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1.
借助于OTC-1型开顶式气室进行了700ppm、500ppm和自然条件下二氧化碳浓度对棉花影响的模拟诊断试验,结果表明:二氧化碳浓度升高,特别是二氧化碳浓度倍增对棉花生育进程、生物量和产量等均有明显的正效应。  相似文献   

2.
储粮过程由微生物及害虫等组成的生物场与温度和湿度等构成的非生物场所造成的影响会降低粮食品质,影响粮食安全。储粮中二氧化碳浓度反应粮库生物场状况,是储粮生物场监测的重要指标。为实现储粮二氧化碳浓度高精度检测,该研究基于可调谐半导体激光吸收光谱(Tunable Diode Laser Absorption Spectroscopy,TDLAS)技术高灵敏度和快速响应的特点研制了一套储粮二氧化碳浓度现场检测系统,并建立了二氧化碳激光光谱分析与数据处理方法。基于便携式要求,系统采用紧凑型设计,集二氧化碳浓度、温度及湿度检测功能于一体,同时实现弱信号调理、二氧化碳浓度计算及生成多参数云图、水势图显示等功能。整机尺寸338 mm×251 mm×88 mm,室温条件下功耗小于1.3 W。试验结果显示:该检测系统能够长时间稳定工作,人机交互功能鲁棒性较好,对储粮二氧化碳浓度检测的响应时间小于20 s,线性误差小于1.2%,检测重复性为0.4%,检测精度为10mg/m3,检测范围为0~20 000 mg/m3,温度的检测范围为-40~120℃,湿度检测范围为0...  相似文献   

3.
不同二氧化碳浓度处理对棉花生长发育和产量形成的影响   总被引:1,自引:0,他引:1  
借助于OTC-1型开顶式气室进行了700ppm,500ppm和6上二氧化碳深度对棉花影响的模拟诊断试验,结果表明,二氧化碳深度升高,特别是二氧化碳浓度倍增加对棉花生育进程、生物量和产量等均有明显的正效应。  相似文献   

4.
日光温室二氧化碳施肥技术研究   总被引:7,自引:0,他引:7  
给出了施与不施二氧化碳(CO2)温室内二氧化碳浓度的日变化状况,分析了施用二氧化碳对蔬菜生长发育和产量的促进作用,提出了对不同种类蔬菜施用二氧化碳的适宜施放期、一天内适宜施放时间以及适宜施放浓度。  相似文献   

5.
为规范科研实验条件,更好地为现代畜牧业产业化服务,检验了农业部动物营养学重点开放实验室程控式人工气候舱(简称环控舱)的通风系统的功能,对装载动物的环控舱在正常运转5d以上的气体成分进行分析。测定结果表明舱内的氨气和二氧化碳浓度分别为11.3~19.7mL/m3和890~1400mL/m3,均低于家畜卫生标准,但鸡试验舱在上午开舱门清粪前的氨气浓度和猪试验舱的二氧化碳浓度较高,接近了卫生标准的上限值。  相似文献   

6.
为规范科研实验条件,更好地为现代畜牧业产业化服务,检验了农业部动物营养学重点开放实验室程控式人工气候舱(简称环控舱)的通风系统的功能,对装载动物的环控舱在正常运转5d以上的气体成分进行分析。测定结果表明舱内的氨气和二氧化碳浓度分别为11.3~19.7mL/m和890~1 400mL/m,均低于家畜卫生标准,但鸡试验舱在上午开舱门清粪前的氨气浓度和猪试验舱的二氧化碳浓度较高,接近了卫生标准的上限值。  相似文献   

7.
长期水分胁迫下氮、钾对夏玉米叶片光合特性的影响   总被引:10,自引:1,他引:9  
采用2 种不同夏玉米基因型(陕单9号,抗旱品种;陕单911,不抗旱品种)的盆栽试验,研究了长期水分胁迫下氮、钾对各生育期叶片净光合速率、蒸腾速率、胞间二氧化碳浓度和叶绿素含量的影响,旨在从光合生理特性揭示这些因子的抗旱机理。结果表明,长期水分胁迫下叶片净光合速率、蒸腾速率、胞间二氧化碳浓度(除成熟期)和叶绿素含量显著降低,不抗旱品种降幅更甚。抗旱品种的净光合速率和叶绿素含量大于不抗旱品种,而蒸腾速率和胞间二氧化碳浓度则相反。两品种苗期光合作用较弱,净光合速率和叶绿素含量均较低,抽雄期达到高峰。施氮能不同程度降低水分胁迫下玉米叶片的蒸腾速率,增加叶绿素含量,提高净光合速率,从而减缓水分胁迫对光合作用的伤害。随氮肥用量增加,不抗旱品种净光合速率和叶绿素含量显著升高,蒸腾速率和胞间二氧化碳浓度明显降低,两种氮肥用量间有显著差异;抗旱品种在低氮用量时效果显著,但高低氮用量间无显著区别。钾对受水分胁迫的玉米表现出比氮肥更突出的效果。相反,在适量供水条件下,氮钾肥的作用明显下降。以上结果表明,适当用量的氮、钾肥,可以有效地改善水分胁迫下作物叶片的光合特性,从而增强作物的抗旱性。  相似文献   

8.
为分析夏、冬季节层叠式笼养肉鸭舍不同位置环境参数的分布规律以及各环境参数对肉鸭出栏质量的影响,本研究以樱桃谷鸭为研究对象,对舍内48个测点进行整个生长周期的测定,以期为肉鸭养殖提供参考依据。结果表明:不同季节舍内不同位置的环境参数存在显著性差异。1)夏季水平方向上距离净道端27.3、45.3 m处温湿度与9.3 、63.3 m处温湿度相比显著降低(P<0.05),9.3 m处风速显著低于其他测点(P<0.05),氨气及二氧化碳浓度由净道端至污道端呈上升趋势;垂直方向上,中层温湿度显著高于上、下层(P<0.05),上层风速显著高于中、下层(P<0.05),下层氨气及二氧化碳浓度较高。2)冬季水平方向上1~3周龄时温度由净道端至污道端呈下降趋势,4~5周龄时温度呈上升趋势,而45.3 m处风速达到最低,氨气和二氧化碳浓度均值达到最大;垂直方向上,中层温度、氨气及二氧化碳浓度显著高于上、下层(P<0.05),中层风速显著低于上、下层(P<0.05)。3)夏、冬季节鸭舍中层平均体重略低于上、下两层,后端平均体重略低于前端。4)相关分析结果表明,夏、冬季节温度与相对湿度呈极显著负相关(P<0.01),风速与氨气浓度及二氧化碳浓度呈极显著负相关(P<0.01),氨气浓度与二氧化碳浓度呈极显著正相关(P<0.01);夏季相对湿度与肉鸭出栏质量呈显著负相关(P<0.05)。该结果建议根据舍内环境参数分布规律,对通风弱区进行定点通风、加大笼间距或者更换冬季供暖设备等,从而提高舍内气流分布的均匀性,降温除湿,减少有害气体的集聚,为肉鸭提供良好的生长环境。  相似文献   

9.
为了研究甘蓝型冬油菜光合特性与抗寒性的关系,本研究以甘蓝型冬油菜为试验材料,在甘肃省兰州市、天水市两个地点进行种植,在油菜越冬前对油菜叶片的光合速率、胞间二氧化碳的浓度以及蒸腾速率进行了测定。结果表明:50个甘蓝型冬油菜品种的越冬率存在地域间的差异,天水市的越冬率明显高于兰州市,天水市的越冬率达到100%的有15个品种,而兰州市越冬率最高的是57%,兰州市品种越冬率为0的有6个,而天水越冬率最低的为9.03%。经过品种的光合速率、胞间二氧化碳浓度、蒸腾速率、越冬率的相关性比较分析表明:光合速率与胞间二氧化碳浓度呈极显著负相关;光合速率与蒸腾速率呈极显著负相关;光合速率与越冬率呈极显著正相关;胞间二氧化碳浓度与蒸腾速率呈极显著正相关;胞间二氧化碳浓度与越冬率呈极显著负相关;蒸腾速率与越冬率呈极显著负相关。  相似文献   

10.
CO2对大豆,花生产量的效应   总被引:2,自引:0,他引:2  
本研究利用开顶式熏气罩进行模拟试验,供试作物为大豆和花生各一组,每组各设4个处理:CO2340ml/L(无罩对照);CO2340mg/L(有罩对照);CO2517mg/L;CO2607mg/L。试验结果表明,大豆和花生的生长和产量是随着二氧化碳浓度的增加而提高,当大气中二氧化碳浓度为607mg/L时,大豆和花生的产量分别比无罩对照增加18.6%和25.5%;用聚乙烯塑料薄膜罩,可使罩内日平均温度提  相似文献   

11.
【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。  相似文献   

12.
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.  相似文献   

13.
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,  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
Arbitrary oligonucleotides were used as primers to amplifygenomic DNA of 48 wild Spanish populations of Agropyroncristatum, Elymus hispanicus,E. caninus,E. repens,Thinopyrum curvifolium, Th.junceum and Th.intermedium. Genetic diversity was analysedusing nineteen primers. The number of amplified products ranged from8 to 18 per primer and a total of 240 markers were scored. Differentlevels of intraspecific genetic diversity were found, the allogamousspecies E. repens andTh. intermedium being themost variable. Jaccard's similarity coefficients for internalmeasure within and between populations were used to produce a clusterdiagram. The results demonstrate differences in the degree ofsimilarity between taxonomic units. Interpopulational variability andinterspecific genomic relationships of these species arediscussed.  相似文献   

20.
The effects of three commonly used fungicides on the colonization and sporulation by a mixture of three arbuscular mycorrhizal (AM) fungi consisting of Glomus etunicatum (Becker & Gerd.), Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe, and Gigaspora rosea (Nicol. & Schenck) in symbiosis with pea plants and the resulting response of the host-plant were examined. Benomyl, PCNB, and captan were applied as soil drenches at a rate of 20 mg active ingredient kg-1 soil 2 weeks after transplanting pea seedlings in a silty clay-loam soil containing the mixed inocula of AM fungi (AM plants). Effects of fungicides were compared to untreated plants that were inoculated with fungi (AM control). The effect of mycorrhizal inoculation on plant growth was also examined by including nonmycorrhizal, non-fungicide-treated plants (non-AM control). Fungicides or inoculation with AM fungi had only a small effect on the final shoot weights of pea plants, but had greater effects on root length and seed yield. AM control plants had higher seed yields and lower root lengths than the corresponding non-AM plants, and the fungicide-treated AM plants had intermediate yields and root lengths. Seed N and P contents were likewise highest in AM control plants, lowest in non-AM plants, and intermediate in fungicide-treated AM plants. All three fungicides depressed the proportion (%) of root length colonized by AM fungi, but these differences did not translate to reductions in the total root length that was colonized, since roots were longer in the fungicide-treated AM plants. Pea plants apparently compensated for the reduction in AM-fungal metabolism due to fungicides by increasing root growth. Fungicides affected the population of the three fungi as determined by sporulation at the final harvest. Captan significantly reduced the number, relative abundance, and relative volume of G. rosea spores in the final population relative to the controls. The relative volume of G. etunicatum spores was greater in all the fungicide-treated soils, while G. mosseae relative volumes were only greater in the captan-treated soil. These findings show that fungicides can alter the species composition of an AM-fungal community. The results also show that AM fungi can increase seed yield without enhancing the vegetative shoot growth of host plants.  相似文献   

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