滨海盐碱地玉米施肥效应及土壤供肥潜力研究

在典型滨海盐碱地区,采用随机区组试验设计,研究了玉米需肥特性、施肥效应及土壤供肥能力,以期为滨海盐碱地区合理施肥提供参考。结果表明,玉米籽粒养分含量平均为：N 1.224%,P2 O50.480%,K2 O 0.377%;秸秆养分含量平均为：N 0.820%,P2 O50.142%,K2 O 2.552%;生产100 kg经济产量所需养分量平均为：N 1.92 kg,P2 O50．60 kg,K2 O 2.55 kg。肥料增产率高低顺序为氮肥(44.39%)>磷肥(13.79%)>钾肥(6.55%);每千克氮、磷、钾肥可分别增产9.44,8.38,2.83 kg籽粒;玉米氮、磷、钾肥当季利用率分别为19.96%,5.60%,30.64%。通过建立玉米施肥效应模型,获得本试验条件下最佳经济施肥量为氮(N)348.5 kg/hm2、磷(P2O5)133.6 kg/hm2、钾(K2O)19.1 kg/hm2。本试验条件下土壤氮、磷、钾养分校正系数分别为52.06%,190.30%,32.67%;氮、磷、钾肥相对产量分别为69.26%,87.88%,93.85%,土壤养分丰缺程度氮处于低水平,磷、钾处于中等水平,高低顺序为钾肥>磷肥>氮肥。因此,滨海盐碱地区玉米施肥应重视氮、磷肥的施用,不施或少施钾肥,即可获得高产并取得较高的经济效益。     

氮磷钾肥配施对潮土花生产量及养分吸收利用的影响

为实现花生科学施肥,采用田间试验研究了氮磷钾配施对花生产量、养分吸收、干物质积累及肥料利用率的影响。结果表明：氮磷钾配施显著增产46.82%,较农户施肥增产7.53%;施氮、磷、钾肥分别增产27.80%、13.56%、21.12%。氮磷钾配施养分积累量较农户施肥分别提高13.30%、36.48%、40.75%,氮、磷、钾肥当季利用率分别为33.39%、15.17%、39.02%。氮磷钾配施(N-90、P2O5-120、K2O-150 kg/hm2)促进了花生对氮、磷、钾养分的吸收利用,提高了花生产量,可作为潮土区花生高产施肥配方。     

黄河三角洲盐渍土棉花施用氮、磷、钾肥的效应研究

为探讨盐渍土抗虫棉施用氮(N)、磷(P)、钾(K)肥的效应及其营养生理机制,指导滨海盐渍土抗虫棉合理施肥,在黄河三角洲盐渍土低、中、高盐棉田种植转Bt基因抗虫棉鲁棉研28,研究N、P、K肥配合施用对其养分吸收利用、Na+吸收积累、光合速率、干物质积累和产量的影响。结果表明,N、P肥配合,尤其是N、P、K肥配合施用显著增加了低、中、高盐田棉花的N、P、K养分吸收量,减少了Na+吸收积累量。低、中、高盐田棉花的N、P、K养分农学利用效率均以N、P、K配施的处理较高,氮养分农学利用效率分别为0.20、1.95和2.07kg皮棉kg-1N,磷养分农学利用效率分别为0.87、8.35和8.71kg皮棉kg-1P,钾养分农学利用效率分别为0.26、2.89和3.77kg皮棉kg-1K。N、P、K肥配合施用还维持了较高的棉株叶面积、叶绿素含量和净光合速率。低、中、高盐田棉花的生物产量和皮棉产量也均以N、P、K配施的处理较高,皮棉产量分别增产2.53%、28.67%和30.47%。中、高盐棉田的施肥效应明显好于低盐棉田。表明根据盐碱程度分类合理施肥是减轻盐渍土营养障碍、改善棉花营养、提高养分农学利用效率和棉花产量的有效途径。     

干旱冷凉区红芸豆施肥效应与养分吸收研究

应用“3414”试验方案,研究了干旱冷凉区红芸豆施肥效应及红芸豆养分吸收状况。结果表明：施肥处理红芸豆产量显著高于不施肥处理,以N2P1K1处理的红芸豆产量和产投比最高。施用氮、磷、钾肥增产率分别为16.4%、8.6%和12.7%,对产量影响依次为：N＞K＞P。三元二次方程拟合结果表明,本试验条件下,氮(N)、磷(P2O5)、钾(K2O)肥最佳经济施肥量分别为99.0、140.6、108.0 kg/hm2。红芸豆生育期地力贡献率为75.7%,供试土壤肥力中等,施肥效果明显。合理施肥可促进红芸豆对N、P和K的吸收。     

氮磷钾配施对杂交玉米禾玉9566农艺性状、产量与养分吸收利用的影响

为优化玉米氮磷钾施用,提高玉米产量和肥料利用效率,开展了杂交玉米禾玉9566氮磷钾配施试验,探讨氮磷钾配施对玉米农艺性状、产量和养分吸收利用的影响。结果表明:氮磷钾配施能有效改善农艺性状,优化产量构成因子,主要是增加穗粒数,从而提高产量,对玉米产量的影响作用为氮磷钾。施氮、钾能提高玉米子粒和茎叶中氮、钾含量,施氮促进植株对氮磷钾的吸收利用,施钾可提高玉米子粒对氮、磷养分吸收量;氮磷钾三因子中促进养分吸收积累作用表现为氮钾磷。氮磷钾配合施用,可有效提高玉米植株对养分的吸收积累,子粒中氮、磷含量和子粒氮磷钾各养分吸收量均为最高,全株养分吸收总量也最高;每100kg经济产量N、P2O5、K2O养分吸收量分别为2.02、0.90、2.21kg,氮、磷、钾肥料利用率为33.28%、15.43%、48.79%,氮、磷、钾肥农学效率分别为13.07、5.59、3.34kg/kg。     

小麦玉米带田高产平衡施肥研究

研究采用土壤养分状况系统研究法,根据土壤养分亏缺状况,平衡微量元素后确定氮磷钾的适宜用量,研究小麦玉米带田的平衡施肥方案。试验结果表明,氮、磷、钾及微量元素的平衡施用改善了小麦、玉米的经济性状,提高了小麦千粒重、玉米的穗粒数、穗粒重和千粒重;平衡微量元素后带田中限制小麦产量的主要因子是氮、磷,限制玉米产量的主要因子是氮、磷、钾;平衡施肥处理的产量、产值与纯收入均增加,其中处理N2P2K2的产值与纯收入最高,分别为17085元/hm2和15240元/hm2。综合分析结果说明,小麦玉米带田高产平衡施肥配方应为N2P2K2。     

养分专家系统推荐施肥对潮土夏玉米产量及肥料效率的影响

为实现潮土区夏玉米科学施肥, 通过2年田间试验研究了玉米养分专家系统推荐施肥对夏玉米产量、收益、养分积累量及肥料利用效率的影响。结果表明, 沙壤质潮土夏玉米施肥两年增产6.55%~39.32%和5.53%~21.19%, 玉米养分专家系统和Agro Services International Inc推荐施肥较农户习惯施肥分别增产4.06%和5.04%, 增收21.90%和27.44%。基于玉米养分专家系统推荐施肥的氮、磷、钾肥农学效率分别为11.46、25.89和9.93 kg kg^-1, 氮、磷、钾肥料利用率分别为41.13%、31.48%和50.35%, 化肥偏生产力平均为36.62 kg kg^-1。玉米养分专家系统推荐施肥提高了沙壤质潮土区夏玉米叶片叶绿素含量, 促进了氮磷钾的吸收利用, 增加了干物质积累量, 具有增产增收效应, 肥料利用效率较高, 可作为该地区夏玉米推荐施肥方法推广应用。     

玉屏县贵农玉188氮、磷、钾最佳配比研究

优化氮、磷、钾施肥方案可实现玉米高产。采用L9(34)正交回归设计,研究了玉屏氮、磷、钾配合施用对高产杂交玉米新品种贵农玉188产量的影响。结果表明:玉米产量(kg/hm2)与氮、磷、钾施用量之间的效应模型为:y=3292.059+11172.890x1-2238.574x2-2899.190x3-3040.609x21+534.492x22+639.352 x1x3+614.031x2x3,经检验回归方程和系数均达到极显著水平。氮、磷、钾三因素对玉米产量的增产作用依次为:氮肥磷肥钾肥,氮、磷养分是玉米产量的限制因子,随着氮、磷肥用量的增加,需要配施一定量的钾肥才能继续增产;通过对回归方程进行模拟寻优,得到氮磷钾的最佳配比为N2.15P3K3,其对应的产量为12 305.81kg/hm2,方案的实施预计使玉米产量比不施肥对照增产277.55%,增收12 424.77元/hm2。     

氮磷钾配施对超高产夏玉米养分吸收和产量性状的影响

旨在深入研究氮磷钾均衡施肥和分别减施氮、磷和钾肥对河北平原超高产夏玉米养分吸收特性和产量性状的影响。本试验以‘郑单958’为材料，采用常规植株养分测试和产量性状分析方法，进行不同养分处理下植株各生育时期氮磷钾含量和成熟期产量测定。与不施肥空白对照(CK)相比，氮磷钾均衡施肥处理(T)和分别减施氮素处理(T-N)、磷素处理(T-P)及钾素处理(T-K)，显著增加各生育时期、生育阶段和全生育期的植株氮、磷和钾的积累量，提高吸收速率、产量、穗粒数和千粒重。T-N、T-P和T-K植株氮磷钾积累量、吸收速率和产量较处理T显著降低，其中以T-N减幅最大，T-P次之，T-K最小。各处理植株生育期间氮磷钾吸收速率呈单峰曲线，氮磷吸收高峰为大口—吐丝期，钾吸收高峰为拔节—大口期。不同处理每生产100 kg 籽粒吸收N为2.07 ~ 2.81 kg、P2O5为0.67~0.83 kg、K2O为2.21~2.52 kg，各施肥处理生产单位籽粒的氮、磷和钾量高于CK。本研究表明，适宜氮磷钾肥配施，具有改善生育期间植株养分积累、提高植株养分含量、增强植株干物质积累和产量形成的作用。     

施肥对黑麦草产量和氮磷钾养分吸收的影响

在田间试验的条件下研究了配方施肥对黑麦草产量和氮磷钾养分吸收的影响。结果表明:施肥能显著提高黑麦草产量,肥料配方1(每公顷施N450kg、P2O545kg、K2O90kg)和配方2(每公顷施N540kg、P2O5180kg、K2O360kg)鲜草产量分别是不施肥处理(26.78t/hm2)的3.7倍和4.1倍。配方施肥能显著提高黑麦草对氮、磷、钾养分的吸收,配方1对氮、磷、钾的吸收量分别是不施肥处理的5.2倍、2.0倍、3.3倍,配方2分别是不施肥处理的5.8倍、2.5倍、4.0倍。在施肥状况下,黑麦草对养分的吸收比例为N:P2O5:K2O=1:0.25～0.28:1.01～1.08。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...