M. Burdukovskii, I. Kiseleva, P. Perepelkina, Y. Kosheleva
Soil aggregate structure and soil organic matter are closely interrelated and commonly considered as key indicators of soil quality. The aim of this study was to evaluate the effects of different fallow durations on indices of soil structure and humus status indicators. Studies were conducted on abandoned agricultural fields (15, 20 and, 35 years after abandonment). As a reference site, we used a cultivated field in the area. The experimental soil fields are classified as Gleyic Cambisols. Soil macroaggregates were separated with the sieve (dry sieve) to seven aggregate size fractions, i.e.> 10, 10–5, 5–2, 2–1, 1–0.5, 0.5–0.25 and < 0.25 mm. The humus status parameters of soils included the following indicators: soil organic carbon (Corg), humus reserves (QH), the degree of humification of organic matter (SOMdh), fractions of humic acids (HA) (free and bound with monovalent cations and Al2O3, Fe2O3, bound with Са2+ which forms humates, bound with clay minerals), fulvic acids (FA) (free aggressive) and ratio of HA to FA (CHA : CFA). After a fallow period of more than 20 years on the surface formation of a sod layer. A long-term fallow period had an impact on the mean weight diameter of the aggregates (MWD) and agronomically valuable aggregates (AVA). Fallow soils have a significantly better structure than soils under a cultivated field. Long-term cultivation leads to the deterioration of soil structure and the formation of large aggregates (>10 mm). The Corg content remains at the level of the background content when the soils are left fallow for less than 15 years and increases over time. The Corg in the upper 0–20 cm soil layer has been shown to increase from 3.55 to 8.74% on arable land that has been fallow for 35 years and has been largely associated with significant accumulation of organic matter within the plant root mass. Mature sites are characterized by an increase of fulvic acids in the humus composition in comparison with their arable analogues. The abandonment of soil agricultural use and the cessation of mechanical tillage results in the restoration of the natural structure of soils and the improvement of their agrophysical properties. Such studies have not been previously conducted in the Primorsky region of the Russian Far East.
{"title":"Impact of different fallow durations on soil aggregate structure and humus status parameters","authors":"M. Burdukovskii, I. Kiseleva, P. Perepelkina, Y. Kosheleva","doi":"10.17221/174/2018-SWR","DOIUrl":"https://doi.org/10.17221/174/2018-SWR","url":null,"abstract":"Soil aggregate structure and soil organic matter are closely interrelated and commonly considered as key indicators of soil quality. The aim of this study was to evaluate the effects of different fallow durations on indices of soil structure and humus status indicators. Studies were conducted on abandoned agricultural fields (15, 20 and, 35 years after abandonment). As a reference site, we used a cultivated field in the area. The experimental soil fields are classified as Gleyic Cambisols. Soil macroaggregates were separated with the sieve (dry sieve) to seven aggregate size fractions, i.e.> 10, 10–5, 5–2, 2–1, 1–0.5, 0.5–0.25 and < 0.25 mm. The humus status parameters of soils included the following indicators: soil organic carbon (Corg), humus reserves (QH), the degree of humification of organic matter (SOMdh), fractions of humic acids (HA) (free and bound with monovalent cations and Al2O3, Fe2O3, bound with Са2+ which forms humates, bound with clay minerals), fulvic acids (FA) (free aggressive) and ratio of HA to FA (CHA : CFA). After a fallow period of more than 20 years on the surface formation of a sod layer. A long-term fallow period had an impact on the mean weight diameter of the aggregates (MWD) and agronomically valuable aggregates (AVA). Fallow soils have a significantly better structure than soils under a cultivated field. Long-term cultivation leads to the deterioration of soil structure and the formation of large aggregates (>10 mm). The Corg content remains at the level of the background content when the soils are left fallow for less than 15 years and increases over time. The Corg in the upper 0–20 cm soil layer has been shown to increase from 3.55 to 8.74% on arable land that has been fallow for 35 years and has been largely associated with significant accumulation of organic matter within the plant root mass. Mature sites are characterized by an increase of fulvic acids in the humus composition in comparison with their arable analogues. The abandonment of soil agricultural use and the cessation of mechanical tillage results in the restoration of the natural structure of soils and the improvement of their agrophysical properties. Such studies have not been previously conducted in the Primorsky region of the Russian Far East.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"1-8"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/174/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41492539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Dumbrovsky, K. Drbal, Veronika Sobotková, J. Uhrová
Soil erosion, including ephemeral gully erosion, is a serious degradation process in the Czech Republic. It currently threatens more than half of the agricultural acreage through negative changes in the whole complex of soil properties. The unfavourable consequences of surface runoff are seen in the erosion processes degrading agricultural soils. The South Moravia Region was selected as the case study area – mainly for its natural conditions and high soil degradation risk . A set of data, collected from 2012 to 2017 in a maize-growing area, especially on deep loess soils in the South Moravia Region, was used to analyse the morphological characteristics of the ephemeral gullies (EGs). The relationship was confirmed between the ephemeral gully (EG) length and the size of its contributing drainage area in accordance with studies conducted in other countries. It is also important that the closest relationship was confirmed between the length of the gully and its calculated volume. Dependence was sought on the data of 51 cases of the detailed, measured and evaluated EGs. These results will become the basis for finding a predictive relationship and the quantification of EG erosion. Locating EGs and predicting their length is crucial for estimating the sediment load and planning conservation strategies. The aim of this paper is to contribute to the understanding of this issue, i.e., define and verify the basic crucial causal factors and propose guidelines for locating the potential EG occurrence and predicting the sediment load. A research effort to better understand the EG mechanism and causal factors over a wide range of watershed conditions is fundamental to the establishment of basic rules for the adoption of optimal conservation strategies.
{"title":"An approach to identifying and evaluating the potential formation of ephemeral gullies in the conditions of the Czech Republic","authors":"M. Dumbrovsky, K. Drbal, Veronika Sobotková, J. Uhrová","doi":"10.17221/231/2018-SWR","DOIUrl":"https://doi.org/10.17221/231/2018-SWR","url":null,"abstract":"Soil erosion, including ephemeral gully erosion, is a serious degradation process in the Czech Republic. It currently threatens more than half of the agricultural acreage through negative changes in the whole complex of soil properties. The unfavourable consequences of surface runoff are seen in the erosion processes degrading agricultural soils. The South Moravia Region was selected as the case study area – mainly for its natural conditions and high soil degradation risk . A set of data, collected from 2012 to 2017 in a maize-growing area, especially on deep loess soils in the South Moravia Region, was used to analyse the morphological characteristics of the ephemeral gullies (EGs). The relationship was confirmed between the ephemeral gully (EG) length and the size of its contributing drainage area in accordance with studies conducted in other countries. It is also important that the closest relationship was confirmed between the length of the gully and its calculated volume. Dependence was sought on the data of 51 cases of the detailed, measured and evaluated EGs. These results will become the basis for finding a predictive relationship and the quantification of EG erosion. Locating EGs and predicting their length is crucial for estimating the sediment load and planning conservation strategies. The aim of this paper is to contribute to the understanding of this issue, i.e., define and verify the basic crucial causal factors and propose guidelines for locating the potential EG occurrence and predicting the sediment load. A research effort to better understand the EG mechanism and causal factors over a wide range of watershed conditions is fundamental to the establishment of basic rules for the adoption of optimal conservation strategies.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"38-46"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/231/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43709813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effects of tillage and crop rotation on the soil carbon, the soil bulk density, the porosity and the soil water content were evaluated during the 6th season of an on-going field trial at the University of Fort Hare Farm (UFH), South Africa. Two tillage systems; conventional tillage (CT) and no-till and crop rotations; maize (Zea mays L.)-fallow-maize (MFM), maize-fallow-soybean (Glycine max L.) (MFS); maize-wheat (Triticum aestivum L.)-maize (MWM) and maize-wheat-soybean (MWS) were evaluated. The field experiment was a 2 × 4 factorial, laid out in a randomised complete design. The crop residues were retained for the no-till plots and incorporated for the CT plots, after each cropping season. No significant effects (P > 0.05) of the tillage and crop rotation on the bulk density were observed. However, the values ranged from 1.32 to1.37 g/cm3. Significant interaction effects of the tillage and crop rotation were observed on the soil porosity (P < 0.01) and the soil water content (P < 0.05). The porosity for the MFM and the MWS, was higher under the CT whereas for the MWM and the MWS, it was higher under the no-till. However, the greatest porosity was under the MWS. Whilst the no-till significantly increased (P < 0.05) the soil water content compared to the CT; the greatest soil water content was observed when the no-till was combined with the MWM rotations. The soil organic carbon (SOC) was increased more (P < 0.05) by the no-till than the CT, and the MFM consistently had the least SOC compared with the rest of the crop rotations, at all the sampling depths (0–5, 5–10 and 10–20 cm). The soil bulk density negatively correlated with the soil porosity and the soil water content, whereas the porosity positively correlated with the soil water content. The study concluded that the crop rotations, the MWM and the MWS under the no-till coupled with the residue retention improved the soil porosity and the soil water content levels the most.
在南非Fort Hare大学农场（UFH）正在进行的一项田间试验的第六季中，评估了耕作和轮作对土壤碳、土壤容重、孔隙度和土壤含水量的影响。两种耕作系统；常规耕作和免耕轮作；玉米（Zea mays L.）-休耕玉米（MFM）、玉米休耕大豆（Glycine max L.）（MFS）；对玉米-小麦（Triticum aestivum L.）-玉米（MWM）和玉米-小麦-大豆（MWS）进行了评价。现场实验是一个2×4的因子，采用随机完全设计。作物残留物保留在免耕地块中，并在每个种植季节后纳入CT地块。耕作和轮作对松密度的影响不显著（P>0.05）。然而，数值范围为1.32至1.37 g/cm3。耕作和轮作对土壤孔隙度（P<0.01）和土壤含水量（P<0.05）有显著的交互作用。然而，最大的孔隙率是在MWS下。免耕显著提高了土壤含水量（P＜0.05）；当免耕与MWM轮作相结合时，土壤含水量最大。免耕对土壤有机碳（SOC）的增加大于CT（P<0.05），并且在所有采样深度（0-5、5-10和10-20 cm），与其他轮作相比，MFM始终具有最低的SOC。土壤容重与土壤孔隙度和土壤含水量呈负相关，而孔隙度与土壤含水量呈正相关。研究表明，轮作、免耕下的MWM和MWS结合留渣对土壤孔隙度和土壤含水量的改善最大。
{"title":"Tillage and crop rotation effects on soil carbon and selected soil physical properties in a Haplic Cambisol in Eastern Cape, South Africa","authors":"Mxolisi Mtyobile, L. Muzangwa, P. Mnkeni","doi":"10.17221/176/2018-SWR","DOIUrl":"https://doi.org/10.17221/176/2018-SWR","url":null,"abstract":"The effects of tillage and crop rotation on the soil carbon, the soil bulk density, the porosity and the soil water content were evaluated during the 6th season of an on-going field trial at the University of Fort Hare Farm (UFH), South Africa. Two tillage systems; conventional tillage (CT) and no-till and crop rotations; maize (Zea mays L.)-fallow-maize (MFM), maize-fallow-soybean (Glycine max L.) (MFS); maize-wheat (Triticum aestivum L.)-maize (MWM) and maize-wheat-soybean (MWS) were evaluated. The field experiment was a 2 × 4 factorial, laid out in a randomised complete design. The crop residues were retained for the no-till plots and incorporated for the CT plots, after each cropping season. No significant effects (P > 0.05) of the tillage and crop rotation on the bulk density were observed. However, the values ranged from 1.32 to1.37 g/cm3. Significant interaction effects of the tillage and crop rotation were observed on the soil porosity (P < 0.01) and the soil water content (P < 0.05). The porosity for the MFM and the MWS, was higher under the CT whereas for the MWM and the MWS, it was higher under the no-till. However, the greatest porosity was under the MWS. Whilst the no-till significantly increased (P < 0.05) the soil water content compared to the CT; the greatest soil water content was observed when the no-till was combined with the MWM rotations. The soil organic carbon (SOC) was increased more (P < 0.05) by the no-till than the CT, and the MFM consistently had the least SOC compared with the rest of the crop rotations, at all the sampling depths (0–5, 5–10 and 10–20 cm). The soil bulk density negatively correlated with the soil porosity and the soil water content, whereas the porosity positively correlated with the soil water content. The study concluded that the crop rotations, the MWM and the MWS under the no-till coupled with the residue retention improved the soil porosity and the soil water content levels the most.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"47-54"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/176/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43987145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erika María López-García, Edgardo Torres-Trejo, L. López-Reyes, Ángel David Flores-Domínguez, R. Peña-Moreno, J. López-Olguín
Deforestation and conversion of natural grasslands to agricultural land constitute two of the main threats to soil and water conservation, causing erosion, and likely, desertification. The objective of this study was to estimate the erosion of the soil in the locality of Tzicatlacoyan, applying the Universal Soil Loss Equation (USLE) through Geographic Information Systems (GIS). The results indicated that Tzicatlacoyan faces risk of soil erosion with an average annual rate of 117.18 t/ha∙year, due to natural factors and anthropogenic activities such as the use of agricultural land without appropriate conservation practices. Four classes of soil erosion risk were identified, according to the rate of erosion (A) in t/ha∙year: extreme risk (114 ≥ A ≤ 234.36), severe risk (59 ≥ A < 114), moderate risk (23 ≥ A < 59), and low risk (A < 23). Most of the area (180.96 km2, 64.83%) was characterised by the low risk of erosion, while a small part (11.64 km2, 4.17%) of the study area showed extreme risk. The results indicated that 13.33% of the territory of Tzicatlacoyan present values of soil loss exceeding tolerable. The assessment of the soil erosion using the USLE model and GIS might allow land users to make better decisions about the use and conservation of the soil and the ecosystem, adding scientific criteria to their traditional knowledge.
{"title":"Estimation of soil erosion using USLE and GIS in the locality of Tzicatlacoyan, Puebla, México","authors":"Erika María López-García, Edgardo Torres-Trejo, L. López-Reyes, Ángel David Flores-Domínguez, R. Peña-Moreno, J. López-Olguín","doi":"10.17221/165/2018-SWR","DOIUrl":"https://doi.org/10.17221/165/2018-SWR","url":null,"abstract":"Deforestation and conversion of natural grasslands to agricultural land constitute two of the main threats to soil and water conservation, causing erosion, and likely, desertification. The objective of this study was to estimate the erosion of the soil in the locality of Tzicatlacoyan, applying the Universal Soil Loss Equation (USLE) through Geographic Information Systems (GIS). The results indicated that Tzicatlacoyan faces risk of soil erosion with an average annual rate of 117.18 t/ha∙year, due to natural factors and anthropogenic activities such as the use of agricultural land without appropriate conservation practices. Four classes of soil erosion risk were identified, according to the rate of erosion (A) in t/ha∙year: extreme risk (114 ≥ A ≤ 234.36), severe risk (59 ≥ A < 114), moderate risk (23 ≥ A < 59), and low risk (A < 23). Most of the area (180.96 km2, 64.83%) was characterised by the low risk of erosion, while a small part (11.64 km2, 4.17%) of the study area showed extreme risk. The results indicated that 13.33% of the territory of Tzicatlacoyan present values of soil loss exceeding tolerable. The assessment of the soil erosion using the USLE model and GIS might allow land users to make better decisions about the use and conservation of the soil and the ecosystem, adding scientific criteria to their traditional knowledge.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"9-17"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/165/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44292256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Konečná, P. Karásek, Hana Beitlerová, P. Fučík, Jirí Kapicka, J. Podhrázská, T. Kvítek
A careful analysis of rainfall-runoff events and patterns of sediment and pollution load to water bodies is crucial for the proper management of agricultural land. This study simultaneously employed the WaTEM/SEDEM long-term erosion model and the HEC-HMS episodic hydrological and erosion model to describe the runoff and sediment load evoked by extreme rainfall events in a small agricultural catchment in Czechia, using the long-term monitoring discharge and water quality episodic data. WaTEM/SEDEM helped to delineate the runoff and sediment critical source areas, subsequently incorporated into HEC-HMS. The acquired results showed that the spatial distribution of land use is a fundamental factor in the protection of watercourses from diffuse pollution sources and the transport and delivery of sediment profoundly depends on the status of crop cover on arable land near a watercourse. Integrating both models, it was shown that the tabulated Curve Number (CN) values as well as the average C-factor values had to be lowered for the majority of the modelled events to match the monitored data. A noticeable role of catchment runoff response most probably played tile drainage, which appeared to profoundly modify the episodic runoff pattern. This study showed a promising approach for the simulation of different rainfall-runoff responses of small agricultural catchments and could be applied for the delineation of areas where soil conservation measures or protective management is of high priority. The results further revealed the obvious need to revise the CN values for tile-drained catchments.
{"title":"Using WaTEM/SEDEM and HEC-HMS models for the simulation of episodic hydrological and erosion events in a small agricultural catchment","authors":"J. Konečná, P. Karásek, Hana Beitlerová, P. Fučík, Jirí Kapicka, J. Podhrázská, T. Kvítek","doi":"10.17221/202/2018-SWR","DOIUrl":"https://doi.org/10.17221/202/2018-SWR","url":null,"abstract":"A careful analysis of rainfall-runoff events and patterns of sediment and pollution load to water bodies is crucial for the proper management of agricultural land. This study simultaneously employed the WaTEM/SEDEM long-term erosion model and the HEC-HMS episodic hydrological and erosion model to describe the runoff and sediment load evoked by extreme rainfall events in a small agricultural catchment in Czechia, using the long-term monitoring discharge and water quality episodic data. WaTEM/SEDEM helped to delineate the runoff and sediment critical source areas, subsequently incorporated into HEC-HMS. The acquired results showed that the spatial distribution of land use is a fundamental factor in the protection of watercourses from diffuse pollution sources and the transport and delivery of sediment profoundly depends on the status of crop cover on arable land near a watercourse. Integrating both models, it was shown that the tabulated Curve Number (CN) values as well as the average C-factor values had to be lowered for the majority of the modelled events to match the monitored data. A noticeable role of catchment runoff response most probably played tile drainage, which appeared to profoundly modify the episodic runoff pattern. This study showed a promising approach for the simulation of different rainfall-runoff responses of small agricultural catchments and could be applied for the delineation of areas where soil conservation measures or protective management is of high priority. The results further revealed the obvious need to revise the CN values for tile-drained catchments.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"18-29"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/202/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67550586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Fiala, J. Podhrázská, J. Konečná, J. Kučera, P. Karásek, P. Zahradníček, P. Štěpánek
The paper deals with the analysis of a river’s regime of a small watercourse and the evaluation of its changes after the construction of a small water reservoir. The aim of the work was to analyse 12 years of flow rate measurements at two profiles of a small watercourse, between which a small water reservoir was built, in the middle of the period of the measurements. The analysis uses traditional characteristics (average flow rate, discharge volume), as well as modern indices from applied hydrology (Richards-Baker flashiness index, hydrogram pulse analysis), which study the variability of the flow rate in hourly and daily intervals. The evaluation showed that at the average flow rate, the effect of the water reservoir was the smoothening of the peak flow rates and prolonging the duration of the discharge waves. At higher flow rates, the water reservoir causes a delay in the culmination and in terms of discharge balance causes a decreased discharge volume, in particular during the vegetation period.
{"title":"Changes in a river’s regime of a watercourse after a small water reservoir construction","authors":"R. Fiala, J. Podhrázská, J. Konečná, J. Kučera, P. Karásek, P. Zahradníček, P. Štěpánek","doi":"10.17221/23/2019-SWR","DOIUrl":"https://doi.org/10.17221/23/2019-SWR","url":null,"abstract":"The paper deals with the analysis of a river’s regime of a small watercourse and the evaluation of its changes after the construction of a small water reservoir. The aim of the work was to analyse 12 years of flow rate measurements at two profiles of a small watercourse, between which a small water reservoir was built, in the middle of the period of the measurements. The analysis uses traditional characteristics (average flow rate, discharge volume), as well as modern indices from applied hydrology (Richards-Baker flashiness index, hydrogram pulse analysis), which study the variability of the flow rate in hourly and daily intervals. The evaluation showed that at the average flow rate, the effect of the water reservoir was the smoothening of the peak flow rates and prolonging the duration of the discharge waves. At higher flow rates, the water reservoir causes a delay in the culmination and in terms of discharge balance causes a decreased discharge volume, in particular during the vegetation period.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"55-65"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/23/2019-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45282549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ullah, R. Nazir, Muslim Khan, Waliullah Khan, M. Shah, S. G. Afridi, A. Zada
The removal of toxic metals like lead (Pb) and cadmium (Cd) is very urgent keeping their hazardous effects in view. In this work, seeds of Albizia lebbeck and Melia azedarach trees were converted into activated carbon adsorbents and applied for the adsorptive removal of Pb and Cd metals from an aqueous solution. The as prepared adsorbents were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The removal efficiencies of both metals were strongly dependent on their initial concentration, contact time, pH, temperature and the quantity of adsorbents. 0.2 g of both adsorbents removed respectively 75 and 62% Pb and 77 and 66% Cd from from 100 ml of a 40 mg/l concentrated solution in 120 min at pH 5 and a temperature of 20°C. Both the Freundlich and Langmuir isotherms were well fitted to the experimental data. We believe that this work will provide a convenient way to synthesise low cost activated carbon adsorbents for the remediation of highly toxic metals from wastewater to safeguard our environment for future generations.
考虑到铅(Pb)和镉(Cd)等有毒金属的有害影响，清除它们刻不容缓。本研究将小檗和苦楝种子转化为活性炭吸附剂，用于吸附去除水中的铅和镉金属。用傅里叶红外光谱(FTIR)和扫描电镜(SEM)对所制备的吸附剂进行了表征。这两种金属的去除效率与它们的初始浓度、接触时间、pH、温度和吸附剂的数量密切相关。在pH为5，温度为20°C的条件下，在120分钟内，0.2 g两种吸附剂分别从100 ml 40 mg/l的浓缩溶液中去除75和62%的Pb和77和66%的Cd。Freundlich等温线和Langmuir等温线都很好地符合实验数据。我们相信这项工作将为合成低成本的活性炭吸附剂提供一种方便的方法，用于废水中高毒性金属的修复，为子孙后代保护我们的环境。
{"title":"The effective removal of heavy metals from water by activated carbon adsorbents of Albizia lebbeck and Melia azedarach seed shells","authors":"M. Ullah, R. Nazir, Muslim Khan, Waliullah Khan, M. Shah, S. G. Afridi, A. Zada","doi":"10.17221/212/2018-SWR","DOIUrl":"https://doi.org/10.17221/212/2018-SWR","url":null,"abstract":"The removal of toxic metals like lead (Pb) and cadmium (Cd) is very urgent keeping their hazardous effects in view. In this work, seeds of Albizia lebbeck and Melia azedarach trees were converted into activated carbon adsorbents and applied for the adsorptive removal of Pb and Cd metals from an aqueous solution. The as prepared adsorbents were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The removal efficiencies of both metals were strongly dependent on their initial concentration, contact time, pH, temperature and the quantity of adsorbents. 0.2 g of both adsorbents removed respectively 75 and 62% Pb and 77 and 66% Cd from from 100 ml of a 40 mg/l concentrated solution in 120 min at pH 5 and a temperature of 20°C. Both the Freundlich and Langmuir isotherms were well fitted to the experimental data. We believe that this work will provide a convenient way to synthesise low cost activated carbon adsorbents for the remediation of highly toxic metals from wastewater to safeguard our environment for future generations.","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":"15 1","pages":"30-37"},"PeriodicalIF":2.3,"publicationDate":"2019-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/212/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42597293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xueya Zhou, D. Guan, Jiabing Wu, F. Yuan, An-zhi Wang, C. Jin, Yu-shu Zhang
Soil water dynamic is considered an important process for water resource and plantation management in Horqin Sand Land, northern China. In this study, soil water content simulated by the SWMS-2D model was used to systematically analyse soil water dynamics and explore the relationship between soil water and rainfall among micro-landforms (i.e., top, upslope, midslope, toeslope, and bottomland) and 0–200 cm soil depths during the growing season of 2013 and 2015. The results showed that soil water dynamics in 0–20 cm depths were closely linked to rainfall patterns, whereas soil water content in 20–80 cm depths illustrated a slight decline in addition to fluctuations caused by rainfall. At the top position, the soil water content in different ranges of depths (20–40 and 80–200 cm) was near the wilting point, and hence some branches, and even entire plants exhibited diebacks. At the upslope or midslope positions, the soil water content in 20–80 or 80–200 cm depths was higher than at the top position. Soil water content was higher at the toeslope and bottomland positions than at other micro-landforms, and deep caliche layers had a positive feedback effect on shrub establishment. Soil water recharge by rainfall was closely related to rainfall intensity and micro-landforms. Only rainfalls > 20 mm significantly increased water content in > 40 cm soil depths, but deeper water recharge occurred at the toeslope position. A linear equation was fitted to the relationship between soil water and antecedent rainfall, and the slopes and R2 of the equations were different among micro-landforms and soil depths. The linear equations generally fitted well in 0–20 and 20–40 cm depths at the top, upslope, midslope, and toeslope positions (R2 value of about 0.60), with soil water in 0–20 cm depths showing greater responses to rainfall (average slope of 0.189). In 20–40 cm depths, the response was larger at the toeslope position, with a slope of 0.137. In 40–80 cm depths, a good linear fit with a slope of 0.041 was only recorded at the toeslope position. This study provides a soil water basis for ecological restoration in similar regions.
{"title":"Soil water response to rainfall in a dune-interdune landscape in Horqin Sand Land, northern China","authors":"Xueya Zhou, D. Guan, Jiabing Wu, F. Yuan, An-zhi Wang, C. Jin, Yu-shu Zhang","doi":"10.17221/142/2018-SWR","DOIUrl":"https://doi.org/10.17221/142/2018-SWR","url":null,"abstract":"Soil water dynamic is considered an important process for water resource and plantation management in Horqin Sand Land, northern China. In this study, soil water content simulated by the SWMS-2D model was used to systematically analyse soil water dynamics and explore the relationship between soil water and rainfall among micro-landforms (i.e., top, upslope, midslope, toeslope, and bottomland) and 0–200 cm soil depths during the growing season of 2013 and 2015. The results showed that soil water dynamics in 0–20 cm depths were closely linked to rainfall patterns, whereas soil water content in 20–80 cm depths illustrated a slight decline in addition to fluctuations caused by rainfall. At the top position, the soil water content in different ranges of depths (20–40 and 80–200 cm) was near the wilting point, and hence some branches, and even entire plants exhibited diebacks. At the upslope or midslope positions, the soil water content in 20–80 or 80–200 cm depths was higher than at the top position. Soil water content was higher at the toeslope and bottomland positions than at other micro-landforms, and deep caliche layers had a positive feedback effect on shrub establishment. Soil water recharge by rainfall was closely related to rainfall intensity and micro-landforms. Only rainfalls > 20 mm significantly increased water content in > 40 cm soil depths, but deeper water recharge occurred at the toeslope position. A linear equation was fitted to the relationship between soil water and antecedent rainfall, and the slopes and R2 of the equations were different among micro-landforms and soil depths. The linear equations generally fitted well in 0–20 and 20–40 cm depths at the top, upslope, midslope, and toeslope positions (R2 value of about 0.60), with soil water in 0–20 cm depths showing greater responses to rainfall (average slope of 0.189). In 20–40 cm depths, the response was larger at the toeslope position, with a slope of 0.137. In 40–80 cm depths, a good linear fit with a slope of 0.041 was only recorded at the toeslope position. This study provides a soil water basis for ecological restoration in similar regions. ","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/142/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47271578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kulhánek, J. Černý, J. Balík, O. Sedlář, F. Vašák
The aim of this study is to describe the changes of bioavailable phosphorus content in soil in long-term 18 years field experiments with different fertilizing systems. The field experiments are located at three sites with different soil and climatic conditions in the Czech Republic (Červený Újezd, Humpolec and Prague-Suchdol). Same fertilizing systems and crop rotation (potatoes (maize) – winter wheat – spring barley) are realized at each site with following fertilizing treatments: (1) unfertilized treatment (control), (2) farmyard manure (FYM), (3) and (4) sewage sludge (SS 1 and SS 3), (5) mineral nitrogen (N), (6) mineral nitrogen with straw (N + straw) and (7) mineral nitrogen with phosphorus and potassium (NPK). The long-term fertilizing effect on available P content changes in soil was observed. Bioavailable phosphorus content in soil increased in treatments with organic fertilization after 18 year experiment at all sites. The treatments SS 3 had the highest increase at all sites. The highest bioavailable P content increase compared to control (258 mg/kg) was determined at site Červený Újezd. On the contrary, available phosphorus content decreased at treatments with mineral fertilization and control treatment among all sites. Bioavailable P content decrease in the treatment NPK was observed, although phosphorus was applied. The lowest differences in available P content among all fertilizing treatments were observed at the location Prague-Suchdol.
{"title":"Changes of soil bioavailable phosphorus content in the long-term field fertilizing experiment","authors":"M. Kulhánek, J. Černý, J. Balík, O. Sedlář, F. Vašák","doi":"10.17221/175/2018-SWR","DOIUrl":"https://doi.org/10.17221/175/2018-SWR","url":null,"abstract":"The aim of this study is to describe the changes of bioavailable phosphorus content in soil in long-term 18 years field experiments with different fertilizing systems. The field experiments are located at three sites with different soil and climatic conditions in the Czech Republic (Červený Újezd, Humpolec and Prague-Suchdol). Same fertilizing systems and crop rotation (potatoes (maize) – winter wheat – spring barley) are realized at each site with following fertilizing treatments: (1) unfertilized treatment (control), (2) farmyard manure (FYM), (3) and (4) sewage sludge (SS 1 and SS 3), (5) mineral nitrogen (N), (6) mineral nitrogen with straw (N + straw) and (7) mineral nitrogen with phosphorus and potassium (NPK). The long-term fertilizing effect on available P content changes in soil was observed. Bioavailable phosphorus content in soil increased in treatments with organic fertilization after 18 year experiment at all sites. The treatments SS 3 had the highest increase at all sites. The highest bioavailable P content increase compared to control (258 mg/kg) was determined at site Červený Újezd. On the contrary, available phosphorus content decreased at treatments with mineral fertilization and control treatment among all sites. Bioavailable P content decrease in the treatment NPK was observed, although phosphorus was applied. The lowest differences in available P content among all fertilizing treatments were observed at the location Prague-Suchdol. ","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/175/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46775177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yali Zhang, Xiaoyang Li, Xingchang Zhang, Huai'en Li
The release and transport of soil chemicals in water erosion conditions are important for the local environment, soil and water resources conservation. According to the artificial rainfall experiments with a constant rainfall intensity of 90 mm/h and different rainfall duration (30, 60, 90, 120 and 150 min), the traits of soil PO43–, K+, and Br– release and transport from soil to surface runoff on the loess slope were analysed, and a model describing the chemical concentration change in surface runoff under soil erosion conditions was developed. The runoff coefficient quickly increased in 15 min or so, and then it was stable in the range of 0.60–0.85. The sediment intensity decreased in 30 min and soon increased after severe sheet erosion occurred on the slope. The concentration curve of Br– in surface runoff can be divided into two stages, quickly decreasing in the initial 30 min after the surface runoff occurred, and then stable. The concentration curve of PO43– and K+ in surface runoff can be divided into three stages, quickly decreasing like Br– was decreasing, then stable, and increasing after severe sheet erosion began. Compared with the exponential function, the power function was found more suitable for fitting the change in chemicals in runoff with unsaturated soil; while neither of them could well fit the PO43– and K+ concentration change after severe erosion occurred. The transport of chemicals under complex soil erosion conditions seems to be a dynamic release process between surface runoff and sediment. Based on the convection-dispersion mechanism and desorption kinetics, the polynomial model under soil erosion conditions was created. For adsorbed PO43– and K+, it is more suitable to simulate that process than the power function, while it is not so good for mobile Br–.
{"title":"Investigating rainfall duration effects on transport of chemicals from soil to surface runoff on a loess slope under artificial rainfall conditions","authors":"Yali Zhang, Xiaoyang Li, Xingchang Zhang, Huai'en Li","doi":"10.17221/98/2018-SWR","DOIUrl":"https://doi.org/10.17221/98/2018-SWR","url":null,"abstract":"The release and transport of soil chemicals in water erosion conditions are important for the local environment, soil and water resources conservation. According to the artificial rainfall experiments with a constant rainfall intensity of 90 mm/h and different rainfall duration (30, 60, 90, 120 and 150 min), the traits of soil PO43–, K+, and Br– release and transport from soil to surface runoff on the loess slope were analysed, and a model describing the chemical concentration change in surface runoff under soil erosion conditions was developed. The runoff coefficient quickly increased in 15 min or so, and then it was stable in the range of 0.60–0.85. The sediment intensity decreased in 30 min and soon increased after severe sheet erosion occurred on the slope. The concentration curve of Br– in surface runoff can be divided into two stages, quickly decreasing in the initial 30 min after the surface runoff occurred, and then stable. The concentration curve of PO43– and K+ in surface runoff can be divided into three stages, quickly decreasing like Br– was decreasing, then stable, and increasing after severe sheet erosion began. Compared with the exponential function, the power function was found more suitable for fitting the change in chemicals in runoff with unsaturated soil; while neither of them could well fit the PO43– and K+ concentration change after severe erosion occurred. The transport of chemicals under complex soil erosion conditions seems to be a dynamic release process between surface runoff and sediment. Based on the convection-dispersion mechanism and desorption kinetics, the polynomial model under soil erosion conditions was created. For adsorbed PO43– and K+, it is more suitable to simulate that process than the power function, while it is not so good for mobile Br–. ","PeriodicalId":48982,"journal":{"name":"Soil and Water Research","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17221/98/2018-SWR","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42549266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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