库尔勒香梨年生长期生物量及养分积累变化规律

以6年树龄的库尔勒香梨为试材,对香梨树生物量及养分吸收规律进行了研究。结果表明,年生长期内香梨单株树体干物质、氮、磷、钾的积累量均随生育期的推进呈增长趋势,与萌芽前期相比,分别增加5804.92 g、75.71 g、27.11 g和103.10 g。其中膨果期的积累量和积累速率都较大,干物质、氮、磷、钾的积累量分别占积累总量的53.52 %、 22.93 %、 44.04%和62.66%。库尔勒香梨每生产1000 kg 果实需要吸收氮（N）7.52 kg、磷（P）4.29 kg和钾（K）6.05 kg。     

库尔勒香梨振动模态的有限元分析及坚实度评估

为了实现香梨坚实度的可靠评估,该文采用有限元法对香梨振动模态分析,以明确库尔勒香梨果形对固有频率的影响,并建立更适于香梨坚实度评价的指标。研究结果表明：香梨梗端和萼端是振动信号激励和感测的适宜位置,其扭转模态、弯曲模态、拉压模态的固有频率?可用于香梨坚实度评估;采用香梨固有频率?、质量m、密度ρ及描述果形的纵横比q建立的公式?2m2/3ρ1/3qt能够有效评估香梨坚实度,各模态的固有频率?对应的t值分别为：扭转模态时,t=1.19;弯曲模态时,t=1.47;拉压模态时,t=0.47。这可为香梨内部品质的振动检测提供研究依据和实践指导。     

氮、磷、钾配施对库尔勒香梨长势与产量的影响

为了掌握库尔勒香梨的生长规律及其对土壤养分氮素、磷素、钾素的响应程度.在田间条件下,设置不同氮、磷、钾施肥处理,对20年树龄的库尔勒香梨进行生育期树体长势与产量监测,结果表明:施肥能促进香梨树体的生长和果实发育,在一定程度上改善果形指数,提高产量.通过模型建立与分析,肥料3要素对香梨产量的贡献顺序为:氮肥＞钾肥＞磷肥,氮磷、磷钾之间具有协同效应,氮钾之间效应不明显.以香梨产量27500～27800kg·hm-2为目标,推荐香梨氮、磷、钾素施肥量分别为280 ～330kg·hm-、250 ～ 300kg·hm-2和50～60kg·hm-2.     

引入人体舒适度指数建立新疆库尔勒香梨主产区赏花气象指数预测模型

采用逐步回归方法对1990-2020年新疆阿克苏、阿拉尔、轮台和库尔勒产区的香梨始花期气象要素与香梨开花始期日序进行分析,结合人体舒适度指数,建立新疆库尔勒香梨主产区赏花气象指数预测模型,以期为判别香梨花期的最适宜赏花日提供气象服务参考依据。结果表明：（1）新疆库尔勒香梨主产区始花期预测模型构成因子为3月平均最高气温、3月0cm地温、3月平均气温、3月40cm地温;阿拉尔、库尔勒始花期日序与气温呈一元线性负相关关系,阿克苏、轮台与地温和气温呈多元线性关系;正常年份模型误差在3d内的概率分别为阿拉尔93.5%、阿克苏93.5%、库尔勒100%、轮台96.8%。（2）人体舒适度指数划分为最适宜、次适宜、一般和不适宜四个等级,2022年花期前后人体舒适度指数最适宜日数分别为阿拉尔22d,阿克苏24d,库尔勒16d,轮台18d。（3）香梨赏花气象指数取适宜花期时段与人体舒适度指数的交集,划分为最适宜（五颗星推荐指数）、次适宜（四颗星推荐指数）、一般（三颗星推荐指数）和不适宜（一颗星推荐指数）四个等级。2022年五颗星推荐赏花日阿克苏为4月11-14日,阿拉尔为4月10-15日,库尔勒为4月10...     

施氮对库尔勒香梨树体氮素吸收和积累的影响

以6年树龄库尔勒香梨为试材,采用整体挖掘和分器官解剖的方法,对不同施氮处理库尔勒香梨树体氮素吸收和积累进行分析。结果表明:年生长周期内库尔勒香梨树体干物质形成及氮素累积主要以当年新生器官侧枝、叶和果实为主,其中叶片对香梨树体干物质积累和氮素吸收、积累的贡献较大。施氮对库尔勒香梨树体干物质、氮素积累和产量形成具有显著的促进作用,但并不是氮肥施得越多越好。结合不同施氮处理下库尔勒香梨树体的当季肥料利用率和农学养分效应,推荐6年生库尔勒香梨最佳施氮量为300 kg·hm~(-2)(0.667 kg·株~(-1))。     

库尔勒香梨土壤主要养分与产量关系的研究

以综合管理水平较高的库尔勒香梨(Pyrus Bretschneideri Rehd,简称香梨)示范园为研究区域,通过测定香梨园土壤主要营养元素含量及标准株的产量,构建库尔勒香梨土壤主要营养元素与产量之间关系模型。结果表明:(1)不同土壤层次,0~20 cm土壤有机质含量和有效磷含量高于20~60 cm,0~20 cm碱解氮含量和速效钾含量低于20~60 cm;(2)0~20 cm和20~60 cm土壤层有机质含量与香梨产量关系显著,分别呈对数(P=0.021)和幂函数(P=0.034);0~20 cm土壤层碱解氮与产量关系不显著,而20~60 cm土壤层碱解氮与产量呈对数函数(P=0.053);0~20 cm和20~60 cm土壤层有效磷与产量关系极显著(P=0.014,0.002),相关模型均为对数函数;0~20 cm土壤层速效钾与产量呈幂函数(P=0.041)。总体而言,库尔勒香梨园20~60 cm土壤有机质、碱解氮、有效磷和速效钾含量与库尔勒香梨产量显著相关,表明香梨施肥应深施为宜,施肥深度应≥20 cm;同时,构建土壤养分(x)和单株产量(y)关系模型,即有机质y=28.56x0.22、碱解氮y=16.02lnx+91.72、有效磷y=16.42lnx+110.11、速效钾y=75.96x0.28,达到通过库尔勒香梨目标产量进行定量推荐施肥的目的。     

稳定同位素技术鉴别库尔勒香梨产地可行性研究

为开展碳、氮、氢、氧(C、H、O、N)稳定同位素鉴别库尔勒香梨产地的可行性研究,明确新疆库尔勒香梨δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值,本研究以甘肃香梨和陕西红香酥梨作为对照,采用稳定同位素比值质谱仪(IRMS)分析新疆库尔勒香梨与对照样品的δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值,并采用正交校正的偏最小二乘判别分析(OPLS-DA) 鉴别新疆库尔勒香梨产地真实性。结果表明,新疆、甘肃两个产区香梨与陕西产区红香酥梨的δ¹³C、δ¹⁵N、δ²H、δ¹⁸O值存在显著差异(P<0.05)。新疆产区的66份库尔勒香梨判别准确率为95.45%;甘肃产区的20份香梨样品判别准确率为60%;陕西产区的23份红香酥梨样品判别准确率为95.65%。C、N、H、O 4种稳定同位素可有效鉴别新疆库尔勒香梨和陕西红香酥梨,但在新疆库尔勒香梨与甘肃香梨鉴别方面,误判率较高,如果能结合其他鉴别技术,则有可能出现较好的鉴别效果。本研究为库尔勒香梨产地真实性鉴别提供了科学依据。     

BP神经网络结合有效积温预测速冻水饺变温冷藏货架期

为了解决速冻食品在温度波动贮藏过程中的货架期预测问题,准确监测其品质变化趋势,该文以速冻水饺为研究对象,将其在-28℃～-12℃进行冷藏,测定酸价、过氧化值、饺皮水分含量、亨特白度等理化指标,并结合感官评价与有效积温理论,应用BP神经网络技术预测速冻水饺的货架期。并与动力学模型预测结果进行比较。结果表明,测试集样本的距货架期终点积温的预测值与实际测定值拟合度较好,最大误差为3.29%,模型验证最大误差为2.74%。BP模型的距货架期终点时间的最大误差为3.45%低于传统动力学模型预测的误差(5.62%)。BP神经网络预测模型为速冻食品货架期预测提供了一种新途径。     

不同施肥处理对库尔勒香梨长势与产量的影响

为了掌握库尔勒香梨的生长规律及其对土壤氮素、磷素、钾素的响应,在田间试验条件下,设置不同的施肥处理,对20a树龄的库尔勒香梨进行生育期长势与产量监测。结果表明:与不施肥处理相比,施肥能明显促进香梨的生长和果实发育,改善果形指数,提高产量。不同施肥处理下,香梨基径、树高、梢粗、梢长及叶片的生长施肥效应均表现为:N>P>K,而单果重和产量的施肥效应表现为:N>K>P。     

基于区域亮度矫正的番茄成熟度定量分级方法

针对现有番茄成熟度分级标准不统一,泛化性有待提高等问题,该研究提出一种基于区域亮度矫正的果面红色着色区域提取的方法。采用R-G法增强番茄表面的红色区域,利用Otsu分割方法提取表面着色区域,判断各着色区域的轮廓树结构以计算着色区域面积占图像总面积的比例作为主要特征,构建多因子融合的随机森林模型以实现番茄成熟度的量化分级。同时,利用基于局部亮度均衡的图像快速修复方法以解决光照变化导致的番茄表面高亮度反射问题。结果表明：以番茄表面着色面积比成熟度评价指标的分级平均正确率为92.96%,相比传统颜色矩和颜色直方图作为评价指标时的分级准确率提高了6.53和20.6个百分点。高亮区域领域像素加权替代法可对番茄高亮区域亮度实现有效矫正,矫正后的未熟、半熟和成熟番茄图像的果面着色区域面积占番茄图像总面积的比例较矫正前提高了0.06、0.15和0.11,分级准确率分别提高了17.24、11.47和4.69个百分点。研究可为番茄成熟度的定量性分级提供决策基础。     

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.