海南农垦橡胶园生态系统养分的物质流分析

对俯仰臂形草(Brachiaria decumber)、网脉臂形草(B.dactylon)、刚果臂形草(B.ruziziensis)和杂交臂形草(B.Hybrid)4种臂形草种子的萌发期及幼苗期在不同盐浓度处理下的耐盐性进行了比较研究,试验结果表明在种子萌发期,刚果臂形草耐盐性较强,其次是网脉臂形草;在幼苗期,网脉臂形草的耐盐性大于刚果臂形草。     

不同施氮水平对俯仰臂形草生产性能的影响

试验表明,在施一定量磷、钾、硫、锌、锰、铜肥的基础上,俯仰臂形草Brachiaria decumbens的干物质产量和粗蛋白含量随施氮量的增加而上升;在施氮处理范围内,氮肥利用率随施氮量的增加而降低.施氮量0～172.5 kg/hm2,种子产量随施氮量的增加而增加;当施氮量达到103.5 kg/hm2时,种子产量最高;达到304 kg/hm2时,随施氮量增加,种子产量呈下降趋势.     

Evaluation of the characteristics of 14 cover crops used in a soil rehabilitation trial

Many of the soils in Santa Cruz Department, Bolivia, are degraded by serious weed infestation, subsoil compaction, and low organic matter and nitrogen contents. Fallow periods with cover crops are frequently used to recuperate the fertility of degraded soils, but little information exists on the desired characteristics of cover crops for this purpose. The aim of this study was to describe those characteristics, believed to be most relevant to the rehabilitation of degraded soils in Santa Cruz, of 14 cover crops, which included three grasses, nine legumes, and two winter cover crops sown after summer soybean (Glycine max). The cover crop characteristics, evaluated over two years, were ease of establishment, competitiveness against weeds, tolerance to drought, dry matter production and nutrient contents of the above-and below-ground residues, nodulation, rooting density and root diameters. The three grasses Tobiata (Panicum maximum var. Tobiatd), Centenario (Panicum maximum var. Centenario) and Brizantha (Brachiaria brizantha) appeared to be the most promising for increasing soil organic matter contents, and the three grasses and groundnuts (Arachis hypogaea)/pigeon pea (Cajanus cajan) for the recuperation of subsoil structure. Mucuna deeringiana and Lablab (Dolichos lablab) were the most promising for increasing soil N status. All of these cover crops competed successfully with weeds.     

Forage Yield and Sucrose Response of Rhodes and Ruzi Grass to Cutting Height and Cutting Frequency Under Irrigation

The development of irrigated pastures in the Sudan is still at its infancy. The present study determined the influence of 2 cutting heights (2.5 and 5.0 cm) and 4 cutting frequencies (4-, 6-, 8-, and 10-week) on forage yield as dry matter and forage sucrose of Rhodes grass ( Chloris gayana Kunth. cv. Massaba ) and Ruzi grass ( Brachiaria ruziziensis Germain et Everard cv. Congo Signal ) under irrigated conditions. Forage yield interactions involving species X cutting height X cutting frequency were significant. These yield interactions were attributed to differences in growth period and growth rhythm of the two species. On average, Rhodes exhibited a short growth period (13 months) compared to Ruzi grass (20 months). Forage yield and forage sucrose were, on average, superior in Ruzi compared to Rhodes grass. Forage yield and forage sucrose averaged 5.2 t ha⁻¹ and 7.2 % fw sucrose in Ruzi compared to 2.8 t ha⁻¹ and 6.9 % fw sucrose in Rhodes grass. Forage yield and forage sucrose of both species were negatively correlated with cutting frequency. The highest forage yield may be obtained at an 8-week cutting frequency in Rhodes (45.6 t ha⁻¹ yr⁻¹) compared to a 10-week cutting frequency in Ruzi grass (88 t ha⁻¹ yr⁻¹). Results suggest that very high forage yields as dry matter and forage sucrose of Rhodes and Ruzi grass may be possible under irrigated conditions in the Sudan at a cutting frequency of between 8 to 10 weeks.     

臂形草品种及其营养价值初评(简报)

臂形草(Brachiaria spp.),又名旗草(英名Palisadegrass或Signalgrass),全属约50种,我国产6种,其中海南产2种,是世界热带、亚热带地区优良的放牧和水保兼用型牧草,在南、中美洲和东南亚等地区均有种植^[1]。二十世纪,由国际热带农业中心(CIAT)育成MulatoⅠ和MulatoⅡ臂形草,现由墨西哥在全球推广;在澳大利亚和泰国的臂形草(Brachiaria decumbenth cv.Baslisk)已成为重要的种子生产基地。臂形草在印度尼西尼作为放牧草种进行林下种植。     

臂形草属种质苗期抗旱性鉴定研究

通过盆栽试验对臂形草属种质苗期进行干旱胁迫,分析测定胁迫不同时期叶片的相对电导率、游离脯氨酸含量、丙二醛含量、叶绿素SPAD值及叶片相对含水量。结果表明,在胁迫15 d时,各指标均存在差异。对这5项指标进行类平均法聚类分析,臂形草属种质可划分为2个抗旱级别,即强抗旱和弱抗旱种质,其中强抗旱臂形草种质包括CIAT26556珊状臂形草、网脉臂形草、热研6号珊状臂形草、CIAT6095刚果臂形草、CIAT16835珊状臂形草。强抗旱和弱抗旱臂形草种质在连续干旱胁迫时,相对电导率、游离脯氨酸含量、丙二醛含量均呈现上升的趋势,而叶绿素SPAD值及叶片相对含水量则呈现下降的趋势。而复水后,强抗旱和弱抗旱臂形草种质均有不同程度的恢复。     

臂形草属牧草的分类及种质资源*

 臂形草（Brachiaria Griseb.）为一年生或多年生禾草，按其生物学特征分为9组 ，另有14种未归为组，全属共97种，中国产9种。主要分布于非洲、美洲、澳大利亚及亚洲，是热带及亚热带种植的主要禾本科牧草。臂形草属牧草资源由于其在草地牧业和生态环境治理中的重要作用，应用前景广阔。     

草料混合养鹅与精料养鹅效益比较

[目的]探讨优质牧草饲养鹅的可行性,为广东发展种草养鹅提供依据。[方法]以矮象草(组Ⅰ)和从美国引进的杂交臂形草Ⅰ(组Ⅱ)、Ⅱ(组Ⅲ)进行牧草混合精料养鹅试验,组Ⅳ用纯精饲料,测定各组肉鹅的日增重。[结果]组Ⅰ、组Ⅱ、组Ⅲ、组Ⅳ的平均日增重分别为39.48、47.104、3.874、4.97 g/只。肉鹅饲养早期各处理的日增重均随天数增加而增加,第2阶段(36~45日龄)最高,第4阶段(61~80日龄)最低,下降最慢的是组Ⅱ。组Ⅱ的料肉比一直平稳降低,说明其对肉鹅的增重效果较佳。采用牧草混合精料饲养肉鹅节约了精料,降低了养殖成本,改善了肉鹅的屠体品质,烹调出来的肉食品味道香。[结论]杂交臂形草Ⅰ混合精料养殖肉鹅的效益较好。     

Arbuscular mycorrhizae in the rehabilitation of fragile degraded tropical lands

The aim of this work was to establish a vegetative cover with an introduced grass on an infertile substrate which contains little mycorrhizal inoculum. A field experiment was carried out in La Gran Sabana, Venezuela, in an area that was disturbed in 1991 and in which no spontaneous recolonization by plant species occurred. Five treatments were set up in which an introduced grass. Brachiaria decumbens, was sown. The treatments were: non-inoculated control (NI); inoculated with a concentrated mix of arbuscular mycorrhizal fungi (AMF) (385 spores g^–1 inoculum) at 1750kgha^–1 (I); fertilized with triple superphosphate, 100kgha^–1 (P); inoculated with AMF and simultaneously fertilized with triple superphosphate (I+P); another control treatment, to which previously sterilized AMF inoculum was added (S). In all cases B. decumbens was seeded at 30kgha^–1. A soil microorganism inoculum free of mycorrhizae was added to all the treatments. Five months after sowing the grass, above and below ground biomass, % arbuscular mycorrhizal (AM) colonization, root length and nutrient uptake were measured. The results showed an increase in plant cover, biomass and uptake of nutrients in the I+P treatment in comparison with all the other treatments. The rehabilitation of degraded lands in La Gran Sabana does not seem possible solely with the application of chemical fertilizers. It was evident that mycorrhizae are required to achieve rehabilitation, given that the I+P treatment led to significantly better results than those achieved with treatment P. The importance of mycorrhizae in the restoration of these lands is supported by the finding that, of the native plants which re-established in the different treatments, 81% were mycorrhizal. Received: 23 February 1997     

施氮对不同定植年限臂形草草场产量与质量的影响

对云南省南亚热带湿热地区的思茅曼中田畜牧场臂形草草场不同定植年限中每年施氮素与否对草场的产草量及养分含量的影响进行了调查和统计分析。结果表明：通过每年施氮肥，能明显地提高全草场的产量和质量，如以１９８６年（１２０）＊与１９８６（０）＊两不同处理在定植的第五年进行比较，一次刈割测产的干物质产量每公顷可提高达１４７．２％、粗蛋白含量则提高２３３．７％，处理间均可达到极为显著的差异（Ｆ＝９．９０＞Ｆ０．０１＝３．３６）。后随着年限的推移，施氮肥的草场产量可保持一定的稳定性之后，再出现稳中有降，而不施氮肥的处理则在定植的第三年急剧下降。为此作者等提出了试验见解，希望对曼中田以及其类似地区禾本科草场的管理上能起到一定生态循环系统的指导作用，并为抑制害草飞机草的孳生危害提供措施。