高水分蔬菜和花卉废物序批式进料联合堆肥的中试

以滇池流域典型蔬菜废物(西芹、白菜)和花卉废物(石竹)为原料,进行了序批式联合堆肥的试验研究.以西芹和石竹作为初始物料,控制初始混合物料的含水率在60%～70%,每隔4d添加一次白菜;采用温度反馈通气量控制的好氧静态堆肥技术,在堆体温度40℃左右时停止通风.试验分析了堆肥过程中堆体温度、通风速率、水分、pH值、有机质、灰分、体积、NH₄⁺-N,NO₃^--N等指标随时间的变化特征.结果表明:采用序批式进料、温度反馈通气量控制的静态好氧堆肥技术进行蔬菜和花卉废物联合堆肥可以有效控制堆肥过程,实现有机物料的快速稳定和去除水分,解决了滇池流域蔬菜废物量远大于花卉废物量时堆肥难以有效进行的技术难题.     

日光温室蔬菜中百菌清残留状况及不同处理对其的影响

近些年来,食品安全问题逐渐成为人们关注的热点,而农药残留由于其对食品安全和人类健康的影响,引起了广泛的关注.随着越来越多的温室蔬菜出现在人们的生活中,其农药残留势必会对人们的健康产生巨大的影响.本文应用气相色谱法研究两种常见温室蔬菜(黄瓜、番茄)的农药百菌清残留情况及不同处理对其的影响.结果表明,百菌清在这两种温室蔬菜中严重超标,而实验中所采取的类似家庭采用的流水洗净和去皮两种不同处理方式都可以有效降低百菌清的残留量,去皮的效果更为显著.     

Fate of Chlorothalonil, Chlorpyrifos and Profenofos in a Vegetable Farm in cameron Highlands, Malaysia

The fate of chlorothalonil, chlorpyrifos and profenofos in sandy loam soil under tropical condition was studied in a vegetable plot in the Cameron Highlands, Malaysia. The plot was treated with chlorothalonil, chlorpyrifos and profenofos according to normal agricultural practices of the Cameron Highlands. Water (runoff and lysimeter), soil and bedload sediment samples were taken according to a sampling schedule. Residues in water, soil and bedload sediment samples were laboratory analysed to determine amount. Chlorothalonil residues were detected in the range of < 0.01–0.08 mg/kg in the soil, < 0.01–0.02 ng/mL in the leachate, < 0.01–0.02 ng/mL in the runoff and < 0.01–0.11mg/kg in the sediment. Field studies of chlorpyrifos showed residue levels of < 0.01–0.06 mg/kg in the soil, < 0.01–0.07 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.62 mg/kg in the sediment. Residue levels of profenofos were detected in the range of < 0.01–0.02 mg/kg in the soil, < 0.01–0.87 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.35 mg/kg in the sediment. The three pesticides dissipated rapidly, with DT50 (time for 50% loss) of less than two days. The study showed that these pesticides dissipated rapidly under the climatic conditions of the Cameron Highlands in Malaysia.     

Towards global climate change mitigation: assessment of an afforestation option for Nigeria

This paper assesses the potential of an intensive afforestation program as a measure of reducing the atmospheric concentration of carbon in Nigeria. The results presented are based on the recently completed Nigerian Country Studies Program on Climate Change Mitigation. A comprehensive mitigation analysis process (COMAP) model was employed to carry out detailed cost/benefit evaluation of the mitigation option. The end-use based scenario adopted was considered the most appropriate strategy to sustainably implement the mitigation option in Nigeria.The analyses showed that the country could significantly reduce net carbon emission while at the same time meet all her essential domestic wood needs, if approximately 7.5×10⁶ ha of wasteland could be committed to an afforestation program over the 40 year period of projection. The initial cost of establishing such forest plantations, taking cognisance of the opportunity cost of land averaged at about US$500/ha, or in carbon terms, a unit cost of about $13 per tonne of carbon. In terms of carbon flow, if all the end-product based plantations considered (i.e. fuelwood, poles, pulpwood, sawlogs and veneer) were fully established and maintained, it was estimated that by the year 2030, the total carbon stored in the afforested land would be about 638.0×10⁶ t of carbon with an annual incremental rate of 16.0×10⁶ t of carbon. Other economic indicators (i.e. net present value of benefits, present value of costs and benefit for reduced atmospheric carbon) when evaluated showed that the afforestation option could be economically viable even when the investment capital was discounted at rates ranging from 9 to 33 percent for different wood products. It should be noted, however that implementation of such a program would require huge sums of money and a high degree of commitment on the part of Federal, State and Local governments if the associated financial, social and environmental benefits were to be derived.     

鲁西北棉田冬季蔬菜越冬种植技术

根据鲁西北棉区冬季蔬菜越冬种植的自然条件和生产实践经验，本文阐述了适合棉区推广的棉田蔬菜越冬种植模式、操作技术规程、技木要点及其效益对比．     

土壤重金属含量对3种常见菊科叶菜重金属累积的影响

为了解蔬菜产地土壤重金属含量对蔬菜重金属累积的影响,以我国南方常见的3种菊科叶菜(苦荬菜Sonchus oleraceus、生菜Lactuca sativa var.crispa、油麦菜Lactuca sativa)为研究对象,选择5种重金属为研究指标,对蔬菜及其产地土壤重金属含量的相关性等进行了分析。3种蔬菜的重金属富集系数表明,3种蔬菜吸收、累积不同重金属元素的能力存在明显差异(p0.05),5种重金属被蔬菜吸收的容易程度从大到小依次为镉、铬(汞)、铅(砷)。各蔬菜品种的重金属超标率和土壤重金属超标率存在不一致现象。其中,蔬菜中镉、铬、砷、汞的超标率均低于土壤的超标率,而蔬菜中铅的超标率则高于其对应土壤的超标率。对3种蔬菜产地土壤与蔬菜重金属质量比的相关性分析表明,其中除生菜中铅和砷与土壤中相应重金属元素相关性不显著外,其他情况下都呈显著相关性(p0.05)。建立了3种蔬菜及其土壤重金属含量的回归分析模型,并据此推算出种植3种蔬菜的土壤重金属安全阈值,其中,除生菜产地土壤中铅阈值在现行标准范围内之外,其他土壤重金属阈值均远高于现行标准。该阈值结合了大田土壤环境的实际情况,对当地农产品安全生产具有更强的针对性和可靠性。     

河口潮滩湿地CH4、CO2排放通量对氮硫负荷增强的响应

以闽江河口区高、中潮滩短叶茳芏湿地为研究对象,于2014年6—11月植物生长季进行氮硫负荷增强实验,利用静态箱-气象色谱法测定土壤CH_4、CO_2排放通量,并同步观测相关环境因子.结果表明,氮硫负荷增强对潮滩湿地CH_4、CO_2排放通量的影响不尽一致.与对照相比,NH_4~+-N输入使高、中潮滩CH4排放通量分别提高了(107.53%,7.19%),使高潮滩CO_2排放通量增加了3.39%,中潮滩减少了3.00%;NO_3~--N输入使高潮滩CH4、CO_2排放通量分别增加了(29.99%,16.99%),使中潮滩分别减少了(3.45%,4.77%);SO_4~(2-)-S输入使高、中潮滩CH4排放通量分别减少了(8.99%,7.67%),使高潮滩CO_2排放通量减少了3.87%,中潮滩增加了5.44%;N-S复合输入使高、中潮滩CH4排放通量分别提高了(72.48%,25.66%),CO_2排放通量提高了(13.32%,13.48%).氮硫负荷增强改变了短叶茳芏沼泽生长季CH_4、CO_2排放通量变化规律,但除了NH+4-N处理对高潮滩CH4通量的影响显著外,其他处理影响均未达到显著性水平.相关分析显示,高、中潮滩湿地CH_4、CO_2排放通量与土壤温度,含水率具有显著的正线性相关关系,与土壤电导率相关性不显著.在全球环境问题日益严重背景下,系统研究湿地生态系统温室气体排放的机制与规律,对于准确估算全球温室气体排放量具有重要而直接的意义.     

生活垃圾制备衍生燃料(RDF-5)——以重庆市为例

以重庆市生活垃圾为例,通过分选、破碎和干燥预处理后,得到以塑料、纸类、竹木、织物和厨余为主要成分的制备衍生燃料(RDF-5)的原料,测试了不同含水率和成型压力条件下制得的RDF-5的理化性质.结果表明,原料含水率为8%,成型压力为10 MPa时,RDF-5的延展率和耐性指数良好,便于贮存和运输.燃烧试验表明,RDF-5燃烧后灰渣的热灼减率满足《生活垃圾焚烧污染控制标准》(GB 18485—2014)的要求(5%).另外,根据2006 IPCC国家温室气体名录导则和生命周期评价(LCA),制备RDF-5对温室气体排放贡献为455.92 g·kg-1RDF-5(以CO2当量计).     

多边形综合指标法在上海市设施菜田农药减量技术评估中的应用

将综合效益分为经济效益、社会效益、生态效益3个元素,综合代价分为经济代价、社会代价、生态代价3个元素,将参加综合代价评价的指标优化矩阵与参加综合效益评价的指标优化矩阵的比称为综合代价效益比矩阵;运用多边形指标法的基本原理和方法,构建了综合代价效益比RCC/CP模型,将其应用于上海市设施菜田农药减量技术评估体系中,并根据不同控害方案产生的综合代价效益比值将控害功能分为优良、较好、一般、较差和很差5个等级.结果表明,"防虫网室2.2m"(RCC/CP=0.4363)、"防虫网室2.7m"(RCC/CP=0.4622)、"防虫网室3.2m"(RCC/CP=0.4786)均达到"较好"等级,"薄膜遮阳防虫网室2.7m"(RCC/CP=0.5153)的控害功能达到"一般"等级,对照"露地常规防治区"(RCC/CP=1.1001)的控害功能为"很差"等级,其中,"防虫网室2.2m"是本试验中最优的农药减量控害措施.     

芜湖市蔬菜硝酸盐污染状况及安全处理效果

对芜湖市蔬菜集散市场的菠菜、青菜、黄瓜、青椒、番茄、马铃薯、莴苣、白萝卜、卷心菜及腌制雪里蕻10种常见蔬菜的硝酸盐含量进行了测定,并分析了低温储存及洗洁精清洗对蔬菜硝酸盐含量的影响。结果表明,洗洁精去除蔬菜中硝酸盐效果较好,常规洗菜前先在"白猫"牌洗洁精水溶液中浸泡15min,可使硝酸盐平均含量降低近100mg·kg-1。随着放置时间的增加,硝酸盐逐渐分解,而冰箱内低温存放,可减缓蔬菜硝酸盐含量的下降。根据GB18406.1—2001《农产品安全质量无公害蔬菜安全要求》对10种蔬菜进行的评价发现,叶菜类蔬菜中菠菜、青菜硝酸盐含量严重超标,其他所测蔬菜均未超标。