毛稃紫羊茅草坪草在河西盐碱地种植研究

河西地区土壤盐碱含量高，一般草坪草种不易成坪。毛稃紫羊茅草具有较强的适应性，据１９９０～１９９４年间引种试验，该草具有独特叶色，观赏价值高等特性，可单播或跟其他草种混播。单播适宜在城市园林、行道两旁；混播与瓦巴斯早熟禾、肯塔基早熟禾搭配较理想。毛稃紫羊茅草坪在河西地区青绿期可达２５０ｄ以上，草坪寿命可达１０年以上，在新建植草坪地施羊粪７５００ｋｇ／ｈｍ＾２，可使草坪成坪提高１５ｄ．     

广西西南部菲尔金早熟禾引种建坪试验初报

为了充分利用优良草坪草资源，将冷季型草坪草菲尔金早熟禾引种到桂西南选点建坪试验。结果表明，菲尔金早熟禾能够安全越夏，耐热耐旱性好，青绿期长，具有较好的建坪效果。     

肯塔基,瓦巴斯草地早熟禾在青岛地区的引种栽培研究

青岛地区自１９８４年引种表塔基草地早熟禾，瓦巴斯草地早熟禾之后，经对其形态学，生物学特征和特性的观察和试验，确认该草不仅具有耐寒，耐瘠薄，抗旱，返青早，枯黄晚，绿期长（３００ｄ以上）的特点，而且色泽鲜艳，单层厚密，繁殖容易，栽培简单，是建造草坪的一种优良草种。在大量栽培试验和推广实践的基础上，总结了肯塔基，瓦巴斯草坪草的播种，移栽技术，并重点介绍了草坪形成后的除草，修剪，施肥，浇水等养护管理措施和     

混播对草坪建植与病害的影响

以我国草坪建植中常用的草地早熟禾、多年生黑麦草和高羊茅为供试种，在兰州市建植了单播与混播草坪，观测了出苗速度、生长速度、成坪速度、盖度、越夏率、越冬率、枯黄率及主要病害。结果表明：黑麦草的出苗和生长速度明显大于高羊茅和早熟禾，而成坪速度则与高羊茅和混播草坪相当；建植后混播草坪中黑麦草的比例逐渐下降，早熟禾的比例逐渐上升，高羊茅的比例则变化不大，但黑麦草在建植后的一年半时间内始终占据优势。3种草坪草的主要病害为早熟禾溶失病、黑麦草叶斑病和高羊茅叶斑病，单播草坪的病蘖率均高于混播条件下各自的病蘖率。     

11种草地早熟禾的品比研究

草地早熟禾是一种具有优良性状的冷地型草坪草，耐寒，抗旱，耐阴性强，草层厚，封闭力强，早春返青早，冬季枯黄晚，绿色期长，可作为北方地区主体草坪草。本文对11个草地早熟禾品种通过室内盆栽实验，从品种的种子质量，生长状况，形态特征及草丛结构等方面进行观测与比较，从而总结出各引进品种在坪用和建坪方面的差异。     

西宁地区草坪草引种品比试验研究

通过对西宁地区5个种16个品种草坪草的引种品比试验,对其环境适应性(青绿期,抗病性,越冬、越夏)和坪用性状指标(密度、颜色、质地、耐践踏性和幼苗生长速度)进行测定,对环境适应性、绿地型、运动型坪用性状进行综合评定.结果表明:草地早熟禾Poa pratensis的午夜和抢手股,加拿大早熟禾P.compressa的印第安酋长,多年生黑麦草Lolium perenne的阳光具较好的环境适应性和较高的坪用性状,既适宜绿地型草坪建植,又适宜运动型草坪建植;高羊茅Festuca elata的2个品种适宜运动型草坪建植;紫羊茅F.rubra派尼是绿地型草坪建植的理想品种;多年生黑麦草的美洲豹较适宜绿地型草坪建植.     

施用ZT－1丰抗素对草坪的影响

对草坪喷洒ＺＴ－１丰抗素，结果草坪草高度增高８．６１ｃｍ，叶加宽０．１２ｃｍ，覆盖度增加１１％，绿期延长１５ｄ     

混播对草坪建植与病害的影响

以我国草坪建植中常用的草地早熟禾、多年生黑麦草和高羊茅为供试种，在兰州市建植了单播与混播草坪，观测了出苗速度、生长速度、成坪速度、盖度、越夏率、越冬率、枯黄率及主要病害。结果表明：黑麦草的出苗和生长速度明显大于高羊茅和早熟，而成坪速度则与高羊茅和混播草坪相当；建植后混播草坪中黑麦草的比例逐渐下降，早熟禾的比例逐渐上升，高羊茅的比例则变化不大，但黑麦草在建植后的一年半时间内始终占据优势。3种草坪草的主要病害为早熟禾溶失病、黑麦草叶斑病和高羊茅叶斑病，单播草坪的病蘖率均高于混播条件下各自的病蘖率。     

冷地早熟禾草坪在呼伦贝尔高寒地区的建植技术

１９９１－１９９３年的试验结果表明，冷地早熟禾草在高寒地区作为美化，绿化城乡环境的草坪草种是适宜，试验成功地探索出一套适合在呼盟高寒地区建植冷地早熟禾草坪的栽培和管理技术，为开发环境绿化找到了一条新途径。     

草坪杂草化学防除试验

草坪杂草化学防除试验本试验分别选在建植第三年的草地早熟禾紫羊茅草坪上，参试药剂有２．４－Ｄ（分析纯），水花生净（２５％），试验时间为１９９４年１０月２日到１１月３日。１处理前的杂草状况１．１２．４—Ｄ试验区处理前平均每平方米有野茼蒿５０株，柳叶酸蓼３...     

刈割残茬对新麦草种子产量和产量构成的影响

禾本科种子收获后的残茬管理对次年的种子产量非常重要。研究了刈割残茬时间和留茬高度对新麦草 Psathyrostachys juncea次年种子产量和产量构成的影响。结果表明：不同刈割残茬时间和不同留茬高度显著影响单位面积生殖枝数和种子产量（P<0.05）。其中,收获后立即刈割处理和齐地刈割处理获得了最高的生殖枝数和种子产量。不同刈割残茬时间和留茬高度处理对生殖枝小穗数、小穗小花数、小穗种子数和千粒重影响不显著（P<0.05）。相关分析表明,在留茬高度处理和刈割时间处理条件下,新麦草的单位面积生殖枝数与种子产量之间存在显著的正相关关系（P<0.05)。     

The effect of discontinuing the use of antimicrobial growth promoters on the productivity in the Danish broiler production.

On 15 February 1998, the Danish poultry industry voluntarily decided to discontinue the use of all antimicrobial growth promoters (AGPs). To investigate how the removal of AGPs influenced the broiler productivity in Denmark, data from 6815 flocks collected from November 1995 to July 1999 by the Danish Poultry Council were analysed. The three flock parameters were: kilogram broilers produced per square meter (per rotation), feed-conversion ratio (total kilogram feed used per rotation/total kilogram live weight per rotation) and total percent dead broilers ((number of dead broilers during the rotation/number of broilers put in the house per rotation)x100). Data were analysed using a mixed model, allowing the correlation structures in the data to be taken into account. The analyses showed that kilogram broilers produced per square meter and percent dead broilers in total were not affected by the discontinued use of AGPs. However, the feed-conversion ratio increased marginally 0.016 kg/kg and has remained at this level throughout the rest of the study period.     

结缕草交播不同量高羊茅试验研究

在已成坪的结缕草草坪上,按１０ｇ／ｍ２、２０ｇ／ｍ２、３０ｇ／ｍ２和４０ｇ／ｍ２播量在秋季交播高羊茅,连续３年按月测定群落中高羊茅和结缕草的密度、盖度和频度,进而探讨较为适宜的交播量和各种交播量的交播效果。４种交播量中以１０ｇ／ｍ２为最佳;增加交播高羊茅播量会显著增加高羊茅的密度（Ｐ＜０．０５）及程度不同的增加其盖度和频度（Ｐ＞０．０５）,但却明显地降低了结缕草的密度、盖度和频度（Ｐ＜０．０５）,使高羊茅的种群竞争能力加强而结缕草的竞争能力减弱,使草坪群落趋向于向高羊茅不同个体组成的单一草坪群落方向演替。     

Epidemiological approach to the association between economic efficiency and productivity on swine farms in Prince Edward Island.

Regression analysis was used to determine the ability of a number of biological parameters to predict economic efficiency. Detailed feed, financial, and production records were maintained by a random sample of eighteen Prince Edward Island (PEI) swine producers (each producing over 1000 market hogs per year). Relative economic efficiency of the operations was measured using return to management and labor (RML). Of the routinely monitored biological parameters, RML on PEI farrow-finish operations was best predicted (R2 = 64.8%) by: marketed per square meter per year (p = 0.008) and marketed per sow per year (p = 0.096). Regression of fixed costs revealed that biological parameters had limited ability to predict fixed costs per hog on farrow-finish operations (R2 = 30.7%). The only parameter contributing to the prediction of the fixed cost component of RML was feeder hog density (p = 0.077). The variable cost component of RML on farrow-finish operations was predicted (R2 = 94.3%) by feed cost per kg gain (p = 0.000), and marketed per sow per year (p = 0.044). The routinely recorded biological parameters on feeder farms had only limited ability to predict RML in this study (R2 = 43.7%). The only parameter of any importance was marketed per square meter per year (p = 0.106). Prediction of the fixed cost component of RML on feeder farms (R2 = 67.4%) was best realized by measuring feeder hog density (p = 0.045). The variable cost component of RML on feeder farms was reasonably well predicted (R2 = 74.7%) by feed cost per kg gain (p = 0.012). Although this parameter is difficult to monitor from records currently maintained on most farms, it points out the need to monitor feed consumption on swine farms.     

Arbuscular Mycorrhizal Fungi Can Accelerate the Restoration of Degraded Spring Grassland in Central Asia

Three years of field inoculation experiments were carried out in a central Asian desert to understand the effects of arbuscular mycorrhizal fungi (AMF) on the restoration process of degraded grassland. The results indicate that the biomass, density, and cover of ephemerals improved significantly after inoculation with AMF. Compared to the control treatment, aboveground biomass per plant of the mycorrhizal plant species Erodium oxyrrhynchum, Hyalea pulchella, Trigonella arcuata, and Schismus arabicus significantly increased in mycorrhizal treatment, but no significant differences were observed in the nonmycorrhizal species Alyssum linifolim and Ceratocarpus arenarius between mycorrhizal and control treatments. The total seedling numbers per square meter in the mycorrhizal treatment were much more than control treatment in all 3 yr. Inoculation with AMF increased the total cover of ephemeral plants from 7% to 14% in 2005, 15% to 38% in 2006, and 39% to 62% in 2009 than control treatment. Moreover, community productivity (shoot dry weight, grams per square meter) in mycorrhizal treatments significantly increased from 6 to 29 in 2005, 11 to 36 in 2006, and 27 to 81 in 2009 compared with the control treatment. It is concluded that AMF can speed up the regeneration process of grassland and this may be used as an effective biological approach in the restoration of degraded desert ephemeral plant communities.     

武威地区天然草地有毒植物及其防除

对武威地区天然草地有毒植物的种类，分布及其对草地的危害情况进行了调查研究，结果表明，全区天然草地共有毒植物１７２号，分属３１科８４属，平均２．１５种／ｍ＾２，盖度达４．４１％地上部分生物量１１．２８ｇ／ｍ＾２。对草地危害的主要黄花棘豆，甘肃棘豆，小花棘豆，狼毒和马草，受侵害的草地主要是山地草甸和山地草原，通过分析，提出了有毒植物防除和利用的建议。     

灌水对新麦草种子产量及产量构成的影响

研究不同灌水次数和灌水量对新麦草(Psathy rostachys juncea)种子产量、产量构成和生长特性的影响。结果表明:不同灌水次数的小穗小花数、小穗种子数和千粒重间差异显著(P<0.05),生殖枝数和生殖枝小穗数差异不显著;从返青到收获,灌水4次(返青期、拔节期、抽穗期和灌浆期)生殖枝数和小穗种子数最高,其实际种子产量也最高,达593.3 kg/hm²;不同灌水次数对生殖枝高度和穗长影响显著(P<0.05);不同灌水量对种子产量和产量构成的影响不显著。     

通过羊群宿营建植改良草地的研究

本文报道了在贵州高原山地条件下通过绵羊夜间宿营的方法建植改良草地的研究。结果表明，羊群宿营不仅能较彻底地清除原有饲用价值不高的植被，而且大幅度提高土壤养分含量，从而使播种的优良牧草得以成功建植。鸭茅、黑麦草和白三叶均为改良草地的宜植草种，而其中尤以鸭茅为最适禾草。7．2羊·夜／m2的宿营载畜率具有最佳草地建植效果。     

Association of environmental air contaminants with disease and productivity in swine.

A cross-sectional epidemiologic study associating air quality with swine health was conducted on 28 swine farms in southern Sweden. Correlation of housing air environment to swine diseases and productivity (data collected over the preceding 12 months) were investigated. The most prevalent swine health problems detected at slaughter were pneumonia and pleuritis. In farrowing and nursery operations, the most prevalent problem was neonatal pig mortality. Several air contaminants (dust, ammonia carbon dioxide, and microbes) were found to be correlated with these swine health problems. Maximal safe concentrations of air contaminants were estimated on the basis of dose-response correlation to swine health or human health problems. Recommended maximal concentrations of contaminant were: dust, 2.4 mg/m3; ammonia, 7 ppm; endotoxin, 0.08 mg/m3; total microbes, 10(5) colony-forming units/m3; and carbon dioxide, 1,540 ppm. The overall quality of the ventilation system was correlated with lower concentration of ammonia, carbon dioxide, microorganisms, and endotoxin, but not with dust concentrations. High animal density was related to high ammonia and air microbe concentrations. Animal density measured as kilograms of swine per cubic meter (compared with kilograms of pig weight or swine per square meter) had the highest correlation to animal health and air contaminants.     

Effects of Nitrogen Availability and Cheatgrass Competition on the Establishment of Vavilov Siberian Wheatgrass

Cheatgrass (Bromus tectorum L.) is the most widespread invasive weed in sagebrush ecosystems of North America. Restoration of perennial vegetation is difficult and land managers have often used introduced bunchgrasses to restore degraded sagebrush communities. Our objective was to evaluate the potential of ‘Vavilov’ Siberian wheatgrass (Agropyron fragile [Roth] P. Candargy) to establish on cheatgrass-dominated sites. We examined Vavilov establishment in response to different levels of soil nitrogen availability by adding sucrose to the soil to promote nitrogen (N) immobilization and examined cheatgrass competition by seeding different levels of cheatgrass. We used a blocked split-split plot design with two sucrose levels (0 and 360 g · m⁻²), two levels of Vavilov (0 and 300 seeds · m⁻²), and five levels of cheatgrass (0, 150, 300, 600, and 1 200 seeds · m⁻²). Seeding was conducted in fall 2003 and 2004, and measurements were taken in June 2004, 2005, and 2006. Sucrose addition decreased availability of soil nitrate but not orthophosphate. In the first year after seeding, sucrose reduced cheatgrass density by 35% and decreased both cheatgrass biomass per square meter and seed production per square meter by 67%. These effects were temporary, and by the second year after seeding, there was a sevenfold increase in cheatgrass density. As a result, the effects of sucrose addition were no longer significant. Sucrose affected Vavilov growth, but not density, during the first year after seeding. Vavilov density decreased as cheatgrass seeding density increased. Short-term reductions in N or cheatgrass seed supply did not have long-term effects on cheatgrass and did not increase Vavilov establishment. Longer-term reductions in soil N, higher seeding densities, or more competitive plant materials are necessary to revegetate areas dominated by cheatgrass.