Metal contamination in Nullah Dek water and accumulation in rice

Corn field experiments with two treatments, NP and NPK, where N in the form of urea, P in the form of calcium phosphate, and K in the form of KCl were applied at rates of 187.5, 33.3, and 125 kg ha^-1, respectively, on soils derived from Quaternary red clay were conducted in the hilly red soil region of Zhejiang Province, China. Plant grains and stalks were collected for determination of K content. Seven equations were used to describe the kinetics of K release from surface soil samples taken before the corn experiments under electric field strengths of 44.4 and 88.8 V cm^-1 by means of electro-ultrafiltration （EUF） and to determine if their parameters had a practical application. The second-order and Elovich equations excellently described K release; the first-order, power function, and parabolic diffusion equations also described K release well; but the zero-order and exponential equations were not so good at reflecting K release. Five reference standards from the field experiments, including relative grain yield （yield of the NP treatment/yield of the NPK treatment）, relative dry matter yield （dry matter of the NP treatment/dry matter of the NPK treatment）, quantity of K uptake in the NP treatment （no K application）, soil exchangeable K, and soil HNO3-soluble K, were used to test the effectiveness of equation parameters obtained from the slope or intercept of these equations. Correlations of the ymax （the maximum desorbable quantity of K） in the second-order equation and the constant b in the first-order and Elovich equations to all five reference standards were highly significant （P ≤ 0.01）. The constant a in the power function equation was highly significant （P 〈 0.01） for four of the five reference standards with the fifth being significant （P ≤ 0.05）. The constant b in the parabolic equation was also significantly correlated （P ≤ 0.05） to the relative grain yield and soil HNO3-soluble K. These suggested that all of these parameters could be used to estimate the soil K supplying capacity and the crop response to K fertilizer.     

Evaluation of Rice and Wheat Cultivars for Tolerance to Salinity and Sodicity in Soil

The large genotypic variation for salt tolerance in rice and wheat is the driving force behind efforts to identify appropriate cultivars for salt‐prone environments where large variations in salinity (electrical conductivity, EC) and sodicity (sodium adsorption ratio, SAR) levels exist. An evaluation of the commonly grown rice and wheat cultivars at different EC/SAR ratios may thus help in coping with the crop failures on salt‐affected soils. Accordingly, we evaluated some salt‐tolerant cultivars of rice and wheat for growth and yield at different soil salinity and sodicity levels in a sandy clay loam soil. Among the cultivars tested, rice ‘SSRI‐8’ produced the highest productive tillers and paddy yield, and wheat cultivar ‘SIS‐32’ produced the highest tillers and grain and straw yields. The high EC/SAR ratios proved more hazardous for rice than for wheat. Irrespective of the varieties tested, the highest levels of EC and SAR (T₅ and T₆) caused significant reduction in paddy yield, whereas at the lowest levels of EC and SAR (T₁ and T₂), paddy yield was not affected significantly when compared with the control. However, in case of wheat crop, all the levels [i.e., the lowest (T₁ and T₂), medium (T₃ and T₄), and the highest (T₅ and T₆) of EC and SAR tested] affected wheat yield adversely with significant differences. For both the crops, there were little or no differences in yield between the two ratios tested (i.e., 1:2 and 1:4) at all the levels of EC and SAR.     

东北地区不同水稻品种对Cd的累积特性研究

采用土培盆栽试验方法,以东北地区大面积种植的32个水稻品种为试验材料,在土壤中未添加和添加Cd（5mg.kg-1Cd）的条件下,研究水稻生长、籽粒产量和Cd在水稻植株不同部位的分配规律。结果表明,土壤中添加Cd后,多数水稻籽粒产量和植株总生物量下降,只有少数品种籽粒产量和生物量有所上升。Cd在水稻植株中的含量遵循根系〉茎叶〉颖壳〉籽粒的规律,但从分配比例来看,土壤中未添加Cd时根系中Cd的分配比例较高,添加Cd后茎叶中Cd的分配比例明显增加。从稻米产量和质量安全角度综合考虑,认为越路早生（3号）品种为农业生产中较理想的种植品种,沈农265（1号）、农林315（30号）、屉锦（31号）、沈稻12（32号）品种可以在中轻度污染的农田土壤条件下种植,而千重浪-1（8号）、辽盐2（14号）、辽盐283（17号）、辽恢190（19号）以及吉03-2843（27号）品种尽量避免在污染土壤上种植。研究结果对东北地区镉污染稻田选择水稻品种,保障稻米安全具有重要意义。     

铜矿区土壤重金属污染与耐性植物累积特征

在铜陵矿区研究了4种植物:商陆(Phytolacca acinosa),鸭跖草(Commelina communis),菌陈蒿(Artemisia capillaries),农田紫云英(Astragalus sinicus)对重金属的富集特征及土壤重金属污染情况。采用ICP-MS分析了土壤中As、Cd、Cr、Cu、Zn、Pb的重金属全量及植物对As、Cd、Cr、Cu、Zn、Pb的积累情况。并计算了四种植物对重金属的生物转移系数BTC(Biological Transfer Coefficient)。结果表明:铜陵狮子山铜矿废弃地鸭跖草(Commelina communis)、菌陈蒿(Artemisia capillaries)群落的土壤养分状况相对较好,农田紫云英的养分状况次之,杨冲山尾矿库分布商陆(Phytolacca acinosa)的土壤养分状况最差。商陆耐瘠薄土壤、尾矿区与附近农田土壤重金属全量分析表明,杨山冲尾矿库附近农田土壤(种植紫云英)铜、镉、铅、锌总量均超过国家农业用地土壤二级标准,尾矿废弃地分布鸭跖草、茵陈蒿的土壤全铜含量超过国家工业用地土壤二级标准,土壤受Cu污染最严重。菌陈蒿、鸭趾草对高含量的土壤铜表现出很好的耐性。鸭跖草对砷和铅的转移系数大于1,茵陈蒿对镉与锌的转移系数大于1。鸭跖草、茵陈蒿、商陆都可以作为矿区生态恢复的先锋植物。     

广东大宝山矿区植物对重金属的富集特征

对大宝山矿区自然定居和人工种植的13种优势植物根际土壤污染状况及其对重金属的富集特征进行研究.结果表明,大宝山矿区土壤受重金属Cd、Pb、Zn、Cu污染,其中以Cd、Cu的污染最为严重.在调查的13种优势植物中,铺地黍地上部分的Pb含量达到1 214.00 mg/kg,泡桐叶中Cu含量达到1 024.80mg/kg,超过了Pb和Cu超富集植物含量的临界值(1 000 mg/kg);其运转系数分别为1.77.13.74,都大于1.0,符合超富集植物的标准,表明铺地黍可能是Pb的超富集植物,泡桐可能是Cu的超富集植物.除铺地綦、泡桐外,其他11种优势植物的重金属吸收能力没有达到超富集植物的标准,但它们能在此区域定居,表现出对重金属有较强的耐性,其中象草、纤毛鸭嘴草、芒萁、五节芒、马尾松对重金属复合污染胁迫的耐性较强,可作为大宝山矿植被重建的先锋物种.     

Phosphorus Requirements of Rice Grown in Soils With Different Sodicity

ABSTRACT

Phosphorus (P) fertilization is reported to alleviate the adverse effects of sodicity on survival of the seedlings, growth, and yield of rice. However, it is not known if required levels of Olsen's P to alleviate the adverse sodicity effects varies with increased sodicity stress. The present study, conducted at various pH values (8.0, 9.3, 9.7, and 9.9) with varying levels of P fertilization (P0.0, P0.2, P0.4, P0.6, and P0.8 kg hm^{? 2}), showed that P requirements of rice increased with increases in sodicity stress. At a pH of 8.0, 4.3 mg kg^{? 1} Olsen's P was sufficient for survival of the seedlings, but not for grain weight (6.3 mg kg^{? 1}). Seedlings required 7.0 and 9.5 mg kg^{? 1}Olsen's P to survive at pH 9.7 and 9.9, respectively. Similarly, high P levels were needed for more total and fertile tillers and spikelets numbers. One thousand (1000) grain weight and grain yield responded to 6.3, 7.7, 8.8, and 10.4 mg kg^{? 1} Olsen's P at pH values of 8.0, 9.3, 9.7, and 9.9, respectively. Total chlorophyll in the leaves was significant in P fertilized plants. At a pH of 9.7, plants with 7.9 mg kg^{? 1} Olsen's P had 52% more chlorophyll per 100 ppm sodium (Na) in the leaves compared to those at 6.3 mg kg^{? 1} Olsen's P. This could possibly be due to improved tissue tolerance to Na in P-fertilized plants. Plants fertilized with P had higher P and potassium (K) concentrations in their shoots. Olsen's P levels of 7.7 mg kg^{? 1}, 7.9 mg kg^{? 1}, and 9.5 mg kg^{? 1} were effective in restricting increases of Na (a potentially toxic ion) in shoots at pH 9.3, 9.8, and 9.9, respectively, thus helping plants have better yields.     

Heavy Metal Contamination in Peach Trees Irrigated with Water from a Heavily Polluted Creek

This study was conducted to characterize the heavy metal contamination in the soils of peach orchards irrigated with water from Nilüfer creek, which is heavily polluted by industrial and municipal wastes. Twenty-one peach orchards with 3 different cultivars in 7 orchards each located along Nilüfer creek were monitored in the experiment. To determine levels of pollution, soils and aboveground parts of the trees were sampled and analyzed for iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd). Total amounts of Ni and Cr were found to be at the excessive levels in soils. Extractable Ni concentration decreased with increasing pH and CaCO₃ content in soils. Leaf metal contents were generally at tolerable levels, but Ni and Pb accumulated to toxic levels in different parts of the fruit (flesh and peel). Except for Fe and Ni, plant concentrations of the metals did not correlate with their total and DTPA-extractable concentrations in the soils. There was no significant difference among the cultivars in accumulation of heavy metals.     

天津潮间带泥螺（Bullacta exarata）对重金属镉的累积与释放特征

生物对重金属的累积与释放实验对研究生物修复、污染物生态毒性和环境风险评价有着十分重要的意义。通过对天津潮间带底栖生物泥螺进行室内镉累积与释放实验,研究了泥螺体和肝脏对镉的累积与释放特征。整个实验过程分为累积和释放两个阶段,实验样品经冷冻、干燥、研磨、混匀和称量后,采用原子吸收分光光度法进行测定。结果表明,泥螺对镉的累积周期为14 d,其身体和肝脏中镉的质量分数均呈现先升高后降低的趋势,在第7 d达到最大值,其中肝脏的累积能力要大于身体;泥螺对镉的释放周期为12 d,在第9 d趋于稳定。泥螺对镉的累积与释放不仅与其自身的生活习性有关,还与其栖息环境密切相关。在自然环境中,应当严格控制镉的人为输入,尤其是含镉工业废水的排放。     

连云港市水稻主产区土壤和灌溉水重金属含量分析及在稻米中的累积效应

对连云港市水稻主产区的土壤、灌溉水和稻米中重金属含量进行了测定。研究结果表明:(1)该地区水稻灌溉水所含重金属污染较轻,没有对稻米品质造成影响,完全符合无公害稻米生产要求。(2)土壤中砷、铅、镉的平均含量超过国家和江苏省背景值,砷、镉、铬、铅和汞的单项污染指数P<1,污染分担率排序为砷(42.56%)>镉(37.00%)>铬(7.78%)>铅(7.22%)>汞(5.54%),土壤主要以砷、镉污染为主;综合污染指数P综=0.59<0.7,属1级,为安全清洁水平,符合无公害农产品生产基地重金属环境质量要求。(3)稻米中4种重金属污染排序为铅>汞>镉>砷,以铅和汞污染为主;除铅外,稻米中重金属富集效应不明显,徐稻3号累积铅的能力较强,稻米中镉的含量与土壤中pH值存在着负相关关系。     

不同浓度镉水灌溉对土壤及水稻品质的影响

通过桶栽土培水稻试验研究不同浓度(0.04,0.08,0.10,0.12,0.20,0.24mg/L)镉水灌溉对土壤及水稻产量和品质的影响。结果表明,重金属Cd主要累积在5-20cm土层,对水稻的株高有明显的抑制作用,对千粒重也有影响,但对水稻的每穗粒数及单株产量无明显影响。不同浓度镉水灌溉对稻米的外观品质、碾米品质有一定的抑制作用,但均能达绿色大米标准;营养品质则不受影响,6个处理下蛋白质、直链淀粉含量均能达标,且与CK无差异。土壤中的Cd含量随着镉水浓度的增大而增大,稻米中的Cd含量也与镉水浓度成正比。镉水中的大部分Cd残留在土壤中,6个处理下残留量分别为99.3%,73.8%,60.4%,55.5%,37.4%,47.6%,由此可见,镉水浓度越小,土壤对Cd的吸收能力越强,镉水浓度越大,土壤对Cd的吸收能力越弱。当镉水浓度大于0.20mg/L时,精米中的Cd含量达到了限量标准值(0.2mg/kg),说明灌溉水中的重金属Cd的浓度应该控制在0.20mg/L以下。     

Arbuscular Mycorrhizal Fungi Contribute to Resistance of Upland Rice to Combined Metal Contamination of Soil

A greenhouse pot experiment was conducted to investigate heavy metal [copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd)] uptake by two upland rice cultivars, ‘91B3’ and ‘277’, grown in a sterilized field soil contaminated by a mixture of Cu, Zn, Pb, and Cd. Rice plants were inoculated with each of three arbuscular mycorrhizal fungi (AMF), Glomus versiforme (GV), Glomus mosseae (GM), and Glomus diaphanum (GD), or remained noninoculated (NM). Both rice cultivars could be colonized by the three AMF used in this experiment. The percentage of mycorrhizal colonization by the three AMFs on the two rice cultivars ranged from 30% to 70%. Mycorrhizal colonization of both upland rice cultivars had a large influence on plant growth by increasing the shoot and root biomass compared with non-inoculated (NM) plants. The results indicate that mycorrhiza exert some protective effects against the combined toxicity of Cu, Zn, Pb, and Cd in the contaminated soil. This conclusion is supported by the partitioning of heavy metals (HMs) in the two cultivars. In the two cultivars, colonization by AMF reduced the translocation of HMs from root to shoot (except that the colonization of AMF increased the Cu translocation of HMs in cultivar ‘277’). Immobilization of the HMs in roots can alleviate the potential toxicity to shoots induced by the mixture of Cu, Zn, Pb, and Cd. The two rice cultivars showed significant differences in uptake of Cu, Zn, Pb, and Cd when uninoculated. GM inoculation gave the most protective effects on the two cultivars under the combined soil contamination.     

三种类型阻控剂对不同品种水稻富集镉的影响

如何降低水稻中镉(Cd)的含量已经成为一个研究热点。在湖南省衡阳县某地受轻度镉污染的农田上种植两季水稻(早稻、晚稻),随机采购市场上销售的阻控剂(石灰、硅肥和叶面锌肥),研究这3种类型阻控剂对水稻富集镉及稻谷中镉含量的影响,这3种类型的阻控剂的施用方式是石灰和硅肥作为基肥施于土壤,叶面锌肥通过叶面喷施。结果表明:与没有施加阻控剂相比,除石灰和晚稻锌处理之外,其他处理增产效果显著。在3种类型的阻控剂中,叶面锌肥对籽实富集镉的阻控效果最佳,分别使早稻Y俩优792和晚稻农香130降低了51.28%和50.92%,基施硅肥阻镉效果次之。田间试验结果进一步表明施硅肥和喷施叶面锌肥可作为当地的水稻镉污染阻控剂,但叶面锌肥与稻谷中镉的交互作用需要更深入的探讨。     

水分处理对专用型小麦后期氮积累及子粒蛋白质含量的影响

采用盆栽方法研究了水分处理对专用小麦各营养器官氮含量积累、运转和子粒蛋白质的影响。结果表明,在不同的水分处理中,开花后随着时间的推移小麦叶鞘和茎中氮含量逐渐降低,而根中氮含量先下降后上升。（1）80％FC提高了各专用小麦叶鞘氮含量;豫麦34茎中氮含量在各处理下差异不大,豫麦49在60％FC下提高茎中氮含量,豫麦50茎氮含量在40％FC下最高。（2）各营养器官氮转运量品种间表现为豫麦50〉豫麦49〉豫麦34,各品种间不同水分处理下各营养器官氮转运量均为80％FC〉60％FC〉40％FC。（3）各品种叶鞘氮转运效率为80％FC〉60％FC〉40％FC;但不同品种间各水分处理下茎氮转运效率因存有差异,豫麦34为：40％FC〉60％FC〉80％FC,豫麦49为：60％FC〉40％FC〉80％FC,豫麦50为：60％FC〉80％FC〉40％FC。（4）各营养器官及总转运氮对籽粒的贡献率为80％FC〉60％FC〉40％FC,各品种器官转运量和贡献率均为：叶鞘〉茎,器官转运效率为：茎〉叶鞘。（5）对豫麦34,蛋白质含量和产量均以60％FC为好,且蛋白产量达显著性差异;豫麦49和豫麦50,蛋白质含量以40％FC最高,蛋白质产量以80％FC最高。豫麦49差异均达到显著水平,豫麦50蛋白质产量达极显著水平。     

钢渣施用对多金属复合污染土壤的改良效果及水稻吸收重金属的影响

通过盆栽实验和大田实验研究了钢渣施用对多金属复合污染土壤pH、有效硅、有效态重金属含量（镉、铅、铜、锌）以及水稻吸收重金属的影响。盆栽实验设置5个处理,分别是CK（无钢渣）、SS3和SS6（分别加入3g·kg-1和6g·kg-1100目钢渣）、FSS3和FSS6（分别加入3g·kg-1和6g·kg-1180目钢渣）;大田实验设置两个处理：CK（无钢渣）和SS（加入3g·kg-1100目钢渣）。结果表明,盆栽实验土壤pH值及有效硅含量随钢渣施用量的增加和粒径的减小显著上升,土壤有效态重金属含量则出现显著下降。水稻地上部重金属浓度在施加钢渣后均显著降低,并且远低于地下部浓度;大部分钢渣施加处理对降低地下部重金属浓度也有显著效果。大田实验结果显示,钢渣改良的处理,不仅提高了水稻产量,稻米中的重金属浓度也得到了大幅降低,并达到了国家食品安全标准。综合来看,施用钢渣可有效改良多金属复合污染土壤的性质,抑制水稻对重金属的吸收和转运,降低水稻特别是其地上部的重金属浓度。     

不同水氮管理对水稻干物质积累和茎鞘物质运转及产量的影响

为了探讨不同类型高产水稻水氮高效利用特性,以大穗型杂交粳稻甬优8号和穗粒兼顾型常规粳稻品种(系)苏10-100为材料,进行实地氮肥管理和全生育期轻干-湿交替灌溉技术联合运用,研究水稻干物质和茎鞘非结构性碳水化合物(NSC)积累与运转特性及其与籽粒产量形成的关系。结果表明,与常规水肥管理相比,实地氮肥管理和轻干-湿交替灌溉联合运用显著增加了幼穗分化期至成熟期的干物质积累量和抽穗期茎鞘中NSC含量,提高了茎鞘干物质和NSC运转率和对籽粒的贡献率,大穗型杂交粳稻甬优8号的运转率和贡献率明显大于常规粳稻苏10-100;水氮处理降低了穗数,但显著或极显著地提高了每穗粒数、结实率、充实度和千粒重,苏10-100和甬优8号分别增加了6.21%、2.53%,1.68%、13.63%,3.3%、8.1%和9.06%、10.35%,其中2个弱势籽粒千粒重的增幅分别达到了16.3%和15.9%,显著大于强势粒。因此,采用实地氮肥管理和轻干-湿交替灌溉水稻具有中后期单位面积干物质积累量大,物质运转率高,穗大且多,结实率高、充实度好的特点,有利于促进弱势籽粒灌浆充实,提高籽粒产量。本研究为水稻超高产栽培和不同类型水稻养分水份高效管理提供理论依据和实践指导。     

不同地表覆盖旱作水稻和水作水稻水分利用效率的研究

通过田间试验研究不同地表覆盖旱作水稻和水作水稻全生育期内水分需求特征与水分利用效率。结果表明,水作稻田当季用水总量是旱作稻田的3倍多,旱作盖草处理的灌溉量为434.5m3/hm2,仅相当于水作的24.6%。不同处理的水分利用效率为:盖草>覆膜>裸露>水作,且旱作与水作间差异极显著。水作、覆膜、盖草和裸露的产量分别为:8250,7207,7867,7253kg/hm2,统计分析结果显示,盖草旱作与水作间产量差异不显著,这表明盖草旱作是一项效果最好的技术。     

Drought Tolerance and Ion Accumulation of Rice Following Application of Additional Potassium Fertilizer

Five levels of water stress cycle (control flooded, control saturated, 5, 10, and 15 days of irrigation interval) and three potassium fertilization levels [80 kg, 120 kg, and kg 160 dipotassium oxide (K₂O) ha^?1] were exposed to investigate the influence of potassium fertilizer for minimizing water stress effect and maximizing productivity of rice. Different phyto-physiological parameters as well as uptake of major nutrient elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe)] were examined. It was observed that rice yield, harvest index, and other physiological parameters reduces with increasing duration of water stress while application of additional potassium fertilizer has progressive impact on those parameters. From our observation, 10 days of watering cycle with potassium fertilization at 120 kg K₂O ha^?1 produces highest grain yield and harvest index. Uptake of major nutrient elements was also enhanced by potassium fertilizer. Therefore, it can be stated that additional potassium fertilizer application could be useful to mitigate water stress effect in rice.     

钠盐胁迫对苹果树体内钠累积的影响

钠盐胁迫严重制约着甘肃中东部地区苹果的生产。本研究以甘肃省秦安县大田生长的‘金冠’苹果为试材,用正常果树和盐碱胁迫果树对比方法,研究了自然条件下钠盐胁迫对果树整个生育期体内各器官（根系、枝条、叶片、花、果实）钠含量的影响。结果表明：钠盐胁迫下,果树根系内Na+含量为1800mg/kg,是正常果树的2倍;苹果花内Na+含量为700mg/kg,是正常果树的1.4倍;在整个生育期,果树枝条内Na+含量变化在800~1400mg/kg,大约是正常果树的2~4倍;叶片内钠含量变化在1700~2500mg/kg之间,是正常果树的3.4~8.5倍;果实钠含量在1200~1500 mg/kg之间,是正常果树的2.1~12倍。本研究科学地提出苹果花期属于钠盐潜在胁迫期。     

滴灌量对北疆复播大豆耗水特性及干物质积累、转运的影响

为北疆麦后复播大豆高产、节水栽培提供理论依据。在大田滴灌条件下,采用单因子随机区组试验设计,研究了不同滴灌量（3 000,3 600,4 200,4 800 m³/hm²,分别用W₁,W₂,W₃,W₄表示）对复播大豆耗水特性及干物质积累、转运的影响。结果表明,随着滴灌量的增加,复播大豆各生育时期0—60 cm土层土壤含水量均呈增大趋势,且处理间0—40 cm土层中土壤含水量差异较大,而40—60 cm土层的差异较小;总耗水量增加,土壤贮水消耗量明显减少。不同处理复播大豆全生育期单株干物质均呈“S”型变化趋势;干物质最大积累速率（V_m）、快增期持续时间（△t）及干物质总量均以W₃处理最高;花前、花后的干物质转运量与籽粒产量均呈正相关关系,但花后干物质转运对产量的影响较大,各处理花后同化物转运量、转运率及对籽粒贡献率均表现为:W₃ > W₄ > W₂ > W₁。产量以W₃处理最高,达3 741.23 kg/hm²,较W₁,W₂和W₄分别高出30.42%,13.98,8.44%,差异显著（p < 0.05）。各处理水分利用效率表现为:W₃ > W₄ > W₂ > W₁;灌溉水利用效率（IWUE）在W₁,W₂,W₃处理间差异不显著,但均显著高于W₄处理。