Multimedia model of atrazine in plant-soil-groundwater system with a fugacity approach

ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｎｔａｍｉｎａｔｉｏｎｏｆｅｄｉｂｌｅｖｅｇｅｔａｔｉｏｎｂｙｐｅｒｓｉｓｔｅｎｔ,ｕｂｉｑｕｉｔｏｕｓｃｈｅｍｉｃａｌｓｓｕｃｈａｓＰＣＢｓ,ｄｉｏｘｉｎｓ,ｐｅｓｔｉｃｉｄｅｓ,ａｎｄｈｅｒｂｉｃｉｄｅｓｐｒｏｖｉｄｅｓａｍａｊｏｒｅｘｐｏｓｕｒｅｒｏｕｔｅｔｏｈｕｍａｎｓ ,ｄｏｍｅｓｔｉｃａｎｉｍａｌｓａｎｄｗｉｌｄｌｉｆｅ .Ｕｐｔａｋｅｏｆｔｈｅｓｅｏｒｇａｎｉｃｃｈｅｍｉｃａｌｓｂｙｐｌａｎｔ,ａｎｄｓｕｂｓｅｑｕｅｎｔｄｉｓｔｒｉｂｕｔｉｏｎｉｎｔｈｅｐｌａｎ…     

Simulation study on vertical transport of atrazine in soil column

ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｒａｚｉｎｅ (2 ｃｈｌｏｒｏ 4 ｅｔｈｙｌａｍｉｎｏ 6 ｉｓｏｐｒｏｐｙｌａｍｉｎｏ ｓ ｔｒｉａｚｉｎｅ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｗｉｄｅｌｙｕｓｅｄｈｅｒｂｉｃｉｄｅａｎｄｍａｉｎｌｙｕｓｅｄｆｏｒｃｏｎｔｒｏｌｏｆｃｅｒｔａｉｎａｎｎｕａｌｂｒｏａｄｌｅａｆａｎｄｇｒａｓｓｗｅｅｄｓａｎｄｐｒｉｍａｒｉｌｙｈａｓｂｅｅｎｃｏｍｍｏｎｌｙｕｓｅｄｉｎｃｏｒｎｏｒｉｎｃｏｒｎ ｗｈｅａｔｄｏｕｂｌｅｃｒｏｐｐｉｎｇｓｙｓｔｅｍｉｎＮｏｒｔｈｅａｓｔａｎｄＮｏｒｔｈｏ…     

作物植株残体还田土壤对除草剂的截留作用

加入成熟作物植株残体还田的土壤（简称秸秆还田土壤）与自然土壤的土柱淋洗对比实验，研究了玉米秸秆还田土壤对除草剂乙草胺和阿特拉津的截留作用以及水稻秸秆还田土壤对丁草胺的截留作用。结果表明，作物秸秆还田土壤对所研究的三种除草剂有明显的截留作用，在土桩的最上部10cm内，秸秆还田土壤对乙草胺、丁草胺和阿特拉津的截留量分别是自然土壤对其截留量的1.33、1.77和1.88倍。     

Simulation study on vertical transport of atrazine in soil column

A simulation experiment on vertical transport of herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in soil column was conducted using lysimeter system. The atrazine concentrations in leaching water and soil samples in column at 8 layers with 10 cm thick of each layer were detected by high-performance liquid chromatography. The results show total atrazine amount in leaching water increases nonlinearly with the leaching time and the herbicide application rate, and the atrazine concentrations in column soil decrease with the vertical depth after water leaching. The distribution of atrazine mass in the system after 154 days were that among the applied atrazine, 0.3 ％ is out through leaching water, 1％ is methanol extractable residues in soil, 46 ％ is methanol nonextractable residues in soil, and 52 ％ is other loss (including volatilization and degradation). The study indicates movement of atrazine in agriculture soil may not only have relation to the properties of herbicide, but also to the herbicide application history.     

莠去津对野生植物群落下土壤微生物功能多样性的影响

为探明亚致死剂量农药对土壤微生物多样性影响,基于大田控制试验,采用Biolog-ECO微平板技术分析喷施亚致死剂量的莠去津对野生植物群落下土壤微生物群落功能多样性的影响.结果表明:① 莠去津的喷施浓度对土壤微生物群落利用全部碳源的能力无显著影响（P>0.05）,但与喷施处理后第30天相比,处理后第60天的土壤微生物群落利用全部碳源的能力有所降低,其中处理Ⅰ〔喷施浓度（以质量浓度计）为1 200 g/hm2〕、处理Ⅲ（喷施浓度为300 g/hm2）显著下降（P < 0.05）,而CK（对照组）、处理Ⅱ（喷施浓度为600 g/hm2）降低程度不显著（P>0.05）,并且其各处理间土壤微生物群落对全部碳源的利用能力大小为CK >处理Ⅲ >处理Ⅱ >处理Ⅰ.② 喷施处理后第30天土壤微生物群落对碳水化合物类碳源的利用能力最强,对羧酸类碳源的利用能力相对较弱;喷施处理后第60天土壤微生物群落对碳水化合物类碳源的利用能力降幅最大,处理Ⅰ、处理Ⅱ、处理Ⅲ分别下降了0.63、0.78、0.85、0.76.③ 喷施除草剂后第30天处理Ⅱ的Shannon-Wiener指数和Simpson指数显著低于其他处理（P < 0.05）,而第60天各处理间多样性指数无显著差异;与喷施处理后第30天相比,第60天各处理多样性指数都有所下降,但没有显著差异（P>0.05）.④ 对土壤微生物群落碳源利用能力进行主成分分析结果显示,提取的与土壤微生物碳源利用相关的主成分累积贡献率为86.6%,主成分1能够区分喷施处理后两个时期的土壤微生物群落特征.⑤ 冗余分析（RDA）表明,pH是土壤微生物利用碳源能力差异的重要影响因素之一.研究显示,除草剂莠去津的施用可在一定程度上降低野生植物群落下土壤微生物群落功能多样性.      

含除草剂非织造布的示范推广试验研究

含除草通的非织布用取农用薄膜的作物地面覆盖材料，经１年来的示范推广试验表明，其防草效果达到９０％以上，与农用黑膜接近，优于农用白膜，其对作物株高，叶片生长无影响，在农田管理得当（生长期保证灌水）条件下，有一定增产效果；对试验作物草莓，茄子，番茄，辣椒的可食部分的除草通残留量测定，未检出，农用薄膜在土壤中残留的模拟试验表明，作物根系能穿过非织造布生长，涂用的除草通在土壤中了最终浓度是非织造布上的喷涂     

除草剂对水稻土微生物的影响

以阿特拉津、丁草胺和甲磺隆 3种除草剂为例 ,采用熏蒸提取法和BIOLOG碳素利用法研究了土壤中除草剂污染与水稻土微生物之间的关系及其环境意义 .结果表明以 10mg·kg-1含量施入水稻土的甲磺隆在施用初期导致微生物生物量下降 ,随培养时间的推移 ,生物量有所恢复 ;相同浓度的阿特拉津和丁草胺对水稻土微生物生物量影响不明显 .BIOLOG数据显示 ,3种除草剂施用初期 (第 2d)微生物碳源利用多样性变化不明显 ,随着培养时间的增加微生物碳源利用多样性发生变化 ,变化趋势因除草剂类型不同而异 :甲磺隆除草剂污染水稻土微生物碳源利用多样性先有明显降低 ,培养后期呈上升趋势 ;阿特拉津和丁草胺除草剂污染水稻土微生物碳源利用多样性基本不受影响 .     

地下水除草剂阿特拉津污染微生物治理的实验研究

采用了从农药厂阿特拉津生产车间排污口污泥中分离出的菌种AT菌,进行了农药阿特拉津的静态降解实验及其污染地下水的微生物治理模拟实验研究结果表明,AT菌在pH值为5.0～10.0时对农药污染质阿特拉津均具有降解能力,且适宜的pH值范围为6.5～8.0;在实验条件(t=10℃,pH=7.5)与野外含水层的条件基本一致情况下,难于生物降解的污染质阿特拉津的一次投菌降解率达到31.08%;同时环境因素也随着AT菌作用的变化而变化,其中,DO、pH随AT菌作用加强而其值减小.另外,设计了细菌的投放方式以模拟野外条件下的菌种投加条件.并且AT菌的作用会造成被治理含水层的渗透性能降低,实验后含水层的渗透系数下降60.54%.清水冲洗10d的渗透性恢复率为48.96%,说明清水渗透恢复的方法效果明显.     

河套灌区土壤水和地下水动态变化及水平衡研究

为探究田间土壤水及地下水在不同作物种植区、不同灌期等情况下的动态变化规律与水平衡特征,以春小麦、玉米、向日葵为典型作物,在河套灌区选取4块2亩的试验田,于2009年4-11月采集田间土壤及地下水样品进行研究.结果表明,不同作物地块间土壤含水率的变化差别主要集中在5-9月的作物生长期.夏灌灌水量不足,土壤含水率呈下降趋势,田间土壤水分变化属于“蒸腾蒸发消耗型”;秋浇期内水量充足,各地块各土层含水率均明显增加,田间土壤水分呈“入渗补给型”.各地块地下水埋深月均变化趋势基本一致,由于优先流的存在,地下水对灌溉降水响应快.本文定量研究了区域土壤水和地下水的变化规律,揭示了灌区水平衡要素间的相互转换关系,可为灌区科学合理的水资源管理提供理论依据.     

Spatial variations of Pb in the vertical zone of the soil-plant system in the Changbai Mountain National Nature Reserve

The characteristics of vertical and horizontal variations of lead element (Pb) in soil-plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR)were studied.The results showed that Pb concentrations in soils of vertical zone are all above 25mg/kg,and the average Pb concentration of each soil zone negatively correlates its degree of variation,i.e.brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones,and the highest horizontal variation;however,mountain soddy forest soil has the highest average Pb concentration,and the lowest horizontal variation;the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant(Clarke),respectively,and plant Pb content order is consistent with soil Pb content order,but their horizontal variations are different from those in soil zones,the variation of mountain tundra forest zone is highest,but Betula ermanii forest zoner the lowest.Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%;the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant;parent material and parent rock,pH values,soil organic matter and soil particle fraction etc.are the main factors influencing variations of Pb contant in soil-plant system of vertical zone in CNNR.     

基于SWAT模型的泗河流域除草剂迁移模拟

泗河流域农药污染对南四湖湖泊乃至南水北调工程具有重要的影响,为了解流域农药迁移过程并对其采取治理措施,本研究在泗河流域通过实地采样与调查、室内实验分析、数据统计等手段,借助SWAT模型对流域除草剂阿特拉津及其代谢产物进行迁移模拟.结果表明,除草剂输出与流域径流量有很高的相关性,输出时间以7~8月份为主,输出量占全年的69%以上.且受河道长度、耕地分布等因素的影响,阿特拉津的输出量以东部上游地区和中部地区为主,流域出水口处的阿特拉津输出量居中等水平;阿特拉津代谢产物DEA和DIA的输出量的空间分布相似,以下游流域出口处和中部地区为主.本研究可为流域除草剂迁移治理提供理论支持.     

我国黑土地农田土壤除草剂残留特征研究及展望

粮食安全是“国之大者”.东北黑土地作为我国重要的粮仓,是保障国家粮食安全的“压舱石”.但黑土地农田除草剂的长期高强度施用,导致除草剂在土壤中积累和迁移,影响土壤质量、作物产量和品质,阻碍黑土地可持续利用和农业可持续发展.解决黑土地农田除草剂残留问题,既要从源头管控除草剂的施用,也要掌握除草剂的残留特征、时空演变和驱动因素,才能做到科学防控、精准施策.系统总结了我国黑土地农田除草剂的施用状况和存在的问题,全面梳理了除草剂的残留现状,指出了当前在黑土地农田除草剂残留特征、空间分布和污染诊断等研究上的不足,提出了我国黑土地农田除草剂残留诊断与风险管理研究思路与重点方向,为保障我国黑土地农田土壤健康、粮食安全和生态系统安全提供科技支撑.     

雄安新区土壤氟地球化学特征及健康风险评价

为科学评估雄安新区表层土壤氟(F)地球化学分布特征及人体健康风险,利用GIS空间分析、相关分析等分析土壤F贫化富集特征及影响因素,开展土壤F健康风险评估,基于蒙特卡罗随机模拟,研究健康风险评价结果的不确定性.结果表明,新区表层土壤ω(F)均值为641 mg·kg^-1,是全国A层土壤背景值的1.34倍,F过剩和高等级样点占比超过85%,F含量整体相对偏高.灌溉水样ρ(F^-)均值为0.85 mg·L^-1, F^-含量空间分布特征受浅层地下水水化学类型和流向的影响.土壤F垂向空间变化不显著,其垂向变化主要受土壤有机碳、质地等土壤理化性质的垂向分布影响.表层土壤F的贫化富集主要受地质背景成因控制,人为因素(农业灌溉水、施肥和大气干湿沉降)等外源输入影响其异常的空间分布.区内土壤F含量与地貌环境“标志性”指标Al₂O₃、 Fe₂O₃、 MgO和K₂O含量,土壤有机碳(Corg.)、阳离子交换量(CEC)...     

除草剂阿特拉津的使用与危害

文章介绍了目前广泛应用的一种除草剂阿特拉津的使用和特性,阿特拉津被认为是安全的除草剂,但大量研究结果表明,其分子结构稳定, 使用后不易降解,在使用过的水体和土壤中均有检出,长期使用后可对水环境、土壤和动物产生一定的危害,尤其是作为一种环境荷尔蒙,已经发现它能够对水生生物的生长繁殖产生影响,可能产生变性反应,是人类潜在的致癌物.通过对其危害的研究和防范管理,可以减少和避免可能对人类、生态环境带来的进一步危害.     

氮磷肥料对HB-5菌株降解莠去津的促进作用及去毒效应的影响

以莠去津降解细菌HB-5为研究对象,进行了氮、磷肥单一及复合施肥对HB-5细菌降解土壤中莠去津的促进作用的研究,探讨了莠去津降解率与土壤中速效氮、速效磷含量之间的关系及莠去津降解过程中生态毒性的变化情况.莠去津在土壤中的残留采用高效液相色谱法进行测定;土壤中速效氮和速效磷分别采用碱解扩散法及0.5mol/L-NaHCO3浸提-钼锑抗比色法测定;土壤的生态毒性采用蚕豆根尖微核法进行测定.结果表明,在实验的前5d,不论氮、磷肥单一或复合施肥均能够明显促进HB-5对莠去津的降解,不同施肥条件下莠去津的降解速率依次为:氮、磷肥复合单施磷肥单施氮肥不施肥料对照;实验5d后,各处理中莠去津降解率没有显著差异(p0.05),均达到了95%以上.土壤中速效氮和速效磷含量随着莠去津的降解而呈现逐渐减少的趋势.土壤的生态毒性试验结果表明,莠去津经HB-5菌株降解后,土壤的生态毒性显著降低;各施肥处理土壤中莠去津的生态毒性均低于不施肥处理的土壤;实验的前5d,各处理土壤中生态毒性的大小依次为:氮、磷肥复合单施磷肥单施氮肥不施肥料对照.实验7d时,各处理土壤中莠去津的生态毒性均恢复到空白对照水平.氮磷肥料的施用不仅能促进HB-5菌株对土壤中莠去津的降解,而且能加速降低土壤的生态毒性,为莠去津污染土壤的快速修复提供了理论依据.     

Persistence and mobility of 2,4-D in unsaturated soil zone under winter wheat crop in sub-tropical region of India

The present study was undertaken to determine the persistence and mobility of 2,4-dichlorophenoxy acetic acid (2,4-D) in unsaturated soil zone under real field conditions for the wheat crop in Roorkee, India. Three experimental plots were chosen in the agricultural field itself to represent the real field conditions in the study area and the potential movement and persistence of herbicide 2,4-D was investigated under three different irrigation treatments. The presence of herbicide along with soil water content was determined in soil at different depths at a temporal scale. The movement of the herbicide was also simulated numerically by solving the coupled soil water content movement and mass transport equations using HYDRUS-1D. The measured soil water content trends and the 2,4-D concentration profiles showed a good agreement with the numerically simulated results. The maximum effect of the herbicide was primarily retained up to 15 cm of the soil profile. The current existing dosage of 0.5 kg ha⁻¹ of pesticide was found to be safe to avoid soil contamination as no residue of 2,4-D was traced at the end of the wheat crop season in any of the plots. Higher concentrations of 2,4-D were also simulated numerically and the simulated results showed that the safe dosage of pesticide application would depend on irrigation treatments.     

江汉平原地下水中硝酸盐的分布及影响因素

基于2011~2014年825个地下水采样点测试结果,采用半方差函数模型和普通克里格插值方法,研究了江汉平原地下水中NO₃-N的空间变异和分布特征.运用证据权重法,选取降雨入渗补给量、地下水位埋深、渗透系数、包气带岩性、土地利用类型、土壤类型和土壤全氮含量7个因子建立预测模型,分析其对硝酸盐分布的影响规律.结果表明,江汉平原地下水NO₃-N含量经Box-Cox变换后服从正态分布,其半方差函数最佳拟合模型为球状模型,空间相关性为87.93%,相关距离为68.02km.研究区地下水NO₃-N含量具有南部高、北部及西部山前平原低的特点.地下水中NO₃-N含量超过10mg/L分布面积所占比例达8.61%.成功率曲线表明模型预测精度为0.91,预测结果较好.江汉平原地下水NO₃-N含量与该区降雨入渗补给量、渗透系数和土壤全氮含量具有良好的正响应关系,与地下水位埋深呈负响应关系.当包气带岩性为砂砾石、土地利用类型为建设用地及土壤类型为冲积土覆盖条件时,地下水极易受硝酸盐污染.     

根茬连续还田对镉污染农田土壤中镉赋存形态和生物有效性的影响

通过盆栽试验研究不同镉污染土壤上分别连作3茬玉米和菜豆,根茬连续还田后对后茬作物生长、镉吸收及土壤中镉赋存形态的影响.结果表明,两种镉污染土壤上分别连作3茬菜豆和玉米,根茬累计还田量占土壤质量的0.4%～1.1%,通过根茬累计还田的镉占土壤全镉的1.3%～3.5%.玉米和菜豆根茬连续还田对后茬大白菜和冬小麦生长均无显著影响,但在镉污染土壤上根茬连续还田后显著增加了后茬大白菜地上部镉含量.根茬连续还田对后茬小麦吸收镉无影响.根茬连续还田增加了土壤轻组有机质含量和模拟镉污染土壤中轻组有机质中镉占土壤全镉的比例.镉污染土壤连续还田玉米根茬后土壤碳酸盐结合态镉含量显著降低,在模拟镉污染土壤上菜豆根茬连续还田显著降低了土壤交换态镉含量,根茬连续还田增加了土壤中氧化物结合态镉含量.     

Simulation of irrigation reuse system nitrate losses and potential corn yield reductions

Places, where intensive row crop irrigated farming is practiced, are experiencing nitrate contamination of groundwater. The farmers are increasingly becoming aware of high nitrate concentrations in the groundwater. As a result, farmers have started to test their groundwater for nitrate concentrations and take account of this concentration in their crop nitrogen budget. If a farmer utilizes an unlined reuse pit and groundwater nitrate concentration to base his nitrogen fertilizer budget on, he may underestimate his nitrogen fertilizer requirement for a given yield goal because of nitrate loss out of the reuse pit. The objective of this study was to compute: (1) nitrate loss from the irrigation reuse pit during an irrigation season, 1 July to 31 August; and (2) the potential corn yield reduction for a field receiving irrigation water from the reuse pit. A computer program based on the Green–Ampt equation was written to simulate these losses and yield reductions. Use of the Green–Ampt infiltration equation allows for a two-layer reuse pit, which may have a clay liner on top of the native soil material. To conceptualize the magnitude of water loss volumes and mass of nitrate leached, the reuse pit was assumed to serve a 32.4-hectare field. The results show that lining the pit with clay can significantly reduce nitrate leaching from a reuse pit and cut yield losses. The results also show the importance of a lined reuse pit in sandy sub-soils. Budgeting for crop nitrogen needs assuming irrigation water from the pit with a substantial nitrate concentration could result in crop nitrogen stress. If ponding were also considered in the reuse pit, it would increase the nitrate and yield losses from the reuse pit.     

土壤中阿特拉津环境行为及降解转化研究

针对土壤中阿特拉津环境行为及降解转化问题,介绍了除草剂阿特拉津,主要包括阿特拉津的基本理化性质和目前阿特拉津的使用状况,环境问题,已成为阻碍经济社会发展的因素.水、大气和土壤都已成为经济发展的绊脚石,人们源源不断地将工业及生活垃圾,废气排放到环境当中,带来了严重影响.全球环境日益被破坏,为了全球粮食的供应,农药的使用也为土壤带来了严重的环境问题.探讨了阿特拉津的环境行为及降解转化,包括阿特拉津的环境行为和阿特拉津的降解转化.