The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Binbin Jiang - One of the best experts on this subject based on the ideXlab platform.
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Soil salinity and Exchangeable Cations in a wastewater irrigated area, India.
Journal of Environmental Quality, 2009Co-Authors: Trent W. Biggs, Binbin JiangAbstract:: The salinity and cation composition of water and soil were documented in a large (98 km(2)) wastewater-irrigated area (WIA) downstream of Hyderabad, India. The wastewater, which flows in a river that passes through the city, had a high to very high salinity hazard (EC = 1.1-3.0 dS m(-1)) that increased with distance from the city. The EC of soil irrigated by wastewater sampled within 8 km of the city was 6.2 to 8.4 times the EC of soil irrigated by uncontaminated groundwater. Between 57 to 100% of soil samples in the upper 10 cm within 8 km of the city exceeded the salinity tolerance of rice (Oryza sativa L.). Soil salinity fell rapidly after 8 km downstream and changed most in the upper 0 to 5 cm of the soil, indicating retention of Cations in the upper soil horizon. The effect of wastewater irrigation on soil Exchangeable Cations was most evident for Na(+) (Exch-Na) near the city (
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soil salinity and Exchangeable Cations in a wastewater irrigated area india
Journal of Environmental Quality, 2009Co-Authors: Trent W. Biggs, Binbin JiangAbstract:: The salinity and cation composition of water and soil were documented in a large (98 km(2)) wastewater-irrigated area (WIA) downstream of Hyderabad, India. The wastewater, which flows in a river that passes through the city, had a high to very high salinity hazard (EC = 1.1-3.0 dS m(-1)) that increased with distance from the city. The EC of soil irrigated by wastewater sampled within 8 km of the city was 6.2 to 8.4 times the EC of soil irrigated by uncontaminated groundwater. Between 57 to 100% of soil samples in the upper 10 cm within 8 km of the city exceeded the salinity tolerance of rice (Oryza sativa L.). Soil salinity fell rapidly after 8 km downstream and changed most in the upper 0 to 5 cm of the soil, indicating retention of Cations in the upper soil horizon. The effect of wastewater irrigation on soil Exchangeable Cations was most evident for Na(+) (Exch-Na) near the city (<8 km downstream), where Exch-Na averaged 20 to 22 times the Exch-Na in soils irrigated by groundwater outside the WIA. Exchangeable Mg(+) and K(+) correlated with clay percentage, though both still had higher concentrations near the city controlling for clay content. Near the city, where salinity and Exch-Na concentrations were highest, farmers had replaced rice with para grass [Brachiaria mutica (Forsk.)], which has higher salinity tolerance and expanding demand as a fodder crop. Salinity may constrain rice production in wastewater-irrigated areas of India and elsewhere.
Trent W. Biggs - One of the best experts on this subject based on the ideXlab platform.
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Soil salinity and Exchangeable Cations in a wastewater irrigated area, India.
Journal of Environmental Quality, 2009Co-Authors: Trent W. Biggs, Binbin JiangAbstract:: The salinity and cation composition of water and soil were documented in a large (98 km(2)) wastewater-irrigated area (WIA) downstream of Hyderabad, India. The wastewater, which flows in a river that passes through the city, had a high to very high salinity hazard (EC = 1.1-3.0 dS m(-1)) that increased with distance from the city. The EC of soil irrigated by wastewater sampled within 8 km of the city was 6.2 to 8.4 times the EC of soil irrigated by uncontaminated groundwater. Between 57 to 100% of soil samples in the upper 10 cm within 8 km of the city exceeded the salinity tolerance of rice (Oryza sativa L.). Soil salinity fell rapidly after 8 km downstream and changed most in the upper 0 to 5 cm of the soil, indicating retention of Cations in the upper soil horizon. The effect of wastewater irrigation on soil Exchangeable Cations was most evident for Na(+) (Exch-Na) near the city (
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soil salinity and Exchangeable Cations in a wastewater irrigated area india
Journal of Environmental Quality, 2009Co-Authors: Trent W. Biggs, Binbin JiangAbstract:: The salinity and cation composition of water and soil were documented in a large (98 km(2)) wastewater-irrigated area (WIA) downstream of Hyderabad, India. The wastewater, which flows in a river that passes through the city, had a high to very high salinity hazard (EC = 1.1-3.0 dS m(-1)) that increased with distance from the city. The EC of soil irrigated by wastewater sampled within 8 km of the city was 6.2 to 8.4 times the EC of soil irrigated by uncontaminated groundwater. Between 57 to 100% of soil samples in the upper 10 cm within 8 km of the city exceeded the salinity tolerance of rice (Oryza sativa L.). Soil salinity fell rapidly after 8 km downstream and changed most in the upper 0 to 5 cm of the soil, indicating retention of Cations in the upper soil horizon. The effect of wastewater irrigation on soil Exchangeable Cations was most evident for Na(+) (Exch-Na) near the city (<8 km downstream), where Exch-Na averaged 20 to 22 times the Exch-Na in soils irrigated by groundwater outside the WIA. Exchangeable Mg(+) and K(+) correlated with clay percentage, though both still had higher concentrations near the city controlling for clay content. Near the city, where salinity and Exch-Na concentrations were highest, farmers had replaced rice with para grass [Brachiaria mutica (Forsk.)], which has higher salinity tolerance and expanding demand as a fodder crop. Salinity may constrain rice production in wastewater-irrigated areas of India and elsewhere.
Kadambot H M Siddique - One of the best experts on this subject based on the ideXlab platform.
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the effects of introducing flemingia macrophylla to rubber plantations on soil water content and Exchangeable Cations
Catena, 2019Co-Authors: Jian Wei Tang, Kadambot H M SiddiqueAbstract:Abstract Rubber-based (Hevea brasiliensis) agroforestry systems are the best way to resolve the environmental problems caused by rubber monoculture. Rubber–Flemingia macrophylla (nitrogen-fixing plants) systems have become popular in Xishuangbanna, Southwest China. Soil water content and Exchangeable Cations (Ca2+, Mg2+, K+, and Na+) are important for sustainably managing forest ecosystems. In this study, we investigated the responses of soil water content and Exchangeable Cations in rubber and rubber–Flemingia macrophylla systems. Soil water content increased in the 0–90 cm soil layer as the rubber plantations aged, and the mature rubber plantations had similar soil water storage to rainforests. The rubber plantations use soil water in the 30–90 cm soil layer to avoid drought stress during the long, dry season. The introduction of Flemingia macrophylla to the young rubber plantations significantly increased soil water depletion in the 30–90 cm soil layer. The introduction of Flemingia macrophylla to the mature rubber plantations had no significant effects on soil water in the 0–90 cm soil layer. The introduction of Flemingia macrophylla to the differently aged rubber plantations mitigated soil acidification by decreasing nitrogen inputs. The total Exchangeable Cations in the 0–90 cm soil layer sharply decreased as the rubber plantations aged due to the acceleration of soil acidification. When soil pH was below 5.5, 7.85 cmol kg−1 of soil Exchangeable Cations were released when the pH decreased by one unit. However, the introduction of Flemingia macrophylla to the differently aged rubber plantations effectively reduced the release of soil Exchangeable Cations by mitigating soil acidification. In conclusion, rubber–Flemingia macrophylla systems can mitigate soil acidification and reduce the release of soil Exchangeable Cations relative to rubber monoculture.
Jiong Li - One of the best experts on this subject based on the ideXlab platform.
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soil acidity and Exchangeable Cations in remnant natural and plantation forests in the urbanised pearl river delta china
Soil Research, 2012Co-Authors: Jianli Li, Lingling Zhang, Yuanwen Kuang, Jiong LiAbstract:Increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the Pearl River Delta (PRD), China. To investigate the status of soil acidity and Exchangeable Cations under these remnant forests and assess the possible impacts of reforestation on soil nutrients in the plantation forests, soils at 0–0.03, 0.03–0.13, and 0.13–0.23 m depths were sampled from 16 forest patches (eight natural and eight plantations), and soil pH in water, organic matter content, and Exchangeable cation (H, Al, Ca, Mg, K, and Na) contents were determined. Results showed that 90% of the soils were strongly acid (pH <4.5) and 70% of the soils had a base saturation <15%. About 50% of the soils had <0.5 mmol(+)/kg of Exchangeable Mg. Soil Exchangeable K and Mg contents were significantly lower under plantation forests than under native forests in all layers, whereas Exchangeable Ca and Na contents showed little difference between two types of forests. Moreover, contents of all Exchangeable Cations except Al showed a significant decrease with depth. These results suggest that remnant forests in the PRD generally experience a high risk of Al and acidity stresses and non-acidic cation deficiencies for plant growth. Reforestation may cause further decline in soil Exchangeable K and Mg contents, but is unlikely to affect soil Exchangeable Ca and Na contents.
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Soil acidity and Exchangeable Cations in remnant natural and plantation forests in the urbanised Pearl River Delta, China
Soil Research, 2012Co-Authors: Jianli Li, Lingling Zhang, Yuanwen Kuang, Jiong LiAbstract:Increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the Pearl River Delta (PRD), China. To investigate the status of soil acidity and Exchangeable Cations under these remnant forests and assess the possible impacts of reforestation on soil nutrients in the plantation forests, soils at 0–0.03, 0.03–0.13, and 0.13–0.23 m depths were sampled from 16 forest patches (eight natural and eight plantations), and soil pH in water, organic matter content, and Exchangeable cation (H, Al, Ca, Mg, K, and Na) contents were determined. Results showed that 90% of the soils were strongly acid (pH
F Arce - One of the best experts on this subject based on the ideXlab platform.
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adsorption of paraquat on soil organic matter effect of Exchangeable Cations and dissolved organic carbon
Journal of Hazardous Materials, 2012Co-Authors: D Gondar, R Lopez, J M Antelo, Sarah Fiol, F ArceAbstract:Abstract Herbicides that interact with soil organic matter do so with both the solid and the dissolved fractions, so that the distribution of herbicide between the soil solution and solid phases is determined by competitive effects. In the present study, adsorption experiments were carried out with the cationic herbicide paraquat and untreated and acid-washed samples of a peat soil, at different values of pH and ionic strength. Less herbicide was adsorbed onto the untreated peat than onto the acid-washed peat; the difference was due to the presence of Exchangeable Cations, as demonstrated in experiments carried out by adding Ca 2+ to suspensions of acid-washed peat. The results were interpreted by an electrostatic model and the fitting parameters indicated that the adsorption constants were the same for both samples of peat, although the number of binding sites available was different. Simultaneous resolution of the adsorption equilibrium of paraquat for the soil organic matter (SOM) and of the binding equilibrium between paraquat and dissolved organic matter (DOM) enabled the distribution of paraquat between the solid and solution phases to be determined. The increased solubility of the SOM with increasing pH led to a decrease in the fraction of paraquat retained on the peat surface above pH 5.5, which favors the mobility of the herbicide in the soil.
