拌种防治玉米二点委夜蛾的药剂筛选及其安全性研究

为了筛选拌种防治二点委夜蛾的有效药剂,并明确其对玉米种子萌发的安全性。本文通过培养皿法和室内盆栽试验比较了9种不同类型杀虫剂拌种对玉米种子萌发的影响以及保苗效果。结果表明,60%溴氰虫酰胺SC和20%氯虫苯甲酰胺SC拌种处理效果较好,保苗效果分别达到90.02%和70.07%,可将死苗率控制在10%以内,被害指数控制在20%以内,且对玉米出苗安全。因此,60%溴氰虫酰胺SC和20%氯虫苯甲酰胺SC可作为拌种防止玉米二点委夜蛾为害的有效药剂。     

2015～2016年河南口岸进境水果截获粉蚧概况及其形态鉴定

粉蚧是一类严重危害农林果树作物的重要害虫,极易随水果等植物产品进行传播.因其个体微小,形态近似,所以鉴定较难.本文对河南口岸近两年截获的粉蚧及其形态特征进行描述,并编制种类检索表,以供检疫人员鉴定参考.     

Inverse identification of early- and latewood hydric properties using full-field measurements

The study and identification of the water diffusion properties of Abies alba Mill at the growth ring scale are investigated in this paper. A full-field measurement technique, the grid method, is used in the experimental tests in order to observe heterogeneities and to measure strain fields in the annual growth rings. In this case, the mechanical behaviour of latewood (LW) and earlywood (EW) is studied under the effect of water stress. This technique is coupled to an inverse method for parameter identification. It enables us to assess the diffusivity of EW and LW in the tangential diffusion direction (T) and their expansion coefficients in the radial direction (R) from strain maps obtained using the grid method. Thus the water diffusion phenomenon and its effect on the deformation of wood specimens are studied. A suitable experimental device is designed to provide direct contact with water on one side of the specimen, and strain maps are obtained over time on the other side. During the experiments, strain gradients that appear are clearly different between EW and LW, highlighting the different diffusion properties at the ring scale level. The results also show changes in the kinetics of the hydric deformation of the material.     

基于Maxent模型的美国西海岸树流感暴发风险时空分析

树流感即栎树猝死病（SOD）自从在美国发现以来,已经造成了美国加利福尼亚州树木大量死亡,并且扩散到了俄勒冈州。对树流感未来暴发风险区域的研究能够为树流感防控提供科学依据,同时为中国防治类似森林病虫害提供借鉴。联合国气候变化政府间专门委员会（IPCC）在第5次评估报告中指出,根据温室气体排放模式的不同未来气候变化有4种可能趋势。该研究基于现在的全球植被覆盖数据、过去的气候数据和未来4种不同排放模式下的气候数据,运用Maxent模型预测了北美西海岸地区在2000年、2050年、2070年树流感暴发风险区域。对预测结果的时空对比分析发现,北美西海岸地区未来树流感暴发高风险区域将会往北和西海岸地区扩张,在各种气候模式下扩张的情况不一样,其中相对于2000年,在RCP85排放模式下2070年北美西海岸地区的高风险区域将会增加174%。     

渭南市花椒窄吉丁虫危害风险分析

花椒窄吉丁虫是危害花椒的主要害虫。通过对该虫的生物学特性、分布与管理、扩散蔓延的可能性、危害影响和检疫防治的难度等5个方面的分析,依据林业有害生物风险分析原则,利用有害生物多指标评价体系,对花椒窄吉丁虫在渭南市的危害风险进行了评估。在定性和定量风险分析的基础上,计算得出风险评估值(R=1.23),属低度危险有害生物,并提出花椒窄吉丁虫的防治办法,为花椒经济林的丰产管理提供参考。     

Prior exposure to diurnal heating influences soil respiration and N availability upon rewetting

On sunny summer days, the top 10 cm of soil in southern Australia are heated to temperatures between 50 and 80 °C for a few hours a day, often for several successive days. These extreme temperature events are likely to have profound effects on the microbiota in these soils, but we do not know how this recurrent heat exposure influences microbial dynamics and associated nutrient cycling. In this study, an air-dry soil from southern Australia was exposed to one or two diurnal heating events with maximum temperature of 50 or 70 °C. The control was left at ambient temperature (Amb). All soils were rapidly rewet. Soil respiration was measured for 7 days after rewetting; microbial biomass C, available N and P were determined before rewetting and 1 and 7 days after rewetting. After heating and before rewetting compared to Amb, microbial biomass C (MBC) was 50–80% lower, but available P was 25% higher in heated soils. Available N differed little between Amb and heated soils. Rewetting resulted in a flush of respiration in Amb and soils heated once, but there was no respiration flush in soils heated twice. Cumulative respiration compared to Amb was about 10% higher in soils heated once and about 25% lower in soils heated twice. In Amb, MBC 1 day after rewetting was similar as before rewetting. But in heated soils, MBC increased from before rewetting to 1 day after rewetting about fourfold. Compared to Amb, available N 1 day after rewetting was 20–30% higher in soils heated to 70 °C. Seven days after rewetting, available N was 10% higher than Amb only in soils heated twice to 70 °C. It can be concluded that diurnal heating kills a large proportion of the microbial biomass and influences soil respiration and nutrient availability after rewetting of soils. The effect of heating depends on both maximum temperature and number of events.     

Effects of soil temperature on biomass production and allocation in seedlings of four boreal tree species

One-year old seedlings of trembling aspen (Populus tremuloides Michx.), black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss), and jack pine (Pinus banksiana Lamb.) were subject to seven soil temperatures (5, 10, 15, 20, 25, 30 and 35 °C) for 4 months. All aspen seedlings, about 40% of jack pine, 20% of white spruce and black spruce survived the 35 °C treatment. The seedlings were harvested at the end of the fourth month to determine biomass and biomass allocation. It was found that soil temperature, species and interactions between soil temperature and species significantly affected root biomass, foliage biomass, stem biomass and total mass of the seedling. The relationship between biomass and soil temperature was modeled using third-order polynomials. The model showed that the optimum soil temperature for total biomass was 22.4, 19.4, 16.0 and 13.7 °C, respectively, for jack pine, aspen, black spruce and white spruce. The optimum soil temperature was higher for leaf than for root in jack pine, aspen and black spruce, but the trend was the opposite for white spruce. Among the species, aspen was the most sensitive to soil temperature: the maximum total biomass for aspen was about 7 times of the minimum value while the corresponding values were only 2.2, 2.4 and 2.3 times, respectively, for black spruce, jack pine and white spruce. Soil temperature did not significantly affect the shoot/root (S/R) ratio, root mass ratio (RMR), leaf mass ratio (LMR), or stem mass ratio (SMR) (P>0.05) with the exception of black spruce which had much higher S/R ratios at low (5 °C) and high (30 °C) soil temperatures. There were significant differences between species in all the above ratios (P<0.05). Aspen and white spruce had the smallest S/R ratio but highest RMR while black spruce had the highest S/R but lowest RMR. Jack pine had the highest LMR but lowest SMR while aspen had the smallest LMR but highest SMR. Both LMR and SMR were significantly higher for black spruce than for white spruce.     

氨化预处理对稻草厌氧消化产气性能影响

为了节省秸秆厌氧消化阶段另加N源调配营养的运行成本,同时又要保持良好产气效率。本试验选用氨化法对秸秆进行预处理,研究了不同浓度的氨对稻草厌氧消化产气性能的影响。以NH3·H2O为预处理药剂,按2%、4%、6%（相对于稻草的干质量）的NH3质量分数对稻草进行氨化,分别以50、65、80 g/L 3个不同负荷进行厌氧消化。结果表明：不同浓度的氨化预处理中,4%NH3氨化预处理效果最好。在65 g/L负荷率下,4%NH3预处理的消化70 d累积产气量为37?010 mL,消化产气量达总体积的90%（计T90）时产气量为33?920 mL,分别比未预处理稻草、2%和6%NH3预处理稻草T90时产气提高了38.3%、14.6%和8.2%,甲烷总产量分别提高了34.8%、15.1%和9.6%,比未预处理稻草同期（45 d）累积产气量以及甲烷总产量分别提高了60.8%和60.3%,产气周期提前10 d结束。消化后总固体（TS）、挥发性固体（VS）的减少量分别由41.6%和46.6%提高到了46.4%和58.6%,半纤维素和木质素质量分数分别由27.7%和6.9%减少到20.8%和5.2%,粗蛋白质量分数从4.0%提高到10.1%。本研究提供了一个有效地提高产气量的方法,研究结果将为大中型秸秆沼气工程提供设计依据。     

陕北黄土高原区日光温室蔬菜产业发展的几点思考

阐述了陕北黄土高原区日光温室蔬菜产业发展的优势和现状,通过深入到陕北蔬菜生产和销售的第一线就其日光温室蔬菜生产等方面的问题进行了调查研究,综合分析陕北黄土高原区日光温室蔬菜产业发展的制约因素。结果认为,主要存在着无公害蔬菜标准化生产和消费的社会意识和氛围不浓,产品质量和生产效益相对较低;蔬菜“优质优价”的市场机制还未建立,蔬菜质量监督检测机构尚未形成;日光温室蔬菜无公害标准化生产的推广服务体系尚未建立,产业化组织机制发育不健全;日光温室蔬菜生产规模小,品牌产品缺乏;农民文化水平偏低等五个方面的制约因素。并就陕北日光温室蔬菜产业可持续发展提出了相应的对策,包括充分发挥气候资源优势,合理规划设施布局;实施品牌战略,推行无公害生产;增强科技意识,提高市场竞争力;科学管理,提高生产水平;加强组织领导,走产业化之路等几个方面。     

2018年山东省淄博市小反刍兽疫免疫效果评估

为科学评估淄博市小反刍兽疫免疫效果,2018年6月采用横断面研究方法,对淄博市部分规模养殖场和自然村（散养户）的小反刍兽疫免疫情况进行评估。采用两阶段随机抽样方法结合部分便利抽样,共采集44个规模养殖场和81个自然村的2 350份羊血清样品,经检测发现,规模场群体合格率为95.45%（42/44）,自然村群体合格率为91.36%（74/81）,个体免疫抗体合格数为2 220份,个体合格率为94.47%,均高于国家和山东省的最低要求。评估结果表明,淄博市的小反刍兽疫总体免疫效果良好。