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不同施肥处理对高羊茅草坪质量的影响 总被引：22，自引：1，他引：21
在新建植的高羊茅草坪上，按照10g/m^2的等N量分别施入尿素、磷酸二铵、包裹型草坪专用肥（国产）和Osmocote控释肥料，以尿素为对照，研究不同施肥处理对草坪颜色、均一度、生长速度、分蘖密度、地下生物量和抗病性的影响。结果表明，Osmocote控释肥料关分释放速率最低、肥效最长，尿素养分释放速率最高、肥效最短；Osmocote肥料处理草坪颜色最好；磷酸二铵处理草坪抵抗夏季病害能力最强；尿素处理草坪一度最差，磷酸二铵处理草坪均一度波动幅度最小；尿素处理草坪分蘖密度最高、地下生物量峰值最高且受环境影响变化剧烈，施用Osmocote控释肥料的草坪分蘖密度和地下生物量适中并且变化较平缓，有利于草坪草健康生长。 相似文献
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施肥对草地早熟禾草坪质量及土壤中硝态氮动态的影响 总被引：20，自引：5，他引：15
通过大田试验研究不同氮肥(缓释肥、尿素、磷酸二铵)、不同施肥次数、不同养分配施对草地早熟禾草坪质量及土壤中硝态氮动态的影响.研究发现速效肥可以迅速改变草坪颜色,缓释肥对草坪颜色的影响更为持久;施氮肥加剧了草坪夏季病害的发生,导致草坪分蘖密度下降,而施用磷酸二铵处理的草坪对褐斑病的抗性最强.整个生长季内尿素、磷酸二铵配施和4次施用缓释肥2处理草坪的均一度最好. 缓释肥的应用减小了草坪生长速率的波动;秋季2次施肥比1次施肥更有利于地下生物量的累积.土壤中0～20 cm土层硝态氮的含量受施肥影响很大,并且与不同类型肥料氮素释放模式有关. 相似文献
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打孔和施肥处理对草地早熟禾草坪质量的影响 总被引：7，自引：0，他引：7
对中国农业大学科学园内建植７年的草地早熟禾草坪进行了打孔和施肥８个处理对草坪质量影响的研究,各处理施氮量均为１０ｇ／ｍ＾２。结果表明,打孔改善了颜色和整齐度,对生长速度、分蘖密度、生殖枝数、地下生物量的影响不明显;在肥料的４个处理中,液体肥提高了整齐度;尿素和草坪专用肥能改善草坪颜色;各处理对生长速度、分蘖密度、生殖枝数、地下生物量的影响不明显;在全部８个处理中,打孔＋微肥＋尿素处理较对照未打孔＋尿素处理显著降低了草坪生长速度,各处理在分蘖密度、地下生物量与对照之间差异不显著;打孔＋尿素处理、打孔＋草坪专用肥处理较对照改善了颜色;打孔＋液体肥＋尿素处理、打孔＋微肥＋尿素处理较对照明显改善了整齐度;打孔＋液体肥＋尿素处理较对照显著增加了生殖枝数。打孔＋微肥＋尿素处理效果较好。 相似文献
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养分管理对北京地区常见高尔夫球场球道用午夜早熟禾生长影响的研究 总被引：3，自引：3，他引：0
以北京地区高尔夫球场球道常用的草地早熟禾为研究对象,采用田间试验和实验室内分析相结合,研究施肥对坪草生长、质量表现的影响。结果表明,草地早熟禾在不同养分处理下,草屑积累量显著不同。增施P、K肥料能提高草坪颜色、均一度,降低夏季草坪褐斑病的危害;增施N肥,也可以增强草坪颜色,但降低草坪的均一度,夏季易受病害影响。不同养分处理草地早熟禾坪草组织N、P、K养分含量随季节的变化趋势相近,且变化幅度不大,草屑中N、P、K养分年带出量的顺序为N>K>P,N、K的带出量以夏末秋初最多,P的带出量多集中在夏季,不同养分处理中养分年带出量差异显著。 相似文献
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施肥对草地早熟禾草坪质量、剪草量及蒸散量的影响 总被引：3，自引：0，他引：3
通过盆栽试验,研究施肥对草坪颜色、剪草量、蒸散量及土壤中速效氮的影响。结果表明:施N肥能够明显改善草坪的颜色,增加草坪的剪草量,提高草坪的蒸散量;苗期施P肥将导致草坪剪草量明显增加;当土壤中速效N和速效P供应充足时,施K肥导致草坪颜色和剪草量明显降低。单施N肥能够加快土壤中铵态氮的硝化过程,氮磷钾平衡施肥则能够延缓土壤中铵态氮的硝化过程,降低土壤中硝态氮的含量,从而降低土壤中硝态氮淋失的风险。草坪的蒸散量与剪草量之间存在着显著的线性正相关(r=0.9965);控释肥料和常规肥料之间养分释放模式存在很大差异,使得施肥初期常规肥料处理草坪颜色、剪草量及蒸散量均高于控释肥料处理,施肥末期情况则相反。 相似文献
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菇渣堆肥对土壤及草坪生长的影响 总被引：5，自引：0，他引：5
为了解决城市草坪绿地土壤性状恶化问题和有效利用菇渣资源,进行了菇渣堆肥绿地土壤改良试验,通过混合(H)、覆盖(F)、混合+覆盖(HF)处理,研究菇渣堆肥不同施入方式对绿地土壤物理性质及草坪生长的影响.结果表明:三种施入方式均能显著降低表层(0～10cm)土壤容重,增加土壤孔隙度,F和HF改良效果最理想;各施人方式均能显著提高土壤渗透性,具有显著的保水作用,含水量由高到低依次是F＞ HF＞H,分别比对照高31％、23％、16％.不同施入方式还均能显著促进草坪生长和分蘖,增加草坪地下生物量,其中F处理的分蘖密度和地下生物量最高,分别比对照高46％和35％ ;F处理的杂草抑制宰在98％以上,HF为56％,H处理未能抑制杂草;依据NTEP对草坪外观质量综合评分,覆盖处理6.73分,草坪质量良好,混合覆盖与混合处理分别为5.91分和5.55分,草坪外观质量尚可;F与HF处理还能减缓土壤温度变化幅度. 相似文献
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几种缓释肥的氮释放特性以及对草坪草生长的影响 总被引：6，自引：2，他引：6
实验室内采用水浸泡法对尿素、3种缓效肥和山西省农业科学院土壤肥料研究所研制(自研草坪肥)的缓效肥的初期溶出率和微分溶出率进行了测定.其中尿素的初期溶出率为22.75%,超出了国际上公认的缓/控释肥的初期溶出率小于15%的指标,而微分溶出率为0.22%,也小于国际上公认的缓/控释肥的微分溶出率(0.25%～2.5%)指标.其他几种缓释肥的初期溶出率为8.73%～14.42%,微分溶出率为0.30%～2.11%,符合国际上公认的缓/控释肥的初期溶出率和微分溶出率指标.田间试验比较和研究了尿素、3种缓效肥和山西省农业科学院土壤肥料研究所研制的缓效肥对草坪草的干草产量和养分含量的影响,尿素和包衣尿素处理的草坪草的生长量前期较高,后期产草量较低,呈马鞍型.其他处理的草坪草干草产量则比较平缓,肥料的氮释放特性与草坪草生长趋势相同.不同肥料处理对草坪草的中量、微量元素含量有一定的影响. 相似文献
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应用盆栽试验研究了释放期为30 d(U30)和80 d(U80)的控释包膜尿素一次性基施对高羊茅Festuca arundinacea草坪建植期生长情况的影响。结果表明：在施氮量相等的情况下,单一施用U80处理草坪成坪时间最短,仅为51 d,播种85 d后,其叶绿素仪读值（SPAD）高于其他处理。出苗后各处理地上生物量呈现先升高后降低的单峰变化趋势。单一施用U80处理草坪成坪后,生长速度较其他处理更为平缓。此外,单一施用U80处理和U80配施30％普通尿素处理,草坪地下生物量积累总量明显高于单一施用普通尿素处理。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献