Patch-Burning Buffers Forage Resources and Livestock Performance to Mitigate Drought in the Northern Great Plains

Summer droughts in North America's northern Great Plains are expected to increase in frequency and duration as precipitation shifts toward spring and fall. Two rangeland experimental stations in North Dakota experienced drought in 2017 relative to 25-year averages. The southwest location had a 170-mm deficit from the 360-mm normal rainfall and was grazed by cattle (Bos taurus L.) and sheep (Ovis aries L.); the south-central location had 109 mm below the 403-mm normal rainfall and was grazed by cattle. We evaluated patch-burn grazing as a drought resilient land management strategy in the northern Great Plains by comparing average daily gains, fecal density, available forage biomass, and forage crude protein content. At the southwest location, livestock performed better during the drought season compared with animals on the same pastures in the previous year, which had near-normal rainfall but no fire. At the central location, cows on patch-burned pastures performed better than cows on continuously-grazed, unburned pastures in the same year under drought conditions; all cows were nursing calves and calf gains did not vary between treatments. In both locations, the burned patches had higher fecal density and lower available forage biomass than patches not yet burned throughout the grazing season, indicating grazer attraction to burned areas. Despite drought, burned patches maintained grazer attraction and animal performance was maintained or even improved, which contrasts with the expected relationship between animal performance and precipitation. This study indicated that prescribed patch-burning might mitigate drought by buffering forage resources (crude protein content and availability) and maintaining animal performance (average daily gains).     

Do Introduced Grasses Improve Forage Production on the Northern Mixed Prairie

Relative benefit of introducing forage species to the Northern Great Plains have been examined with contradictory conclusions. In most cases, studies were either confounded by time of establishment or treatments were not randomized and lacked independence. We examined aboveground net primary production (ANPP) in northern mixed prairie using a randomized complete block design with four treatments: crested wheatgrass (Agropyron cristatum [L.] Gaertn.), Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski), a native control that was not harvested, and a harvested native. The experiment was conducted in a Stipa–Agropyron–Bouteloua site and a Stipa–Bouteloua site over 13 yr and 12 yr, respectively. The data were analyzed by sampling period (Stipa–Agropyron–Bouteloua: 1, 1994 to 1997; 2, 1998 to 2001; 3, 2002 to 2006; and Stipa–Bouteloua: 1, 1995 to 1998; 2, 1999 to 2002; 3, 2003 to 2006). ANPP among treatments was influenced (P < 0.05) by site and its interaction with treatment and sampling period (1 to 3). ANPP from the native-control, harvested-native, crested wheatgrass, and Russian wildrye treatments was 220.9, 183.9, 300.8, and 189.6 g · m^–2 (SEM = 11.2), respectively, in the Stipa–Agropyron–Bouteloua site and 122.9, 98.2, 216.3, and 115.9 g · m^–2 (SEM = 12.0), respectively, in the Stipa–Bouteloua site. Mean ANPP (SEM) within each sampling period (1 to 3) was 186.4 (9.1), 135.4 (5.8), and 263.9 (8.8) g · m^–2 in the Stipa–Agropyron–Bouteloua site, respectively, and 124.5 (6.4), 138.6 (6.1), and 151.3 (10.5) g · m^–2 in the Stipa–Bouteloua site, respectively. Russian wildrye in the Stipa–Bouteloua site and crested wheatgrass in both sites was relatively more productive in the first period after establishment than in subsequent years. The study confirms the relative ANPP advantage of crested wheatgrass over native on the Stipa–Bouteloua site but not on the Stipa–Agropyron–Bouteloua site, whereas Russian wildrye exhibited no ANPP advantage over the native on either site.     

草本植物三种真菌新病害

经田间采集、分离培养、室内鉴定及致病性测定。本文报道了寄生于菊科Compositae和桑科Moraceae等9种草本植物上的3种尾孢菌及其病害:蒿褐斑病(C ercospora artenmisiae Y.L.Guo&Y.Jiang)、蓟褐斑病(Cercospora cirsii Ellis&Everh.)和草褐斑病(Cercospora humuligena Y.L.Guo&L.Xu)。上述病害在国内外均未见报道,属国内3种新病害,其中9种草本植物为国内新纪录寄主。并对每一种病害的症状和病原形态进行了描述。     

5种野生牧草的营养成分分析

野生牧草是许多牧区、半农半牧地区重要的草种资源。通过对四川崇州市怀远镇常见的5种野生牧草进行营养成分测定,分析其粗灰分、粗纤维、粗脂肪、粗蛋白和无氮浸出物含量,结果表明,羊蹄和蒲公英粗纤维含量较低,无氮浸出物含量高,粗蛋白含量中等,可以作为当地农民饲养家兔的优良饲草来源。     

甘肃马先蒿对五种禾草的化感潜力研究

为了探讨甘肃马先蒿（Pedicularis kansuensis）不同浸提液处理对几种禾草化感潜力的差异,本研究采用室内生物测定法,研究了甘肃马先蒿植株浸提液和粉末浸提液以及根区土壤浸提液对5种禾草种子发芽和幼苗生长的影响,旨在揭示甘肃马先蒿对人工草地退化的潜在作用,为退化高寒草甸恢复和人工草地的建植提供理论依据。结果表明：甘肃马先蒿不同浸提液处理对5种牧草种子萌发和幼苗生长均有不同的化感效应,总体而言,粉末浸提液对5种禾草的抑制作用比整株浸提液的抑制作用大。甘肃马先蒿整株浸提液和粉末浸提液对5种禾草种子发芽和幼苗生长的化感综合效应表现为：对青海中华羊茅（Festuca sinensis ‘Qinghai’）的化感潜力最大,对同德老芒麦（Elymus sibiricus ‘Tongde’）最弱,而根区土壤浸提液对同德老芒麦的化感潜力最大,对垂穗披碱草（Elymus nutans）最弱,对其它3种的作用介于两者之间。     

NaCl胁迫下禾本科草坪草和牧草萌发特性的研究

应用室内培养皿萌发试验,在0和150mmol/L NaCl胁迫下对三个类型草坪草、五个类型牧草的46个品种进行了研究.结果表明,150mmol/L NaCl胁迫下草坪型多年生黑麦草、牧草型一年生黑麦草和多年生黑麦草的耐盐性较强;草坪型高羊茅、牧草型苇状羊茅次之;雀麦、鸭茅、翦股颖的耐盐性最差.前7d相对发芽率作为鉴定禾草耐盐性指标较好,并鉴定出部分耐盐品种.     

3种禾本科牧草抗旱性的初步鉴定

以当前贵州主栽品种努依黑麦草为对照，利用生物学鉴定方法对贵州省草业研究所选育的黔草1号、2号苇状羊茅的抗旱性加以初步鉴定。结果表明：在干旱逆境条件下，随着土壤的干涸，引起3种牧草失水，导致蛋白质合成减弱和分解增强，致使其含量下降，且叶绿素的形成受到抑制，含量迅速减少，甚至耗尽。3种牧草的抗旱性强弱顺序为：黔草1号〉黔草2号〉努依黑麦草。     

3种禾本科牧草抗旱性的初步鉴定

以当前贵州主栽品种努依黑麦草为对照,利用生物学鉴定方法对贵州省草业研究所选育的黔草1号、2号苇状羊茅的抗旱性加以初步鉴定。结果表明:在干旱逆境条件下,随着土壤的干涸,引起3种牧草失水,导致蛋白质合成减弱和分解增强,致使其含量下降,且叶绿素的形成受到抑制,含量迅速减少,甚至耗尽。3种牧草的抗旱性强弱顺序为:黔草1号>黔草2号>努依黑麦草。     

农田种草养畜可行性初步分析

从经济效益、生态效益和社会效益方面对农田种草养畜的可行性进行了探讨,分析了当前农田种草养畜产业发展受阻的主要原因,并进一步指出促进农田种草养畜产业发展的对策.     

Impact of Native Grasses and Cheatgrass (Bromus tectorum) on Great Basin Forb Seedling Growth

Re-establishing native communities that resist exotic weed invasion and provide diverse habitat for wildlife are high priorities for restoration in sagebrush ecosystems. Native forbs are an important component of healthy rangelands in this system, but they are rarely included in seedings. Understanding competitive interactions between forb and grass seedlings is required to devise seeding strategies that can enhance establishment of diverse native species assemblages in degraded sagebrush communities. We conducted a greenhouse experiment to examine seedling biomass and relative growth rate of common native forb species when grown alone or in the presence of a native bunchgrass or an exotic annual grass. Forb species included bigseed biscuitroot (Lomatium macrocarpum [Nutt. ex Torr. & A. Gray] J.M. Coult. & Rose), sulphur-flower buckwheat (Eriogonum umbellatum Torr.), hoary aster (Machaeranthera canescens [Pursh] Gray), royal penstemon (Penstemon speciosus Douglas ex Lindl.), and Munro's globemallow (Sphaeralcea munroana [Douglas ex Lindl.] Spach ex Gray); and neighboring grass species included bottlebrush squirreltail (Elymus elymoides [Raf.] Swezey), Sandberg bluegrass (Poa secunda J. Presl); and cheatgrass (Bromus tectorum L.). Forbs and grasses were harvested after 6, 9, or 12 wk of growth for biomass determination and calculation of relative growth rates (RGR) of forbs. Neither bunchgrass reduced biomass of any forb. RGR was reduced for royal penstemon when grown with either native grass and for Munro's globemallow when grown with bottlebrush squirreltail. Although only assessed qualitatively, forbs with vertically oriented root morphologies exhibited no reduction in RGR when grown with native grasses, compared to forbs with dense lateral branching, similar to the root morphology of native grasses. Biomass of forbs was reduced by 50% to 91% and RGR by 37% to 80% when grown with cheatgrass. Understanding native forb interactions with native grasses and cheatgrass will aid land managers in selecting effective seed mixes and making better use of costly seed.     

沿海滩涂地区不同栽培措施对禾本科牧草产量及品质的影响

为探讨沿海滩涂地区牧草高产栽培技术,以4种禾本科牧草为材料,研究了3种不同的栽培措施对不同饲草品种的饲草产量和品质的影响.结果表明:覆秸秆与添加保水剂处理饲草的产量和叶/茎比显著高于对照(P＜0.05).同一品种,覆秸秆处理饲草的可溶性碳水化合物(WSC)、粗蛋白(CP)、干物质体外消化率(IVDMD)和体外可消化干物质产量最高,粗灰分(Ash)、酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量最低,品质最好,其次是添加保水剂处理,对照最差.不同品种之间的饲草产量和品质差异显著(P＜0.05),其中青贮玉米(Zea mays L.)和高丹草(Sorghum bicolor×Sorghum s     

贵州地方优良禾本科牧草抗病性初步研究

2004-2006年对发生在贵州地方优良禾本科牧草上的锈病、禾草云斑病和褐斑病进行田间调查,经统计分析和新复极差检验,结论是贵州地方草种对3种病害的抗性显著优于引进品种.     

不同基肥对弃荒地牧草产量和质量的影响

在贪瘠的弃荒地使用不同组合的基肥探讨对牧草产量和质量的影响。结果表明,在相同的肥水管理条件下,以“复合肥 牛粪 石灰”基肥组合(A处理),可使多花黑麦草(特高)、多年生黑麦草(保利)的年产草量分别比“猪粪 牛粪 石灰”的基肥组合(B处理)提高10.6%和29.2%,差异显著(p<0.05);粗蛋白质、粗脂肪、粗灰分分别有所提高;粗纤维、无氮浸出物有所降低。     

三峡地区奶牛牧草引种栽培试验报告

由于政府的优惠政策和龙头企业的驱动,夷陵区奶牛发展速度较快,但也面临一系列问题,其中最突出的问题之一就是“草”,饲草资源不足,质量低劣,优质青绿饲草供应严重短缺,已成为制约奶牛产业发展,影响奶牛效益的主要因素。为此,我们根据“三峡奶业关键技术研究与产业化技术集成示范项目”牧草与饲料作物生产技术研究与产业化开发课题的要求,开展本项试验,通过试验,筛选适合夷陵区推广种植的“当家”草种。1试验内容与方法1.1试验地点试验区分别设在夷陵区小溪塔街办官庄村、龙泉镇水府庙村、鸦鹊岭镇龙潭村、雾度河镇普垭村,除普垭村为海拔300…     

Stand Establishment and Persistence of Perennial Cool-Season Grasses in the Intermountain West and the Central and Northern Great Plains

The choice of plant materials is an important component of revegetation following disturbance. To determine the utility and effectiveness of various perennial grass species for revegetation on varied landscapes, a meta analysis was used to evaluate the stand establishment and persistence of 18 perennial cool-season grass species in 34 field studies in the Intermountain and Great Plains regions of the United States under monoculture conditions. Combined across the 34 studies, stand establishment values ranged from 79% to 43% and stand persistence values ranged from 70% to 0%. Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D. R. Dewey), tall wheatgrass (Thinopyrum ponticum [Podp.] Z.-W. Liu & R.-C. Wang), crested wheatgrass (Agropyron spp.), Siberian wheatgrass (Agropyron fragile [Roth] P. Candargy), and meadow brome (Bromus riparius Rehmann) possessed the highest stand establishment (≥ 69%). There were no significant differences among the 12 species with the largest stand persistence values. Basin wildrye (Leymus cinereus (Scribn. & Merr.) Á. Löve), Altai wildrye (Leymus angustus [Trin.] Pilg.), slender wheatgrass (Elymus trachycaulus [Link] Gould ex Shinners), squirreltail (Elymus spp.), and Indian ricegrass (Achnatherum hymenoides [Roem. & Schult.] Barkworth) possessed lower stand persistence (≤ 32%) than the majority of the other species, and Indian ricegrass (0%) possessed the lowest stand persistence of any of the species. Correlations between environmental conditions and stand establishment and persistence showed mean annual study precipitation to have the most consistent, although moderate effect (r = ～0.40) for establishment and persistence. This relationship was shown by the relatively poor stand establishment and persistence of most species at sites receiving less than 310 mm of annual precipitation. These results will be a tool for land managers to make decisions concerning the importance of stand establishment, stand persistence, and annual precipitation for revegetation projects on disturbed sites.     

贵州野生禾本科牧草引种驯化试验

在贵州省境内不同生态环境条件下采集的３２属８７种优良野（逸）生禾本科牧草，经种植观察，于１９９２～１９９６年对升圃的１９份材料在栽培条件下经过几代种子繁殖和人工选择，各个材料的开花期，种子成熟期等性状渐趋一致，并基本稳定。再生能力强，叶量增多。鲜草产量在３４ｔ／ｈａ～８７ｔ／ｈａ范围内。种子产量８５ｋｇ／ｈａ～２８１６ｋｇ／ｈａ。拔节期粗蛋白质含量８．８３％～１８．９３％。     

海南省禾本科饲用植物资源及其营养评价

全面考察海南省及其周边岛屿的禾本科饲用植物资源及其分布情况,其中海南省可供饲用的禾本科饲用植物104属270种,并对49个种的234份材料进行化学成分分析。     

Short-Term Response of Sage-Grouse Nesting to Conifer Removal in the Northern Great Basin

Conifer woodlands expanding into sage-steppe (Artemisia spp.) are a threat to sagebrush obligate species including the imperiled greater sage-grouse (Centrocercus urophasianus). Conifer removal is accelerating rapidly despite a lack of empirical evidence to assess outcomes to grouse. Using a before-after-control-impact design, we evaluated short-term effects of conifer removal on nesting habitat use by monitoring 262 sage-grouse nests in the northern Great Basin during 2010–2014. Tree removal made available for nesting an additional 28% of the treatment landscape by expanding habitat an estimated 9603 ha (3201 ha [± 480 SE] annually). Relative probability of nesting in newly restored sites increased by 22% annually, and females were 43% more likely to nest within 1000 m of treatments. From 2011 (pretreatment) to 2014 (3 yr after treatments began), 29% of the marked population (9.5% [± 1.2 SE] annually) had shifted its nesting activities into mountain big sagebrush habitats that were cleared of encroaching conifer. Grouping treatments likely contributed to beneficial outcomes for grouse as individual removal projects averaged just 87 ha in size but cumulatively covered a fifth of the study area. Collaboratively identifying future priority watersheds and implementing treatments across public and private ownerships is vital to effectively restore the sage-steppe ecosystem for nesting sage-grouse.     

冰草属牧草硝酸还原酶的活性与其产量营养的关系

试验选择7种冰草属牧草为研究对象,测定硝酸还原酶的活力,并与大田栽培试验的同种牧草生产性能、营养成分测定结果进行分析,证明硝酸还原酶的活力作为生理指标之一可以正确的反应牧草品种的品质和产量,是一项筛选优良牧草品种的重要的生理指标,为禾草施氮提供了科学依据.