温室缀铝膜保温幕节能性能的实验研究初报

用国产缀铝保温膜幕在温室内进行了保温节能实验。测定比较了有、无保温幕二种情况下的室内气温,结果表明,在该实验条件下,采用缀铝膜保温幕时温室内外温差提高了3～5℃,保温幕上、下40cm处温差平均达到8.8℃。测定了温室有、无保温幕时的供暖量,并计算了屋面传热系数,得出缀铝膜保温幕的节能率达到37%,保温性能良好     

华北型连栋塑料温室节能对策与实践

华北型连栋塑料温室采用双层充气膜覆盖、移动式内保温幕、地中热交换系统和砖结构北山墙等节能措施。实践表明,北京地区冬季不供暖时室内最低温度达到８℃以上,室内外温差达到１１℃,节能效果显著。     

连栋温室简易内保温幕保温节能研究

对连栋温室内简易内保温幕保温节能研究结果表明,使用简易内保温幕初冬时节可使供暖设施启动时间推延14d左右,早7:0 0平均气温提高2 .6 5℃,比双层充气膜温室约节煤6 2 5 0 .5 g/m2 ,节能率达38.2 4 % ;启动供暖设施后可使温室内早7:0 0平均气温提高2 .16℃,比阳光板温室约节煤70 g/m2 ·d ,节能率为11.84 %。简易保温幕降低了试验开间内光照度,但其透光率仍高于双层充气膜温室和阳光板温室     

彩钢板保温装配式节能日光温室的温光性能

针对传统日光温室防雨、防雪、防风、防火能力差,以及室内光温环境分布不均匀等问题,研制开发彩钢板保温装配式节能日光温室,该温室骨架为半圆弧形钢结构,采用岩棉彩钢板滑动保温覆盖形式和可移动保温山墙方法,温室跨度12 m、脊高5.5 m、长度65 m,屋面采光角高达41.5°。该日光温室采用水循环系统和空气-地中热交换系统代替土墙和砖墙等蓄热体,解决了装配式日光温室的蓄放热问题,实现了日光温室部件的工厂化生产和安装的标准化装配。与对照（辽沈Ⅲ型土墙日光温室）比较,彩钢板保温装配式节能日光温室脊高前移、位于温室中部,温室后部遮光减少,土地利用率提高20%以上,屋面采光角增加16.3°,采光率提高5.3%,晚间室外大气温度在-25.8℃时,室内气温在13℃以上,室内外温差达到39.1℃,比对照温室提高2.3～3.5℃。彩钢板保温装配式节能日光温室栽培空间大,采光好,升温快,室内横向和纵向光照和温度分布均匀,植株生长整齐,有效解决了传统日光温室抵御雨、雪、风、火自然灾害能力差的问题。该温室集成了大型连体温室温光分布均匀和传统日光温室蓄热保温好的优点,提高了太阳能的利用效率,温室总体温光性能超过对照温室,且滑动覆盖易于实现日光温室保温覆盖件的精准控制,为中国日光温室的自动化控制和现代化提供新途径。     

地面加热系统温室热环境测定与经济分析

温室加热系统对温室冬季耗能有一定的影响。地面加热系统能够合理地利用加热系统的供暖热能，使之充分有效地供给座落在地面上的植物，并降低植物冠层上部温室空间的气温，减少了温室的能耗，这也是温室冬季节能的一种非常有效的方法。该文研究了应用地面加热系统的温室热环境，测试结果表明，温室有较好的空气温度分布。温度水平分布均匀，南北方向上温度差异在1℃左右；温度垂直梯度分布为从地面附近到保温幕下气温逐渐降低，但温度降低幅度比较小，在1℃以内，与传统加热方式的保温幕下高地面附近低的温度垂直梯度分布有明显不同。温室夜间植物根部温度在19～25℃。与传统加热方式相比，采用地面加热的温室热环境比较有利于植物生长。该文还以传统加热系统为比较对象，简单分析了地面加热系统的节能效果、散热器投资和运行效益，结果表明地面加热系统比传统加热系统节约能源28%，散热器投资费用可以节省34.1%，每年降低运行费用3万多元。     

外保温连栋温室光热环境及保温性能分析

为解决中国北方地区连栋温室冬季加温能耗大、盈利性和可持续性差等问题,该研究以降低屋面热损失为出发点,设计了大屋面外保温连栋温室,将外保温系统创新应用于连栋温室,并在山东寿光地区,以文洛型连栋温室为参照,对该温室光热环境及保温性能进行试验测试与分析。结果表明：1)连续40d白天(10:00—16:00),外保温连栋温室作物冠层上方平均太阳辐射为152 W/m²,总透光率(含天沟下方)为40%,比文洛型连栋温室高7个百分点。外保温连栋温室跨中采光最佳,跨东、跨西及天沟下方太阳辐射强度与跨中相比分别减少17%、29%及46%。2)太阳升起后,外保温连栋温室东、西屋面外保温被依次收拢,09:30—12:00室内气温升速为1.9℃/h,较文洛型连栋温室低0.3℃/h,收拢保温后10min内室内气温骤降幅度比文洛型连栋温室低0.3℃。温室采用空气内循环加温,地面出风,再由设备间风机组内侧窗回风;加温期间(20:00—07:00)室内空气水平方向平均温差不超过1.2℃,垂直方向不超过1.0℃。外保温连栋温室水平方向气温分布均匀,垂直方向温差小于文洛型连栋温室。3)夜间,外保温连...     

日光温室内反光膜补光的实践与理论探析

试验结果表明 ,温室后墙悬挂反光膜进行补光后 ,对温室内测定点处最大光照度值无影响 ,但平均提高测定点处水平光照度值 15 4 8% ;温室内凌晨时气温、地温、墙温和被反光膜遮掩处墙温分别比对照温室低 1 1℃、1 5℃、0 9℃和 1 8℃ ,但正午时分别比对照温室高 1 6℃、1 4℃、0 3℃和低 11 4℃。温室经济产量增加 7 4 % ,当期经济效益增加 2 1元 /m2 。     

冬季塑料大棚多重覆盖及电加热增温效果研究

对普通塑料大棚内加设中棚、小棚,再覆盖无纺布被、地膜以及用电热线加热等不同处理,沉淀了棚内冬季的温度动态变化规律。结果表明,每增加一层覆盖物,都可以提高夜间温度1～2℃,且保温效果具有累加效应,晴天白天棚内升温加快。在小棚内使用空气加热线的增温效果比单纯覆盖措施效果好。采用大棚内多层覆盖,再辅之以电热线加温,长江流域地区冬天塑料大棚内可栽培番茄等喜温作物     

多层覆盖连栋温室热环境模型构建

建立了多层覆盖连栋温室的温、湿度动态机理模型，定量描述了温室内的对流换热、土壤热传导、太阳辐射、长波热辐射、植物蒸腾、地面蒸发、水汽凝结、机械通风和自然通风等物理过程，根据质能平衡原理，对覆盖材料、室内空气、作物、土壤等建立了质能平衡方程。在给定的边界条件下，通过求解质能平衡方程，可求得室内温、湿度和各组成部分如覆盖材料、土壤、植物等的温度以及各部分间的能流、蒸汽流密度。利用有效辐射的概念，推导出了内外遮阳幕、内外覆盖材料、作物冠层、地表、室外天空之间的辐射热交换计算方法。利用压力分布法，推导出了具有顶窗、侧窗和湿垫等多个通风口时的风压和热压通风量计算式。与其他研究者提出的温室环境模型相比，本模型具有更为广泛的适用性。     

双膜双被装配式日光温室在郑州地区的小气候测试

2020年11月1日-2021年2月28日,在河南郑州地区对冬春季双膜双被装配式日光温室内外温度、光照和湿度小气候进行测定,以探明其温光性能。在温室内外分别布置环境自动记录仪,每台记录仪均连接温湿度传感器和光照传感器,实现数据的自动监测与传输。结果表明：观测期内,温室内旬平均气温为11.4～21.4℃,旬平均最低气温为9.4～16.7℃;温室内0.1m深处旬平均土壤温度为15.4～22.9℃,旬平均最低土壤温度为15.0～22.1℃,温室内外最大气温差和土温差分别为17.0℃和15.6℃。全年最冷时段（1月上旬）温室外旬平均最低气温为−7.9℃,0.1m处土壤温度旬平均最低值为2.2℃,而此时段温室内旬平均最低气温和0.1m处土壤温度旬平均最低值分别达到9.9℃和15.8℃。11月−翌年2月,温室内光照度逐渐增大,晴天光照度在2000～22000lx,11月、12月、1月和2月晴天日平均透光率分别为42%、52%、49%和45%,12月透光率最高,不同月份透光率存在明显差异;阴天温室光照度在300～4000lx,各月阴天日平均透光率分别为34%、35%、36%和33%,透光率差异不明显。11月下旬−1月下旬,温室内夜间湿度为95.4%～99.0%,夜间叶片沾湿时长占比为89.1%～99.5%,温室内湿度大。观测结果说明双膜双被结构日光温室在黄淮地区冬春季具有较好的保温性能,有利于进行喜温果菜类的越冬生产,具有一定的推广应用价值,但是存在温室透光率偏低、光照弱等问题。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.     

Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater

Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Increase in auxiliary photoprotective photosynthetic pigments in wheat seedlings induced by Azospirillum brasilense

Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.     

In-situ enrichment and analysis of atrazine-degrading microbial communities using atrazine-containing porous beads

We examined the community composition of microbes that colonized atrazine-containing beads buried in agricultural soils that differed in atrazine treatment history. Bacterial abundance was 5-40-fold greater in atrazine-fortified beads. In beads containing 20 mg atrazine kg⁻¹ buried in soil with a history of atrazine application (conditioned soil), the abundance of Actinobacteria increased approximately 80-fold whereas in control soil, Actinobacteria were enriched only 10-fold and the gamma-Proteobacteria and Planctomycetes increased by 60- and 25-fold, respectively. The gamma-Proteobacteria were enriched by 120- and 230-fold in beads containing 200 mg atrazine kg⁻¹ in conditioned and control soil, respectively. The results demonstrate that BioSep^® beads are a suitable matrix for recruiting a diverse subset of the bacterial community involved in atrazine degradation.