不同补播配置模式对宁夏荒漠草原土壤有机碳和全氮储量的影响

以不同人工补播配置模式(禾本科牧草混播、豆科牧草混播、禾本科+豆科牧草混播、禾本科牧草+豆科牧草+小灌木混播及封育未补播)为研究对象,研究补播不同牧草配置模式对宁夏荒漠草原土壤有机碳和全氮储量的影响.结果表明:在0～10cm和10～20cm土层间,禾本科牧草混播模式土壤有机碳和全氮含量最高;在20～40cm土层,封育未...     

羊草草原豆科牧草生物固定量研究

采用样线和样方相结合的方法测定东北羊草草原豆科牧草的频度、密度和生物量,用微量凯氏定氮法测定豆科牧草和参照植物的氮浓度,用15N同位素稀释法测定豆科牧草的氮素固定比例,并结合生物量测定结果,计算豆科牧草的年际生物固氮量为1.5kgN/hm2.     

羊草草原豆科牧草生物固定量研究

采用样线和样方相结合的方法测定东北羊草草原豆科牧草的频度、密度和生物量,用微量凯氏定氮法测定豆科牧草和参照植物的氮浓度,用¹⁵N同位素稀释法测定豆科牧草的氮素固定比例,并结合生物量测定结果,计算豆科牧草的年际生物固氮量为1.5kgN/hm²。     

施肥对黔中地区混播草地牧草生长性能的影响

本文研究了氮磷钾不同配比施肥量对黑麦草和紫花苜蓿混播草地牧草生长的影响,结果表明:氮肥促进禾本科牧草叶的生长(P<0.05),增施钾肥对禾草的生长有利;磷能促进豆科牧草根的生长(P<0.05)且豆科牧草株高随着施磷量的增加各处理间差异显著(P<0.05),高氮抑制豆科牧草的生长;最高产量的施肥方式:N:P_2O_5:K_2O为20:30:20,比对照处理的草地产量增加63.92％。     

豆科牧草研究进展

豆科牧草的属间、属内、种间与种内均存在着巨大的遗传变异，利用这种变异，通过育种与选择，已培育出可良好地适应广泛的环境与管理条件的品种，遗传操作为此提供了更为广阔的空间，在豆科牧草固氮方面，对固氮过程、氮向伴生禾草的传送途径及残余氮对后继农作物的价值均有了进一步的理解。对包括施氮、采摘策略和影响混播草地中禾本科－豆科牧草平衡的胁迫等相互作用因素均已给予了阐明。在禾草／白三叶草草地为基础的家畜生产系统中，氮素的损失及其对环境产生的不良作用低于大量施氮的禾草草地系统。与禾草相比，豆科牧草无是用作放牧、青贮或用作干草，其物理、化学和解剖学等方面的特性均可增加家畜的嗜食性和自由采食量。由于豆科牧草的营养价值、可利用营养成分和采食特征，在单一豆科牧草或豆科牧草比重较大的禾草－豆科牧草混播草地上采食的不同种类、不同类型家畜的个体生产性能均优于在禾草草地上采食者。值得注意的是浓缩单宁在动物营养中的有益作用，这类单宁存在于诸如百脉根（Lotus corniculatus）、红豆草（Onobrychis viciifolia）和冠状岩黄芪（Hedys-crum coroharium）等植物中，其防止家畜患膨胀病，通过使较多的氨态氮到达小肠而提高氮的利用，并减轻绵羊肠道中线虫的作用。显然，培育含浓缩单宁的转基因豆科牧草是植物育种者现阶段的主要目标之一。此外，豆科牧草亦有许多其他用途，例如，在葡萄园中用作保护性植被，禾谷类作物的下层植被和为制药业提供次生化合物等。豆科牧草以其植物多态性和花朵的颜色等亦在美化景观和自然保护区中发挥着作用。可以预见，豆科牧草的作用在温带可持续农业中的作用将会增加，充分发掘现有的知识和相关研究成果，及有效的技术将是未来豆科牧草利用的主要特色。     

4种牧草不同生长期C、N生态化学计量特征

摘要：在甘肃庆阳（降水量517 mm）和榆中（降水量350 mm）的大田栽培条件下,研究了3种豆科牧草陇东苜蓿（Medicago sativa cv. Longdong）、红豆草（Onobrychis viciaefolia）和箭筈豌豆（Vicia sativa）以及1种禾本科牧草一年生黑麦草（Lolium multiflorum）主要生长期的C、N含量及计量比变化。结果表明,不同生长期牧草有机碳含量差异不大;全氮含量随生长期呈降低趋势或在孕穗（蕾）期较低,叶全氮含量高于茎和根;C/N随生长期呈增加趋势或在孕穗（蕾）期较高,叶C/N低于茎和根,禾本科牧草C/N高于豆科牧草。榆中一年生黑麦草C/N高于庆阳,而豆科则相反。牧草C/N随生长期的变化与不同植物不同阶段C同化和N吸收有关。     

巴基斯坦热带豆科和禾本科牧草营养价值评价

为了评价牧草营养价值,对四种热带豆科牧草:埃及三叶草、豇豆、革荚豆、苜蓿和两种饲料作物燕麦和玉米的营养成分,蛋白质品质和体外蛋白质消化率作了研究。结果表明,豆科牧草含粗蛋白比禾本科高,而且富含Ca、P和Fe三种元素。豆科牧草蛋白质缺乏蛋氨酸、胱氨酸,但是以谷物类为基础日粮的家禽饲料是很好的赖氨酸补充料。豆科牧草蛋白质体外消化率比禾本科牧草高。得出的结论是,豆科牧草和禾本科牧草作物配合使用,能为畜牧生产提供平衡饲料。     

巴基斯坦热带豆科和禾本科牧草营养价值评价

对在巴基斯坦生长的四种热带豆科牧草:埃及的白三叶草、豇豆、草荚豆、苜蓿和两种禾谷类作物燕麦和玉米的营养成分、蛋白质品质和体外蛋白质消化率进行了研究评价其在动物营养方面的作用。结果表明,豆科牧草含粗蛋白比禾本科高,它们也是Ca、P、Fe三种元素的好资源。豆科牧草蛋白质虽然缺乏蛋氨酸、胱氨酸,但是以谷类饲料为基础的家禽日粮能得到良好的赖氨酸的补充。豆科牧草蛋白质体外消化率比禾本科牧草高。得出的结论是,豆科牧草和禾本科牧草作物配合使用能为畜牧生产提供平衡饲料。     

豆科—禾本科牧草混播对豆科牧草生长和共生固氮的影响

<正> 豆科一禾本科牧草混播较之其单播具有某些优点。豆科牧草所固的氮,一部分直接或间接为混播禾草利用。它们间在根系分布和养分需要方面的差异使其能有效地利用土壤中的养分。因此,豆科—禾本科牧草混播可望提供高产、优质和季节性变动较小的饲草。     

川西南山原地区高产人工草地建植技术研究

通过对白三叶、多年生黑麦草等9个草种的18个品种进行混播,得出豆科牧草年鲜草产量大于禾本科牧草,其中以豆科牧草白三叶的Lisepa品种年鲜草产量最高,为122 279.4 kg/hm2。同时禾本科与豆科牧草混播,施磷可使草群中白三叶明显增加,增产显著。氮、磷混合施用,施氮180 kg/hm2、磷120 kg/hm2时增产鲜草21 429.0 kg/hm2,干物质收获量达14 656.5 kg/hm2以上。     

基于马营养需求的多年生豆禾混播草地生产性能的评价

用鸭茅、猫尾草、无芒雀麦、紫花苜蓿、红三叶、红豆草建植多年生混播草地,混播草地种类为5种豆禾牧草混播、6种豆禾牧草混播,豆∶禾混播比例分别为3∶7和2∶8。依据建植第1年(2013年)和第2年(2014年)的牧草产量、牧草营养物质产量和消化能产出,以使役马(中型)、使役马(重型)、妊娠马(妊娠11个月)和泌乳马(产驹后3个月均值)营养物质和消化能需求为评价准则,采用营养物质和消化能"产出-需求相对差额"法对几种豆禾混播组合的生产性能进行评价。结果表明:以使役马(中型)、妊娠马营养物质和消化能需求为评价准则,豆∶禾为3∶7的混5组合(紫花苜蓿+红豆草+鸭茅+猫尾草+无芒雀麦)生产性能最高;以使役马(重型)、泌乳马营养物质和消化能需求为评价准则,豆禾比3∶7的另一混5组合(紫花苜蓿+红三叶+鸭茅+猫尾草+无芒雀麦)生产性能最高。     

几种豆科牧草地上部水浸提液对稗草种子和幼苗的化感效应

用砂培法研究毛苕子(Vicia villosa)、紫花苜蓿(Medicago sativa.)、白三叶(Trifolium repens)、红三叶(Trifolium pratense)和黄花草木樨(Melilotus officinalis)花期地上部水浸提液对稗草(Echinochloa crusgalli)的化感效应。结果表明,供试草种水浸提液对稗草种子萌发和幼苗生长的化感作用具有明显的种间差异;其中对毛苕子和黄花草木樨种子发芽的抑制作用强于其它3种,抑制率达60%以上;紫花苜蓿对稗草幼苗生长的抑制作用强,特别是对根的抑制作用显著强于其它4个草种;白三叶和红三叶仅在水浸提液浓度0.1g/mL时,对稗草鲜根重表现出显著的抑制效应(P<0.05);此外,供试草种浸提液对稗草的化感作用,随着浓度的升高,抑制作用随之增强。     

混播种类和群体结构对豆禾牧草混播系统氮素利用效率的影响

为从物种多样性和空间结构方面阐明豆禾牧草混播系统高效生产机制,将混播种类(单播、2种牧草混播、4种牧草混播和6种牧草混播)、混播群体空间结构(行距+同行/异行/异行阻隔)作为影响因素,从豆科牧草固氮能力、转氮效率、氮素营养竞争、种间相容性和生产性能分析和比较豆禾牧草在不同混播方式中氮素固定、转移和利用效率对混播系统生态功能的贡献程度。结果表明:1)混播处理的牧草产量、N产量均显著高于单播(P<0.05),生产性能显著提高;但生产性能未随混播种类的增加而提高,异行混播+30 cm行距的混播群体结构具有较高的生产性能。2)固氮量随混播种类的增加而呈下降趋势,转氮量和转氮率随混播种类的增加而呈先下降后上升的趋势,而固氮率和贡献率变化不明显;异行混播+30 cm行距的混播群体结构具有较高的转氮量、转氮率和贡献率。3)营养竞争比率随混播种类的增加变化不明显,豆科牧草相对产量和相对产量总和随混播种类的增加而呈增加趋势;异行混播+30 cm行距的混播群体结构具有较高的豆科牧草相对产量和相对产量总和,但营养竞争比率较低。4)牧草产量与转氮量呈极显著正相关(P<0.01),而相对产量总和与氮素营养竞争比率呈极显著负相关(P<0.01)。因此,混播种类对于豆禾牧草混播系统生产性能的提升作用有限,高养分利用效率的物种组合可能更为关键;通过混播群体空间结构的优化可以使豆禾混播牧草根系氮素固定、转移、利用途径和效率得到提高,为混播系统生产性能的提升提供了重要途径。     

几种热带牧草饲喂肉牛效果的研究

用四种热带牧草（葛藤、矮象草、皇草、atratum雀稗）饲养肉牛，以评价它们的饲用价值和养牛效果。结果表明：在四种热带牧草中以豆科牧草葛藤最好，它含氮19．63g／kgDM、钙19．2g／kgDM、磷2．5g／kgDM、消化能8．85MJ／kgDM，具有最高的饲养价值，用它作为唯一日粮养牛与其它三种牧草相比可取得最大的增重效果和经济效益；在三种禾本科牧草中，矮象草有较好的养牛效果，它含消化能8．97MJ／kgDM、氮8．13g／kgDM、钙7．2g／kgDM、磷2g／kgDM。总的来看，用生长后期的热带牧草养牛应添加一定量的精料补充料，以促进肉牛增霞。     

川西北高寒牧区老芒麦和虉草青贮效果初步研究

为探讨川西北高寒牧区主推草种青贮效果,以收种后的老芒麦(Elymus sibiricns L.)和虉草(Phalaris arundinacea L.)为原料,对其叶围微生物进行计数,使用纤维素酶、蔗糖、尿素和乙酸作为添加剂,灌装青贮60 d后进行品质分析。结果表明:老芒麦和虉草附着的乳酸菌数量远低于霉菌、酵母菌和丁酸菌;蔗糖和尿素处理下,乳酸含量显著高于对照,氨态氮与总氮比值显著低于对照(P<0.05),能够改善老芒麦青贮饲料和虉草青贮饲料发酵品质;乙酸处理下,pH值、氨态氮与总氮比值显著低于对照,乙酸含量显著高于对照(P<0.05),能够改善老芒麦青贮饲料和虉草青贮饲料的发酵品质;纤维素酶对改善虉草青贮饲料发酵品质无显著影响。     

Effect of supplementing Rhodes grass hay (Chloris gayana) with Berchemia discolor or Zizyphus mucronata on the performance of growing goats in Kenya

Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.     

Apparent digestibility and microbial protein yield of Desmodium uncinatum,Mucuna pruriens and Vigna unguiculata forage legumes in goats

This study examined the effects of adding forage legumes as protein supplements to poor-quality natural pasture (veld) hay offered to goats on microbial protein yield and nitrogen metabolism. Four indigenous Nguni-type goats were used in a 4×4 Latin cross-over design experiment. Goats were randomly allocated to four dietary treatments comprising commercial goat feed (GF), veld hay supplemented with cowpea (CW), velvetbean (VB) or silverleaf desmodium (SD). Microbial protein yields were determined using the purine derivatives technique and nitrogen retention was calculated from the digestible organic matter intake. Total nitrogen intake was significantly higher in the GF followed by CW, SD and VB, respectively. Microbial protein supply, calculated microbial true protein and digestible microbial true protein were affected (P<0.05) by legume supplementation. Animals on poor-quality forages had the most efficient microbial protein synthesis. However, supplementation of hay failed to meet the maintenance requirements of animals as evidenced by negative nitrogen balances in VB and SD. The efficiency of utilisation of nitrogen in the supplements could have been limited by unavailable fermentable metabolisable energy in the diets. Supplementation of poor-quality veld hay with legume forages could improve utilisation, especially in the dry season.     

Comparing relative feed value with degradation parameters of grass and legume forages

Relative feed value (RFV) was evaluated relative to in situ degradation parameters of grass and legume forages. Early-cut alfalfa (n = 20), late-cut alfalfa (n = 26), cool-season grass (n = 11), warm-season grass (n = 4), and grass-legume (n = 20) samples were collected from duplicate hay bales submitted to the 2002 and 2003 Missouri State Fair Hay Contests. Subsamples were incubated in the rumen of 2 lactating Holstein cows for 0, 6 or 8, 12, 24, and 48 h to determine in situ degradation of DM, ADF, NDF, CP, and hemicellulose over time. Degradation data were fit to a variety of candidate models to estimate degradation parameters. Correlation coefficients between degradation parameter estimates [sorted according to forage (early-cut alfalfa, late-cut alfalfa, grass, or grass-legume)] and RFV were determined. For further comparison, correlations between NDF degradation parameter estimates and digestible DMI were determined with data from a previous study. Degradation data were best fit to a single, gamma 2-distributed pool model without a lag phase. Relative feed value was significantly correlated (P < 0.05) with potentially digestible DM and CP for early-cut alfalfa, potentially digestible DM for late-cut alfalfa, and potentially digestible DM, NDF, and hemicellulose for grass-legume. The percentage of significant correlations (10.7%) across the entire data set was low and no correlations were significant for grass. Relative feed value did not account for the variation in degradation parameters, especially for grasses. A further correlation analysis, which compared digestible DMI with degradation parameter estimates reported from another data set, revealed that digestible DMI and degradation parameter estimates were related for grass but not for alfalfa forages. These results suggest that RFV is limited by its failure to include degradation parameters.     

Assessing legumes indigenous to South Africa,Lesotho and Swaziland for their pasture potential

In contrast to the exploration and use of southern African grass plant genetic resources over the past century, only a few indigenous legume species are currently used as forages, notwithstanding the vast untapped legume diversity available in southern Africa. The aim of this study was to assess legumes, indigenous to South Africa, Lesotho and Swaziland and propose a list of species with pasture potential for further evaluation. Towards this end, legume species documented as being cultivated, grazed or browsed as well as plant collection data from the National Herbarium, South Africa, were used. The majority of cultivated, grazed or browsed species were recorded in the Central Bushveld, Lowveld and Mopane Bioregions, the Drakensberg Foothill and Coastal Region, Savanna Group and Northern Mistbelt leguminochoria and is largely enclosed by the Wolkberg Centre of Plant Endemism. The Phaseoleae tribe was found to contain the highest percentage of cultivated legume species. Legume species adapted to low soil phosphorus levels were identified, with 22 of these species previously noted for their pasture potential. It is suggested that the results of this study be used in the continued search for alternative indigenous legumes species for eventual integration into local and international pasture systems.