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桑园催芽肥氮磷钾配比试验 总被引：1，自引：0，他引：1
以往桑园春肥的施用多偏重于氮肥,有的虽然也强调施用磷钾肥,但也未能明确指出磷钾肥的配比及用量以多少为佳.为此作者于1991年3月15日在本场选择桑树生长 相似文献
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我县滩地桑园占总桑园面积的85.7%.近年来随着蚕桑生产经济效益的稳定和提高,蚕农普遍重视对桑园的高肥投入,特别是夏肥的施用水平逐年提高,但肥效较低.为探求我县滩地桑园夏肥的合理施用量及氮、磷、钾、饼配施的优良组合,笔者进行了本试验,兹将结果报告如下:一、试验方法1.基础情况试验于1991年6月至1992年5月在衢县高家镇高家村高土根户的滩地桑园进行,亩栽1300株7年生低干 相似文献
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为了给内蒙古高原紫花苜蓿（Medicago sativa L.）测土施氮奠定科学基础，本研究采用“零散实验数据整合法”和“养分平衡-地力差减法”新应用公式，开展了该自然区域紫花苜蓿土壤氮素丰缺指标和推荐施氮量研究。结果表明：内蒙古高原生长第1年紫花苜蓿土壤碱解氮第1~6级丰缺指标为≥48，20~48，8~20，4~8，2~4和<2 mg·kg-1，土壤全氮第1~5级丰缺指标为≥1.4，0.8~1.4，0.4~0.8，0.2~0.4和<0.2 g·kg-1，土壤有机质第1~6级丰缺指标为≥17，10~17，6~10，3~6，2~3和<2 g·kg-1。当紫花苜蓿目标产量9~18 t·hm-2、氮肥利用率40%时，内蒙古高原紫花苜蓿第1~6级土壤推荐施氮量分别为0，68~135，135~270，203~405，270~540和338~675 kg·hm-2。 相似文献
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低丘红壤茶园氮磷钾平衡施肥的探讨 总被引：2，自引：0，他引：2
本文以低丘红壤茶园为对象,从反应条件,有机物的积累和分解,氮、磷、钾的固定、转化与平衡等方面,探讨了茶园土壤的主要农化性质,进而对茶树地上部和地下部,不同生长季节,以及营养生长与生殖生长对养分的需求和平衡关系作了研究。在此基础上,对我国8个茶叶主产省区20余个有代表性的茶叶生产单位,进行了茶园氮、磷、钾配合施肥的试验,明确了多元复合肥对茶树生长和茶叶增产提质的影响。根据最佳配比,茶叶专用肥“中茶Ⅰ号”已得到了大面积的推广与应用。最后,作者对茶园施肥提出三条建议:①要重施农家有机肥;②要多施以氮为主的多元复合肥;③要提倡测土施肥。 相似文献
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氮磷钾化肥的用量和配比与桑叶产量及桑叶中氮磷钾含量的关系 总被引：3，自引：0，他引：3
供试桑园为8年生、低干、红沧桑,亩栽1500株;土壤含有机质1.32%,全氮0.991%,全磷0.023%,碱解氨90ppm,速效磷8ppm,速效钾186ppm,缓效钾263ppm.pH值5.7.试验结果:在施磷钾基础上施氮肥25～50kg的增叶最多,肥效最好;在施用氮、钾基础上,施磷肥15kg的增产效果最显著,效益最好;在施用氮磷基础上,增施钾肥可以增加产叶量,但在本试验地条件下,增施钾肥20～60kg,其增产效果远不如磷氮明显. 相似文献
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对小坑林场杉木初级种子园球果产量３年株调查分析，表明无性系结实存在着真实的遗传差异，根据无性系结实主效ｃ１和Ｃ×Ｙ互作（ｃｈ）ｉｊ等指标，对种子园无性系统进行选择评价，为营建１．５代种子园提供结实力强、后代生长快的无性系和初级种子园去劣疏伐提供依据。 相似文献
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对我省典型蚕种场桑园土壤肥力，施肥状况进行调查的基础上，在不同土壤类型的桑园中进行ＮＰＫ配比试验，明确了肥料配比与桑叶产质量的关系，提出平原、海涂、溪滩等土壤基础肥力较高的桑园以ＮＰＫ比为１０：５：５，在土地条件差，土壤贫瘠的丘陵上以１０：５－６：６－８的比例实施配方施肥，具有较高的增产潜力。 相似文献
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3 groups of 8 Wistar rats each of a live weight of ca. 215 g received graded N supplements. A number of N metabolism parameters were ascertained and discussed. Among other things, the protein synthesis and degradation quotas were ascertained by means of the 15N tracer technique. For the assessment a 3-pool model was used, the content of which was in so far extended as growth and metabolic faecal nitrogen are concretely taken into consideration. A quasi-continuous method of supplementing the tracer was chosen; it was discontinued in approximately the middle of the experiment. Thus the labelling and abatement phases in urine could at the same time be included in the calculation. The protein synthesis quota increases with N intake. It can be concluded from the course of the graph that it gravitates towards a saturation value. 相似文献
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氮素(N)是陆地生态系统尤其是草地生态系统第一生产力的重要限制性养分之一.陆地生态系统N素的可利用性由土壤N素的转化速率决定,其中包括氨化和硝化2个重要过程.准确测定N素在各转化过程中的量,对于估算陆地生态系统N转化非常重要.稳定性同位素15N由于其安全、准确且不干扰自然生态系统等特点,近年来在生态系统N循环研究方面得到广泛应用,常用方法包括15N自然丰度法、15N还原法、15N库稀释法和15N示踪法.在查阅大量文献的基础上,搜集整理了15N库稀释法和15N示踪法的详细操作流程并综述了其在草地生态系统应用的最新进展,分别从不同草地管理方式(增施氮肥、放牧、火烧和刈割等)和全球气候变化(增温、增雨、大气氮沉降和CO2浓度升高等)对草地生态系统N转化过程的影响进行论述.同位素15N在草地生态系统应用的方法同样适用于森林、农田以及其他陆地生态系统. 相似文献
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Mihelić D Mihelić D Slavica A Dezdek D Trbojević-Vukicević T Dzaja P Majić-Balić I 《Anatomia, histologia, embryologia》2007,36(6):401-407
Two hundred and twelve dog cadavers belonging to different breeds were examined, to investigate the formation of the femoral, obturator and the sciatic nerve. Besides the commonly described formation patterns of the mentioned nerves, some variations were also found. These variations were not gender-related, but on the other hand we discovered a certain correlation between the variations appearing in the formation of the femoral, obturator and the sciatic nerve. In 74.05% of cases, the femoral nerve was formed from ventral branches of the 4th, 5th and 6th lumbar nerve, and 16.98% of the dogs had the nerve formed from ventral branches of the 3rd, 4th and 5th lumbar nerve. Many dogs (i.e. 2.30%) had the femoral nerve formed from the ventral branches of the 5th, 6th and 7th, the 3rd, 4th, 5th and 6th or the 4th, 5th, 6th and 7th lumbar nerve, respectively. In 1.88% of dogs in particular, the femoral nerve was formed from ventral rami of the 4th and 5th lumbar nerve. In 66.98% of the examined dogs, the obturator nerve was formed from the ventral branches of the 4th, 5th and 6th lumbar nerve, followed by 16.59% of the dogs with the obturator nerve formed from the ventral rami of the 4th and 5th lumbar nerve and 9.43% of dogs in which the nerve was formed from the ventral branches of the 5th and 6th lumbar nerve. In 4.71% of dogs, the obturator nerve was formed from the ventral rami of the 4th, 5th, 6th and 7th lumbar nerve, while only 2.30% of the examined dogs had the same nerve formed from the ventral branches of the 5th, 6th and 7th lumbar nerve. The sciatic nerve was formed from ventral branches of the 6th and 7th lumbar nerve and the 1st sacral nerve in 86.79% of the dogs. In 5.18% of cases, the same nerve was formed from a junction of the ventral branches of the 7th lumbar and the 1st and 2nd sacral nerve, and, in the same percentage of cases, it was formed from a junction of ventral branches of the 6th and 7th lumbar nerve and the 1st and 2nd sacral nerve. In 2.83% of the dogs, it was formed from a junction of the ventral branches of the 6th and 7th lumbar and the 1st sacral nerve. The correlation of variations established in the formation of the femoral, obturator and the sciatic nerve was not statistically significant. 相似文献
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V. de Raphélis‐Soissan J. V. Nolan I. R. Godwin J. R. Newbold B. D. Eyre D. V. Erler R. S. Hegarty 《Journal of animal physiology and animal nutrition》2018,102(1):e176-e182
Supplementing ruminants with nitrate reduces their enteric methane (CH4) emissions; however, the greenhouse gas (GHG) mitigation achieved can be partially offset by small emissions of nitrous oxide (N2O), a more potent GHG. Sheep were dosed intraruminally with 15 to investigate whether dietary is a precursor of N2O and/or di‐nitrogen gas (N2), and to quantify the amounts of recovered as N2O and N2 in gas emissions from sheep adapted or not adapted to dietary . Ruminally cannulated sheep were adapted to a hay diet supplemented with (n = 3; 10 g /kg DM) or urea (n = 3; 5.3 g urea/kg DM). On the day of the experiment all sheep were dosed intraruminally with 15 and quickly moved into gas‐tight chambers to enable recovery of 15N in N2O and N2 to be measured. Measurements of gases accumulating in the chambers were made over 10 successive 50 min periods; this enabled the amount of N2O produced, and the recovery of 15‐N in N2O and N2 to be determined over a total of 10 hr. Only 0.04% of labelled ‐N was recovered as N2O, and this was not dependent (p > .05) on whether or not the animals had been adapted to dietary . Approximatively 3% of 15‐N was recovered as 15N2, which was also not dependent (p > .05) on whether sheep had been adapted to . Because the kinetics of rumen ammonia (NH3) were uncertain, the recovery of 15N from in rumen NH3 could not accurately be quantified, but our results suggest that approximately 76% of dietary was converted to NH3 in the rumen. We conclude that the small amount of recovered in N2 was evidence of denitrification, previously thought not to occur in the rumen. 相似文献
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Yoshizawa K Sasaki T Uehara N Kuro M Kimura A Kinoshita Y Miki H Yuri T Tsubura A 《Journal of toxicologic pathology》2012,25(1):27-35
Seven-week-old male Lewis rats received a single intraperitoneal injection of N-ethyl-N-nitrosourea (ENU) (100, 200, 400 or 600 mg/kg), and retinal damage was evaluated 7 days after the treatment. Sequential morphological features of the retina and retinal DNA damage, as determined by a TUNEL assay and phospho-histone H2A.X (γ-H2AX), were analyzed 3, 6, 12, 24 and 72 hr, 7 days, and/or 30 days after 400 mg/kg ENU treatment. Activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) was analyzed immunohistochemically by poly (ADP-ribose) (PAR) expression in response to DNA damage of the retina. All rats that received ≥ 400 mg/kg of ENU developed retinal degeneration characterized by the loss of photoreceptor cells in both the central and peripheral retina within 7 days. In the 400 mg/kg ENU-treated rats, TUNEL-positive signals were only located in the photoreceptor cells and peaked 24 hr after ENU treatment. The γ-H2AX signals in inner retinal cells appeared at 24 hr and peaked at 72 hr after ENU treatment, and the PAR signals selectively located in the photoreceptor cell nuclei appeared at 12 hr and peaked at 24 hr after ENU treatment. However, degeneration was restricted to photoreceptor cells, and no degenerative changes in inner retinal cells were seen at any time points. Retinal thickness and the photoreceptor cell ratio in the central and peripheral retina were significantly decreased, and the retinal damage ratio was significantly increased 7 days after ENU treatment. In conclusion, ENU induced retinal degeneration in adult rats that was characterized by photoreceptor cell apoptosis through PARP activity. 相似文献
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The renal excretion of N4-acetyl sulphanilamide and N4-acetyl sulphadimidine was studied in 19 experiments with 6 goats during continuous intravenous administration of the 2 sulphonamide derivatives. Deacetylation of both compounds takes place to a small extent only. Further it is shown that both sulphonamide derivatives are bound to plasma proteins to a greater extent than sulphanilamide and sulphadimidine. The excretion of the N4-acetylated sulphonamides is compared with the renal excretion of creatinine. The non-protein-bound fraction of the 2 N4-acetylated sulphonamides is excreted by filtration and active tubular secretion. The renal clearances of the acetyl derivatives are higher than those of the parent compounds. 相似文献
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猪流感病毒H1N1、H1N2和H3N2亚型多重RT-PCR诊断方法的建立 总被引：2，自引：3，他引：2
对我国分离到的猪流感病毒和GenBank数据库中已有的猪流感病毒H1N1、H1N2和H3N2亚型毒株的HA、NA基因核苷酸序列进行分析,分别选出各个病毒亚型HA和NA基因中高度保守且特异的核苷酸区域,设计扩增猪流感病毒H1和H3、N1和N2亚型的2套多重PCR特异性引物,建立了猪流感H1N1、H1N2和H3N2亚型病毒多重RT-PCR诊断方法。采用该方法对H1N1、H1N2、H3N2亚型猪流感病毒标准参考株进行RT-PCR检测,结果均呈阳性,对扩增得到的片段进行序列测定和BLAST比较,表明为目的基因片段。其它几种常见猪病病毒和其它亚型猪流感病毒的RT-PCR扩增结果都呈阴性。对107EID50/0.1mL病毒进行稀释,提取RNA进行敏感性试验,RT-PCR最少可检测到102EID50的病毒量核酸。对40份阳性临床样品的检测结果是H1N1、H1N2和H3N2亚型分别为16份、1份和20份,其它3份样品同时含有H1N1和H3N2亚型猪流感病毒,和鸡胚分离病毒结果100%一致。试验证明建立的猪流感病毒H1N1、H1N2和H3N2亚型多重RT-PCR诊断方法是一种特异敏感的诊断方法,可用于临床样品的早期快速诊断和分型。 相似文献
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