迎春始花期预报方法的研究

分析石家庄 1982～ 2 0 0 3年迎春始花期与气温资料发现 :迎春始花期与 2～ 3月气温呈明显负相关 ;迎春始花期所需 >0℃积温为 15 4 0℃·d ;近年来与冬季负积温呈负相关关系 ,此外近 2 0年间迎春始花期有明显提前趋势 ,在此基础上建立了迎春始花期的预报模式     

重庆永川地区气象因子与黄花梨花期关系分析

以逐年的观察记载资料为基础,分析重庆市永川区2007—2014年8年间气象因子与黄花梨花期的关系,结果表明:黄花梨花期平均时长为24.75 d,期间降雨量17.74 mm,5℃积温平均313.05℃,10℃积温平均269.98℃,总日照时数平均63.31 h。相关及回归分析结果表明,开花期天数与降雨量、5℃积温、10℃积温、日照时数呈显著正相关关系,其中,5℃积温相关性最好,可作为预测黄花梨花期天数的重要依据。     

逐步回归及模糊聚类分析气候条件对苹果产量的影响

<正> 结果与分析对祝光、金冠、元帅、国光4个品种的气象产量与1～2月平均温度(X_1)、7月份平均温度(X_2)、6～8月降水量(X_3)、上年6～8月降雨量(X_4)、7～8月日照时数(X_5)、上年4～10月积温(X_6)6个气象因素进行逐步同归,筛选出对产量有重要影响的气象因子,在10％信度下得出以     

菏泽牡丹初花期的中长期预报模型

菏泽牡丹开花期短并且每年初花期离散度较大,这对办好菏泽国际牡丹花会造成严重困扰。本文通过牡丹初花期偏早、偏晚样本前期500hPa大气环流特征对比分析得出,牡丹初花期偏早和偏晚年份其前期环流有明显差异,因此,用1964-2006年牡丹花期序列对4月-翌年3月北半球500hPa月平均高度逐月进行相关分析,得出41个优势相关区,其中有4个是正相关区,其余为负相关区,正、负相关区出现有一定的时间性和区域性：正相关区出现在冬季太平洋和大西洋北部高纬地区,负相关区于上年4-5月在印度洋北部海区及赤道北太平洋海区出现并向北传播;再从优势相关区中筛选格点作为预报因子,建立一组牡丹花期中长期预报方程,最长预报时效超过150d。经几年试用效果较好。本方法对延长花卉花期预报时效有一定参考价值。     

气候变化对库尔勒香梨始花期的影响及其预测模型

利用1980-2010年库尔勒市气象局农业气象站香梨物候观测资料和地面气象观测资料,对影响香梨始花期的气象因子进行分析。结果表明,近31a来,受气候变化影响,库尔勒香梨始花期有明显的提前趋势(P<0.01);香梨始花期与冬季平均气温、春季气温以及不同深度地温呈显著负相关关系(P<0.01);而与开春日期及5日平均气温>10℃日期呈显著正相关关系(P<0.01)。利用偏最小二乘法回归分析,建立了香梨始花期的预测模型,并进行校正,通过检验模型效果良好,可为香梨始花期预报提供参考。     

眉山市东坡区樱花盛花日预测

基于东坡区气象站2013—2016年气温观测资料和2017年气温预报资料,对眉山晚樱盛花日和气温进行了相关性分析,并应用线性回归模型和积温方法,对2017年晚樱盛花日进行预测,取得了较好效果。结果表明:盛花日受上年11月、12月气温影响较小,与当年1—3月平均气温的相关性最高;利用回归模型和积温方法分别预测出2017年盛花日为3月25日、24日,和实际花期有2 d左右的差异;利用实况气温进行盛花日回测,结果与悦兴镇樱花花期有3~4 d的差异,但与樱花博览园花期较吻合。     

共和盆地界限温度初终日和积温对气候变化的响应

利用青海省共和盆地海南州气象台1953—2010年逐日平均气温,以5 d滑动平均法确定稳定通过≥0℃、≥3℃、≥5℃、≥10℃初、终日,求算初终日间持续日数、活动积温和有效积温,分析界限温度初终日、持续日数和积温的变化,应用Pearson函数求算界限温度初终日、初终日期间持续日数、活动积温和有效积温与年平均气温的相关性并建立回归模型。结果表明:共和盆地各级界限温度初日均呈提前趋势,终日均呈推后趋势,初终日间持续日数呈增加趋势,活动积温和有效积温均表现为增大趋势;各界限温度初日与年平均气温呈负相关,终日与年平均气温呈正相关,初终日间持续日数呈正相关,活动积温和有效积温与年平均气温极显著相关;若年平均气温升高1℃,则各界限温度初日提前3～6 d,终日推迟3～4 d,各界限温度期间的持续日数延长6～10 d,活动积温增加165～190℃,有效积温增加164～183℃。     

杂交稻制种的叶龄净积温推算法

一、净效积温及其求算近几年来,我们在杂交稻的制种试验中,进行了花期稳定相遇的研究。曾在大量的亲本中,用播始历期间的资料,将当前广泛使用的生育期法、叶龄法,积温法(有用活动积温、有效积温、净效积温)进行筛选,其结果为:净效积温最稳定,变异度小于4％,其次是叶龄,变异度在5％左右,而生育期、活动积温、有效积温其变异度均在10％以上。从几年的生产实践证明,在高温地区或     

西峰黄土高原冬季积温变化对作物发育期的影响

用黄土高原西峰站1965-2005年冬季积温和1981—2005年冬小麦、苹果、梨树发育期资料，分析了冬季积温和作物发育期的变化规律，用相关计算和典型年份对比方法探讨了冬季积温对作物发育期的影响。结果表明：1965—2005年冬季积温增加率为5．5℃·d／a，2000年以来持续为正距平，1994年以后作物发育期持续变早；冬季积温与冬小麦各发育期呈明显的负相关，最显著的是返青期，其次是抽穗期，再次是起身期；冬季积温典型偏高年份（1986、1998、2000年）均比典型偏低年（1983、1984、1988年）的发育期提前，冬小麦最明显的是全发育期提前了21d，苹果最明显的是叶变始期提前了19d，梨树最明显的是叶变盛期提前了20d。研究结果对掌握作物发育期的变化规律以及物候预测有一定意义。     

基于危害积温的枸杞花期霜冻指标试验

为得到枸杞花期受霜冻危害的温度范围,探究低温及其持续时间对枸杞花期的影响,利用人工霜冻实验箱于2016—2019年开展了枸杞花期霜冻模拟试验,统计了不同温度及其不同持续时间下枸杞花期3个阶段(花蕾期、初花期、盛花期)的受冻率,引入危害积温的概念进行了分析,结合霜冻灾害的实际情况对危害积温的公式进行了修订,建立了基于危害积温的枸杞花期霜冻指标,并利用野外实地调查结果对该指标进行了验证。结果表明,当气温降至-1℃时枸杞花朵未出现受冻迹象,降至-2℃时枸杞花朵开始出现受冻迹象,-8℃时受冻率达到100%,说明枸杞花期受霜冻危害的温度范围为-8～-1℃,在此温度范围内,温度越低、低温持续时间越长,花朵受冻率越高。枸杞花蕾的抗冻能力最强,初花次之,盛花最弱。修订后的危害积温公式对受冻情况的解释更加客观全面,计算结果与野外调查结果基本一致,建立的指标能够应用于枸杞花期霜冻灾害预报、预警以及评估。     

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,     

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.     

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.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

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,     

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,     

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.