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242篇 您的检索式:作者名="Sardar"
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1Soil enzymatic activities and microbial community structure with different application rates of Cd and Pb显示文摘This study focused on the changes of soil microbial diversity and potential inhibitory effects of heavy metals on soil enzymatic activities at different application rates of Cd andor Pb. The soil used for experiments was collected from Beijing and classified as endoaquepts. Pots containing 500 g of the soil with different Cd andor Pb application rates were incubated for a period of 0, 2, 9, 12 weeks in a glasshouse and the soil samples were analyzed for individual enzymes, including catalase, alkaline phosphatase and dehydrogenase, and the changes of microbial community structure. Results showed that heavy metals slightly inhibited the enzymatic activities in all the samples spiked with heavy metals. The extent of inhibition increased significantly with increasing level of heavy metals, and varied with the incubation periods. The soil bacterial community structure, as determined by polymerase chain reaction-denaturing gradient gel electrophoresis techniques, was different in the contaminated samples as compared to the control. The highest community change was observed in the samples amended with high level of Cd. Positive correlations were observed among the three enzymatic activities, but negative correlations were found between the amounts of the heavy metals and the enzymatic activities.KHAN Sardar CAO Qing HESHAM Abd El-Latif XIA Yue HE Ji-zheng 2007Journal of Environmental Sciences2007,19,7:28
2中小型规模智慧农业物联网终端节点设计显示文摘为了能够向中小规模农业生产经营者提供深度定制的农业物联网技术,该研究研发了一种可用于农业设备信息化的智慧农业物联网终端节点。通过该终端节点将农业设备柔性接入物联网体系,并依托管理服务层App实现应用层App功能开发。系统硬件利用可编程片上系统的IP核重用技术实现对各种农业设备的接入,实现各农业场景中根据设备具体情况进行定制化应用。系统传输层采用LoRa广域网与蓝牙技术,支撑集中式与分布式农业管理服务体系。管理服务层App对底层节点设备操作与Android功能操作进行封装,实现应用层与底层功能结构的解耦,避免了应用层App开发时结构复杂、对底层功能结构变化适应性差、开发周期长等问题。实践应用结果表明,该农业物联网终端节点可有效实现对农业设备的接入,具有1500VDC的电磁隔离能力;节点的LoRa无线数据通道在无严重降雨的天气中数据包传输成功率接近100%,蓝牙可支持周围3m范围内的移动设备现场接入;管理服务层App可有效支撑应用层功能快速开发;在直连上位机模式下,应用层App到节点设备间的功能延时分别小于400与1700 ms,系统运行稳定,功能支撑可靠。该方法可为国内中小规模农业经营者的物联网信息化建设提供支持与参考。万雪芬 郑涛 崔剑 蒋学芹 Sardar Muhammad Sohail 杨义 2020农业工程学报2020,36,13:21
3地下LoRa无线传感器网络的传输测试系统研究显示文摘【目的】以智能手机为核心,研制成本低、使用简单的面向LoRa地下无线数据传输的测试系统。【方法】该测试系统由安装了测试用的App智能手机和与之匹配的地下测试节点组成。利用该系统进行场景测试,测定影响土壤中LoRa无线数据传输效果的因素并讨论对应的数据传输方法。【结果】测试结果表明,该系统运行可靠、使用方便灵活,LoRa低功耗广域网技术亦可以较为可靠地满足土壤介质中的无线传感器网络数据传输需求。【结论】本系统可为未来地下LoRa无线传感器网络的工程应用提供相应的测试手段。万雪芬 崔剑 杨义 蒋学芹 Sardar Muhammad SOHAIL 2018华南农业大学学报2018,39,3:19
4Accumulation of Pb,Cu,and Zn in native plants growing on contaminated sites and their potential accumulation capacity in Heqing,Yunnan显示文摘Phytoremediation is one of the cost-effective and environmental friendly technologies used to remove contaminants from contaminated soils,which has been intensively studied during the last decade.Presently,few economical and effective remediation methods are available for the remediation of Pb contaminated sites.This study was conducted to assess the potential of 19 plants growing on contaminated sites in Pb mine area.Plants and associated soil samples were collected and analyzed for total metal concentrations. While total soil Pb,Cu and Zn concentrations varied from 1,239 to 4,311,36 to 1,020 and 240 to 2,380 mg/kg,those in the plant shoots ranged from 6.3 to 2,029,20 to 570,and 36 to 690 mg/kg,respectively.Among the plants,we found that one cultivated crop(Ricinus communis L.)and two native species(Tephrosia candida and Debregeasia orientalis)have a great potential for phytoremediation of Pb contaminated soils,the Pb hyperaccumulation capacity of the 3 plants was found as the order:R.communis>D.orientalis>T. candida in the investigated area.Sardar Khan 2008Journal of Environmental Sciences2008,20,12:14
5Health risks associated with heavy metals in the drinking water of Swat,northern Pakistan显示文摘The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources(surface and groundwater) collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake(CDI) and health risk index(HRI) were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr > Mn >Ni > Zn > Cd > Cu > Pb and Cd > Ni > Mn > Cr > Cu > Pb > Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.Kifayatullah Khan Yonglong Lu Hizbullah Khan Shahida Zakir Ihsanullah Sardar Khan Akbar Ali Khan Luo Wei Tieyu Wang 2013Journal of Environmental Sciences2013,25,10:12
6基于智能手机的LoRa无线传输效能测试研究显示文摘基于LoRa的低功耗广域网技术有望成为未来物联网的主干支撑技术之一。为了给工作在不同应用环境中的LoRa无线传感器网络节点间的传输提供简单有效、易于使用、成本低廉的测试手段,提出一种基于智能手机的LoRa无线传输效能测试系统。该系统由智能手机及与之配套的低成本测试节点组成。对组成系统的智能手机端App及测试节点设计进行讨论,系统完成后利用其在智能楼宇与智慧农业的应用场景下进行测试。测试结果表明,LoRa无线传输在不同的应用环境中会受到外界因素的干扰,通过本系统可方便、有效、快捷地获得分散在较长时间周期内的数据,为基于LoRa的无线传感器网络在设计、安装与维护中提供以数据传输效果为表征的参考测试数据。万雪芬 崔剑 杨义 蒋学芹 SARDAR Muhammad Sohail 2018现代电子技术2018,41,21:10
7限制性片段长度多态性分析(ARDRA)方法对重金属污染土壤中细菌群落多样性的研究显示文摘限制性片段长度多态性分析(ARDRA)是用限制性内切酶消化扩增后的细菌16SrDNA,通过凝胶电泳分析微生物种群多样性的分子标记技术,该技术在微生物生态学领域有着广泛的应用.实验采用2种途径评价了这种方法应用于研究土壤中细菌种群多样性的可行性.通过对未污染土壤细菌16SrDNA的克隆,获得了经内切酶HaeⅢ消化的不同16SrDNA的ARDRA类型,并对测序的19个克隆子建立了系统发育树.此外,还对不同Cd和Pb污染水平的土壤微生物进行了群落水平上的ARDRA分析.结果表明,5mg·kg-1Cd和500mg·kg-1Pb污染对微生物群落组成有一定影响,但此范围内的重金属含量对微生物群落多样性没有相关性影响.夏月 Sardar Khan 贺纪正 朱永官 2007环境科学学报2007,27,6:9
8用于煤矿设备信息化升级的无线数据传输节点显示文摘针对现有煤矿无线数据传输技术存在多径效应显著、传输距离短、耐噪特性较差和灵敏度较低等不足,以及煤炭行业大规模设备信息互联互通的需求,设计了用于煤矿设备信息化升级的无线数据传输节点。该节点通过LoRa-CSS技术建立设备间的可靠无线数据通道,利用基于IP核结构的可编程片上系统PSoC灵活适配各种煤矿设备的数据接口,并采用统一规格化数据格式进行指令和数据信息交互。电磁隔离特性测试结果表明,该节点具有较强的隔离特性,不受冲击电压影响,可以有效地将短时高强度浪涌信号降到设备容限值以下。实际应用结果表明,各无线数据传输节点与上位机和煤矿设备之间的数据通信效果较为理想,可以有效地构建由中心站到设备的稳定数据传输通道。万雪芬 崔剑 杨义 SARDAR Muhammad Sohail 2019工矿自动化2019,45,6:8
9Takotsubo cardiomyopathy:Pathophysiology and role of cardiac biomarkers in differential diagnosis显示文摘Takotsubo cardiomyopathy(TC) is characterized by reversible ventricular dysfunction, not limited to the distribution of an epicardial coronary artery. A disease primarily afflicting post-menopausal women, it is frequently mistaken for acute anterior wall myocardial infarction. Alternatively called Stress Cardiomyopathy, physical or emotional triggers are identified in only three fourths of TC patients. Long considered a benign condition, recent findings suggest poor short term prognosis similar to acute coronary syndrome(ACS). Despite the widely recognized pathophysiological role of catecholamine excess, its diagnostic role is uncertain. TC is suspected based on typical wall motion abnormalities in ventriculogram or echocardiogram. Several additional electrocardiographic, laboratory and imaging parameters have been studied with the goal of clinical diagnosis of TC. While several clinical clues differentiate it from ACS, a clinical diagnosis is often elusive leading to avoidable cardiac catheterizations. Natriuretic peptides(NPs), a family of peptide hormones released primarily in response to myocardial stretch, play a significant role in pathophysiology, diagnosis as well as treatment of congestive heart failure. TC with its prominent ventricular dysfunction is associated with a significant elevation of NPs. NPs are elevated in ACS as well but the degree of elevation is typically lesser than in TC. Markers of myocardial injury such as troponin are usually elevated to a higher degree in ACS than in TC. This differential elevation of NPs and markers of myocardial injury may play a role in early clinical recognition of TC.Prabhakaran Gopalakrishnan Ramsha Zaidi Muhammad Rizwan Sardar 2017World Journal of Cardiology2017,9,9:7
10Transfer of Heavy Metals from Soils to Vegetables and Associated Human Health Risks at Selected Sites in Pakistan显示文摘Contamination of the food chain with heavy metals is considered as one of the major environmental pathways of human exposure to metals leading to potential health risks. This study aimed to investigate the concentrations of heavy metals such as copper(Cu),zinc(Zn), chromium(Cr), nickel(Ni), and manganese(Mn) in agricultural soils and food crops(fruit, leaf, and root vegetables), and their associated health risks to the local population in selected southern districts of Khyber Pakhtunkhwa Province, Pakistan. The concentrations of the selected metals in soil varied over a wide range, in the following decreasing order: Mn > Zn > Cr > Ni > Cu.The bioaccumulation of metals in vegetables was within the permissible risk limits, except for Cr which showed higher contamination in all the tested food crops. The trend of metal transfer factors for different vegetables was in the order of Cu > Ni > Cr > Mn >Zn, while the calculated daily intake of metals(DIM) in adults and children through consumption of food crops was in the decreasing order of Mn > Zn > Ni > Cr > Cu. The health risk index(HRI) values for the heavy metals for both adults and children were less than 1. Therefore, no significant health risk is anticipated for the local consumers through ingestion of these food crops.Zahir Ur REHMAN Sardar KHAN Mohammad Tahir SHAH Mark L.BRUSSEAU Said Akbar KHAN Jon MAINHAGU 2018Pedosphere2018,28,4:7
11基于LoRa与可编程片上系统的纺织设备无线数传节点显示文摘为满足纺织企业设备信息化、智能化升级中对无线数据传输的需求,基于LoRa技术,并结合可编程片上系统,设计一种可用于纺织设备的无线数传节点。该节点具有功能伸缩性强、传输效果好、使用方便、网络拓扑简洁、面向设备开发维护便捷、电磁隔离效果好、成本低廉等优点。测试结果表明,该无线数传节点可以有效地作为纺织企业中设备无线信息交互的手段。万雪芬 杨义 崔剑 Sardar Muhammad Sohail 兰芸 2019现代电子技术2019,42,7:7
12Feeding of processed vegetable wastes to bulls and its potential environmental benefit显示文摘The study was conducted with the objectives to quantify year round availability of different vegetables waste(VW) in a wholesale market and to determine the inclusion level of a processed VW(VWP) in the diets of bulls. The daily VW biomass availability at Kawran bazaar, Dhaka, Bangladesh was quantified by weighing the vegetable supply and their wastes by visiting 2 days in a week. Concurrently, VW of cucumber, bitter gourd, spotted gourd, brinjal, pumpkin, potato, tomato, ladies finger, and snake gourd representing 0.21, 0.18, 0.17, 0.16, 0.09, 0.07, 0.06, 0.03, and 0.02 as fresh fractions, respectively were blended, dried and stored while adding rice polish and common salt at 200 and 20 g/kg DM, respectively;it was tested in bulls as an ingredient of concentrate mixture. Four dietary groups, each of 6 bulls, with initial average live weight(LW) of 85.47 ± 17 kg, were fed fresh German grass(Echinochloa polystachya)ad libitum supplemented with 4 different concentrates containing 0, 10%, 20% and 30% VWP at the rate of1% of LW for 89 days. The availability of VW biomass of the market was 42.51 t/d and recycling of them as feed, instead of using landfills, might reduce annual methane emission by 0.43 Gg. The inclusion of VWP in the diet up to 9.7% of DM, or 0.30% of LW of bulls showed no significant effect on the DM intake,digestibility, growth performance and health status of bulls. The dietary DM intake represented 3.10%,3.09%, 3.20% and 3.14% of LW resulting in daily gain of 302, 300, 312 and 344 g, respectively. The digestibility of DM of diets was 56.9%, 62.8%, 62.8% and 63.4%, respectively. It was concluded that VWP may be included at a level of 9.7% of the diet(DM basis) or 0.30% of LW of bulls.Nani G.Das Khan S.Huque Sardar M.Amanullah Harinder P.S.Makkar 2019Animal Nutrition2019,,1:6
13温和提取法评估老化前后土壤中菲的生物有效性显示文摘采用温和溶剂提取方法对不同老化时间土壤中的菲进行提取,研究了正丁醇、二氯甲烷、2-羟丙基-β-环糊精(2-Hydroxypropyl-beta cyclodextrin,HPCD)提取量与生物吸收之间的相关性。结果表明,温和有机溶剂(二氯甲烷、正丁醇)提取与温和HPCD提取法对菲的提取量与蚯蚓蓄积量有很好的相关性(p<0.05)。与其他温和试剂提取相比,温和正丁醇提取可以更好地预测菲在土壤中的生物有效性。张聪恺 Muhammad Imran Khan Sardar Alam Cheema 沈超峰 唐先进 申开丽 陈蕾 陈新才 施积炎 陈英旭 2011土壤学报2011,48,1:5
14Magnetic and optical properties of NaGdF4:Nd^3+, Yb^3+, Tm^3+ nanocrystals with upconversion/downconversion luminescence from visible to the near-infrared second window显示文摘我们设计了并且综合 NaGdF <潜水艇class=“ a-plus-plus ”> 4 :Nd3+, Yb <啜class=“ a-plus-plus ”>3+, Tm <啜class=“ a-plus-plus ”>3+有联合双模式的 downconversion ( DC )和 upconversion ( UC )的磁性的 nanophosphors 在 800 nm 刺激之上的光致发光。六角形阶段的 NaGdF < 潜水艇 class= “ a-plus-plus ” > 4 :Nd3+, Yb < 啜 class= “ a-plus-plus ” >3+, Tm < 啜 class= “ a-plus-plus ” > 有一般水准的 3+ nanocrystals (NC ) 21 nm 的尺寸用一条 solvothermal 途径被综合。 Nd <啜class=“ a-plus-plus ”>3+, Yb <啜class=“ a-plus-plus ”>3+, Tm <啜class=“ a-plus-plus ”>3+做三元组的 NaGdF <潜水艇class=“ a-plus-plus ”> 4 NC 展出盖住的大量光致发光山峰一近红外线第一/第二扇窗户( 860900 , 1,000 ,和 1,060 nm ),并且可见排放包括蓝色( 475 nm ),绿色( 520 和 542 nm )和在在 800 nm 的刺激以后的黄( 587 nm )。在 Gd 上包含精力的循环的机制 < 啜 class= “ a-plus-plus ” > 是的 3+ sublattices 桥离子并且由起始的使活跃之物离子的最后的套住(Nd < 啜 class= “ a-plus-plus ” >3+) 被建议了。穿入深度研究显示 NIR 排放容易甚至在 10 公里的大织物厚度被检测。这些顺磁的 nanophosphors 在 20 kOe 和 1.2537 公里的纵的 relaxivity 价值表明 1.88 emu/g 的大磁化价值 < 啜 class= “ a-plus-plus ” > 1 ??(Xianwen Zhang Zhi Zhao Xin Zhang David B. Cordes Brandon Weeks Bensheng Qiu Kailasnath Madanan Dhiraj Sardar Jharna Chaudhuri 2015Nano Research2015,8,2:5
15Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae)显示文摘Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and cancer.Methods: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, respectively.Results: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBSB had a significant(P < 0.05) radical scavenging activity than standards. In lipid peroxidation inhibition assay, the inhibitory activity of the extracts and the standard was in the following order: DBSB > DBRB > CA > DBL.Also, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer properties.Conclusions: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity.Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.Muhammad Ali Khan Mahbubur Rahman Nazmul Sardar Saiful Islam Arman Badrul Islam Jahangir Alam Khandakar Mamunur Rashid Golam Sadik AHM Khurshid Alam 2016Asian Pacific Journal of Tropical Biomedicine2016,6,5:3
16面向农业观光服务的无线传感网节点布局优化显示文摘【目的】探讨面向农业观光园区分布式服务的无线传感器网络节点布局优化方案,为提高农业观光园区服务质量及提升游客游园体验提供依据。【方法】利用社会力模型结合观光园区规划信息,采用Anylogic行人仿真平台获取游客在园中的空间分布数据,用传统K-means算法和改进K-means算法分别对游客空间分布数据进行聚类分析,并根据节点优化布局评价指标,计算节点最优位置。【结果】采用传统K-means算法和改进K-means算法对选取的12组游客空间分布数据进行单日游客聚类分析得到两组节点位置;改进K-means算法聚类得到的节点最终位置对节点被接入次数的均衡效果均优于传统K-means算法,其节点被接入次数均方差的均值降低约41.8%。因此,改进K-means算法更适合运用于观光园区节点的布局优化,得到的节点最终位置即为该观光园区节点最优位置。【建议】在面向农业观光服务的混合型无线传感器网络建设中,应基于社会力模型预估游客空间分布,实现观光服务优化;通过合理部署节点位置,延长融合智能设备的混合型无线传感器网络生存时间;更好地打造面向游客服务、整合移动智能设备的农业物联网系统。杨义 张静文 万雪芬 郑涛 崔剑 Sardar Muhammad Sohail 2018南方农业学报2018,49,8:3
17Accumulation of polycyclic aromatic hydrocarbons and heavy metals in lettuce grown in the soils contaminated with long-term wastewater irrigation显示文摘Sardar Khan Lin Aijun Shuzhen Zhang Qinhong Hu Yong-Guan Zhu 2007Journal of Hazardous Materials2007,,2:2
18Potentially harmful metals,and health risk evaluation in groundwater of Mardan,Pakistan:Application of geostatistical approach and geographic information system显示文摘This study investigates the values of pH,total dissolved solids(TDS),elevation,oxidative reduction potential(ORP),temperature,and depth,while the concentrations of Br,and potentially harmful metals(PHMs)such as Cr,Ni,Cd,Mn,Cu,Pb,Co,Zn,and Fe in the groundwater samples.Moreover,geographic information system(GIS),XLSTAT,and IBM SPSS Statistics 20 software were used for spatial distribution modeling,principal component analysis(PCA),cluster analysis(CA),and Quantile-Quantile(Q-Q)plotting to determine groundwater pollution sources,similarity index,and normal distribution reference line for the selected parameters.The mean values of pH,TDS,elevation,ORP,temperature,depth,and Br were 7.2,322 mg/L,364 m,188 mV,29.6℃,70 m,0.20 mg/L,and PHMs like Cr,Ni,Cd,Mn,Cu,Pb,Co,Zn,and Fe were 0.38,0.26,0.08,0.27,0.36,0.22,0.04,0.43 and 0.86 mg/L,respectively.PHMs including Cr(89%),Cd(43%),Mn(23%),Pb(79%),Co(20%),and Fe(91%)exceeded the guideline values set by the world health organization(WHO).The significant R^(2)values of PCA for selected parameters were also determined(0.62,0.67,0.78,0.73,0.60,0.87,-0.50,0.69,0.70,0.74,-0.50,0.70,0.67,0.79,0.59,and-0.55,respectively).PCA revealed three geochemical processes such as geogenic,anthropogenic,and reducing conditions.The mineral phases of Cd(OH)_(2),Fe(OH)_(3),FeOOH,Mn_(3)O_(4),Fe_(2)O_(3),MnOOH,Pb(OH)_(2),Mn(OH)_(2),MnO_(2),and Zn(OH)_(2)(-3.7,3.75,9.7,-5.8,8.9,-3.6,2.2,-4.6,-7.7,-0.9,and 0.003,respectively)showed super-saturation and under-saturation conditions.Health risk assessment(HRA)values for PHMs were also calculated and the values of hazard quotient(HQ),and hazard indices(HI)for the entire study area were increased in the following order:Cd>Ni>Cu>Pb>Mn>Zn>Cr.Relatively higher HQ and HI values of Ni,Cd,Pb,and Cu were greater than one showing unsuitability of groundwater for domestic,agriculture,and drinking purposes.The long-term ingestion of groundwater could also cause severe health concerns such as kidney,brain dysfunction,liver,stomach problems,and even cancer.Abdur Rashid Muhammad Ayub Asif Javed Sardar Khan Xubo Gao Chengcheng Li Zahid Ullah Tariq Sardar Juma Muhammad Shahla Nazneen 2021Geoscience Frontiers2021,12,3:2
19Metabolism of chlorpyrifos in relation to its effect on the availability of some plant nutrients in soil显示文摘Devashis Sardar Ramen K. Kole 2005Chemosphere2005,,9:2
20Effects of the nitrification inhibitor nitrapyrin and the plant growth regulator gibberellic acid on yield-scale nitrous oxide emission in maize fields under hot climatic conditions显示文摘Nitrification inhibitors are widely used in agriculture to mitigate nitrous oxide(N_(2)O)emission and increase crop yield.However,no concrete information on their mitigation of N_(2)O emission is available under soil and environmental conditions as in Pakistan.A field experiment was established using a silt clay loam soil from Peshawar,Pakistan,to study the effect of urea applied in combination with a nitrification inhibitor,nitrapyrin(2-chloro-6-tri-chloromethyl pyridine),and/or a plant growth regulator,gibberellic acid(GA_3),on N_(2)O emission and the nitrogen(N)uptake efficiency of maize.The experimental design was a randomized complete block with five treatments in four replicates:control with no N(CK),urea(200 kg N ha^(-1))alone,urea in combination with nitrapyrin(700 g ha^(-1)),urea in combination with GA_3(60 g ha^(-1)),and urea in combination with nitrapyrin and GA_3.The N_(2)O emission,yield,N response efficiency,and total N uptake were measured during the experimental period.The treatment with urea and nitrapyrin reduced total N_(2)O emission by 39%–43%and decreased yield-scaled N_(2)O emission by 47%–52%,relative to the treatment with urea alone.The maize plant biomass,grain yield,and total N uptake increased significantly by 23%,17%,and 15%,respectively,in the treatment with urea and nitrapyrin,relative to the treatment with urea alone,which was possibly due to N saving,lower N loss,and increased N uptake in the form of ammonium;they were further enhanced in the treatment with urea,nitrapyrin,and GA_3 by 27%,36%,and 25%,respectively,probably because of the stimulating effect of GA_3 on plant growth and development and the reduction in biotic and abiotic stresses.These results suggest that applying urea in combination with nitrapyrin and GA_3 has the potential to mitigate N_(2)O emission,improve N response efficiency,and increase maize yield.Khadim DAWAR Kamil SARDAR Mohammad ZAMAN Christoph MÜLLER Alberto SANZ-COBENA Aamir KHAN Azam BORZOUEI Ana Gabriela PÉREZ-CASTILLO 2021Pedosphere2021,31,2:2
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