FAAS). Significantly high concentrations of zinc and copper were observed in water in both the wet and dry season. Concentrations of chromium, copper, zinc iron and nickel in water in both the wet and dry seasons surpassed World Health Organization (WHO) thresholds. The significant difference (ANOVA, p < 0.05) in seasonal/temporal variation in metal concentrations in water indicate different pollutant sources within the catchment of the river. Ameliorative effects of metals were also observed seasonally in the Gwebi River, with Fe and Zn playing a prominent role in both sediment and water phases.

A new methodology for estimating the discharge starting from the monitoring of surface flow velocity, u surf , is proposed. The approach, based on the entropy theory, involves the actual location of maximum flow velocity, u max , which may occur below the water surface (dip phenomena), affecting the shape of velocity profile. The method identifies the two-dimensional velocity distribution in the cross-sectional flow area, just sampling u surf and applying an iterative procedure to estimate both the dip and u max. Five gage sites, for which a large velocity dataset is available, are used as a case study. Results show that the method is accurate in simulating the depth-averaged velocities along the verticals and the mean flow velocity with an error, on average, lower than 12% and 6%, respectively. The comparison with the velocity index method for the estimation of the mean flow velocity using the measured u surf , demonstrates that the method proposed here is more accurate mainly for rivers with a lower aspect ratio where secondary currents are expected. Moreover, the dip assessment is found more representative of the actual location of maximum flow velocity with respect to the one estimated by a different entropy approach. In terms of discharge, the errors do not exceed 3% for high floods, showing the good potentiality of the method to be used for the monitoring of these events.

Agricultural activities are considered as one source of greenhouse gas emissions (GHG). Researchs on GHG emission from agricultural land are mostly done on peat soils, while researchs on mineral soil are still limited. This research was aimed to find out and to compare CO2 flux from vegetable garden, forest, and bare land on Andosol, and to compare CO2 flux from peat soils with these of mineral soils. This research was carried out at tea plantation area of PT Sumber Sari Bumi Pakuan, Tugu Utara Village, Cisarua District, Bogor Regency (Puncak area). Gas samples were taken using a chamber method and CO2 measurement was done using a CO2 Analyzer. The results of CO2 flux measurement of each of the land uses on Andosol indicate that CO2 flux from vegetable garden and forest were almost similar, about 4,26 g C- CO2 m-2 d-1 and 4,28 g CO2 m-2 d-1, while that of bare land showed smaller results, about 2,01 g C- CO2 m-2 d-1. The results of analysis of soil respiration showed the same thing ...

Aridisols are the most abundant soil order in Nevada, in terms of numbers of soil series and land area. This chapter discusses the distribution, properties and processes, and use and management of Aridisols in Nevada. 8.1 Distribution Aridisols are the most abundant soil order in Nevada, in terms of numbers of soil series (42%) and land area (52%) (Table 7.2). Aridisols occur in all of the 10 Major Land Resource Areas in Nevada except for MLRA 22A, the Sierra Nevada Mountains. They are most common in MLRA 30 (63% of all soil series), MLRA 29 (54%), and MLRA 24 (53%) (Table 4.1). Aridisols also occur in MLRA 27 (45%), MLRA 28B (42%), MLRA 23 (36%), MLRA 25 (36%), MLRA 28A (34%), and MLRA 26 (33%). On an area basis, 37% of the Aridisol soil series are Argids, followed by Durids (26%), Calcids (19%), Cambids (13%), with Gypsids and Salids composing less than 0.5% each (see Table 7.2). Nevada ranks first nationally in area of Durids, third for Salids, and fifth for Gypsids. Five great groups account for 84% of the Aridisols soil series, including the Haplargids (30%), Haplocalcids (15%), Haplocambids (14%), Haplodurids (13%), and Argidurids (12%) (Table 7.2). Thirteen Aridisol soil series each cover more than 1,000 km 2 , including the Stewval,

Recent years have seen an increase in the use of computer-based numerical models to test the stability of earth dams and to simulate the impact of all the factors that affect their safety. Geo-Studio software and its sub-programs SLOPE/W, and QUAKE/W are used to determine the factors of safety and stability of dams, and investigations of dynamic analysis, a finite element serves as its base to do the numerical modeling for this study. The Hemrin Dam represents the case study and is regarded as the study&#39;s major focus. The results showed that the values of the safety factor increased from (1.439) to (1.583) when the water level is 8m, from (1.365) to (1.549) when the water level is 16 m, and from (1.084) to (1.317) maximum water level is 32m, without and with a vertical drainage column, because the pore water pressure is reduced and the effective stress is increased. In the case of a Rapid drawdown of water when a vertical drainage column is added, the value of the factor of safe...

Sustainable land management is a great challenge for land users and other stakeholders around the world. Disturbance of dryland ecosystems can quickly lead to severe land degradation and thus desertification. This study evaluated the management methods that have been adopted for the semi-arid slopes in the Southern Al Jabal al Akhdar, and their effects, by measuring some field and laboratory indicators, the soil fertility status, and some physical and chemical properties of the bare and cultivated areas. The results indicated that there are relative differences in some soil quality-related parameters when cultivated and bare lands are compared. Higher CEC values, as well as a significant increase in soil content of organic matter and total nitrogen, were recorded within the cultivated land compared to the bare land. The study showed that the applied land management practices have improved some soil properties that are directly related to the production function and quality, as a result, more fertile and productive areas were available within these semi-arid cultivated lands. Considering the output of the present research, it can put forward some recommendations to be used for strengthening sustainable land management practice and to relieve the negative impact of land degradation and soil fertility deterioration. This recommendation could include adapting the recent agricultural technology, establishing sustainable land management practices, efficient use of both organic and chemical fertilizers. In addition, more research for soil fertility management practices will be essential for the success of future soil conservation plans within these fragile areas. .

Practical concept of velocity distribution of pressure flow in the bends is interesting and hence, the professional engineering design has been investigated in the current study. This paper shows that velocity distribution in the bends can be analyzed in terms of the probability distributions. The concept of entropy based on the probability is an applied and new approach to achieve velocity profiles in bends, presented by the probability distribution and tsallis entropy maximization under the importing constraints. Due to the lack of a specific equation of velocity distribution in the bends, the particular equation in the various band sections was obtained through the numerical simulation of three dimensional flow in the 90-degree bend (via Fluent). In this simulation, flow regime was laminar and the Reynolds number was in the range of 100 to 2000. Then, for m=2, the velocity distribution function was obtained. Studies showed that the proposed model for the mentioned range of Reynolds numbers is in a good agreement with other study results. The calculated error values indicated a reasonable accuracy. The model can directly calculate the velocity at each point of the spatial position. The calculated values were also compared with the results obtained from the velocity distribution based on the Shannon entropy. The results showed a reliable estimate of the velocity profiles.

The extensive use of silver nanoparticles (AgNPs) in consumer and medical products leads inevitably to release of such particles into environment and soil resources. This study was conducted to provide evidences for biological effects of AgNPs in two calcareous soils with different textures and salinity levels. Basal respiration (BR) and substrate-induced respiration (SIR), as indicators of soil microbial activity and biomass, respectively, were determined in the calcareous soils spiked with a dilution series of AgNPs and AgNO 3. Urease and alkaline phosphatase activities were also measured in the spiked and control soils. Finally, dose-response approach was used to model the sensitivity of the soil biological properties to AgNPs and AgNO 3 contamination. The results revealed that the effects of AgNPs and AgNO 3 on the soil respiration and enzyme activities depended on Ag dose and soil type. For instance, soil respiration was not affected or even stimulated by low doses of AgNPs and AgNO 3 , but negatively affected by high doses (N 20 mg Ag kg −1). Soil urease and phosphatase activities were generally inhibited in the presence of AgNPs and AgNO 3 , though in low Ag concentrations there was no inhibition or even stimulation. Generally, the ecological dose (ED) values of AgNPs were smaller than those of AgNO 3 , suggesting that AgNPs have more negative effects than AgNO 3 on the soil microbial and enzyme activities, at the same level of Ag dose. The results also revealed that suppression of microbial and enzyme activities by AgNPs and Ag ions are greater in the soil with lower clay content and ionic strength.

Fertilization is one of the components of maintenance activities that cost relatively high and it has a considerable influence on the achievement of the oil palm productivity. The addition of one nutrient element through fertilization will shift the balance of nutrients in the soil. Therefore, fertilization activities should pay attention to nutrient balance aspect so that fertilizing will be more efficient and effective. The research aims were to determine of K, Ca, and Mg balance in the soil for oil palm. This study used exploration survey method by collecting data of soil analysis and oil palm productivity from several oil palm plantations that spread across several provinces in Indonesia. The results showed that with the assumption of upper boundary line of productivity of 25.96 ton FFB ha-1 year-1 the ranges of nutrients balance for Ca/K,

Boron is an important micronutrient required for the growth of various types of plants. Both a deficiency in boron and its toxicity may lead to marked yield reduction and quality loss of many crop species. The range between these extremes is quite narrow. Therefore, the management of boron in soil has become a worldwide agricultural problem in the recent years. Facing this situation, the present research was undertaken in order to better understand boron distribution effect on sugar beet crop yield in two soils of Dour Ismail irrigated perimeter (North Tunisia). Two pits P1 and P2 were dug in field plots that had not received any boron fertilization. We followed the dynamic of the available boron and its depth distribution according to the three sugar beet cycle stages. Soil samples were taken from different horizons of the profile and analyzed for the main physicochemical properties. Both studied soils are Stagnic Fluvisols (Clayic) and the water used for irrigation comes from Oued Medjerda River. Our results showed that the highest boron values were recorded in surface horizons of the two studied soils. These amounts decreased with depth following different patterns according to the sugar beet cycle stages. The boron vertical distribution was similar to the total organic carbon and clay contents but was greatly affected by some soil properties such as pH, carbonate calcium content, and salinity. Sugar beet yield in P2 (100 t ha −1) was less than that of P1 (114 t ha −1) indicating a problem of boron availability.