Yield and Forage Quality of Different ×Festulolium Cultivars in Winter

×Festulolium ssp. are of particular interest as autumn‐saved herbage in the winter grazing system, but information concerning their performance in this low‐input system is not available. To this end, we examined dry matter (DM) yield and forage quality in winter of four different cultivars of ×Festulolium ssp. (×Festulolium pabulare, Festulolium braunii), either with festucoid or loloid attributes, compared with Festuca arundinacea Schreb. Furthermore, pre‐utilization (accumulation since June or July) and date of winter harvest (December or January) were varied examining the influence of different sward management. DM yield, crude protein, metabolizable energy (ME) (in vitro rumen fermentation technique), acid detergent fibre (ADF) and ergosterol concentration were determined. Within all years, the festucoid cultivars (mean 3.4 t ha^?1) attained significant higher yields during winter than the loloid cultivars (mean 1.6 t ha^?1), but their yields were comparable with F. arundinacea (mean 3.0 t ha^?1). Crude protein was decisively influenced by the different yield levels of the cultivars resulting in higher values for the loloid cultivars. Energy concentrations decreased with later winter harvest, whereas ADF as well as ergosterol concentrations frequently increased from December to January. The greatest differences between festucoid and loloid cultivars were generally observed during severe winters. Obviously, the festucoid cultivars were better adapted to a utilization as autumn‐saved herbage than the cultivars with rather loloid attributes. However, the hybrids did not surpass F. arundinacea regarding yield and quality.     

The Effect of Sward Management on the Mineral Content of Winter Grazed Herbage

No information is available regarding the mineral content of autumn‐saved herbage during winter grazing under Central European conditions. Therefore, P, K, Na, Mg and Ca concentrations of autumn‐saved growths of Festuca arundinacea and Lolium perenne were analysed considering the potential influence of pre‐utilization (saved from June or July), date of winter harvest (December, January, February) and year (three winters). For all years date of winter harvest was the main source of variance, whereas date of preceding cut had no relevant effect on the mineral concentrations during winter. Already in December P [2.3 to 4.0 g kg^?1 dry matter (DM)], Na (0.3 to 3 g kg^?1 DM) and Mg (1.0 to 2.4 g kg^?1 DM) concentrations were mostly below the required levels for ruminants. The lowest values were detected in February. K levels ranged between 6.6 g kg^?1 DM in February and 23.4 g kg^?1 DM in December; on average, K concentrations decreased about 10 g kg^?1 DM with advancing winter. Ca concentrations (2.9 to 7.4 g kg^?1 DM) hardly changed during winter. Related to higher growth rates of F. arundinacea before December, P and Ca concentrations were diluted, but regarding Mg, more wintergreen F. arundinacea reached higher values than L. perenne especially at the beginning of winter.     

低量施肥对高燕麦草草地植被及绵羊择食行为的影响

于１９９５年８～１１月在新西兰ＴａｒａＨｉｌｓ山地草地试验站进行草地施肥和放牧研究。结果表明，在所有小区的施肥区域，绵羊的分布比例都显著多于非施肥区域（Ｐ＜０．００５）。通过复相关分析，发现这种分布由于施肥量、建群植物、观测日期和观测时间的不同而略有差异，而这又与施肥促进豆科牧草的生长（主要是兔足三叶草Ｔｒｉｆｏｌｉｕｍａｒｖｅｎｓｅ）、提高高燕麦草的适口性、提高草群的含水量等有直接关系。     

西部高寒地区草业面临的问题与可持续发展

阐述了草业在西部环保与发展中的意义，西部高寒地区草业发展中自然生态系统，草地使用权，草与畜供求关系，草地退化等方面存在的主要问题；提出了西部高寒地区草业可持续发展中关于落实草地使用权，加强天然草地管理与利用，人工草地建设，克服各种弊端，搞好退耕还草，防治有毒有害植物与鼠类危害，加强特色草产业及其产业化，提高草业科技水平与从业者素质等需要特别产注的问题，以及对今后草业发展项目的建议。     

“畜大壮”对农区放牧绵羊的增重效果

为探索“畜大壮”对农区放牧绵羊的增重效果，于１９９４年８月１日至１０月２０日进行８０天的“畜大壮”增重试验。试验结果：在放牧条件下，试验组羊平均增重８．８ｋｇ，较对照组羊多增重５．２ｋｇ，增重率提高１７．５１个百分点，平均胴体重较对照组多２．４１ｋｇ，每只羊增加纯收入３８．６元。     

青海省草地等级划分标准的探讨

确定草地等级是草地承包前的准备工作，可为公平合理地承包草地提供科学依据。根据青海省地形的特征及其对草地植被的影响，结合草地的使用价值，提出了青海省草地等级划分的方法。     

高山草原放牧系统控制的研究

高山草原夏季牧场的牧草营养物质富余达1倍以上，秋季牧草供需相当，冬季可满足80％左右，春季不到40％；草地上的载畜量和畜增重夏牧场是5．08羊单位／hm^2和27.22kg/hm^2，秋牧场是5．59羊单位／hm^2和31.83kg/hm^2，冬季牧场是1．64羊单位/hm^2和－4.38kg/hm^2 ,春季牧场是1．64羊单位／hm^2和-7.10kg/hm^2。在牧草增长率和绵羊种群采食率轨迹图中出现2个平衡点，表明夏，秋牧场的牧草生产有贮藏效应，冬，春牧场为牧草亏缺期。只有采用系统耦合的效应力，方可使放牧系统健康发展。     

混合放牧对高寒草地矮生嵩草生殖枝与营养枝性状的影响

本研究依托高寒草地-家畜系统适应性管理技术平台,通过研究建群种矮生嵩草（Kobresia humilis）叶片宏观性状、资源投入和生殖枝、营养枝潜在关系,以期揭示矮生嵩草种群在中度放牧强度下对放牧方式调控的响应机理。结果表明：牦牛藏羊放牧比例1：6处理矮生嵩草营养枝高度、数量、重量显著高于牦牛藏羊放牧比例1：4处理和牦牛单独放牧处理;单位长度矮生嵩草营养枝重量、生殖枝重量均不受放牧方式影响,且单位长度营养枝重量与单位长度生殖枝重量呈正相关关系;个体生殖枝、营养枝特征呈现协同变化关系,营养枝重量会显著影响营养枝数量,生殖枝数量显著影响生殖枝重量。综上所述,放牧干扰下矮生嵩草在生殖枝和营养枝的资源投入上不存在权衡关系,而是通过增加单位长度的生殖枝、营养枝资源投入量来提高资源分配模式。     

不同管理措施对青海湖流域高寒草地土壤养分的影响

本文通过野外采样及室内分析比较了围栏封育(FE)、传统放牧(TG)和草灌结合(CGB)3种管理措施对青海湖流域高寒草地不同土层深度土壤养分的影响。结果表明：土壤有机质、速效氮磷和硝态氮含量在不同管理措施下均随土层深度的增加而降低(P<0.05);FE有机质含量均显著高于CGB和TG (P<0.05);不同管理措施对土壤全量养分含量影响较小,主要对0~10 cm土层全氮含量产生影响,该层中FE全氮含量显著高于CGB和TG;不同管理措施对土壤速效养分含量的影响较大,主要体现在0~10 cm和10~20 cm土层,均表现为FE土壤速效养分含量最高(P < 0.05)。综上,围栏封育更有利于青海湖流域土壤养分的固持和青海湖流域退化高寒草地的恢复。     

放牧强度对高寒草甸群落特征及植被生存状态的影响

植物群落特征和生存状态变化能够反映植物群落内种间关系和演替进程。本研究以青海海北地区高寒草甸的冷季放牧场为研究对象,分析比较了禁牧封育(CK,禁牧)、轻度放牧(LG,4.5只羊·hm?2)、中度放牧(MG,7.5只羊·hm?2)和重度放牧(HG,15只羊·hm?2) 4种放牧压力对植物群落特征及各功能群代表性植物生存状态指数的影响。结果表明：1)禾本科的重要值在轻度放牧时最大,莎草科的重要值在禁牧样地中最大,杂草类植物的重要值在重度放牧样地中最大。2) Shannon-Wiener多样性指数、Simpson优势度指数、Patrick丰富度指数随着放牧强度的增加均呈增加趋势。3)轻度放牧样地中垂穗披碱草(Elymus nutans)和山地早熟禾(Poa orinosa)的生存状态指数最高,禁牧样地中矮生嵩草(Kobresia humilis)和钝苞雪莲(Saussurea nigrescens)的生存状态指数最高,但随着放牧强度的增加,钝苞雪莲(Saussurea nigrescens)的生存状态指数也随之增加。研究结果表明放牧强度增加能提高高寒草甸群落多样性,禾草类生存状态和在群落中的优势地位下降,杂草类生存状态和在群落中的优势地位上升,草地质量下降。