首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
豆科牧草研究进展   总被引:18,自引:7,他引:11  
豆科牧草的属间、属内、种间与种内均存在着巨大的遗传变异,利用这种变异,通过育种与选择,已培育出可良好地适应广泛的环境与管理条件的品种,遗传操作为此提供了更为广阔的空间,在豆科牧草固氮方面,对固氮过程、氮向伴生禾草的传送途径及残余氮对后继农作物的价值均有了进一步的理解。对包括施氮、采摘策略和影响混播草地中禾本科-豆科牧草平衡的胁迫等相互作用因素均已给予了阐明。在禾草/白三叶草草地为基础的家畜生产系统中,氮素的损失及其对环境产生的不良作用低于大量施氮的禾草草地系统。与禾草相比,豆科牧草无是用作放牧、青贮或用作干草,其物理、化学和解剖学等方面的特性均可增加家畜的嗜食性和自由采食量。由于豆科牧草的营养价值、可利用营养成分和采食特征,在单一豆科牧草或豆科牧草比重较大的禾草-豆科牧草混播草地上采食的不同种类、不同类型家畜的个体生产性能均优于在禾草草地上采食者。值得注意的是浓缩单宁在动物营养中的有益作用,这类单宁存在于诸如百脉根(Lotus corniculatus)、红豆草(Onobrychis viciifolia)和冠状岩黄芪(Hedys-crum coroharium)等植物中,其防止家畜患膨胀病,通过使较多的氨态氮到达小肠而提高氮的利用,并减轻绵羊肠道中线虫的作用。显然,培育含浓缩单宁的转基因豆科牧草是植物育种者现阶段的主要目标之一。此外,豆科牧草亦有许多其他用途,例如,在葡萄园中用作保护性植被,禾谷类作物的下层植被和为制药业提供次生化合物等。豆科牧草以其植物多态性和花朵的颜色等亦在美化景观和自然保护区中发挥着作用。可以预见,豆科牧草的作用在温带可持续农业中的作用将会增加,充分发掘现有的知识和相关研究成果,及有效的技术将是未来豆科牧草利用的主要特色。  相似文献   

2.
<正> 冷季禾草在单播时为了获得高额干物质产量所必需的商品氮肥成本费的提高,所以禾草——豆科牧草混播又重新为人们所重视。对于混播中所用的禾草和豆科牧草的比较生产性能以及有关禾草——豆科群落中植株动态方面的更为基本的资料的需要将会日见增加。  相似文献   

3.
混播草地禾草及土壤主要养分变化研究   总被引:4,自引:0,他引:4  
在干旱条件下研究了豆科、禾本科牧草混播草地禾草粗蛋白质含量以及土壤耕层主要养分的变化。结果表明,生长第4年混播草地禾草叶片的粗蛋白质含量比单播禾草提高19.1%,茎的粗蛋白质含量提高18.1%;生长第3年混播草地土壤0 ̄30cm的有机质提高8.5%,全氮提高13.3%,速效钾提高16.2%,全磷降低4.8%。  相似文献   

4.
播种牧草前要备好种子材料,如粒种、果实、块根、块茎等。种子要求纯净度高,粒大饱满,整齐一致,生活力强,健康而无病虫害。休眠的种子需要打破休眠。禾本科种子芒多则需去芒,豆科牧草需要时应进行根瘤菌接种。种子播前需作消毒处理。苜蓿等牧草的菌核病、免丝子病以及禾草的麦角病等,可通过盐水渍选或筛除。豆科草的叶斑病,禾草的根瘤病、赤霉病、秆黑穗病、散黑穗病等,可用1%的石灰水浸种。  相似文献   

5.
禾本科与豆科牧草的混播,是人工草地建植的最主要方式之一,而了解其之间的种间互作机理,对于维持混播草地的持续稳定生产具有重要意义。本研究从光照、养分、水分和空间等资源方面展开探讨了禾草和豆科牧草在混播时所采取的不同生存策略,阐述了豆—禾混播草地草种之间的竞争与促进关系,分析了豆科牧草固氮和转氮能力的影响因素及深根系豆科牧草与浅根系禾草的共存机制,提出了可以通过混播建植技术、草地管理措施及草地利用方式避免或减弱混播草地豆禾牧草之间的竞争,以此提高混播草地的生产力并维持混播草地持久力和稳定性。  相似文献   

6.
本试验在不放牧利用的条件下,对豆禾草地和禾草草地土壤中的铵和硝酸盐的积累的季节性分配进行了评价。两年期间,对土壤表层20cm内氮积累的两种形式进行了观察。试验结果表明,上述草地的植物生长活动使土壤中硝酸盐的积累量很少,在夏季使其积累量增大则靠调节牧草种类和豆科牧草的比例。夏天土壤中铵的积累也有所增加,但其积累量的多少不受牧草种类或豆科牧草比例的影响。  相似文献   

7.
豆科牧草来源匮乏始终是制约高寒牧区畜牧业发展的短板之一。除了天然草地资源本身的限制以外,豆科牧草人工草地的建植也存在诸多限制因素,其中一个重要的限制因素就是鼢鼠(Myospalax)危害。研究表明,鼢鼠对豆科等轴根系植物具有强烈的采食偏向性,而对禾本科等须根系植物则表现为相对冷淡。据此,本研究采用在豆科草地外围种植禾本科草隔离带的方式,从草种选择、隔离带宽度、种植方式等技术环节对此种方法的有效性和技术要点进行了探索。结果表明:禾草隔离技术是防控豆科人工草地鼢鼠危害的有效方法,平均可减少危害量82.4%以上;一年生禾草的隔离效果明显优于多年生禾草(P0.01),短期多年生禾草明显优于长期多年生禾草(P0.01);隔离带宽度应控制在3~5m之间;豆科草地建植当年以一年生、短期多年生和长期多年生混播隔离带效果最佳。  相似文献   

8.
<正> 豆科一禾本科牧草混播较之其单播具有某些优点。豆科牧草所固的氮,一部分直接或间接为混播禾草利用。它们间在根系分布和养分需要方面的差异使其能有效地利用土壤中的养分。因此,豆科—禾本科牧草混播可望提供高产、优质和季节性变动较小的饲草。  相似文献   

9.
中原地区多年生禾草物候期特点与分蘖动态的研究   总被引:2,自引:1,他引:1  
郭孝  陈二秋 《草业科学》2002,19(6):35-38
研究了中原地区3种主要禾本科牧草(苇状羊茅,多年生黑麦草,无芒雀麦)在1年内的物候期特点以及分蘖动态。结果表明,禾草在生长期内都在进行不同程度地分蘖,分蘖速度在1年内有3个高峰期(分蘖期,孕穗期和果后营养),1个平缓期和1个负增长期,分蘖速度最快的为分蘖期,物候内单株分蘖数和全年分蘖总数在果后营养期中达到最大。另外,与直根系的豆科牧草混播有利于禾草秋季分蘖。  相似文献   

10.
<正> 引言草地改良及饲料生产的研究,经常涉及到禾本科牧草与豆科牧草混播问题。人们常常希望知道不同的种在草地中所占的比例。因为这个比例经常是牧草产量与质量的重要决定因素。已经用来估计混播草地中豆科牧草与禾草比例的方法很多,有费时的人工分离样品法,也有快速而不甚准确的目测法。  相似文献   

11.
Many horse owners are concerned about sugar and fructosan levels in pastures and hay. While levels of these components have not changed in forages over the last century, the needs of horses have. Significant range in nonstructural carbohydrate contents of all grass species would allow for selection of varieties with lowered levels of these components. However, the grass seed industry must perceive a market for these types of grass before they would invest in the development of varieties and seed production and marketing of such types. Levels of these components currently vary with species, management, and the environment in which the plant is/has grown. Horse owners should be aware of these differences and use them to the benefit of their horses. Significantly lower levels of sugars and fructosans can be obtained by selecting grass species for low water soluble carbohydrate, then pastures can be managed or hay harvested with management practices favoring lowered nonfibrous carbohydrates. Forage can be analyzed for fructan or sugar, starch, and fructan can be estimated from nonfibrous carbohydrate analysis which is commonly determined in forage analysis.  相似文献   

12.
高原鼢鼠的采食造丘活动影响草地植被群落组成和结构,造成草地植被的空间异质性——土丘和植被斑块。本研究以冬季牧场中不同高原鼢鼠种群密度干扰下的植被性状为研究对象,探索植被群落组成结构对高原鼢鼠不同种群密度干扰的功能性响应。结果表明:植被高度随着鼢鼠种群密度的增加呈显著增加趋势(P<0.05),群落盖度和禾草丰富度呈显著下降趋势(P<0.05),而物种丰富度及杂类草丰富度随鼢鼠种群密度的增加表现出单峰曲线格局。地下总生物量随鼢鼠种群密度的增加呈显著下降趋势(P<0.05),杂类草生物量则表现出相反的趋势,而禾草类生物量表现出先降低后增加的趋势。由此可见,适宜密度的鼢鼠干扰有利于物种丰富度的提高,而低密度和高密度的鼢鼠干扰有利于草地中禾草生物量的提高。  相似文献   

13.
Defoliation aimed at introduced cool-season grasses, which uses similar resources of native grasses, could substantially reduce their competitiveness and improve the quality of the northern tallgrass prairie. The objective was to evaluate the use of early season clipping and fire in conjunction with simulated increased levels of atmospheric nitrogen deposition on foliar canopy cover of tallgrass prairie vegetation. This study was conducted from 2009 to 2012 at two locations in eastern South Dakota. Small plots arranged in a split-plot treatment design were randomized in four complete blocks on a warm-season grass interseeded and a native prairie site in east-central South Dakota. The whole plot consisted of seven treatments: annual clip, biennial clip, triennial clip, annual fire, biennial fire, triennial fire, and undefoliated control. The clip plots consisted of weekly clipping in May to simulate heavy grazing. Fire was applied in late April or early May. The subplot consisted of nitrogen applied at 0 or 15 kg N · ha?1 in early June. All treatments were initially applied in 2009. Biennial and triennial treatments were reapplied in 2011 and 2012, respectively. Canopy cover of species/major plant functional groups was estimated in late August/early September. Annual clipping was just as effective as annual fire in increasing native warm-season grass and decreasing introduced cool-season grass cover. Annual defoliation resulted in greater native warm-season grass cover, less introduced cool-season grass cover, and less native cool-season grass cover than biennial or triennial defoliation applications. Low levels of nitrogen did not affect native warm-season grass or introduced cool-season cover for any of the defoliation treatments, but it increased introduced cool-season grass cover in the undefoliated control at the native prairie site. This study supports the hypothesis that appropriately applied management results in consistent desired outcomes regardless of increased simulated atmospheric nitrogen depositions.  相似文献   

14.
During 1964/66 the Molopo and adjacent semi‐arid ranching areas experienced the most severe drought in living memory. The effects of the drought on the more important grass species in particular, were investigated on three farms in the Vryburg district (namely Buttermere, Seruruble and Fontein). A highly significant decrease in the three dominant grass species (Stipagrostis uniplumis, Schmidtia bulbosa and Eragrostis lehmanniana) was recorded in camps with a moderate stand of woody plant species at the Buttermere and Seruruble sites. Overall mean losses of 82 per cent and 80 per cent of. the three major grass species were recorded at these respective sites. No significant differences in the mortality of these grass species were dectected on plots from which all woody plant species had been eradicated immediately before the drought. The mean hay yields recorded (1965/66 season) from bushed and debushed camps at the Buttermere site were 96 lb and 998 lb respectively. The botanical analysis data of four “dolomite” grassveld camps of the Fontein site revealed significant decreases in the total percentage basal cover and the basal cover of the major grass plant species.  相似文献   

15.
为了探测大气氮沉降对高山草甸的影响,设置对照(N_0)、低氮14.3g·m~(-2)(N_5)、中氮28.6g·m~(-2)(N_(10))和高氮57.1g·m~(-2)(N_(20))4个氮素(NH_4NO_3)添加水平,连续3年对青藏高原东部的高山草甸群落进行施氮处理,测定各添加水平下群落生物量及物种多样性的变化。结果表明,随着氮素添加量的增加,地上生物量逐渐增加,在N_(20)达到最大,且地上生物量在空间格局上呈现向上转移的趋势;随氮素的增加,地下生物量先增大后减小,在N_(10)最大,且有向浅层表土(0-10cm深度)转移的趋势。各功能群中,禾草类植物的地上生物量从N_0到N_(20)逐渐增加,在N_(20)达到最大,其在地上总生物量中所占的比例也在N_(20)达到最大。另外,随着施氮量的增加,植物物种多样性呈现出逐渐降低的趋势。可以看出,氮素添加对高山草甸群落的结构有着明显的影响。  相似文献   

16.
应用RFV评价鄂尔多斯荒漠草原优势牧草营养价值   总被引:1,自引:0,他引:1  
将采自内蒙古鄂尔多斯地区的禾本科牧草3种、豆科牧草3种和菊科牧草3种分别于6月、7月和9月刈割晾干,共制得27个样本。通过应用饲料相对指数(RFV)进行综合评定可知:将6月、7月和9月分别刈割的同一品种牧草混合后,品质最好的为中苜2号,其次是沙打旺,再次是沙蒿,最差的是花棒;同种牧草不同刈割期比较可知:对于禾本科牧草来说,针茅、冰草和中苜2号在不同刈割期营养价值的大小顺序为6月7月9月;对于豆科牧草来说,花棒、沙打旺在不同刈割期营养价值的大小顺序为6月7月9月,但草木樨在不同刈割期营养价值的大小顺序则为6月9月7月;对于菊科牧草来说,沙蒿、猪毛蒿、籽蒿在不同刈割期营养价值的大小顺序为7月6月9月。  相似文献   

17.
抗污草种筛选利用试验初报   总被引:3,自引:0,他引:3  
为解决我国南方冶炼厂矿企业重污区绿化抗污草种缺乏的难题,选用10个不同类型,适合南方亚热带气候、土壤等自然条件下种植的多年生草本植物,在株洲冶炼厂重污区进行了集中抗污品比试验。同时,对10个参试草种的主要有毒成分蓄积量进行了分析测定。结果表明,在厂内重污区生长较好、抗污能力强的草种有天堂419、岸杂1号狗牙根、本地狗牙根、结缕草等4个草种。在8种有毒成分中,试验区与对照区区相比,天堂419的砷、铅  相似文献   

18.
为从物种多样性和空间结构方面阐明豆禾牧草混播系统高效生产机制,将混播种类(单播、2种牧草混播、4种牧草混播和6种牧草混播)、混播群体空间结构(行距+同行/异行/异行阻隔)作为影响因素,从豆科牧草固氮能力、转氮效率、氮素营养竞争、种间相容性和生产性能分析和比较豆禾牧草在不同混播方式中氮素固定、转移和利用效率对混播系统生态功能的贡献程度。结果表明:1)混播处理的牧草产量、N产量均显著高于单播(P<0.05),生产性能显著提高;但生产性能未随混播种类的增加而提高,异行混播+30 cm行距的混播群体结构具有较高的生产性能。2)固氮量随混播种类的增加而呈下降趋势,转氮量和转氮率随混播种类的增加而呈先下降后上升的趋势,而固氮率和贡献率变化不明显;异行混播+30 cm行距的混播群体结构具有较高的转氮量、转氮率和贡献率。3)营养竞争比率随混播种类的增加变化不明显,豆科牧草相对产量和相对产量总和随混播种类的增加而呈增加趋势;异行混播+30 cm行距的混播群体结构具有较高的豆科牧草相对产量和相对产量总和,但营养竞争比率较低。4)牧草产量与转氮量呈极显著正相关(P<0.01),而相对产量总和与氮素营养竞争比率呈极显著负相关(P<0.01)。因此,混播种类对于豆禾牧草混播系统生产性能的提升作用有限,高养分利用效率的物种组合可能更为关键;通过混播群体空间结构的优化可以使豆禾混播牧草根系氮素固定、转移、利用途径和效率得到提高,为混播系统生产性能的提升提供了重要途径。  相似文献   

19.
A fence‐line contrast study compared erosion levels, herbage production and grass species diversity in Umfolozi Game Reserve (UGR) and adjacent KwaZulu (KWZ). There was no significant difference in soil loss or A‐horizon depths measured in KWZ and UGR, but there were significant differences in both parameters when measurements from upper, mid and lower slope sites were compared. Similarly, there was no significant difference between herbage accumulated in KWZ and UGR in the absence of grazing, but there was a significant difference between the upper, mid and lower slope plots. There was also no significant difference between grass species richness measured on plots in KWZ and UGR, but there was a highly significant difference when the grass species richness was compared between upper, mid and lower slopes. The major conclusion drawn from these results was that differences in the topographical position of the plots, rather than differences in land‐use practices, explained the greater amount of variability in the data.  相似文献   

20.
硬秆仲彬草〔Kengyiliarigidula(keng)J.L.Yang,YenetBaum〕是分布于我国西部的一种多年生六倍体植物。将其与犬草〔Elymuscaninus(L.)L.,2n=28,SSHH〕、鹅观草(RoegneriakamojiOhwi,2n=42,SSHHYY)、糙毛仲彬草〔K.hirsuta(Keng)J.L.Yang,YenetBaum,2n=42,PPSSYY〕3个种进行了杂交,对亲本及杂种F1代花粉母细胞减数分裂中期Ⅰ染色体配对行为进行了观察。减数分裂平均构型分别为:E.caninus×K.rigidula24.08Ⅰ+5.28Ⅱ+0.12Ⅲ;R.kamoji×K.rigidula17.22Ⅰ+11.81Ⅱ+0.28Ⅲ+0.08Ⅳ;K.rigidula×K.hirsuta4.32Ⅰ+17.45Ⅱ+0.58Ⅲ+0.21Ⅳ+0.04Ⅴ。根据以上结果,结合种的形态特征,硬秆仲彬草从鹅观草属(RoegneriaC.Koch)拟冰草组(ParagropyronKeng)中组合到仲彬草属(KengyiliaYenetYang)是正确的。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号