Distribution of seven heavy metals among hot pepper plant parts

The main objective of this investigation was to monitor concentrations of seven metals (Cd, Pb, Ni, Mo, Cu, Zn, and Cr) in the fruits, leaves, stem, and roots of Capsicum annuum L. (cv. Xcatic) plants grown under four soil management practices: yard waste (YW), sewage sludge (SS), chicken manure (CM), and no-much (NM) bare soil. Elemental analyses were conducted using inductively coupled plasma mass spectrometer. Pb and Cd concentrations in soil amended with YW, SS, and CM were not significantly different (P < 0.05) compared to NM soil, whereas Mo and Cu concentrations were significantly greater in YW compared to SS, CM, and NM treatments. Concentrations of Cd in the fruits of plants grown in NM soil were greater compared to the fruits of plants grown in other treatments. Total Ni concentration (sum of Ni in all plant parts) in plants grown in NM bare soil was greater than in plants grown in SS-, YW-, and CM-amended soils. Values of the bioaccumulation factor indicated that pepper fruits of plants grown in YW, SS, and CM did not show any tendency to accumulate Pb, Cr, and Ni in their edible fruits.     

Carbon dioxide emission in relation with irrigation and organic amendments from a sweet corn field

Soil moisture and organic matter level affects soil respiration and microbial activities, which in turn impact greenhouse gas (GHG) emissions. This study was conducted to evaluate the effect of irrigation levels (75% [deficit], 100% [full], and 125% [excess] of reference crop evapotranspiration requirements), and organic amendments (OA) type (chicken manure [CM] and bone meal [BM]) and OA application rates (0,168, 336 and 672 kg total N ha^?1) on (i) soil physical properties (bulk density, organic matter content and soil moisture content) and (ii) soil carbon dioxide (CO₂) emissions from a highly weathered tropical Hawai'ian soil. Carbon dioxide readings were consistently taken once or twice a week for the duration of the cropping season. A drip irrigation system was used to apply the appropriate amount of irrigation water to the treatment plots. Treatments were randomly selected and corresponding organic amendments were manually incorporated into the soil. Plots were cultivated with sweet corn (Zea mays ‘SS-16’). Soil moisture content within and below the rootzone was monitored using a TDR 300 soil moisture sensor (Spectrum Technologies, Inc., Plainfield, IL, USA) connected with 12 cm long prongs. Soil bulk density and organic matter content were determined at the end of the cropping season. Analysis of variance results revealed that OA type, rate, and their interaction had significant effect on soil CO₂ flux (P < 0.05). Among the OA rates, all CM mostly resulted in significantly higher soil CO₂ fluxes compared to BM and control treatment (p < 0.05). The two highest rates of BM treatment were not significantly different from the control with regard to soil CO₂ flux. In addition, organic amendments affected soil moisture dynamics during the crop growing season and organic matter content measured after the crop harvest. While additional studies are needed to further investigate the effect of irrigation levels on soil CO₂ flux, it is recommended that in order to minimize soil CO₂ emissions, BM soil amendments could be a potential option to reduce soil CO₂ fluxes from agricultural fields similar to the one used in this study.     

半胱胺对鸡血液中IgA含量的影响研究

在灌喂两种剂量半胱胺的基础上应用新城疫弱毒疫苗对鸡进行消化道粘膜免疫,采用ELISA双夹心法测定了鸡血液中IgA的含量,结果表明:结果表明首免后第三周和第四周两种剂量半胱胺组的血液中IgA含量与新城疫免疫组的相比分别呈极显著增加(P<0.01)和显著增加(P<0.05);提示血液中IgA含量受SS影响较大,饲喂半胱胺降低SS水平后,应用新城疫弱毒疫苗进行消化道粘膜免疫,可以提高血液中IgA的含量,增强机体的系统免疫力.图1,参8.     

生物炭和鸡粪对镉低积累油菜吸收镉的影响

采用田间试验,研究在污灌菜地上施用生物炭和鸡粪对镉低积累油菜生长和镉吸收的影响,并通过重金属形态分析探讨其作用机理.结果表明,施用添加剂可提高油菜地上部产量,高剂量生物炭和鸡粪复配处理增产效果最佳,最大增产率为174%.施用添加剂可显著降低油菜地上部镉含量,其中,高剂量生物炭和鸡粪复配处理降低效果最佳,最大降低率为72.0%,使所有供试品种地上部镉含量满足食品安全标准要求.施用添加剂可显著降低土壤TCLP提取态镉含量,最大降低率为36.5%.施用生物炭和鸡粪促进土壤镉由活性高的可交换态向活性低的有机结合态或残渣态转化,从而显著降低镉的生物有效性和可迁移性.以上结果表明,种植镉低积累品种同时施用生物炭和鸡粪可以满足油菜在镉污染土壤上安全生产的需要.     

抗生素杆菌肽锌对鸡粪厌氧水解酸化的影响

以上海某养鸡场产生的粪便为研究对象,探讨抗生素杆菌肽锌(ZnBc)对鸡粪厌氧水解酸化的影响。结果表明:(1)相比于发酵前的pH,发酵后的pH变化幅度不大,在6.65～7.40变化。(2)氨氮和ZnBc浓度对数(lgc)呈负线性相关,经拟合方程测算出ZnBc对氨氮的半抑制常数(IC50)为15.23mg/L。当ZnBc>5 105mg/L时,氨氮的产生完全受抑制。添加ZnBc对发酵液氨氮的影响极显著。(3)溶解磷(SP)和lgc满足Boltzman方程。添加ZnBc对发酵液SP的影响极显著。(4)ZnBc不仅影响挥发性脂肪酸(VFAs)浓度,还影响VFAs组分。(5)添加ZnBc对发酵液总有机碳(TOC)有极显著影响。(6)相比原鸡粪,发酵后固体有机N、C、H均下降,并分别在ZnBc为0.10、0.01、0.01mg/L时达到最低值,说明鸡粪在厌氧水解酸化过程中固体有机组分向液体转移。     

集约化蛋鸡场鸡粪混合液资源化无害化处理

本研究采用离心分离法、高温好氧发酵法和中温厌氧发酵对鸡粪混合液进行资源化、无害化综合处理。实验结果:鸡粪回收率53.0%～91.8%;发酵后,鸡粪含水率31%～44%;废水厌氧处理的体积负荷12.14kg·COD_(cr)/m~3·d;产沼比0.52m~3/kg·COD_(cr);甲烷含量>70%。通过综合处理,COD_cr)、BOD_5的总去除率均大于90%。实验表明,本工艺具有投资少、能耗低、费用省和效益比较明显等优点。     

不同堆肥方式对鸡粪与秸秆混合堆肥效果

以鸡粪和玉米秸秆为堆肥原材料,进行了露天堆肥和反应器堆肥对比实验。结果表明,反应器堆肥（堆体P2）较露天堆肥（堆体P1）升温快,堆体P2达到了《粪便无害化卫生标准（GB7959—87）》的要求,堆体P1未达到;在整个堆肥过程中,堆体P1的水分总损失量（26．5％）大于堆体P2的水分总损失量（20．6％）;堆体P1和P2的有机质降解主要发生在堆肥前期0～21d,分别完成了81．4％和84．5％的有机质降解量;堆体P1和P2的C／N比在堆肥过程中均呈下降趋势,最终C／N比分别为18．3和14．8;种子发芽指数GI_P1〈GI_P2,表明采用堆体P2的堆肥产品的植物毒性较堆体P1更小。各指标实测数据表明,反应器堆肥的堆肥产品的稳定性和腐熟程度较露天堆肥更好。     

进料浓度对鸡粪连续中温厌氧消化的影响

针对高固体鸡粪厌氧消化运行困难问题,利用完全混合式厌氧反应器(CSTR),通过逐级提高进料总固体浓度(TS)的方法,研究不同进料TS((5.20±0.56)%、(7.24±0.36)%、(9.30±0.26)%和(6.22±0.26)%)的鸡粪连续中温厌氧消化效果。实验结果表明,进料TS由(5.20±0.56)%提高为(9.30±0.26)%,挥发性固体(VS)产气率由(0.64±0.05) L·g⁻¹下降为0.07 L·g⁻¹,有机物去除率明显减少,挥发性脂肪酸(VFAs)由(0.53±0.02) g·L⁻¹累积至(1.62±0.02) g·L⁻¹,总氨氮浓度(TAN)和游离氨浓度(FA)分别由(1.06±0.11) g·L⁻¹和(0.07±0.02) g·L^-1累积至3.40 g·L⁻¹和0.68 g·L⁻¹,消化过程受到氨抑制。采用Boltzmann模型对不同氨氮浓度下VS产甲烷率和VS去除率进行模拟,拟合结果表明,TAN升高所引发的FA持续累积导致高固体鸡粪厌氧消化氨抑制逐步形成,与VS产甲烷率相比,VS去除率对氨氮的抑制响应具有滞后性。降低进料TS至(6.22±0.26)%,氨抑制得到有效缓解,但反应器处于“抑制稳定状态”。因此,为保证反应器长期高效平稳运行,建议鸡粪连续中温厌氧消化的进料浓度不超过7.24%。研究为高固体鸡粪厌氧消化的工程化应用提供参考。     

鸡败血型葡萄球菌病的诊断与治疗

鸡葡萄球菌是由致病性金黄色葡萄球菌引起鸡的一种环境性传染病,已成为一些养鸡场的常见病之一,本病的特点是引起鸡的急性败血症,发病率和死亡率都很高,造成的经济损失很大。     

不同药物防疫程序对三黄鸡育雏效果的比较研究

采取3个不同药物防疫程序对2 100羽三黄鸡进行了为期8周的育雏试验,其成活率均在96%以上,其中试验2组效果最好,成活率达98.42%,此预防程序可在实际生产中应用。