The contamination of soils with heavy metals(HMs)and their accumulation in local plants has become an increasing issue because of industrial activities.This study investigated the extent of HMs contamination in soils ...The contamination of soils with heavy metals(HMs)and their accumulation in local plants has become an increasing issue because of industrial activities.This study investigated the extent of HMs contamination in soils and Purslane(Portulaca oleracea)in the Bassa Industrial Zone,Douala-Cameroon,focusing on the implications for environmental health and ecosystem sustainability.We collected 17 surface soil samples and 4 composite purslane leaf samples from different sampling locations in the industrial site.The HMs(Cd,Pb,As,Cr,Cu and Ni)were analyzed with an Inductively Coupled Plasma-Optical Emission Spectroscopy(ICP-OES).The results revealed that,the HM concentrations(except for Cd and Ni)in most locations exceeded the Soil Quality Guidelines for industrial land use.The Pollution Load Index confirmed the presence of heavy metal pollution in all the sample locations.Potential Ecological Risk In dex highlighted varying levels of risk across locations,presenting moderate,high,and significantly high ecological risk.The primary contributors to eco-logical risk were Pb,Cd,and Cu.Furthermore,the geo-accumulation index revealed heavily to extremely high contamination in several locations.Princi pal Component Analysis suggested that Cd,As,Cr,Cu,and Ni likely originated from common sources,while Pb had a distinct source,all due to anthropogenic activities.Additionally,Cr concentrations in purslane leaves exceeded the nor-mal range,with one location recording a value(5.41 mg kg^(-1))which was within the maximum toxicity threshold for plants.These findings underline the need for remedial measures to mitigate the adverse effects of heavy metal contami nation in the Bassa Industrial Zone.展开更多
Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and vola...Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and volatilization losses. The practice also results in greater crop lodging, lower water use efficiency, and crusting of the soil surface. In contrast, bed planting of wheat not only saves water but improves fertilizer use efficiency and grain yield. Three years of pooled data from the present study showed that wheat planting on beds and nitrogen application at 120 kg ha-1produced 15.06% higher grain yield than flat planting at the same nitrogen rate. Similarly, 25.04%, 15.02%, 14.59%, and 29.83% higher nitrogen uptake, nitrogen use, and agronomic and recovery efficiencies, respectively, were recorded for bed compared to flat planting. Wheat planting on beds with a nitrogen application of80 kg ha-1gave a yield similar to that of flat planting with 120 kg ha-1nitrogen. However,the economic return was 29% higher in bed planting as compared to flat planting, when nitrogen was applied at 120 kg ha-1.展开更多
文摘The contamination of soils with heavy metals(HMs)and their accumulation in local plants has become an increasing issue because of industrial activities.This study investigated the extent of HMs contamination in soils and Purslane(Portulaca oleracea)in the Bassa Industrial Zone,Douala-Cameroon,focusing on the implications for environmental health and ecosystem sustainability.We collected 17 surface soil samples and 4 composite purslane leaf samples from different sampling locations in the industrial site.The HMs(Cd,Pb,As,Cr,Cu and Ni)were analyzed with an Inductively Coupled Plasma-Optical Emission Spectroscopy(ICP-OES).The results revealed that,the HM concentrations(except for Cd and Ni)in most locations exceeded the Soil Quality Guidelines for industrial land use.The Pollution Load Index confirmed the presence of heavy metal pollution in all the sample locations.Potential Ecological Risk In dex highlighted varying levels of risk across locations,presenting moderate,high,and significantly high ecological risk.The primary contributors to eco-logical risk were Pb,Cd,and Cu.Furthermore,the geo-accumulation index revealed heavily to extremely high contamination in several locations.Princi pal Component Analysis suggested that Cd,As,Cr,Cu,and Ni likely originated from common sources,while Pb had a distinct source,all due to anthropogenic activities.Additionally,Cr concentrations in purslane leaves exceeded the nor-mal range,with one location recording a value(5.41 mg kg^(-1))which was within the maximum toxicity threshold for plants.These findings underline the need for remedial measures to mitigate the adverse effects of heavy metal contami nation in the Bassa Industrial Zone.
基金国家科技支撑计划资助项目(2013BAD11B03)国家重点基础研究发展计划项目(973计划)(2012CB955904)+1 种基金The University of Melbourne Early Career Research Grant Scheme 2014中央级公益性科研院所基本科研业务费专项资助项目
文摘Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and volatilization losses. The practice also results in greater crop lodging, lower water use efficiency, and crusting of the soil surface. In contrast, bed planting of wheat not only saves water but improves fertilizer use efficiency and grain yield. Three years of pooled data from the present study showed that wheat planting on beds and nitrogen application at 120 kg ha-1produced 15.06% higher grain yield than flat planting at the same nitrogen rate. Similarly, 25.04%, 15.02%, 14.59%, and 29.83% higher nitrogen uptake, nitrogen use, and agronomic and recovery efficiencies, respectively, were recorded for bed compared to flat planting. Wheat planting on beds with a nitrogen application of80 kg ha-1gave a yield similar to that of flat planting with 120 kg ha-1nitrogen. However,the economic return was 29% higher in bed planting as compared to flat planting, when nitrogen was applied at 120 kg ha-1.
