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1.
《中国麻业》2020,(1)
采集2个剑麻园套种平托花生与不套种、套种4个月和9个月4种种植模式的0～20 cm、20～40 cm和40～60 cm 3个层次土壤样品,对比分析土壤的水分、矿质氮、速效磷和速效钾变化。结果表明,套种平托花生可以提高不同层次土壤含水量,保水性能优良,其中0～20 cm层次土壤保水效果最好。套种平托花生时间越长,地表覆盖度越大,0～20 cm土壤保水性能越好。剑麻园套种平托花生且不增加施肥量的情况下,0～20 cm、20～40 cm 2个层次土壤的矿质氮和速效磷,20～40 cm、40～60 cm 2个层次土壤的速效钾含量均显著降低;无套种平托花生剑麻园,0～20 cm、20～40 cm和40～60 cm 3个土层矿质氮、速效磷和速效钾含量随土层深度依次降低,而套种平托花生剑麻园,20～40 cm和40～60 cm土层矿质氮、速效磷和速效钾含量无差异,但显著低于0～20 cm土层的;套种平托花生0～60 cm土层矿质氮、速效磷和速效钾含量明显降低,平托花生和剑麻争夺氮磷钾养分。剑麻园套种平托花生时,为了维持土壤氮磷钾水平,避免平托花生和剑麻争夺养分,应适当增加氮磷钾施用量。 相似文献
2.
砖红壤香蕉园土壤养分空间变异研究 总被引：1，自引：1，他引：0
运用统计学和ArcGIS软件的地统计分析模块对海南砖红壤香蕉园59个土壤采样点两个取样土层（0～20 cm和20～40 cm）养分进行空间变异性研究。结果表明：香蕉园土壤各养分变异系数均为中等变异。0～20 cm土层土壤各养分含量大于20～40 cm土层。0～20 cm和20～40 cm土层中的碱解氮、交换性钙和交换性镁及0～20 cm土层的有机质均符合高斯模型，0～20 cm土层速效磷与20～40 cm土层速效钾符合球状模型，而20～40 cm土层速效磷与0～20 cm土层速效钾符合圆形模型，20～40 cm土层有机质符合指数模型。各养分的变程范围为109.217～279.796 m，有机质具有强烈的空间相关性。0～20 cm土层速效钾的块金效应值小于20～40 cm土层，0～20 cm土层碱解氮、速效磷、交换性钙、交换性镁高于20～40 cm土层。有机质、20～40 cm土层速效磷、0～20 cm土层速效钾的块金效应小于25%，其它养分均在25%～75%，具有中等的空间相关性。确定了合理取样数，0～20 cm碱解氮、速效磷、速效钾、交换性钙、交换性镁、有机质合理取样数分别为：5、30、26、29、25、3；20～40 cm碱解氮、速效磷、速效钾、交换性钙、交换性镁、有机质合理取样数分别为：4、44、30、26、25、3，就可以满足变量施肥的要求。 相似文献
3.
减施氮肥对稻田土壤剖面养分分布特征的影响 总被引：2，自引：0，他引：2
为探讨减施氮肥对养分在剖面垂直的分布与迁移的影响,采用大田试验,探讨了减施氮肥对稻田剖面养分累积和分布的影响.结果表明:3个处理下土壤剖面养分累积的趋势是:有机质、全氮、全磷、碱解氮、速效磷含量随土层深度的增加而降低,而全钾及速效钾含量则随土层深度的增加而提高.T3(80％的习惯施氮量)处理中除耕层的有效氮、速效磷及速效钾含量较T2(习惯施氮量)处理降低外,土壤其它各层有机质、全氮、全磷、全钾、有效氮、速效磷以及速效钾含量均较T2处理有所增加.T3处理有机质的增加主要集中在0～60 cm土层中,氮素主要集中在0～40 cm土层中,钾素则主要集中在0～20 cm土层中,土壤中各层的磷素在两个施肥处理中无显著差异,说明T3处理增加的养分主要集中在作物能吸收的范围内,这意味着对土壤培肥和作物生产更有利. 相似文献
4.
海南省乐东县橡胶园土壤养分的空间变异特征研究 总被引：2，自引：0，他引：2
通过GIS和地统计学相结合的方法研究海南省乐东县橡胶园土壤速效氮、磷和钾含量的空间变异特征。结果表明:(1)土壤速效氮、磷、钾具有强烈或中等程度的空间自相关性,相关距离变化范围为1 623~61 100 m,块金值/基台值变化范围为4.7%~49.97%;(2)0~20 cm和20~40 cm土层,速效氮、钾养分第四、第五等级分布面积较广,0~20 cm土层速效磷含量第四等级、20~40 cm土层速效磷含量第五等级分布较广;(3)不同土壤类型上,速效氮、磷和钾含量差异不显著,地形地貌和成土母质主要影响速效氮和速效钾含量,而速效磷含量主要受人为管理措施的影响;(4)乐东县胶园土壤速效氮、磷、钾养分含量缺乏,空间结构特征明显,在县级尺度进行养分的宏观分区管理切实可行。 相似文献
5.
采用免耕撬窝移栽高产栽培技术4年后,测定0～20 cm土层的速效氮、全氮、有机质、容重和总孔隙度。结果表明,速效氮0～5 cm土层与CK差异小,5～15 cm土层比CK高出40%左右;全氮0～5 cm土层比CK低0.019个百分点,5～10 cm、15～20 cm土层比CK高0.010个百分点左右,10～15 cm土层比CK高0.016个百分点;有机质0～5 cm土层比CK低0.5个百分点,5～20 cm土层比CK高0.2个百分点左右;土壤容重0～10 cm土层低于CK,10～20cm土层则高于CK;0～20 cm土层的总孔隙度逐层降低,0～10 cm土总孔隙度高于CK,10～20 cm土层则相反。 相似文献
6.
为探明春麦冬播高产、高效水氮运筹模式,2019-2021年在田间进行两因素三水平裂区试验,灌水量设3 150(W1)、3 600(W2)和4 200 m3·hm-2(W3)三个水平;施氮量设0(N0)、135(N1)和210 kg·hm-2(N2)三个水平,研究了9种水、氮处理组合对春小麦品种新春48号0~100 cm土层耗水量、群体叶面积指数、干物质积累量、产量及水、氮利用效率的影响。结果表明,增加灌水量提高了0~40 cm 土层含水量,减少了40～100 cm土层储水消耗量,增加了总耗水量;同一灌水量条件下,施氮量对总耗水量影响不显著;水、氮协同增产效应大于其单因素效应,增加滴水量或氮肥量均增加小麦群体叶面积指数、总光合势和干物质积累量,水分利用效率（1.12～1.23 kg·m-3）和氮肥农学利用效率（7.58～11.17 kg·kg-1）呈先增后降趋势。水、氮协同增产是叶面积指数、总光合势和干物质积累量提高的结果。北疆春麦冬播适宜的水、氮运筹模式为总灌水量3 600～4 200 m3·hm-2、总施氮量135～210 kg·hm-2。 相似文献
7.
夏玉米氮、磷、钾积累和分配态势研究 总被引：23，自引：7，他引：23
紧凑型玉米掖单12号每公顷产10410公斤,需吸收N183.75公斤、P2O569.9O公斤和K2O118.5公斤,每100公斤籽粒需要N1.76 公斤、P2O50.67公斤和K2O1.13公斤,氮素吸收量最多,钾次之,磷最少.高产夏玉米对氮、磷、钾的吸收强度,均在玉来抽雄受精期前后达到最大值,茎秆和叶片对产量形成做出的贡献最大.土壤中氮、磷、钾含量的变化与植株氮、磷、钾的吸收积累进程之间无明显相关,但增施肥料,培肥地力,乃是获取玉米高产极其重要的措施之一. 相似文献
8.
稻田春玉米氮、磷、钾配方施肥数学模型的初步研究 总被引：6，自引：1，他引：6
采用氮、磷、钾三因素旋转组合设计,通过计算机模拟寻优,建立了稻田春玉米--杂交晚稻种植制度中玉米产量--施肥量,玉米生产利润--施肥量数学模型:分析了氮(X1)、磷(X2)、钾(X3)的主效应及交互效应与产量的关系,它们对产量的影响为氮＞钾＞磷.筛选出玉米产量≥8250kg/hm2的最优方案为:N394.96～401.25kg/hm2、P2O5116.99～121.8kg/hm2、K2O 232.29～237.06kg/hm2,其比例为N∶P2O5K2O=3.4∶1∶2.并筛选出玉米利润≥6800元/hm2的最优方案为:N380.60～385.55kg/hm2,P2O5104.73～108.03kg/hm2、K2O222.20～225.12kg/hm2.其比例为N∶P2O5K2O=3.6∶1∶2.1。 相似文献
9.
为提高云南干旱地区芒果园管理技术和水平,通过田间试验研究不同豆科植物行间间作后土壤养分的变化。结果表明：生草间作两年后,0～60 cm土壤有机质降低;20～60 cm土壤全氮和全磷增加,0～60 cm土壤全钾增加;新诺顿豆和大翼豆将20～60 cm土壤pH从酸性提高至中性;饭豆＋绿肥提高了0～60 cm土壤碱解氮和速效磷,饭豆＋绿肥、饭豆以及田箐提高了0～60 cm土壤速效钾。试验所选生草可以增加20～60 cm土壤全氮、全磷和全钾的积累,饭豆＋绿肥轮作可以有效提高0～60 cm土壤碱解氮、速效磷和速效钾 相似文献
10.
利用“3414”回归设计方案对锦科杂1号高产优质栽培施肥用量进行试验,对试验结果进行统计建模,建立了以子棉产量为目标函数的氮、磷、钾三因素肥料效应模型.经模拟仿真因素取值和统计分析,得出子棉产量3982.11～4015.17 kg·hm-2的施肥量的95%置信区间分别为纯氮311.91～328.73 kg·hm-2,P2O5 151.87～162.33 kg·hm-2,K2O 238.88～255.86 kg·hm-2。并对两因素互作效应及单因素效应进行了剖析。通过对氮磷钾、氮磷、氮钾、磷钾及氮、磷、钾三类7种模型提供的施肥量和期望产量进行经济效益分析,据此提出锦科杂1号高产优质高效栽培的推荐施肥措施：每公顷施纯氮300 kg,P2O5 145.53 kg,K2O 232.85 kg,产量期望为4029.42 kg·hm-2,产投比12.57。 相似文献
11.
12.
《Journal of Crop Improvement》2013,27(2):81-114
Summary The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices. 相似文献
13.
Novel food and non-food uses for sorghum and millets 总被引：4，自引：3，他引：4
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity. 相似文献
14.
Alexander N. Shikov Elena V. Flisyuk Ekaterina D. Obluchinskaya Olga N. Pozharitskaya 《Marine drugs》2020,18(11)
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future. 相似文献
15.
Résumé
Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences
d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les
champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents
en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.
Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.相似文献
16.
Yanhua Lu Chongwei Zhang Peter Bucheli Dongzhi Wei 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(2):55-63
Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China. 相似文献
17.
Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.
The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).
The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors. 相似文献
18.
Alejandro M. S. Mayer Aimee J. Guerrero Abimael D. Rodríguez Orazio Taglialatela-Scafati Fumiaki Nakamura Nobuhiro Fusetani 《Marine drugs》2021,19(2)
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories. 相似文献
19.
《Journal of Crop Improvement》2013,27(1-2):55-98
SUMMARY Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia. 相似文献
20.
Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive.
Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated
seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk.
Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than
in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d. 相似文献