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皇草不同种植密度对植被恢复速度的影响 总被引：1，自引：0，他引：1
通过种植密度对皇草植被恢复速度的影响研究,结果表明:随着栽植密度的加大,皇草植被恢复速度加快。处理2500株/667m2恢复植被盖度达90%以上只需2个月,产草量达134331.0kg/hm2。从经济角度出发,采用皇草进行植被恢复和刈割利用,以栽植22500～30000株/hm2较为适宜。 相似文献
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6种植密度对玉草1号产量与品质的影响 总被引：2，自引：0，他引：2
研究了种植密度对玉草1号产量、品质及植株性状的影响。结果表明,45 000与52 500株/hm2 2种密度的总鲜草产量差异不显著（分别为128 944和133 167 kg/hm2）,但二者均显著的高于密度为37 500株/hm2的总鲜草产量（117 370 kg/hm2）;但这3种密度处理的总干草产量差异不显著。分析这3种密度间各品质指标、植株性状指标总体表现,结果密度为37 500株/hm2的粗蛋白（CP）含量、CP产量、相对饲用价值（RFV）、分蘖数、总茎粗、干物率均为最高,密度为45 000株/hm2次之,处理52 500株/hm2最低;中性洗涤纤维（NDF）含量密度为37 500株/hm2最低,52 500株/hm2最高。综合产量与饲用品质比较研究表明,玉草1号种植密度为45 000株/hm2左右在我国南方最适宜。 相似文献
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对黑龙江省的3个主栽桑树品种秋雨、青龙、泰来进行无干栽植密度试验的结果表明,不同桑树品种有不同的适宜栽植密度。秋雨和青龙在60000株/hm2、泰来在75000株/hm2栽植密度下产叶量达到最高。桑树合理密植对桑叶质量影响不显著,但增加到60000~75000株/hm2后,随栽植密度的增加,养蚕质量也随之下降。栽植密度对养蚕质量各因素的影响,因桑树品种不同有差异。 相似文献
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甘草种子人工繁育暨配套栽培技术研究初报 总被引：9，自引：3，他引：6
野生乌拉尔甘草Glycyrrhiza uralensis采用适宜的人工栽培技术,可在生长第5年进入种子生产期,产量达292.5 kg/hm2,种子质量及其栽培学性状都优于野生甘草种子.自繁甘草种子经育苗,用倾斜式方法移栽定植,密度15万株/hm2,于生长第3年秋冬时采挖,甘草产量达7 140kg/hm2,等级草比例达60%以上,甘草酸等有效成分含量均达到药用指标.不同采挖季节对甘草品质有显著影响,秋末冬初采挖时品质最好.不同栽植方式,施肥方法、灌水次数及生育年龄对甘草产量都有明显影响,多因素综合考虑,以移栽后第3年采挖经济效益最好. 相似文献
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云南山地灌草丛植被恢复研究 总被引：1，自引：1，他引：0
通过对云南山地灌草丛植被恢复研究表明,围栏封育、浅耕翻、浅耕翻+补播3种技术措施均可有效恢复山地灌草丛植被,提高草地产量和品质,改良土壤,增强保水保土功效;浅耕翻+补播对退化山地灌草丛植被的恢复效果优于围栏封育和浅翻耕;在浅耕翻+补播处理中,3年平均草层高54.0cm、植被盖度95.4%、植株密度2250.1株/m2、鲜草产量7701.1kg/hm2,分别较对照提高210.34%、147.12%、123.60%和93.25%;土壤全氮(2.05g/kg)和有机质(62.61g/kg)分别较对照增加79.82%和109.82%,容重(0.83g/kg)较对照降低25.89%;地表径流量(5.73m3/hm2)及土壤侵蚀量(6.32kg/hm2)分别较对照下降93.59%和78.85%。 相似文献
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试验结果表明,41%草甘膦异丙胺盐水剂1107 g/hm2、1660.5 g/hm2、2214 g/hm2,250 g/L百草枯水剂750 g/hm2对弥猴桃园杂草有一定的速效性和持效性,防除效果好。药后15天总草株防效达82.9%~91.0%,药后30天总草株防效达87.6%~94.9%,鲜重防效达95.5%~98.9%。 相似文献
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接穗品种据美国佛罗里达州(以下简称佛州)农业统计署2004年统计数据,佛州柑桔总面积达30.2万hm2,9794.5万株,其中,甜橙25.2万hm2,葡萄柚3.6万hm2,宽皮柑桔1.36万hm2。平均栽植密度323株/hm2。2004—2005年佛州商业苗圃售出的苗木中,柑桔品种结构为:甜橙65%,葡萄柚25%,宽皮柑桔6 相似文献
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玉米与菊苣不同密度间作试验 总被引：3，自引：1，他引：2
采用二因素饱和D最优设计,进行粮食作物玉米Zea mays与牧草菊苣Cichorium intybus cv. Puna不同密度间作试验,将试验数据建立玉米籽粒产量与玉米密度、菊苣密度的回归模型和菊苣鲜草产量与玉米密度、菊苣密度的回归模型。解析回归模型得知,当玉米密度为22 966株/hm2,菊苣密度为11 1851株/hm2时,玉米籽粒产量为5 993.69 kg/hm2;菊苣密度为258 834.3株/hm2时,菊苣鲜草产量为106 014.51 kg/hm2,玉米密度对菊苣鲜草产量的影响呈负增长效应。以玉米籽粒产量和菊苣鲜草产量同步增长为目标,对回归模型进行模拟寻优,提出实现玉米、菊苣共同增产技术方案,即玉米籽粒产量≥5 475 kg/hm2、菊苣鲜草产量≥82 500 kg/hm2时的玉米、菊苣间作密度为玉米43 446～50 499株/hm2、菊苣105 713～204 158株/hm2。 相似文献
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对当地野生草种麦宾草进行了驯化栽培的初步研究。结果表明:麦宾草在海拔高度3 800m左右的果洛地区在栽培条件下能完成整个生育期生长,栽培当年高度可达到16.0cm,盖度达到60%,第2年株高可达到110cm,盖度达到96%;栽培当年干草产量为1 266.8kg/hm2,第2年、第3年和第4年的干草产量分别为7 959.4kg/hm2,6 462.4kg/hm2,5 244.1 kg/hm2,种子产量分别为1 000.2kg/hm2,880.6kg/hm2,790.5kg/hm2。该草种是适合三江源区黑土滩退化草地植被恢复与重建的优良草种,也是高寒草甸地区建植高质量的生态型或刈用型黑土滩人工草地的优良草种。 相似文献
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《当代畜牧》2017,(27)
笔者以南方C4植物巨皇草为试验材料,采取茎段扦插繁殖的方法,设置不同垄距处理,固定株距进行垄上单行栽培,秋季一次性收割作为青贮利用,以65 cm垄作"中原丹32号"青贮玉米为CK,从产草量、株高、叶茎比、分蘖数等方面,初步研究了皇竹草在大庆地区奶牛场饲料基地使用垄作栽培法对其生产性能的影响。结果表明,各处理中65 cm行距垄作栽培方式巨皇草产草量最高,为191.25 t/hm2,比常规玉米垄作栽培方式的产量高近2.5倍(常规玉米垄作栽培单产为75.69 t/hm2)。表明巨皇草具有较佳的产量效应,可以大幅度降低青贮饲料的生产成本。巨皇草是一种北方值得推广应用的超高产青贮型饲草。 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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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献