岷县草产业发展现状及策略

岷县地处秦岭、黄土高原和青藏高原的交汇带。本研究通过分析其草产业现状,指出岷县草产业发展主要存在天然草地退化严重、栽培草地管理粗放和特色草产业加工技术不完善的问题,提出岷县草产业今后发展的方向是分区管理和分类经营,从建立草地生态补偿基金、发展草地观光旅游业、提高栽培草地生产力、提高草地资源的利用效率和培训农民能手等方面提出了岷县草产业的发展策略。     

亚热带牧用草地中威提特东非狼尾草的种子繁殖研究

在3月和4月对全日制放牧的东非狼尾草草地上的风干牛粪取样,进行发芽试验,分别测定其中的东非狼尾草发芽种子数量。结果,3月取样平均432.5 g的牛粪中东非狼尾草平均发芽种子数量为118.25粒,4月取样平均437.8 g的牛粪中东非狼尾草平均发芽种子数量为52.8粒,二者平均牛粪重为435.15 g,平均发芽种子为85.5粒,说明牛粪中东非狼尾草种子数量较多,是其繁殖扩展较快的主要原因;3月取样的种子数量为4月取样数量的1.38倍,说明人工利用牛粪进行东非狼尾草繁殖时,需在有降雨来临前准备,即1～3月进行牛粪的准备工作。     

青藏铁路植被恢复和“黑土型”退化草地治理的实践与启示

由于高、寒和旱的独特特点,青藏高原生态系统具有特殊的环境敏感性和脆弱性。近年来,工程扰动、放牧等人类活动的加剧对青藏高原生态系统稳定性的影响日渐凸显,集中表现为植被退化、土壤贫瘠化和水土流失加剧等。目前,为了尽可能避免人类活动对生态系统造成的负面影响,遏制生态环境的进一步恶化,已采用了多种方式和手段进行环境保护和植被恢复。本研究以青藏铁路工程植被恢复和"黑土型"退化草地治理两个典型案例为例,总结了青藏高原进行植被恢复的经验,提出了青藏高原植被恢复的基本原则和注意事项,对今后青藏高原工程扰动和草地退化后进行植被恢复具有指导意义。     

Osteomalacia as a result of phosphorus deficiency in beef cattle grazing subtropical native pastures in Uruguay

We investigated 2 outbreaks of osteomalacia as a result of phosphorus (P) deficiency in herds of lactating beef cows grazing subtropical native pastures in Uruguay. Cows exhibited pica, difficulty to stand and walk, rib fractures, and body weight loss even with adequate forage availability. Osteopenia and severe osteomalacia were observed on gross and histologic examination. The concentrations of bicarbonate-extractable P in soil (4.0, 4.1 mg P/kg), total P in pasture (0.9, 1.1 g P/kg), inorganic P in serum (1.0, 0.71 mmol P/L), and P in bone (73 mg P/mL) were all low. Although injectable and mineral salt supplements provided additional P in both outbreaks, these supplementary amounts were insufficient to prevent P deficiency. The P ingested by the cows from the pasture and supplements would have provided 20–55% of their daily P requirements of ~21 g P/d. Osteomalacia occurred in cattle at the 2 ranches as a result of severe P deficiency in the soil and forage, and inadequate P supplementation. Following diagnosis, control of P deficiency in beef cattle requires estimation of the amount of pasture P ingested and provision of sufficient additional supplementary P to meet the animals’ requirements.     

Effect of temperature on germination and early growth of subterranean clover, capeweed and Wimmera ryegrass

Germination of annual pasture species was studied under controlled‐environment conditions in south‐western Australia at temperatures in the range from 4°C to 35°C. Subterranean clover (Trifolium subterraneum) and Wimmera ryegrass (Lolium rigidum) had a germination of 90% between 12°C and 29°C, whereas capeweed (Arctotheca calendula) had a high germination percentage in a much narrower temperature range with an optimum of 25°C. Growth of subterranean clover, capeweed and Wimmera ryegrass between 28 and 49 days after sowing (DAS) was also studied at two photon flux densities, 13 and 30 mol m^?2 d^?1, and at diel temperatures in the range from 15/10°C to 33/28°C. Pasture species grown at a density of 1000 plants m^?2 accumulated at least twice the amount of shoot dry matter when subjected to temperatures of 21/16°C and 27/22°C, compared with a lower temperature of 15/10°C and a higher temperature of 33/28°C. Except at the highest temperature and at high photon flux density, capeweed had lower green area indices (GAI) than the other two species at 28 DAS. Crop growth rates between 28 and 49 DAS were higher in Wimmera ryegrass than in the other two species, whereas subterranean clover had a lower relative growth rate than the other two species at all temperatures and both photon flux densities. Subterranean clover and capeweed intercepted a greater proportion of the incident radiation compared with Wimmera ryegrass. The values of radiation interception and GAI were used to estimate the number of DAS to reach 75% radiation interception [f_(0·75)]. The number of days to reach f_(0·75) decreased with increasing temperature from 15/10°C to reach a minimum at 27/22°C. The time taken to achieve f_(0·75) was always shorter by about 10 d when the photon flux density was 30 mol m^?2 d^?1 in the autumn compared with 13 mol m^?2 d^?1 in the winter. These results are discussed in relation to the early growth of annual pasture in the field.     

青海草地建设投资与草地产出灰色关联分析

用灰色关联分析方法，对青海省草地建设投资与草地产出作相关分析。结果表明：两者相关性较强，关联度系数γｙ０１８＝０．７１６８（畜牧业产值）和γｙ０２８＝０．７２４４（畜产品产量）；在草地建设分项投资中，与草地产出关联度最大的为灭鼠投资，分别为γｙ０１５＝０．９１６２（牧业产值）和γｙ０２５＝０．８８８５（畜产品产量），其次顺序为种草投资（γｙ０１２＝０．８２６６和γｙ０２２＝０．８１３１），草地围栏     

退耕后的还林和还草

易水土流失的陡坡地退耕后的还林和还草应遵循：首先符合当地天然植被分布、生长发育规律、其次符合自然生态进展演替的规律；第三、符合当地产业结构的调整，增加农民经济收入的需要。第四、符合市场发展规律，建立超前持久的产业经济。做到宜林则林，宜草则草、乔、灌、草结合，生态效益优先，促使 生态环境的改善。     

延安市封山绿化舍饲养畜情况调查

本文通过调查延安市封山绿化、舍饲养畜工作的现状，总结了该项工作的成绩与主要经验，明确了当前延安市在封山禁牧、舍饲养畜工作中存在的主要问题，并提出了今后延安市封山绿化、舍饲养畜工作的重要建议。     

旱作红豆草人工草地建植管理利用技术的研究

在天山北坡山地草原和山地荒漠草原过渡地带,进行旱作红豆草人工草地的研究和大田生产结果表明:在建植中对地形选择、抓苗、保苗的管理和刈割技术等措施的配套实施,是保证稳产高产的关键。     

人工草地杂草生态学研究Ⅰ杂草入侵与放牧强度之间的关系

本文分析了白三叶草十多年生黑麦草混播人工草地上杂草入侵与放牧强度之间的关系，得出如下初步结论：１）杂草入侵的种数主要决定于放牧强度；２）α物种多样性随放牧加重而有增－减－增的趋势；３）入侵的主要杂草种为点腺过路黄等８个种；４）所论人工草地都处在恢复演替的先锋阶段，因而草地退化的进程还是能予以遏制的。