青海东部农区6个 饲用玉米品种生产性能的比较

摘要：为了筛选适合青海东部干旱地区高产饲用玉米品种,选用6个饲用玉米品种采用单因素随机排列,3次重复,进行了各品种间生产性能和种植效益比较研究。试验结果表明：豫青贮23株高达到288.62cm,显著高于其他试验品种（P＜0. 05);豫玉22号饲草平均产量达到13.57万kg/hm2,与豫青贮23和甘玉23饲草平均产量间差异不显著( P＞0. 05),与铁研53号、陇单6号和中原单32号差异显著（P＜0. 05);豫玉22号盈利达到1.6万元/hm2,较豫青贮23和甘玉23分别高16.79%和18.52%,较铁研53和中原单32号分别高33.33%和52.38%,较陇单6号高出105.13%。从综合表现来看豫玉22号、豫青贮23和甘玉23号三个饲用玉米品种在青海东部干旱地区具有高产性能和较高的经济效益,值得大力推广种植。     

山西省西山地区退耕还林还草后续产业的发展与保障问题分析

本文通过随机抽取5个典型县区的有关数据,从退耕与林草建设的模式入手,利用比较和综合分析的方法,分析了山西省西山地区以林牧业发展为主的退耕还林还草后续产业的现状和趋势,以及后续产业发展的保障性等问题。结果认为,从整体上看,山西省西山地区退耕还林还草后续产业发展过程可分为倒退式发展(2000—2003年)、明显加快发展(2003—2006年)和迅速发展(2006—2009年)3个时段。选定的典型县区总体情况表明,在区域耕地减少、人口增多的情况下,粮食总产量和人均粮食产量均有所增长,表明典型区域耕地质量明显提高和后续产业持续发展的趋势;从典型县区个案情况看,在某一定时段内粮食总产量和人均粮食产量均出现不同幅度的负增长态势,也显示了该区后续产业存在严重的发展问题。最后提出了稳定耕地数量、保障人均粮食拥有量是后续产业发展的根本,以及需要进一步分析的主要问题。     

NaCl胁迫对4种豆科牧草萌发的影响

为研究盐渍化对4种牧草种子盐胁迫下发芽成苗的影响,探索不同牧草种子盐胁迫下的萌发表现,试验借鉴农作物研究的理论和方法,并在实验室条件下用不同浓度的NaCl溶液对种子进行处理,并观察其萌发特性,以期为生产实践提供有用的依据,减少在生产中的损失,提高草业生产的经济效益。1     

水氮供应对地下滴灌紫花苜蓿生长特征及草地小气候的影响

为探讨不同水氮处理条件下紫花苜蓿生长状况与草地小气候特征的关系,以2年生紫花苜蓿“巨能7号”为研究对象,采用田间试验和室内分析相结合的方法,研究了宁夏引黄灌区地下滴灌条件下不同滴灌量和施氮量处理下紫花苜蓿生长特征和草地小气候的变化。结果表明:1)滴灌量和施氮量对紫花苜蓿的株高、叶面积和鲜草产量都有显著的影响,表现为紫花苜蓿的株高、叶面积和鲜草产量均随滴灌量和施氮量的增加而增加,当施氮量增加到一定值时,继续增施氮肥,其鲜草产量增产效果在不同滴灌量处理下表现出不同的趋势。2)与不施氮处理相比,增施氮肥降低了紫花苜蓿株间空气温度、浅层土层温度和株间光照强度,而增加了群体内部空气相对湿度。3)不同滴灌量对紫花苜蓿的生长微环境的调节作用不同,随着滴灌量的增加,紫花苜蓿群体相对湿度逐渐提高,而紫花苜蓿株间气温和浅层土层温度降温效应越明显。4)紫花苜蓿生育期间株高与叶面积、草产量和群体内部相对湿度呈极显著正相关(P<0.01),与群体内光照强度、株间气温、浅层土壤温度呈极显著负相关(P<0.01)。合理减少滴灌量和施氮量不仅能维持紫花苜蓿良好的生长特征,而且能提高鲜草产量和改善草地生态环境条件。本研究旨在为紫花苜蓿群体微环境生态因子的改善及高产优质栽培措施提供科学依据。     

饲料中添加紫花苜蓿鲜草对肉牛生长性能及养分表观消化率的影响

为研究紫花苜蓿鲜草对肉牛生长性能及养分表观消化率的影响,采用单因素设计试验,选择体重相近的肉牛90头,随机分成3组,每组3个重复,每个重复10头。1组为空白对照组饲喂基础日粮,2、3组分别在风干物质的基础上添加5%、10%的紫花苜蓿鲜草,预试验10 d,试验期为60 d,在试验期间测定肉牛生长性能和养分表观消化率。结果表明:(1)试验3组的试验末重、平均日增重分别较对照组提高3.30%、14.77%(P <0.05),试验2组和3组的平均日采食量均高于1组(P> 0.05),试验3组的料重比分别较对照组降低7.20%(P <0.05);(2)试验2、3组的粗脂肪、粗灰分、钙、磷的表观消化率均高于1组(P> 0.05);试验3组粗蛋白质、中性洗涤纤维、酸性洗涤纤维表观消化率分别较对照组提高13.85%、18.83%、21.03%(P <0.05)。结论,10%紫花苜蓿鲜草可以提高肉牛的生长性能和养分表观消化率。     

Examining the impact of shade on above-ground biomass and normalized difference vegetation index of C3 and C4 grass species in North-Western NSW,Australia

Previous investigations have detected a directional trend in the normalized difference vegetation index (NDVI) of pastures around scattered paddock trees and identified shade from the tree as the most likely causal factor. This study uses a field experiment to quantify the effect of varying levels of shade on the above-ground biomass and NDVI of three grass species native to Australia (Microlaena stipoides, C₃, shade tolerant; Austrodanthonia richardsonii, C₃, prefers full sunlight, and Chloris ventricosa, C₄, prefers full sunlight) in different seasons. The study demonstrates that shade had little influence on the above-ground biomass of C₃ species but significantly reduced biomass in the C₄ species. Until early winter, the NDVI of each species was generally significantly higher in all shaded treatments than in the no-shade treatment. This suggests that shaded plants retained a higher proportion of green biomass and/or changed leaf shape, increased leaf area and chlorophyll content. Regardless, although not proven in this experiment, it is likely shade prolonged the retention of green plant material into mid to late winter. Overall, this experiment explains the directional trends in NDVI around scattered trees found in previous work and suggests that shade from scattered trees prolongs green pasture production in a range of native grass species, without loss of C₃ pasture biomass.     

铜尾矿污染土壤几种牧草的重金属抗性及微生物群落功能多样性研究

Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China. All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture. However, on pure mine tailings, the growth was minimal, whereas the growth was maximum for the control without mine tailings. The tolerance of grasses to heavy metals followed the sequence： Paspalum notatum 〉 Festuea arundinaeea 〉 Lolium perenne 〉 Cynodon daetylon. The planting of forage grasses enhanced the soil microbial biomass. The Biolog data indicated that the soil microbial metabolic profile values （average well color development, community richness, and Shannon index） of the four forage grasses also followed the sequence： P. notatum 〉 F. arundinaeea 〉 L. perenne 〉 C. daetylon. Thus, P. notatum, under the experimental conditions of this study, may be considered as the preferred plant species for revegetation of Cu mine tailing areas.     

牧草替代防制紫茎泽兰的研究

本研究采用牧草替代防制紫茎泽兰,充分利用紫茎泽兰的侵袈地发展种草养畜。研究表明,适当密度种植王草、牛鞭草等牧草,既可保证牧草的产量、品质,又可有效防制紫茎泽兰的扩散蔓延,是充分利用紫茎泽兰侵袈地和防制紫茎泽兰的好方法。     

放牧条件下绒山羊绒毛季节性生长变化规律的研究

本试验研究放牧条件下绒山羊绒毛季节性生长变化的规律。选择体重及产绒性能相近的2.5岁内蒙古白绒山羊羯羊10只,随机均分为2组,分别接受自然光照和短光照处理,短光照组每天的光照时间比自然光照组减少2小时,两组试羊在同一草场放牧。结果表明,放牧条件下,随牧草营养值下降(CP含量13.9%～6.0%)和光照递减(14.6～9.4h/d),绒毛生长呈慢—快—慢增长模式,主要的生长期在9月下旬～12月上旬,11月份为高峰期;减少光照可刺激绒毛生长,使快速生长的时间提前至8月下旬,绒毛长度增加10.9%,但生长模式不变。绒毛细度(14.6～14.9μm)和强度(6.9～5.9g)不受季节影响,但绒毛伸度下降54.3%;减少光照不改变绒毛强度和伸度,但绒毛细度增加5.6%、产绒量提高12.5%。     

Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends,current status and future research priorities

Despite their ecological, economic and social importance, grasslands in areas with Mediterranean climates continue to receive limited scientific, political and media attention. The main objectives of this review are to compare and contrast dryland grasslands in the ‘Old World’ regions of the Mediterranean basin (southern Europe, western Asia and North Africa) with those of ‘New World’ regions with Mediterranean climates (Australia and Chile) and to identify common research priorities. The common characteristics and differences in climate, soils, native vegetation, importance of the livestock sector and the socio‐economic background for the different Mediterranean environments are examined. Past trends and the current status of temporary and permanent Mediterranean grasslands are also described. Some common issues between these regions are as follows: (i) adaptation to climate change; (ii) increasing persistence and drought survival of both annual and perennial species; (iii) the important role of forage legumes; (iv) maintaining grassland plant diversity; and (v) improved ecosystem services, such as carbon sequestration, control of soil erosion and wildfires, and preservation of both wild and domestic biodiversity. The favourable climate in these regions, which allows year‐round grazing and the growth of legumes, should be exploited to improve the sustainability of grassland‐based, extensive farming systems and the quality of their animal products, while at the same time improving ecosystem services. The decreasing support for grassland research and development programmes requires increased international scientific and technical cooperation among the few institutions operating in the different Mediterranean‐climate areas of the World to provide innovative and sustainable solutions to farmers.