Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and...Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions.展开更多
In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source fo...In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source for soil fertigation and groundwater(GW)recharge.However,major risks can be expected when the irrigation water is of poor quality.This study aims for evaluating the potential risk of TWW and GW irrigation on soil parameters.Accordingly,we evaluated the suitability of water quality through the analysis of major and minor cations and anions,metallic trace elements(MTEs),and the sodium hazard by using the sodium adsorption ratio(SAR)and the soluble sodium percentage(SSP).The risk of soil sodicity was further assessed by SAR and the exchangeable sodium percentage(ESP).The degree of soil pollution caused by MTEs accumulation was evaluated using geoaccumulation index(Igeo)and pollution load index(PLI).Soil maps were generated using inverse spline interpolation in ArcGIS software.The results show that both water samples(i.e.,TWW and GW)are suitable for soil irrigation in terms of salinity(electrical conductivity<7000μS/cm)and sodicity(SAR<10.00;SSP<60.00%).However,the contents of PO_(4)^(3-),Cu^(2+),and Cd^(2+)exceed the maximum threshold values set by the national and other standards.Concerning the soil samples,the average levels of SAR and ESP are within the standards(SAR<13.00;ESP<15.00%).On the other hand,PLI results reveal moderate pollution in the plot irrigated with TWW and no to moderate pollution in the plot irrigated with GW.Igeo results indicate that Cu^(2+)is the metallic trace element(MTE)with the highest risk of soil pollution in both plots(Igeo>5.00),followed by Ni^(2+)and Pb^(2+).Nevertheless,Cd^(2+)presents the lowest risk of soil pollution(Igeo<0.00).Statistical data indicates that Ca^(2+),Na+,Ni^(2+),and Pb^(2+)are highly distributed in both plots(coefficient of variation>50.0%).This study shows that the use of imagery tools,such as ArcGIS,can provide important information for evaluating the current status of soil fertility or pollution and for better managing soil irrigation with TWW.展开更多
Ecological restoration by Taman'x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations ...Ecological restoration by Taman'x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations of soil water content and salinity around natural individual Tamarix ramosissiraa Ledeb. were invetigated in a semi-arid saline region of the upper Yellow River, Northwest China. Specifically, soil water content, electrical conductivity (EC), sodium adsorption ratio (SARa), and salt ions (including Na+, K+, Ca2+, Mg2+ and 8042-) were measured at different soil depths and at different distances from the trunk of T. ramasissima in May, July, and September 2016. The soil water content at the 20-80 cm depth was significantly lower in July and September than in May, indicating that T. ramosissima plants absorb a large amount of water through the roots during the growing period, leading to the decreasing of soil water content in the deep soil layer. At the 0-20 cm depth, there was a salt island effect around individual T. ramosissima, and the ECe differed significantly inside and outside the canopy of T. ramosissima in May and July. Salt bioaccumulation and stemflow were two major contributing factors to this difference. The SAR at the 0-20 cm depth was significantly different inside and outside the canopy of T. ramosissima in the three sampling months. The values of SAR~ at the 60-80 cm depth in May and July were significantly higher than those at the 0-60 cm depth and higher than that at the corresponding depth in September. The distribution of Na+ in the soil was similar to that of the SAI, while the concentrations of K+, Ca2+, and Mg2+ showed significant differences among the sampling months and soil depths. Both season and soil depth had highly significant effects on soil water content, ECe and SARa, whereas distance from the trunk of T. ramosissima only significantly affected ECe. Based on these results, we recommend co-planting of shallow-rooted salt-tolerant species near the Tamarx plants and avoiding planting herbaceous plants inside the canopy of T. ramodssima for afforestation in this semi-arid saline region. The results of this study may provide a reference for appropriate restoration in the semi-arid saline regions of the upper Yellow River.展开更多
In the northern part of Algeria,the intensive exploitation of groundwater resources and pollution has considerably affected the aquifer water quality,especially in rural areas where groundwater is the main source of w...In the northern part of Algeria,the intensive exploitation of groundwater resources and pollution has considerably affected the aquifer water quality,especially in rural areas where groundwater is the main source of water supply for most uses.This study was performed to evaluate the groundwater quality and its suitability for drinking and irrigation purposes through the hydrogeochemical study on the groundwater in Bougaa region(Northeastern Algeria).Fourteen groundwater samples were collected and analyzed for p H,T,EC,TDS,and major ions.Most samples are suitable for drinking based on the permissible limits of the Bureau of Indian standards(Indian standard specification for drinking water(IS 10500:2012),but only 35%of the samples are good enough for drinking purposes based on the water quality index of the groundwater.Assessment of groundwater samples from various parameters and methods such as"Electrical conductivity,Sodium adsorption ratio,Soluble sodium percentage,Magnesium adsorption ratio,Residual sodium carbonate,Permeability index,Kelly’s ratio,Wilcox’s diagram,and US salinity laboratory classification"showed that groundwater in the area is chemically suitable for irrigation uses.The Piper trilinear diagram suggests that the groundwater mainly belongs to the hydrochemical facies Ca–Mg–Cl and Na–Cl.The combination of ionic ratios,Gibbs plots,and saturation indices show that water–rock interaction,particularly the dissolution of carbonate,evaporation minerals,and ion exchange processes affects hydrogeochemistry of the area.Additional processes such as evaporation and anthropogenic pollution from various sources can also have major impacts on groundwater salinity.展开更多
Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and...Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and sodium adsorption ratio(SAR) in saline-sodic soil under the infiltration of saline ice meltwater.Soils were treated using saline water of three irrigation volumes(1 600, 2 400 and 3 200 mL) at four salinity levels.These four salinity levels included salt free(0 g L^(-1)), low salinity level(1.4 g L^(-1)), moderate salinity level(2.7 g L^(-1)) and high salinity level(4.1 g L^(-1)).The prepared saline water was frozen into ice, and then the ice was put on the surface of soil columns.After 96 h, the infiltration rate and soil moisture content of saline ice treatments were greater than those of salt-free ice treatments, increasing with the increase of ice salinity.Infiltration of saline ice meltwater increased soil moisture content in the upper layers for all treatments.Both salt contents and SAR values in the upper soil layers decreased in all saline ice treatments and were lower than those in salt-free ice treatment.However, this trend was reversed in the deeper(below 20 cm) soil layers.The highest desalting rate and lowest SAR were observed in high-salinity treatment under three irrigation volumes in the 0–15 cm soil layer,especially under irrigation volume of 2 400 mL.These results indicate that saline ice(0–20 cm) meltwater irrigation is beneficial to saline-sodic soil reclamation, and the best improvement effect would be achieved when using high-salinity ice under optimal irrigation volume.展开更多
Salt and sodicity of saline-alkali soil adversely affect the construction of ecological landscapes and negatively impact crop production.The reclamation potential of biochar(BC,wheat straw biochar applied at\%by weigh...Salt and sodicity of saline-alkali soil adversely affect the construction of ecological landscapes and negatively impact crop production.The reclamation potential of biochar(BC,wheat straw biochar applied at\%by weight),gypsum(G,0.4%by weight),and gypsum coupled with biochar(GBC)was examined in this laboratory-based study by evaluating their effects on a saline-alkali soil(silt loam)with no amendment as a control(CK).Saline ice and fresh water(simulated rainfall)were leached through soil columns to investigate changes in salt content,sodium adsorption ratio(SAR),alkalinity,and pH of the leachate and the soil.Results showed that saturated water content and field water capacity(FWC)significantly increased by 4.4%and 5.6%,respectively,in the BC treatment after a short incubation time.Co-application of biochar and gypsum(GBC)increased soil saturated hydraulic conductivity(Ks)by 58.4%,which was also significantly higher than the sole addition.Electrical conductivity(EC)of the leachate decreased sharply after saline ice leaching;subsequent freshwater leaching accelerated the removal of the rest of the salts,irrespective of the amendment application.However,the application of gypsum(G and GB)significantly enhanced the removal of exchangeable Na^+and reduced leachate SAR.After leaching,the soil salt content decreased significantly for all treatments.The application of gypsum resulted in a significantly lower soil pH,exchangeable sodium percentage(ESP),SAR,and alkalinity values than those recorded for the CK and BC treatments.These results demonstrated that the co-application of gypsum and biochar could improve saline-alkali soil hydraulic conductivity and decrease leaching-induced sodicity over a short period.展开更多
基金Under the auspices of National Key Research and Development Program of China(No.2022YFD1500501)National Natural Science Foundation of China(No.41971066)+1 种基金Key Laboratory Foundation of Mollisols Agroecology(No.2020ZKHT-03)High Tech Fund Project of S&T Cooperation Between Jilin Province and Chinese Academy of Sciences(No.2022SYHZ0018)。
文摘Groundwater mineralization is one of the main factors affecting the transport of soil water and salt in saline-sodic areas.To investigate the effects of groundwater with different levels of salinity on evaporation and distributions of soil water and salt in Songnen Plain,Northeast China,five levels of groundwater sodium adsorption ration of water(SARw)and total salt content(TSC mmol/L)were conducted in an oil column lysimeters.The five treated groundwater labeled as ST0:0,ST0:10,ST5:40,ST10:70 and ST20:100,were prepared with NaCl and CaCl2 in proportion,respectively.The results showed the groundwater evaporation(GWE)and soil evaporation(SE)increased firstly and then decreased with the increase of groundwater salinity.The values of GWE and SE in ST10:70 treatment were the highest,which were 2.09 and 1.84 times the values in the ST0:0 treatment with the lowest GWE and SE.There was a positive linear correlation between GWE and the Ca^(2+)content in groundwater,with R^(2)=0.998.The soil water content(SWC)of ST0:0 treatment was significantly(P<0.05)less than those of other treatments during the test.The SWC of the ST0:0 and ST0:10 treatments increased with the increase of soil depth,while the other treatments showed the opposite trend.Statistical analysis indicated the SWC in the 0–60 cm soil layer was positively correlated with the groundwater TSC and its ion contents during the test.Salt accumulation occurred in the topsoil and the salt accumulation in the 0–20 cm soil layer was significantly(P<0.05)greater than that in the subsoil.This study revealed the effects of the salinity level of groundwater,especially the Ca^(2+)content and TSC of groundwater,on the GWE and distributions of soil water and salt,which provided important support for the prevention and reclamation of soil salinization and sodificaton in shallow groundwater regions.
文摘In Tunisia,water scarcity is only adding pressure on water demand in agriculture.In the context of sustainable development goals,Tunisia has been reusing treated wastewater(TWW)as a renewable and inexpensive source for soil fertigation and groundwater(GW)recharge.However,major risks can be expected when the irrigation water is of poor quality.This study aims for evaluating the potential risk of TWW and GW irrigation on soil parameters.Accordingly,we evaluated the suitability of water quality through the analysis of major and minor cations and anions,metallic trace elements(MTEs),and the sodium hazard by using the sodium adsorption ratio(SAR)and the soluble sodium percentage(SSP).The risk of soil sodicity was further assessed by SAR and the exchangeable sodium percentage(ESP).The degree of soil pollution caused by MTEs accumulation was evaluated using geoaccumulation index(Igeo)and pollution load index(PLI).Soil maps were generated using inverse spline interpolation in ArcGIS software.The results show that both water samples(i.e.,TWW and GW)are suitable for soil irrigation in terms of salinity(electrical conductivity<7000μS/cm)and sodicity(SAR<10.00;SSP<60.00%).However,the contents of PO_(4)^(3-),Cu^(2+),and Cd^(2+)exceed the maximum threshold values set by the national and other standards.Concerning the soil samples,the average levels of SAR and ESP are within the standards(SAR<13.00;ESP<15.00%).On the other hand,PLI results reveal moderate pollution in the plot irrigated with TWW and no to moderate pollution in the plot irrigated with GW.Igeo results indicate that Cu^(2+)is the metallic trace element(MTE)with the highest risk of soil pollution in both plots(Igeo>5.00),followed by Ni^(2+)and Pb^(2+).Nevertheless,Cd^(2+)presents the lowest risk of soil pollution(Igeo<0.00).Statistical data indicates that Ca^(2+),Na+,Ni^(2+),and Pb^(2+)are highly distributed in both plots(coefficient of variation>50.0%).This study shows that the use of imagery tools,such as ArcGIS,can provide important information for evaluating the current status of soil fertility or pollution and for better managing soil irrigation with TWW.
基金funded by the Fundamental Research Funds for the Central Universities (2016ZCQ06)the Forestry Industry Research Special Funds for Public Welfare Projects (201504402)the Application Technology of Seaweed Fertilizer Based on Desertification Control and Saline-alkili Soil Improvement (2016HXFWSBXY002)
文摘Ecological restoration by Taman'x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations of soil water content and salinity around natural individual Tamarix ramosissiraa Ledeb. were invetigated in a semi-arid saline region of the upper Yellow River, Northwest China. Specifically, soil water content, electrical conductivity (EC), sodium adsorption ratio (SARa), and salt ions (including Na+, K+, Ca2+, Mg2+ and 8042-) were measured at different soil depths and at different distances from the trunk of T. ramasissima in May, July, and September 2016. The soil water content at the 20-80 cm depth was significantly lower in July and September than in May, indicating that T. ramosissima plants absorb a large amount of water through the roots during the growing period, leading to the decreasing of soil water content in the deep soil layer. At the 0-20 cm depth, there was a salt island effect around individual T. ramosissima, and the ECe differed significantly inside and outside the canopy of T. ramosissima in May and July. Salt bioaccumulation and stemflow were two major contributing factors to this difference. The SAR at the 0-20 cm depth was significantly different inside and outside the canopy of T. ramosissima in the three sampling months. The values of SAR~ at the 60-80 cm depth in May and July were significantly higher than those at the 0-60 cm depth and higher than that at the corresponding depth in September. The distribution of Na+ in the soil was similar to that of the SAI, while the concentrations of K+, Ca2+, and Mg2+ showed significant differences among the sampling months and soil depths. Both season and soil depth had highly significant effects on soil water content, ECe and SARa, whereas distance from the trunk of T. ramosissima only significantly affected ECe. Based on these results, we recommend co-planting of shallow-rooted salt-tolerant species near the Tamarx plants and avoiding planting herbaceous plants inside the canopy of T. ramodssima for afforestation in this semi-arid saline region. The results of this study may provide a reference for appropriate restoration in the semi-arid saline regions of the upper Yellow River.
文摘In the northern part of Algeria,the intensive exploitation of groundwater resources and pollution has considerably affected the aquifer water quality,especially in rural areas where groundwater is the main source of water supply for most uses.This study was performed to evaluate the groundwater quality and its suitability for drinking and irrigation purposes through the hydrogeochemical study on the groundwater in Bougaa region(Northeastern Algeria).Fourteen groundwater samples were collected and analyzed for p H,T,EC,TDS,and major ions.Most samples are suitable for drinking based on the permissible limits of the Bureau of Indian standards(Indian standard specification for drinking water(IS 10500:2012),but only 35%of the samples are good enough for drinking purposes based on the water quality index of the groundwater.Assessment of groundwater samples from various parameters and methods such as"Electrical conductivity,Sodium adsorption ratio,Soluble sodium percentage,Magnesium adsorption ratio,Residual sodium carbonate,Permeability index,Kelly’s ratio,Wilcox’s diagram,and US salinity laboratory classification"showed that groundwater in the area is chemically suitable for irrigation uses.The Piper trilinear diagram suggests that the groundwater mainly belongs to the hydrochemical facies Ca–Mg–Cl and Na–Cl.The combination of ionic ratios,Gibbs plots,and saturation indices show that water–rock interaction,particularly the dissolution of carbonate,evaporation minerals,and ion exchange processes affects hydrogeochemistry of the area.Additional processes such as evaporation and anthropogenic pollution from various sources can also have major impacts on groundwater salinity.
基金supported by the National Key Research and Development Program of China(No.2016YFC0501200)the National Natural Science Foundation of China(Nos.41571210 and 41601583)the Natural Science and Technology Basic Work of China(No.2015FY110500)
文摘Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and sodium adsorption ratio(SAR) in saline-sodic soil under the infiltration of saline ice meltwater.Soils were treated using saline water of three irrigation volumes(1 600, 2 400 and 3 200 mL) at four salinity levels.These four salinity levels included salt free(0 g L^(-1)), low salinity level(1.4 g L^(-1)), moderate salinity level(2.7 g L^(-1)) and high salinity level(4.1 g L^(-1)).The prepared saline water was frozen into ice, and then the ice was put on the surface of soil columns.After 96 h, the infiltration rate and soil moisture content of saline ice treatments were greater than those of salt-free ice treatments, increasing with the increase of ice salinity.Infiltration of saline ice meltwater increased soil moisture content in the upper layers for all treatments.Both salt contents and SAR values in the upper soil layers decreased in all saline ice treatments and were lower than those in salt-free ice treatment.However, this trend was reversed in the deeper(below 20 cm) soil layers.The highest desalting rate and lowest SAR were observed in high-salinity treatment under three irrigation volumes in the 0–15 cm soil layer,especially under irrigation volume of 2 400 mL.These results indicate that saline ice(0–20 cm) meltwater irrigation is beneficial to saline-sodic soil reclamation, and the best improvement effect would be achieved when using high-salinity ice under optimal irrigation volume.
基金This study was jointly supported by the National Key Research and Development Project of China(No.2016YFD0200303)the Natural Science Foundation of China-Shandong Joint Key Project(Nos.U 1806215 and U1906221)+1 种基金the Key Project of Chinese Academy of Sciences(No.KFZD-SW-112-03-02)the National Natural Science Foundation of China(No.41977015).
文摘Salt and sodicity of saline-alkali soil adversely affect the construction of ecological landscapes and negatively impact crop production.The reclamation potential of biochar(BC,wheat straw biochar applied at\%by weight),gypsum(G,0.4%by weight),and gypsum coupled with biochar(GBC)was examined in this laboratory-based study by evaluating their effects on a saline-alkali soil(silt loam)with no amendment as a control(CK).Saline ice and fresh water(simulated rainfall)were leached through soil columns to investigate changes in salt content,sodium adsorption ratio(SAR),alkalinity,and pH of the leachate and the soil.Results showed that saturated water content and field water capacity(FWC)significantly increased by 4.4%and 5.6%,respectively,in the BC treatment after a short incubation time.Co-application of biochar and gypsum(GBC)increased soil saturated hydraulic conductivity(Ks)by 58.4%,which was also significantly higher than the sole addition.Electrical conductivity(EC)of the leachate decreased sharply after saline ice leaching;subsequent freshwater leaching accelerated the removal of the rest of the salts,irrespective of the amendment application.However,the application of gypsum(G and GB)significantly enhanced the removal of exchangeable Na^+and reduced leachate SAR.After leaching,the soil salt content decreased significantly for all treatments.The application of gypsum resulted in a significantly lower soil pH,exchangeable sodium percentage(ESP),SAR,and alkalinity values than those recorded for the CK and BC treatments.These results demonstrated that the co-application of gypsum and biochar could improve saline-alkali soil hydraulic conductivity and decrease leaching-induced sodicity over a short period.