低温季节不同禾草对富营养水体净化能力的研究

为选出低温季节净化富营养水体的优势植物,对矮蒲苇(Cortaderia selloana‘Pumila’)和3个多花黑麦草(Lolium multiflorum)品种的水体净化能力进行了比较研究。处理5d后,供试植物的水体中铵态氮(NH₄⁺-N)含量接近0,矮蒲苇对总氮(Total nitrogen,TN),硝态氮(NO₃^--N)和化学需氧量(Chemical oxygen demand,COD)去除率显著高于3个多花黑麦草品种;3个多花黑麦草品种中‘特高’和‘剑宝’的净化能力显著高于'美克斯'。处理20d后,供试植物对TN,NH₄⁺-N,NO₃^--N的去除率达90%以上,对总磷(Totalphosphorus,TP)和COD的去除率达79%和59%以上;水上部干重增长量占增长总量的50%以上,植株氮磷积累量占总去除量的80%以上。表明矮蒲苇、‘特高’与‘剑宝’的净化能力优良,可在低温季节的富营养水体净化中进行推广。     

重金属Cu2+、Cd2+和Pb2+对8种禾草种子萌发和幼苗生长的影响

研究了不同浓度Cu²⁺（200、300、400和500 mg·L^-1）、Cd²⁺（1、50、150和200 mg·L^-1）、Pb²⁺（500、1 000、1 500和2 000 mg·L^-1）对8种禾本科牧草种子萌发和幼苗生长的影响。结果表明：重金属离子胁迫对禾本科植物种子的发芽和幼苗生长的影响因植物种类及重金属离子不同而有差异。随着Cu²⁺,Cd²⁺和Pb²⁺浓度的增大,8种禾本科草种的相对发芽率、相对发芽指数和相对活力指数均呈不同程度的下降。供试不同浓度的Cu²⁺,Cd²⁺和Pb²⁺对8种植物幼苗生长均有抑制作用,高浓度胁迫下会出现“无根苗”。通过采用性状相对值对本试验进行隶属函数值综合评价,8种禾本科植物耐Cu²⁺的强弱顺序为：玉米 > 高丹草 > 燕麦 > 黑麦 > 无芒雀麦 > 黑麦草 > 垂穗披碱草 > 高羊茅,耐Cd²⁺的强弱顺序为：高丹草 > 黑麦 > 玉米 > 燕麦 > 无芒雀麦 > 垂穗披碱草 > 黑麦草 > 高羊茅,耐Pb²⁺的强弱顺序为：高丹草 > 燕麦 > 玉米 > 黑麦 > 无芒雀麦 > 垂穗披碱草 > 黑麦草 > 高羊茅。     

利用禾草隔离技术防控鼢鼠危害豆科人工草地的研究

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。     

Salt Tolerance and K/Na Ratio of Some Introduced Forage Grass Species Under Salinity Stress in Irrigated Areas

Salinity is a limiting factor for forage productivity in irrigated areas. The aim of this study was to evaluate the salt tolerance index (STI), the K/Na ratio, and the forage quality of several introduced cool season grass species in irrigated agriculture. Four irrigated water salinity concentrations were used (control, 4000, 8000, and 12000 ppm sodium chloride (NaCl)), and four grass cultivars belonging to three species were established under greenhouse conditions at the Qassim University Agricultural Research and Experimental Station during the 2012 and 2013 growing seasons (perennial ryegrass (Lolium perenne L., cvs. Aries and Quartet), endophyte-free tall fescue (Festuca arundinacea Schreb., cv. Fawn), and orchardgrass (Dactylis glomerata L., cv. Tekapo)). A randomized complete block design (RCBD) using three replications was used. Cultivars were evaluated based on their dry weights (g m^?2) and forage quality. Additionally, the STI and potassium (K⁺) and sodium (Na⁺) concentrations in the studied grass cultivars were evaluated. The dry weights of the grasses decreased significantly as the salinity level of the irrigation water increased. At a salinity of 4000 ppm, the Aries perennial ryegrass had the highest dry weight at both sample cuttings. The Aries, Fawn, and Quartet grasses had the highest STI values. The percent of K⁺ and the K/Na ratio increased as the salinity of the irrigation water increased for the Fawn tall fescue and Quartet perennial ryegrass. In the previously cultivars, the percentage of Na⁺ decreased as the salinity level of the irrigation water increased, which was in contrast with the results observed for the Tekapo orchardgrass.     

内蒙古地区12种牧草的粗饲料分级指数及粗饲料相对值的测定及比较

本论文通过对内蒙古地区常见的12种禾本科牧草和豆科牧草的常规营养成分测定及粗饲料分级指数(G I)和粗饲料相对值(RFV)的估测,对各种牧草进行营养价值的评定,得知用单一的营养指标不能准确的评价牧草的营养价值,只有综合的考虑粗饲料分级指数,养分含量等指标才能对牧草的营养价值做出正确的评价。试验结果表明卢德勋提出的粗饲料分级指数(G I)的计算公式把牧草中可摄入的净能和粗蛋白结合起来,同时把牧草中NDF或ADL包括在内,能明显区分养分含量差异很小的不同牧草,说明用粗饲料分级指数(G I)来评价牧草营养价值比美国提出的粗饲料相对值(RFV)更符合牧草的实际营养价值。     

Influence of Initial Plant Size and Temperature on Competitive Interactions in Pasture Grasses

Research has suggested that larger initial seedling size conferred a distinct advantage on the more competitive species. Therefore, competitive relationships between ryegrass, prairie grass and cocksfoot were evaluated using seedlings at the same growth stage, in order to minimise the advantages of seedling size differences between species. This study demonstrated that the performance of species in mixtures and their competitive abilities were related to their ability to accumulate dry matter. Simulated spring and autumn temperatures showed that temperature had no significant effect on the competitive relationships between these species.     

果园生草试验及适生草种评价

试验以自然生草和自然生草＋人工生草（紫花苜蓿、白三叶、红三叶、早熟禾、高羊茅和黑麦草）的‘寒富’苹果园为研究对象,以清耕为对照,研究了自然生草对土壤理化性质、微生物数量和酶活性的影响,并对自然生草条件下的人工草种进行了初步评价。结果表明,与对照相比,自然生草处理土壤pH值、有机质、全氮、全磷、碱解氮、速效磷、速效钾、细菌、真菌、放线菌、脲酶和磷酸酶明显升高,全钾增幅较小,但含水量降低了。通过适宜草种评价的初步研究可知,以生草覆盖为目的、刈割次数少的可选择白三叶、高羊茅和黑麦草等品种;为增加土壤有机质、提高土壤肥力,需要刈割用于覆盖的则应选择紫花苜蓿、红三叶等产草量较高的草种。     

Breeding Improved Grasses for Semiarid Rangelands

Vast areas of semiarid rangelands in western USA are severely degraded and infested with troublesome weeds such as cheatgrass (Bromus tectorum) and medusahead rye (Taeniatherum asperum). Reseeding with appropriate plant materials that are adapted to the site and competitive enough to replace existing undesirable vegetation is often the most plausible way to reclaim such sites. Unfortunately, many of our native grasses are more difficult to establish and are not as competitive with these exotic weedy grasses as their introduced counterparts, including crested and Siberian wheatgrass (Agropyron cristatum, A. desertorum, and A. fragile). Most native grasses did not evolve under intense management or in association with species as competitive as cheatgrass. Genetically improved germplasms and cultivars of native and introduced (naturalized) grasses have been and are being developed by the Forage and Range Research Laboratory (FRRL) of the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) in cooperation with the Utah Agricultural Experiment Station (UAES) and other agencies. These plant materials have demonstrated the potential for increasing the genetic diversity, protecting watersheds and soil resources, and improving the habitat and grazing potential for livestock and wildlife on semiarid rangelands. Research is also in progress at FRRL to develop germplasm and methodology whereby introduced grasses may be used in combination with natives, and in some instances assist in the establishment of native stands. The proper choice of plant materials must be based on objective criteria if we are to protect our lands and natural resources from further degradation.     

我国南方双季稻区冬闲田种草模式探讨

利用冬闲田土秋冬种草能产生较高的经济效益和生态效益。介绍了我国南方双季稻区冬闲田的种草概况、存在的问题,提出了种植豆科（紫云英）牧草、禾本科（小黑麦、黑麦草）牧草、十字花科（油菜）牧草、豆科牧草和禾本科牧草混播4种模式。     

A technique for the production of polyploids in grasses

Summary A satisfactory technique has been developed whereby vegetative grass tillers can be successfully treated with colchicine to produce polyploid sectors. It is particularly useful for producing polyploids in sterile hybrid material and as an alternative technique to seedling treatment if the number of seeds available is in limited supply.