种植王草防制紫茎泽兰的技术研究

王草是象草和美洲狼尾草杂交育成的多年生直立型丛生性禾本科牧草,是我国热带和亚热带地区继象草之后又一种收割型速生性青饲料,原产于南美洲,与紫茎泽兰生活习性近似.     

暖地型草坪草品种选育及开发利用研究

通过对热带、亚热带地区暖地型草坪草的引种试种和品种比较，初步选育出马尼拉结缕草、矮生百慕大草、杂交结缕草３种不同用途的优良草坪草种，并经试验与生产，初步掌握了草坪栽培种植与养护管理的技术措施，有利于促进海南，甚至热带、亚热带地区草坪业的发展。     

种植王草防制紫茎泽兰的技术研究

<正> 王草是象草和美洲狼尾草杂交育成的多年生直立型丛生性禾本科牧草,是我国热带和亚热带地区继象草之后又一种收割型速生性青饲料,原产于南美洲,与紫茎泽兰生活习性近似。王草作为饲料具有品质好、叶量多、适口性好、种植粗放、须根发达、分蘖快、侵占力强、适应性好等特点。王草生长快,凡是紫茎泽兰能生     

王草栽培法

王草是象草(母本)与美洲狼尾草(父本)的种间杂交种(其反交杂种叫杂交狼尾草),据报道第一株这种杂交草是在南非产生的,其后逐渐扩展至中美洲、亚洲和澳大利亚等热带亚热带地区。古巴对这种草称为王草(King grass),我区于1985年引入,首先试种于广西农学院,其后,柳州种畜场等相继引种,都已成功,面积在100～200亩以上,并已正常用于生产。现在分布于南宁、     

优良牧草新品种—皇草的栽培利用

皇草是由中国热带农科院热带牧草中心从哥伦比亚引进的象草与美洲狼尾草杂交选育而成的新品种。 1 998年 ,经全国牧草品种审定委员会审定通过 ,正式审定登记为热研 4号皇草。又叫杂交狼尾草 (四川叫皇竹草 )。目前 ,除南方地区种植外 ,北方部分地区也开始栽培利用 ,表现良好 ,是一种很有饲用价值的高产优质牧草。1　特征特性皇草是禾本科多年生单性繁殖草本植物 ,一般不开花结实 ,茎、根扦插栽培 ,种质不易退化 ,一次引种 ,多年利用。栽培当年 ,大部分须根分布在 0～30ｃｍ的土层中。茎秆坚硬粗壮 ,圆形 ,茎粗 1～2ｃｍ。株高 4～ 5ｍ ,不倒…     

几种热带禾草烧草效应的初步观察

本文主要说明20种热带禾本科牧草火烧效应的初步结果。烧草后,表现优的品种有甘巴草、坚尼草、汉密尔坚尼草、湿生臂形草、旗草、巴拉草、南迪狗尾草、卡松古鲁狗尾草,青绿黍、杂交象草:表现良的品种有巴夫草、内洛克狗尾草、象草、粽籽雀稗;表现中等的品种有格顿坚尼草、罗得草、危地马拉草:表现差的品种有糖蜜草、红苞茅、岸杂一号狗牙根。     

杂交臂形草引种栽培利用简介

杂交臂形草由中国热作院引自国际热带农业中心,2002年我站从中国热带作物院引入我区。经过多年进行栽培试验和动物饲喂试验,以及在广西部分县市种植试验,结果表明:该草抗逆性强,产草量高,营养价值高,适口性好,值得推广。1特征特性杂交臂形草为禾本科臂形草属,多年生,密丛型草本     

杂交狼尾草栽培及其喂猪技术

杂交狼尾草(Pnnisetum amerieanum XP．purpureum)是美洲狼尾草(母本Pnnisetum amerieanum)和象草(父本Pnnisetum purpureum)的杂交种。它较好地综合了父本象草高产、多年生和母本美洲狼尾草品质好的特点。我国栽培的杂交狼尾草有两个来源．一是1981年从美国引进，另一个是1984年从哥伦比亚国际热带农业中心引进。由于母本美洲狼尾草是二倍体，而父本象草是四倍体，     

臂形草14品种在滇南的适应性及其评价

2006-2007年通过对14个臂形草品种的生产性能和品质特性的研究,旨在筛选出适宜于热带、亚热带地区种植的高产、优质牧草品种,为热带水土保持和畜牧业的持续发展提供依据,结果表明,1)所引种牧草的存活率、越冬率都在97%以上,说明所引种牧草的适应性强;除MG-4珊状臂形草感染了叶锈病以外,其他牧草的抗病虫害能力强。2)种植第1年Mulato 1杂交臂形草干物质产量最高为(34.84±3.98) t/hm² ,与刚果臂形草、Mekong珊状臂形草、杂交臂形草、MG-5×Araes珊状臂形草、MG-5 Vitoria珊状臂形草、MG-4珊状臂形草、Mulato 2杂交臂形草之间差异不显著。3)相关性分析表明,丛径、叶长、叶宽、株高、叶/茎、种子产量与地上生物量呈正相关,对地上生物量的影响大小为:叶宽＞种子产量＞叶/茎＞株高＞叶长＞丛径。4)选择干草产量、粗蛋白、适口性、抗逆性作为综合评价供试品种优劣的指标,用灰色关联法评价牧草,结果表明,杂交旗草、Mulato 1杂交臂形草、Mekong珊状臂形草、Mulato 2杂交臂形草、MG-5×Araes珊状臂形草、刚果臂形草、MG-5 Vitoria珊状臂形草居前7位,它们属高产、质优、适口性好、抗性强的高产优质牧草品种。     

王草引种栽培及适应性研究

王草原产于热带非洲,属热带高产优质的杂交牧草,产量高,叶柔软,无毛,适口性好,消化率高,茎微甜,糖和蛋白质含量均高于象草,是勐旺乡饲喂草食动物的主要饲料品种。这对解决西双版纳傣族自治州旱季缺草问题创造了有利条件,为改良勐旺乡牧草品质,提高载畜量,发展节粮型的草食动物,提供了最为理想的物质基础,值得大面积推广。     

Reproductive and leptospiral studies on beef cattle in central Queensland

The effect of rainfall on reproductive performance in beef cattle and the effects of rainfall and soil type on the prevalence of leptospirosis in beef cattle in inland central Queensland are described. Low annual rainfall produced a significant (P less than 0.05) decrease in calf branding rates. Leptospirosis (due to serovar hardjo) was serologically more prevalent after rain and on farms with high water holding capacity soils but there was no significant difference in branding rates between cattle on high or low water holding capacity soils. As a secondary mid-year rainfall peak is a feature of the area, leptospirosis due to serovar hardjo will tend to spread when most of the breeding herd is in the last trimester of pregnancy. The prevalence of leptospirosis due to serovar pomona is significantly lower in the region.     

Native Plant Growth and Seedling Establishment in Soils Influenced by Bromus Tectorum

The invasion of 40 million hectares of the American West by cheatgrass (Bromus tectorum L.) has caused widespread modifications in the vegetation of semi-arid ecosystems and increased the frequency of fires. In addition to well-understood mechanisms by which cheatgrass gains competitive advantage, it has been implicated in reducing arbuscular mycorrhizal fungi (AMF) abundance and taxa diversity. We evaluated this possibility at a high elevation site in a two-pronged approach. To test whether cheatgrass changed native AMF communities in ways that affected subsequent native plant growth, we grew cheatgrass and native plants in native soils and then planted native plants into these soils in a greenhouse experiment. We found that cheatgrass-influenced soils did not inhibit native plant growth or AMF sporulation or colonization. To test whether soils in cheatgrass-dominated areas inhibited establishment and growth of native plants, cheatgrass was removed and six seeding combinations were applied. We found that 14.02 ±  seedlings · m⁻² established and perennial native plant cover increased fourfold over the three years of this study. Glyphosate reduced cheatgrass cover to less than 5% in the year it was applied but did not facilitate native plant establishment or growth compared with no glyphosate. We conclude that cheatgrass influence on the soil community does not appear to contribute to its invasion success in these high elevation soils. It appears that once cheatgrass is controlled on sites with sufficient native plant abundance, there may be few lingering effects to inhibit the natural reestablishment of native plant communities.     

Veld replacement by improved grasslands in Natal

Success with legume introduction into veld appears to be closely linked with a modification of the edaphic environment to suit the introduced species. In the high rainfall areas of South Africa where legume introduction probably holds most promise, excess soil acidity is a major factor limiting the growth of perennial, temperate legumes. The paper is largely devoted to a discussion of the effects of soil pH, calcium, phosphorus, and molybdenum deficiencies, manganese and aluminium toxicities, and symbiotic nitrogen fixation on the growth of calciphile legumes on acid soils. Results of field experiments and legume introduction trials in the Eastern Cape are included. The importance of fertility studies on cultivated soils and in the greenhouse, as a first step in the research programme, is indicated.     

Soil and agronomic factors associated with cadmium accumulations in kidneys of grazing sheep

SUMMARY Mean concentration of cadmium (Cd) in kidneys of hogget sheep from 67 flocks grazing in the Agricultural Region of Western Australia was tested for association with soil, pastoral, climatic and nutritional factors. Hoggets grazing pastures on acidic soils and soils with a sandy-textured surface had higher Cd concentrations in kidneys than hoggets grazing pastures on more alkaline soils or soils with a clay-textured surface. Application of more than 100 kg of phosphatic fertiliser during the past 3 years to loamy soils was also associated with greater Cd concentration in kidneys of the grazing animals.     

野生大麦对土壤磷吸收及其酸性磷酸酶活性的基因型差异

在土培盆栽条件下,以野生大麦磷高效基因型IS-22-30、IS-22-25和磷低效基因型IS-07-07为材料,研究施磷量为 0,30,60 和 90 mg/kg土条件下其磷素吸收能力及酸性磷酸酶活性变化的差异,为探明磷高效野生大麦高效吸收利用磷素机理提供依据。结果表明,1)随施磷量的增加,不同磷效率野生大麦生物量、磷积累量均有不同程度的增加,而根冠比呈显著降低的趋势,且不同施磷处理下,野生大麦生物量、磷积累量和根冠比均表现为磷高效基因型显著高于低效基因型。2)不同施磷处理下,野生大麦根际土壤有效磷和水溶性磷含量均显著低于非根际土壤。不施磷、施磷 30 和 60 mg/kg土条件下,磷高效基因型较低效基因型根际土壤有效磷和水溶性磷亏缺程度突出。3)与非根际土壤相比,在不施磷、施磷 30 mg/kg土条件下,磷高效基因型IS-22-30、IS-22-25根际土壤酸性磷酸酶活性的效应范围为4 mm,均明显大于低效基因型IS-07-07的活性效应范围2 mm。不同施磷处理下,磷高效基因型根际土壤酸性磷酸酶的活性明显高于低效基因型,且在不施磷、施磷 30 mg/kg土条件下差异显著,表明磷高效野生大麦具有较强的低磷土壤环境适应能力和土壤磷素活化能力。随施磷量的增加,不同磷效率野生大麦植株叶片和根系酸性磷酸酶的活性均显著降低,且高效基因型叶片和根系酸性磷酸酶的活性较低效基因型高,表明高效基因型植株体内磷素的重复再利用能力较强。低磷胁迫下,磷高效基因型较高的酸性磷酸酶活性是其磷素高效吸收利用的重要特征。     

Establishment of Native Species in Soils From Russian Knapweed (Acroptilon Repens) Invasions

Russian knapweed (Acroptilon repens [L.] DC.), an exotic perennial forb, has invaded many native ecosystems in western North America. Russian knapweed's success is attributed to allelopathy, extensive tap rooting, zinc accumulation in soils, and a lack of North American predators. Revegetation following chemical control slows exotic reestablishment, but the impacts of Russian knapweed-invaded soils on the establishment of native forbs and shrubs have not been determined. In a greenhouse experiment, we monitored the establishment of two native forbs, Indian blanketflower (Gaillardia aristata Pursh) and purple prairie clover (Dalea purpurea Vent.) and two native shrubs, winterfat (Krascheninnikovia lanata [Pursh] A.D.J. Meeuse & Smit syn. Ceratoides lanata) and Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis [Hook.] Nutt.) in soils obtained from three Russian knapweed invasions and adjacent noninvaded areas. We analyzed soils collected near Greybull and Riverton, Wyoming, and Greeley, Colorado, for cation exchange capacity, organic matter, electroconductivity, pH, and total nitrogen, carbon, and plant-available potassium, zinc, manganese, copper, and phosphate. We documented seedling emergence of the four natives and Russian knapweed every two days for 14–17 weeks, harvested seedlings biweekly to assess their growth, and determined their zinc accumulation. All species established in invaded soil and seedlings were larger in invaded than in noninvaded soils. Invaded rangeland soils had greater organic matter (8.6% and 1.1% in invaded vs. 2.5% and 0.4% in noninvaded soils) and lower pH (7.4 in invaded versus 8.0 noninvaded soils). Zinc concentrations in invaded soils (from 0.15 to 6.56 mg · kg^-1) were not high enough to limit plant growth. Reports that Russian knapweed is a hyper-accumulator of zinc are not supported by our seedling data, which suggests that previously invaded soils may not limit native seedlings.     

Soil quality effects on regeneration of annual Medicago pastures in the Swartland of South Africa

Annual medic (Medicago spp.) pastures are widely used as the forage component of crop rotation systems in the Mediterranean region of South Africa. Reliable establishment of medics can be challenging. This may be related to poor soil quality, an inherent problem of soils in the region often aggravated by poor management. The aim of this study was to determine the underlying soil quality factors that result in classifying soils as having low, medium and high medic pasture production potential. The study was carried out on two farms that have followed crop/pasture rotation systems for the past 20 years. Two growing seasons (2015 and 2016) were evaluated on areas within fields that were identified to have poor, medium and high production potential. Soil samples were taken to evaluate soil quality and to determine the medic seed density in soil. Above-ground seed production and herbage production were monitored during the growing season. The low productivity soils had the lowest below-and above-ground seed density, medic seedlings establishment and medic herbage yield. Soil sodicity was one of the main factors decreasing pasture productivity. In a production system where medics need to regenerate effectively following good seed production, soil sodicity may be especially detrimental.     

Accumulation and consumption of odorous compounds in feedlot soils under aerobic, fermentative, and anaerobic respiratory conditions.

Agricultural odors present an increasingly difficult challenge to livestock producers, yet very little information is available on the microbiology of odor production or microbial factors that regulate the emission of odors. This study examined the microbial potential for odor production and odor consumption in two soils from a cattle production facility in central Nebraska. The two soils tested were collected from a feedlot pen and a runoff ditch below the pen and contained high- and low-fecal matter content, respectively. These soils were tested for their ability to produce and consume a mixture of VFA and aromatic compounds (phenols and indoles) under aerobic, fermentative, and anaerobic respiratory conditions, with NO3-, Fe(III), Mn(IV), and SO4(2-) serving as anaerobic terminal electron acceptors, over a 6-wk incubation. The pen soil had greater (P < 0.05) initial total VFA content (40 micromol/g soil) and produced more VFA during incubation than the feedlot ditch soil, whereas total aromatic compound concentrations were not significantly different between soils. The general pattern of odor compound accumulation and consumption did not differ between soils. Oxygen and nitrate treatments produced very little VFA and consumed acetate more rapidly than the other treatments, which produced large quantities of short-chain VFA and consumed acetate only after all other VFA were consumed. When VFA and aromatic compound consumption was compared across all the treatments, aerobic incubation proved most effective, and all compounds were rapidly consumed by the second day of incubation. Of the anaerobic treatments examined, nitrate proved most effective, followed by Fe, with VFA consumed by d 5 and 21, respectively. Anaerobic incubation with sulfate produced more VFA than the fermentative incubation, and anaerobic incubation with oxidized Mn produced the largest quantities of VFA, which remained high throughout the six-wk incubation. Aromatic compounds were more easily consumed aerobically and were only slowly consumed in the anaerobic treatments. We conclude from this study that cattle feedlot soils possessed a varying, potentially exploitable capacity for odor consumption when alternate electron acceptors were available.     

干旱区典型绿洲土壤盐渍化特征分析——以渭干河-库车河三角洲为例

渭干河-库车河三角洲绿洲地处世界第二大沙漠塔克拉玛干沙漠的北缘,该绿洲现已成为新疆主要的农业区和棉花基地。但随着经济的快速发展,土地资源开发强度开始加大。而土壤盐渍化是该绿洲可持续发展面临的主要环境问题之一。本研究在野外考察、GPS定点和土壤采样分析的基础上,借助Statistics、Excel等统计软件对盐离子含量、土壤总碱度与离子含量的关系、土壤含盐量与电导率的关系以及盐离子间相关性作了探讨。结果表明,该绿洲土壤pH值的平均值为7.86,属于碱性土壤。土壤含盐量较高,0~10 cm土层中的含盐量最大,平均值达到4.68%。土壤阳离子主要以Na 、K 、Ca2 和Mg2 为主,各阴离子在土体中的含量为Cl->SO42->HCO3-,而CO32-在实验中未检测到。在0~10和10~50 cm土层中Na 与Cl-均呈极显著正相关,相关系数达到0.99,从而进一步说明该绿洲盐渍化土壤为氯化物盐化土。随着一系列环境问题的日益突出,同盐渍化作斗争已成为本绿洲大农业发展的长期任务之一。