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1.
稻季施肥管理措施对后续麦季N2O排放的影响   总被引:4,自引:1,他引:3  
马静  徐华  蔡祖聪  八木一行 《土壤》2006,38(6):687-691
2003─2004年选用江苏省宜兴市稻-麦轮作试验田,研究了水稻生长季秸杆(0和3.75×103kg/hm2两个水平)和N肥施用(N0、200和270kg/hm23个水平)对后续麦季N2O排放的影响。结果表明:稻季秸杆施用显著减少了后续麦季N2O的排放,这些减少量主要体现在小麦播种-返青期,方差分析达显著水平(P<0.05)。稻季施用N肥,后续麦季N2O排放减少,但N200和270kg/hm2N肥施用水平的处理间无显著差异。麦季土壤水分情况与N2O排放通量存在显著正相关(P<0.05)。  相似文献   

2.
Biogenic amines, polyphenols, and resveratrol were analyzed quantitatively in 25 different Hungarian wines from the same wine-making region, harvest of 1998. Polyphenols were determined according to a spectrophotometric method, whereas other substrates were analyzed using overpressured-layer chromatography (OPLC). Principal component analyses (PCA) were performed on data matrices consisting of substrates (columns) and different sorts of wines (rows) from the region of Pécs (southern Hungary). It was found that four (unrotated) principal components account for >80% of the total variance in the data. The plots of component loadings showed significant groupings for concentrations of biogenic amines (and polyphenols). Similarly, the component scores grouped according to the different sorts of wines. The loading plots reveal that there is no need to measure all of the variables to achieve the same characterization. It is enough to measure one variable per group. Naturally, this conclusion is valid only within the limits of the present study; wines from other regions may behave differently.  相似文献   

3.
The element contents of wheat from four major wheat-producing regions of China were analyzed and used in multivariate statistical analysis to classify wheat according to geographical origin. The concentrations of 15 elements (Be, Na, Mg, Al, K, Ca, V, Mn, Fe, Cu, Zn, Mo, Cd, Ba, and Th) in 240 samples from the 2007/2008 and 2008/2009 harvests were determined by inductively coupled plasma mass spectrometry. The analysis of variance and linear discriminant analysis were applied to classify wheat origin, and the effects of region, variety, and harvest year on the element contents were analyzed in this study. It was concluded that the multielement analysis is a promising method to provide reliable origin information for wheat, although the element profiles and discriminant models were affected by wheat varieties, harvest years, and agricultural practices.  相似文献   

4.
利用电感耦合等离子体-质谱(ICP-MS)和电感耦合等离子体-发射光谱(ICP-OES)对不同种植地的青岛大花、札一和马可波罗3个新疆主产啤酒花品种中的22种矿物元素在生长期的含量进行跟踪测定。结果表明,啤酒花对矿物元素的吸收和积累存在"地域差异"和"时间差异",其中Sr、Na、Rb、Li、Ba、Ga、Co和V的含量受种植地的影响较大;但在整个生长周期内,啤酒花对重金属无明显吸收和富集作用。基于22种元素的主成分分析结果进一步证实,前3个主成分的累计贡献率达到84.36%,且由PC 1和PC 2构成的得分散点图可以很好地区分不同产地的啤酒花样本;而由PC 1和PC 3组成的得分散点图主要可以区分啤酒花的"成熟度"。其中,Mg、K、Li、Na可以用来判别啤酒花的产区;Al、Pb、V对于评价啤酒花的成熟度具有较大价值。  相似文献   

5.
The relative effectiveness of average-well-color-development-normalized single-point absorbance readings (AWCD) vs the kinetic parameters mu(m), lambda, A, and integral (AREA) of the modified Gompertz equation fit to the color development curve resulting from reduction of a redox sensitive dye from microbial respiration of 95 separate sole carbon sources in microplate wells was compared for a dilution series of rhizosphere samples from hydroponically grown wheat and potato ranging in inoculum densities of 1 x 10(4)-4 x 10(6) cells ml-1. Patterns generated with each parameter were analyzed using principal component analysis (PCA) and discriminant function analysis (DFA) to test relative resolving power. Samples of equivalent cell density (undiluted samples) were correctly classified by rhizosphere type for all parameters based on DFA analysis of the first five PC scores. Analysis of undiluted and 1:4 diluted samples resulted in misclassification of at least two of the wheat samples for all parameters except the AWCD normalized (0.50 abs. units) data, and analysis of undiluted, 1:4, and 1:16 diluted samples resulted in misclassification for all parameter types. Ordination of samples along the first principal component (PC) was correlated to inoculum density in analyses performed on all of the kinetic parameters, but no such influence was seen for AWCD-derived results. The carbon sources responsible for classification differed among the variable types with the exception of AREA and A, which were strongly correlated. These results indicate that the use of kinetic parameters for pattern analysis in CLPP may provide some additional information, but only if the influence of inoculum density is carefully considered.  相似文献   

6.
Major and minor (K, P, Ca, Mg, Na, Fe, Mn, Zn, and Sr) and trace (Ba, Ni, Pb, V, Co, Cd, and Sb) elements from wine samples from the Denomination of Origin (DO) Empordà-Costa Brava (Catalonia, Spain) were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and mass spectrometry (ICP-MS) respectively. Previously, a comparison of different calibration methodologies and sample digestion treatments had been carried out using ANOVA statistical tool. The obtained results demonstrated that internal standardization provides reliable results with the advantage that no further manipulation of the sample is needed. A principal component analysis of the concentration data was performed to differentiate the samples of DO Empordà-Costa Brava from wine samples from other wine-producing regions in Spain (i.e., Penedès, Somontano, and Rioja). It was found that Sr and Ba contents discriminate the two DO groups. Moreover, a discriminant analysis function involving both variables distinguishes the two groups with a 100% classification rate. At the level of the leave-one-out cross-validation, all of the Empordà-Costa Brava samples were well classified, whereas the other DOs presented two borderline misclassifications.  相似文献   

7.
Abstract

Two field experiments measured variation of phosphorus (P) concentration in dried tops (plant‐test P) of individual lupin (Lupinus angustifolius cv. Merrit) and wheat (Triticum aestivum cv. Cadoux) plants collected from random locations in experimental plots treated with different levels of superphosphate. Plant‐test P for the individual tops varied by between 4 to 65% of mean values. Coefficient of variation for the 10 individual plants per plot varied from 10 to 24%. For each plot, mean plant‐test P for the 10 individual tops were similar to values for bulk samples of 30 plants collected at random within the plot. It is concluded that a bulk sample of 30 lupin or wheat plant tops need to be collected from uniform areas in farmer paddocks to provide a representative estimated of the current P status of the crop.  相似文献   

8.
Agricultural productivity relies on a wide range of ecosystem services provided by the soil biota. Sustainable management practices, such as tillage and residue management, can influence structure and function of the soil microbiota, with direct consequences for the associated ecosystem services. Although there is increasing evidence that different tillage regimes alter the soil biological indices, we only have a limited understanding of their temporal changes in a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping system. We evaluated the effects of combinations of tillage, crop residue management and green manuring on soil biological indicators after 5 years of the practising rice–wheat system (RWS). Four main plot treatments in rice included the following: (a) PTRW0, puddled transplanted rice with no wheat straw retained; (b) PTRW25, puddled transplanted rice with 25% anchored wheat stubbles retained; (c) PTRW0 + Sesbania aculeate L. green manure (GM); and (d) PTRW25+GM, puddled transplanted rice with 25% anchored wheat stubbles retained+ GM. There were three subplot treatments in the subsequent wheat crop: (a) CTWR0, conventional tillage wheat with rice residue removed; (b) ZTWR0, zero tillage wheat with rice residue removed; and (c) ZTWR100, ZTW with 100% rice residue retained as mulch. The PTRW25+GM treatment, followed by ZTWR100, significantly increased soil microbial biomass carbon, basal soil respiration, microbial quotient and mineralization quotient measured during wheat-growing season. These biological indicators were higher at vigorous vegetative wheat growth stage than at flowering stage and decreased at maturity. The principal component analysis of the assayed variables showed that all the variables significantly contributed to the variability in parameters examined and were more related to maximum tillering stage of wheat growth than to maturity or at sowing of wheat. Three highly effective biological indicators were microbial biomass carbon, microbial quotient and mineralization quotient, which responded significantly to changes in tillage and residue management practices in the RWS. We conclude that crop residues and green manure have significant to improve soil biochemical processes by improving soil organic carbon and soil biological indicators in rice–wheat cropping system.  相似文献   

9.
Genetic diversity was investigated in 73 accessions of emmer wheat (Triticum dicoccon Schrank) from 11 geographical regions using a set of 29 simple-sequence repeat (SSR or microsatellite) markers, representing at least two markers for each chromosome. The SSR primers amplified a total of 357 different alleles with an average of 12.31 alleles per locus. The number of fragments detected by each primer ranged between 6 (Xgwm1066) and 21 (Xgwm268). Null alleles were detected in nine of the 29 primers used. A high level of gene diversity index was observed. Across the 29 primers, gene diversity ranged from 0.60 (Xgwm46) to 0.94 (Xgwm655), with a mean of 0.82. There was a highly significant correlation (r=0.882; p<0.01) between gene diversity index and the number of loci, showing the number of loci per se is a strong indicator of diversity. Analysis of genetic diversity within and among eleven geographical regions revealed most of the genetic diversity of the total sample resided within regions. The coefficient of gene differentiation (Gst = 0.27) showed that the genetic variation within and among the 11 geographical regions was 73 and 27%, respectively. High value of mean number of alleles per locus was found in Iran (4.86) followed by Morocco (4.10) and Armenia (4.03). On the contrary, lower mean number of alleles per locus was detected in Yemen (2.83). The average gene diversity index across regions ranged from 0.52 (Slovakia) to 0.67 (Morocco) with an average of 0.60. Multivariate techniques of principal component analysis and clustering were employed to examine genetic relationship among the 73 emmer wheat accessions vis-à-vis geographical regions of collections. The genetic distance coefficients for all possible 55 pairs of regional comparisons ranged from 0.63 (between Iran and Armenia, Georgia and Azerbaijan, Georgia and Slovakia) to 0.97 (between Morocco and Yemen, Spain and Georgia, and Turkey and Iran) with a mean of 0.82. From the PCA results, a two dimensional plot of PC1 versus PC2 was constructed. The scatter plot of the first two principal components which explained altogether 27% of the total variation depicted the presence of a clear pattern of geographical differentiation except in few cases like accessions from Caucasian region. Similar pattern of genetic relationships among accessions was observed in cluster analysis. The study provided genetic information of emmer wheat in relation to geographical regions of origin. The information could be utilized in crop improvement, germplasm conservation programs, and in further investigation.  相似文献   

10.
贺媛媛  孙倩倩  郭波莉  张磊 《核农学报》2021,35(7):1565-1573
为明确矿质元素指纹对粉葛产地鉴别的可行性,筛选出鉴别粉葛产地的有效指标,本研究采用电感耦合等离子体质谱仪(ICP-MS)测定陕西、湖北、广西3个地域粉葛和土壤样品中B、Na、Mg、P、K、Ca、Mn、Co、Cu、Zn、Rb、Sr、Mo、Cd、Cs、Ba、La、Ce、Pr、Nd、Sm和Ti 22种矿质元素含量,并结合主成分分析、逐步判别分析和聚类分析对不同地域样品进行分类。结果表明,除B、Cu元素外,其余元素含量在不同地域粉葛间均存在显著差异(P<0.05);不同地域间粉葛矿质元素含量表现出独有的地理指纹特征,经逐步判别分析筛选出Mg、P、Co、Rb和Sr 5种元素,经回代检验和交叉检验的整体判别率分别为97.7%和93.0%;相关性分析结果表明,粉葛中Rb、Sr和Ti元素含量与对应土壤中的元素呈极显著正相关(P<0.01)。因此,矿质元素指纹结合多元统计分析能够在一定程度上实现不同产地粉葛的鉴别,这为粉葛产地溯源的可行性提供了技术支持。  相似文献   

11.
基于河南省及周边39个气象站1996-2015年逐日气象观测资料和冬小麦产量数据,采用灰色关联分析方法,分析生育期各气候要素与河南省县域冬小麦产量关联度的时空变化特征。结果表明:总体来看,各气候要素与河南省冬小麦产量的关联度中,气温的关联度最大,日照时数次之,降水量最小;关联度空间分布上呈现北部地区高于南部地区的格局,南北过渡性明显,尤其是南部信阳市的关联度较其它地区明显偏低。分时段来看,各气候要素与冬小麦产量关联度在1996-2010年有所下降,在2011-2015年突变上升,有明显的年际变化特征,尤其是位于西南部和南部地区的县域单元变化显著,而北部、东部和中部地区的县域单元变化较小。各气候要素与冬小麦产量关联度总体呈上升趋势,气候变化对冬小麦产量的影响逐渐显著,应积极采取策略应对气候变化的影响。  相似文献   

12.
本文利用FTIR技术分别检测不同产地紫金牛及其易混淆植物的化学成分的光谱特征,并通过主成分分析模型以及主成分载荷因子等化学计量学方法,对各样本进行鉴别,找出各测试样本化学组成的差异。结果表明:f1)两种紫金牛在3378cm^-1、2923cm^-1、1735cm^-1、1621cm^-1、1444cm^-1、1373cm^-1、1321cm^-1、1238cm^-1、1153cm^-1、1033cm^-1及776cm^-1附近均有吸收峰。(21由于融水县和永福县两地相距最近,在PCA检测模型二维散点图上,这两产地样品的距离也最近,恭城县与融水县及广西兴安县相距较远,故在散点图上的距离也较远;广西兴安县的月月红是紫金牛属植物,但不属于紫金牛种,所以,在散点图上的距离也就偏离各产地紫金牛。(3)提取PCA模型的载荷因子,分析表明,在种问比较,样品月月红中脂类、苯醌、黄酮及皂苷类成分的含量较紫金牛样品丰富。在紫金牛种内比较,广西永福县的样品香豆素、酮脂及皂苷类成分的含量比其它产地高,相反地,广西恭城药市的样本中尤其是酮脂及皂苷类成分的含量最低;但是,广西恭城县的紫金牛中香豆素、苯醌、甾醇,黄酮类等成分,较其它产地丰富。  相似文献   

13.
Red and white wheats must be segregated for marketing purposes because they have different end uses. Identification of wheat color is not straightforward, and currently there is interest in characterizing red and white wheats using spectroscopic methods and chemical tests. The kernels of both red and white wheats exhibit natural fluorescence that can be readily viewed under UV light, although it is not possible to differentiate the fluorescence spectra of red and white wheats by visual inspection only. Fluorescence emission spectra in the wavelength range of 370–670 nm for 91 wheat samples consisting of 48 red (from 30 cultivars) and 43 white (from 18 cultivars) were analyzed by partial least squares (PLS) and neural networks analyses (NNA). Samples included cultivars that were difficult to classify visually as well as wheat harvested after rainfall. Classification accuracies were ≈85% for calibration and ≈72% for the validation samples by both analyses. A plot of β‐coefficient vs. wavelength in PLS analysis indicated that fluorescence of red wheat cultivars was greater than that for white wheat cultivars at 425 (±20) nm wavelength. Fluorescence of white wheat cultivars was greater than that for red cultivars at 587 (±35) nm. Fluorescence emission at ≈450 nm from wheat samples increased in intensity after treatment with NaOH. The increase was greater for red than for white wheat. Wheat harvested after rainfall also exhibited a slight increase in fluorescence.  相似文献   

14.
谷物联合收割机收获小麦含杂率高光谱反演研究   总被引:1,自引:1,他引:0  
为了实现机械化收获小麦含杂率的快速检测,以金大丰4LS-7型自走式稻麦联合收割机收获的小麦样本为研究对象,利用ASDFieldSpec4Wide-Res型地物光谱仪获取小麦样本的原始光谱,经数学变换获得光谱原始反射率(raw spectral reflectance, REF)和光谱反射率倒数的对数(inverse-log reflectance, LR)2种光谱指标。通过主成分分析法(principal componentanalysis,PCA),利用贡献率高的成分的权值系数,优选出不同指标的小麦样本光谱的特征波长,并采用最小二乘支持向量机(least squares support vector machine, LS-SVM)构建了基于不同指标的小麦样本含杂率的反演模型,在此基础上对反演结果进行精度验证和比较。试验结果表明:建立的含杂率反演模型的建模决定系数均大于0.9,验证决定系数均大于0.85,均方根误差均小于0.29,相对分析误差均大于2,模型具有较强的拟合效果和预测能力;利用REF光谱数据指标建立的反演模型的反演效果优于LR光谱数据指标。该文建立的机械化收获小麦样本含杂率光谱反演模型能够实现含杂率的精准识别,可为后续构建便携式含杂率光谱检测仪提供参考,有助于客观、定量地表征机械化收获的小麦含杂率,为机械化收获的小麦的快速检测提供新途径。  相似文献   

15.
A procedure is proposed for the determination of the authenticity of white wines from four German wine-growing regions (Baden, Rheingau, Rheinhessen, and Pfalz) based on their content of some major, trace, and ultratrace elements. One hundred and twenty-seven white wine samples possessing a certificate of origin, all of the 2000 vintage, were analyzed. The concentrations of 13 elements (Li, B, Mg, Ca, V, Mn, Co, Fe, Zn, Rb, Sr, Cs, and Pb) were determined in wine diluted 1:20 by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Indium was routinely used as internal standard. Supervised pattern recognition techniques such as discriminant analysis and classification trees were applied for the interpretation of the data. A quadratic discriminant analysis (QDA) allowed the four regions to be discriminated with 83% accuracy when using only eight variables (Li, B, Mg, Fe, Zn, Sr, Cs, and Pb), and the prediction ability for classifying new samples was 76%. By use of a second method, a decision tree, the classification of samples coming from the four regions could be performed with an accuracy of 84% when only four elements were used: Li (very low in samples from Baden), Zn (abnormally low in the samples from the Rheingau), and Mg and Sr (both important for the differentiation between Pfalz and Rheinhessen samples). For this method, the prediction ability was only 74% in the identification of unknown samples. The robustness of the QDA model was not good enough, and therefore the tree is better recommended for the classification of new wine samples from these areas of German wine production.  相似文献   

16.
基于主成分与聚类分析的苹果加工品质评价   总被引:42,自引:13,他引:29  
为了探讨苹果品种间理化品质的差异,给选育新品种和苹果合理加工利用提供理论支持,采集了30个苹果品种为试材进行模式识别分析。该试验所用苹果在2011年8-10月份按照苹果可采成熟度(九成熟)在辽宁省兴城市国家种质资源圃进行采集。试验测定了单果质量、体积、密度、果皮颜色、硬度、糖酸比、维生素C等20项理化品质指标,采用描述性统计、主成分和聚类分析方法对苹果品种和品质关系进行了分析。结果显示,30个品种苹果的密度、果型指数和含水率3项指标未表现出差异。对剩余17项品质指标进行了主成分分析,依据主成分解释总变量和碎石图提取了6个主成分反映原变量的82.3%的信息。第一主成分主要综合了可滴定酸、糖酸比及固酸比的信息即口尝品质因子;第二主成分主要综合了L值,a值和b值的信息,命名为颜色因子;其余主成分依次为甜度因子、质构因子、内在品质因子和果个大小因子。结合主成分得分图直观地显示了苹果品种和理化指标间关系:辽伏、理想、早金冠和瑞光分布在PC1和PC2的正向区间,糖酸比和固酸比值较大、口感好,但是果皮颜色较绿,是品质较好的早熟苹果;寒富、赤阳和红富士依次落在PC1和PC2第四区间,食用品质好、果皮颜色较红,是较为常见的晚熟苹果。分布在第二区间的普利阿姆,白星,Pvma果皮颜色绿且口感酸涩,不适宜鲜食,这些品种可能较为适宜进行加工。第三区间品种固酸比、甜酸比取值较小但是果皮颜色红,为选育果皮颜色受消费者喜爱且内在品质好的早熟品种提供了理论支持。聚类分析将30个品种苹果分为5类,聚类结果与主成分得分图结果基本一致,该试验初步判定30个品种苹果是否适宜鲜食,为苹果品种选育和加工应用利用提供理论依据。  相似文献   

17.
生态环境与施氮量协同对小麦籽粒微量元素含量的影响   总被引:6,自引:1,他引:5  
【目的】铁、 锰、 铜、 锌等微量元素含量的高低不仅直接关系到小麦植株的生长发育也直接影响到小麦籽粒的营养价值。不同地区、 品种以及种植方式小麦微量元素营养品质不稳定。本试验主要研究不同生态环境与栽培措施协同对小麦籽粒微量元素含量的影响,以期为小麦高产优质生产提供参考。【方法】试验位于生态环境差异较大的北京、 河北任丘和河北赵县,采用裂区设计,以试验点为主区,即任丘、 北京、 赵县; 施氮量为副区,设5个氮素水平0、 90、 180、 270、 360 kg/hm2; 小麦品种为副副区,为济麦20、 皖麦38、 京冬8号、 中麦8号。收获后于每个小区中随机取样测定籽粒样品中Fe、 Mn、 Cu、 Zn等4种微量元素的含量。比较微量元素含量的差异显著性,分析不同试点生态条件与施氮量对小麦微量元素含量的影响,探讨不同生态环境下小麦微量元素含量的稳定性以及氮肥的调控补偿效应。【结果】 1)小麦籽粒中铁、 锰、 铜、 锌微量元素含量受生态环境、 栽培因素及品种遗传因素的共同作用,各试验因子均对其有显著影响。其中以生态环境的影响最大,生态环境差异越大,对小麦微量元素的影响作用越大。降水量可以影响小麦对铁和锰的吸收, 锌则受土壤有机质含量和试点纬度影响较大; 土壤中的钾可以促进小麦对铁、 锰、 铜、 锌的吸收利用。2)在0~360 kg/hm2 施氮范围内,氮肥有利于促进小麦对土壤中铁、 铜和锌的吸收,不利于锰的吸收积累。适当施用氮肥有利于缩小小麦籽粒铁、 锰、 铜元素含量的生态环境变异,提高其生态稳定性,但对锌元素试点间稳定性影响较小。施用氮肥对不同小麦品种微量元素含量差异有不同程度的调节效应,有利于缩小小麦品种间铁、 锰、 锌含量的差异。【结论】栽培环境对小麦籽粒微量元素含量的影响大于遗传因素,即小麦籽粒微量元素含量有较强的栽培可塑性。施氮有利于弥补生态环境或品种差异引起的微量元素含量不稳定性,调节品种差异并补偿生态环境对小麦造成的不利影响。适宜的栽培环境对提高小麦籽粒微量元素含量有明显效果。  相似文献   

18.
基于无人机数码影像的冬小麦氮含量反演   总被引:9,自引:7,他引:2  
准确、快速地获取关键生育期冬小麦氮素含量,对农业管理者进行田间氮素施肥有重要的决策作用。利用无人机(unmannedaerialvehicle,UAV)搭载数码相机,可以短时间内获取冬小麦长势信息,实现对冬小麦氮素含量动态监测。该研究利用2015年北京市小汤山冬小麦无人机数码影像,采用3种阈值分割方法,将田间植株作物与土壤背景分离。对比影像分割方法的时效性与准确性,最终确定可见光波段差异植被指数VDVI(visible-band difference vegetation index)提取植被信息。按照试验方案要求,在不同的氮肥与水分胁迫管理下,将冬小麦3次重复试验分成48个试验小区,依据小区边界提取小区的红、绿和蓝通道的平均DN(digitalnumber)值,选取25个植被指数,同时与各个试验小区冬小麦不同器官氮含量进行相关性分析,筛选数码影像变量。由于植被指数之间耦合度较高,因此采用主成分分析对原始数据进行成分提取,提取特征向量参与建模,最后利用多元线性回归分析建立氮素反演模型,通过决定系数(R2)、均方根误差(RMSE)和归一化的均方根误差(nRMSE)3个指标筛选出最佳模型,探究各器官氮素含量与数码变量的相关性。结果表明,实验室实测氮素含量与UAV数码影像氮素反演结果及基本一致。在反演模型构建精度方面,3种数据处理结果整体部分植被指数,反演效果叶氮植株氮茎氮。以冬小麦挑旗期为例,叶片氮含量整体信息提取验证模型的R2、RMSE和nRMSE分别为0.85、0.235和6.10%,比部分信息提取验证模型的R2高0.14,RMSE和nRMSE分别降低0.068和1.77个百分点;比植被指数信息提取验证模型的R2高0.43,RMSE和nRMSE分别降低0.141和3.67个百分点。研究表明,基于UAV数码影像利用多元线性回归构建冬小麦氮素含量反演模型,对试验小区整体提取作物信息的方式反演冬小麦叶氮含量效果最好,相比传统反演方法,模型稳定性更高,可为冬小麦田间水肥决策管理提供参考。  相似文献   

19.
基于矿物元素指纹图谱的黑龙江黄豆产地溯源   总被引:1,自引:0,他引:1  
该研究探讨了矿物元素指纹分析技术对黑龙江黄豆产地溯源的可行性,筛选出判别黑龙江黄豆产地溯源的有效指标。利用电感耦合等离子体质谱仪(inductively coupled plasma mass spectrometry,ICP-MS)测定来自齐齐哈尔和北安2个地域50份黄豆样品中52种矿物元素的含量,并对数据进行了方差分析、主成分分析和判别分析。研究表明,46种矿物元素含量在地域间存在显著差异,通过逐步判别分析筛选出8项元素指标建立黄豆产地判别模型,所建立的模型对黄豆产地整体交叉检验判别率为95.7%。As、Ru、Gd含量在黄豆与土壤间呈显著正相关(P0.05),Tb含量在黄豆与土壤间呈极显著正相关(P0.01),由4种元素建立的判别模型对产地判别准确。因此,上述元素是黄豆矿物元素产地鉴别较可靠的指纹信息指标。  相似文献   

20.
【目的】探索宁夏引黄灌区春小麦不同生育时期氮(N)、磷(P)、钾(K)养分吸收利用对气候变暖的响应机制,为预测气候变暖对干旱半干旱区春小麦生长的影响提供依据。【方法】试验于2018年3月在宁夏银北引黄灌区宁夏大学试验站进行。供试春小麦品种为‘宁春50号’,供试肥料为磷酸二铵和尿素。采用自动控制红外线辐射器进行野外增温,每个小区内分别设置一组红外灯管作为增温装置、一套自动控温电子设备与一组可移动温度传感器作为控温装置,增温装置直接连接控温装置以使增温梯度达到预设水平,增温时间为昼夜不间断增温。以春小麦冠层自然温度为对照温度 (增温0℃,CK),设置4个增温梯度 (0.5℃、1℃、1.5℃、2.0℃) 处理。于苗期、拔节、抽穗、灌浆、灌浆后10天、成熟期采集植株样品,测定叶、茎、穗的N、P、K养分含量,计算地上部各器官的养分累积吸收量、养分分配率和地上部植株养分累积量,并测定春小麦植株地上部干物重和产量。【结果】增温0.5℃,春小麦植株苗期干物重、拔节期地上部各器官N、P、K养分含量及养分累积吸收量均显著高于CK。增温1.0℃,苗期植株N、K含量和N素吸收量以及拔节期叶片的N、P、K含量显著高于CK,较对照提高3.2%~23.7%。增温1.5℃,仅苗期植株K含量显著高于CK,较对照提高22.2%。增温2.0℃,从苗期开始各项指标均显著低于CK。拔节期以后,除增温0.5℃春小麦K素含量与CK差异不显著外,其余指标均显著低于CK,春小麦成熟期小穗数、穗粒数、千粒重、产量均随温度的升高呈下降的趋势,增温2.0℃,分别较对照降低53.7%、24.1%、13.4%、21.7%。增温梯度越大,各指标下降的幅度越大。【结论】春小麦苗期温度升高0.5℃~1.0℃尚有利于拔节期前春小麦对N、P、K养分的吸收,但拔节期后增温超过1.0℃以上都会对N、P、K养分吸收产生显著负作用,导致使生育后期干物质的累积量减少,千粒重、穗粒数等降低,并最终导致产量和品质的下降。  相似文献   

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