3种观赏草的持水性能

本研究以福建地区比较常见的3种观赏草旱伞草（Cyperus alternifolius）、狼尾草（Pennisetum alopecuroides）和麦冬（Ophiopogon japonicus）为研究对象，应用浸泡法分别测定3种观赏草根、茎、叶的持水量并进行分析。研究表明，3种观赏草的持水性能存在差异，其中狼尾草的持水性能最强。观赏草的各部位持水性同样存在差异，浸泡时间与持水率呈极显著正相关关系，与吸水速率呈极显著负相关关系（P<0.001）。3种观赏草均有良好的持水性能，对园林造景和生态保护具有积极的作用。     

Growth of Roots Emerged from Excised Phytomers of Three Gramineous Species under a Low Osmotic Potential

Abstract

The growth of crown and lateral roots emerged from the excised phytomers of pearl millet (Pennisetum typhoideum Rich.), barnyard millet (Echinochloa frumentacea Link.) and maize (Zea mays L.) was studied under normal and low osmotic potential conditions. The plants were grown in two solutions with osmotic potentials of –0.02 and –0.54 MPa for 6 days. The relative growth rate of the roots in total length (RGR_L) , was not affected by osmotic stress in pearl and barnyard millets, but that in stressed maize was reduced to 64% of the control. Similarly, the relative growth rate of the roots in dry weight (RGR_W), was not affected by osmotic stress in pearl and barnyard millets, but significantly reduced in maize. Osmotic stress increased the specific root length of the lateral roots in pearl and barnyard millets, but did not affect that of maize. The photosynthetic rate (Pr) in the two millets was decreased to ca. 60% of the control by the stress, and that in maize was reduced to 21%. Under the stress, Pr in the three species was limited mainly by low stomatal conductance, but no clear relationship was found between Pr and osmotic adjustment of the leaf. The relative water content of the leaf was lower in maize than in the two millets. The resistance to water flow through the phytomer (R) was significantly increased by osmotic stress in maize, but not significantly in the two millets. The mean root length (RL) was decreased by the stress in maize, but not in the two millets. The maintenance of RGR_L in the two millets was associated with sustained R, RL and also with the maintenance of Pr and allocation of assimilates to roots.     

Comparative performance of four multi-purpose trees associated with four grass species in the humid regions of Southern India

The results of a field trial conducted at the Livestock Research Station, Thiruvazhamkunnu, Kerala to study the compatibility of different components in a silvo-pastoral system revealed that growth and yield of fodder species were significantly influenced by the tree components only after tree canopy formation. The fodder species such as Pennisetum purpureum Schum., Panicum maximum Jacq., Brachiaria ruziziensis Griseb. and Euchlaena mexicana Schrad. grown in association with Casuarina equisetifolia J. R. & G. Forst. and Ailanthus malabarica DC recorded comparatively higher forage yield even after canopy formation. However, forage crops grown in combination with Acacia auriculiformis A. Cunn. ex Benth. and Leucaena leucocephala (Lam.) de Wit. registered relatively lower values for growth and yield. Increased light infiltration into the understorey due to the cladophyllous canopy can be attributed as reason for the higher fodder productivity under Casuarina. Due to the combination of crown size and shape, tree height and spacing the amount of light intercepted by Ailanthus also was very low. Among the four multi-purpose trees used, Acacia recorded the maximum growth rate followed by Casuarina, Ailanthus and Leucaena. Forage productivity of the four species was in the order: Pennisetum purpureum > Panicum maximum > Brachiaria ruziziensis > Euchlaena mexicana. Casuarina with Pennisetum/ Panicm were found to be optimal tree — forage combinations for silvo-pastoral systems.     

添加纤维素酶和乳酸菌对“桂牧1号”杂交狼尾草青贮品质的影响

为研究纤维素酶和乳酸菌单独添加、混合添加对“桂牧1号”杂交狼尾草青贮品质和营养价值的改善效果,将杂交狼尾草经全株收割、粉碎后,分别添加纤维素酶（CEL）、乳酸菌（LD1、LD2）、乳酸菌+纤维素酶（CEL+LD1 ～ LD2）,密封袋密封60 d后,测定饲料品质和营养成分。结果表明：纤维素酶组、LD2组青贮料pH含量和对照组差异不显著（P > 0.05）,纤维素酶+乳酸菌（CEL+LD1 ～ LD2）组青贮料pH分别为4.54、4.50,比对照组高。纤维素酶组及纤维素酶+乳酸菌组氨态氮含量比对照组含量分别低18.44%、26.95%、16.31%。LD2组青贮料中无丙酸、丁酸产生。杂交狼尾草青贮时单独添加纤维素酶,青贮饲料粗蛋白质（CP）含量较对照组高6.08%（P < 0.05）,酸性洗涤纤维（ADF）、中性洗涤纤维（NDF）分别低于对照组2.93%、4.81%（P < 0.05）,表明单独添加纤维素酶能够提高青贮品质。青贮料中添加乳酸菌益4-J1,可有效抑制丙酸、丁酸产生,对青贮品质有改善作用。 [关键词] 纤维素酶|乳酸菌|“桂牧1号”杂交狼尾草|青贮品质     

4种草用于南方稀土尾砂地种植的适宜性之比较

采用野外小区试验和盆栽试验相结合的方法,对百喜草(Paspalum notatum)、狗芽根(Cynodon dactylon)、弯叶画眉草(Eragrostis curvula)和狼尾草(Pennisetum alopecuroides)在稀土尾砂基质上通常条件下、不施肥条件下和经历干旱胁迫下的生长状况进行观测,从生长力、耐旱性和耐瘠性3方面对4种植物在稀土尾砂地的适宜性进行了比较。结果表明,生长力以弯叶画眉草为最优,耐旱性最强的为百喜草,耐瘠性最好的是狼尾草。3个方面综合比较,百喜草和狼尾草最好,其次为弯叶画眉草,狗芽根居末位。试验结果可为南方稀土尾砂地植被恢复时根据具体情况应用这些草种提供参考。     

紫穗狼尾草和狗牙根茎叶水文生态效应比较

研究了紫穗狼尾草Pennisetum alopecuroides地上部的生长状况、水文效应和生态效应。结果表明,紫穗狼尾草的成坪速度、成坪时间、草层高度和地上生物量均明显优于狗牙根Cynodon dactylon;其茎叶最大截留率45.35%,最大截留量5.12 mm,均高于狗牙根;其枯落物有效蓄水率304.88%,有效蓄水量0.19 mm,均低于狗牙根;其茎叶覆盖对降低地表温度和保持土壤水分更为明显、有效。     

Napier grass strips and livestock: a bioeconomic analysis

Napier grass strips are gaining some acceptance in Southeast Asia as a vegetative means of soil erosion control, due to the relative ease of establishment and management. In addition, the napier grass strips aid productivity of agroforestry systems by providing mulch or by being fed to livestock. In this paper, a bioeconomic comparison of different ways of utilising the napier grass cuttings is undertaken. The three uses examined for the cuttings were: as mulch in the alley areas, sold as fodder, and fed to animals with manure applied back to the system. The analysis linked the soils-oriented SCUAF model with economic and animal component models. SCUAF was parameterized using field data based on farmer interviews and field visits. Farmer interviews and field visits were conducted at Claveria, Misamis Oriental to gather additional data regarding costs and returns associated with animal production, and also to obtain the farm gate price of napier. Predicted biophysical results produced by the SCUAF model showed that application of napier grass cuttings, back into the system, directly as mulch or indirectly as animal manure resulted in higher maize and napier yields, lower soil erosion rates, and less of a reduction in soil mineral nitrogen and soil labile carbon levels. The comparison was made with the case where napier was sold off-farm as fodder. Cost-benefit analysis showed that higher economic returns were gained when napier grass cuttings were fed to animals, rather than applied directly as mulch. This economic benefit was attributed to the draught and transport services rendered by the animal and to a change in the value of the animals. This analysis highlights the value of utilizing animals within a napier grass strip system for control of erosion.This revised version was published online in November 2005 with corrections to the Cover Date.     

栽种对象草生产性能的作用

对象草 Pennisetum purpureum 采用扦插、平埋2种植入方式和40、80、120 cm 3个行距水平进行组合栽种试验,结果表明,扦插和平埋的繁殖成活率分别为90%和87%,两者间的差异不显著(P<0.05).方差分析显示,行距水平间的草产量存在显著差异(F>F0.01),植入方式、植入方式与行距互作效应均不显著(F0.05).5次刈割的年合计产量表明,平埋 80 cm行距、平埋 40 cm行距的产量显著高于平埋 120 cm行距、扦插 120 cm行距的产量(P<0.05);平埋 80 cm行距与扦插 120 cm行距间的产量差异达到极显著水平(P<0.01).     

巨菌草饲粮对七彩山鸡血液指标和脂肪相关基因的影响

旨在探究日粮中添加巨菌草对七彩山鸡血液生理生化指标以及脂蛋白脂酶(LPL)基因和钙激活蛋白酶抑制蛋白(CAST)基因表达影响.在为期3周预试验后,选取1周龄(无外观上缺失,无精神、食欲不振等情况)健康的七彩山鸡(母)210只,随机分为1个对照组和4个处理组,每组3个重复,每个重复14只,5个组分别是在基础饲料中添加0％...