屋顶花园栽培基质中添加海泡石的效果研究初报

在屋顶花园条件下,以葱兰和佛甲草为实验材料,对它们的栽培基质中添加海泡石,通过与未加海泡石的实验作对照,发现,将适量海泡石加入屋顶花园的栽培基中,可明显改良植物的根际环境,提高土壤肥力,提高基质保水供水的能力,使植物生长旺盛,提高抗病能力。但大雨时,加入海泡石的基质,水分下渗慢,基质表层留水量及流水量增大,易冲走混合基质中的轻型材料部分,在坡面屋顶使用时,不宜加入过多。     

中草药防治鸡霉形体病的研究

将自然感染MG的土杂鸡,随机分为7组,1、2、3组分别为病毒I号,按每kg体重0.25ml、0.50ml、1.00ml给药,4、5、6组分别为泰乐星,按每kg体重50mg、100mg、200mg给药,2次/d,连续7d,7组为空白对照。投药后,进行临床症状及气囊病理评分、MG血清抗体检测和疗效试验。结果显示:病毒I号与泰乐星在缓解临床症状、减少气囊炎病变率、降低气囊病变程度和死亡率等方面两者均无显著差异(P>0.05),而试验组与对照组差异显著(P<0.05)。说明病毒I号与泰乐星达到同样的治疗效果。     

Soil erosion potential of organic versus conventional farming evaluated by USLE modelling of cropping statistics for agricultural districts in Bavaria

Abstract. Organic agriculture (OA) aims to identify a production regime that causes less environmental problems than conventional agriculture (CA). We examined whether the two systems differ in their susceptibility to soil erosion by water. To account for the large heterogeneity within the rotations practised on different farms, we chose a statistical evaluation which modelled erosion using the USLE method from the cropping statistics for 2056 districts in Bavaria (70 547 km²; 29.8% arable). Physical conditions of erosion were determined in a rectangular grid yielding 13 125 grid-cells of c. 5 km² each. For validation, erosion was measured in 10 sub-watersheds on two neighbouring OA and CA farms over 8 years (287 erosive events). On average, about 15% less erosion on arable land was predicted for OA than for CA due to the larger area of leys, although OA occupies areas that are susceptible to erosion more often than CA. The same conclusions could be drawn from the validation data. These data also demonstrated that erosion could be reduced considerably below 1 t ha⁻¹ yr⁻¹ with best management practices under both farming systems. In contrast, at the countrywide scale, cropping did not change adequately with site conditions favouring erosion. The need for erosion control seems not to influence crop rotation decisions on erosion-prone sites.     

石蒜球茎生物学性状及营养成分年变化规律

对不同年份石蒜生物学性状差异性及营养物质含量进行分析,结果表明:(1)球体形成在生长的第2年到第3年内基本完成,球茎由扁圆形向球体形发展;(2)鲜物质积累主要在第2到第3年完成,干物质积累主要在第3年到第4年完成,各生物学性状存在显著的相关性,第3年与第4年球高差异不显著,其他生物学性状在年份间差异显著;(3)石蒜中淀粉、蛋白质含量随着生长发育年份的增长而增加,可溶性糖含量随着年份的增长而降低,还原糖含量随着年份的增长先增加后降低。     

白银地区优良林草品种选择与林草复合经营技术试验

对优良林草品种的选择和林草复合经营技术试验结果表明 :引进的速生杨、速生柳各无性系间的扦插繁育和植苗造林成活率均不存在显著性差异 ;速生杨、柳苗期生长量与对照 (新疆杨、旱柳 )相比差异显著 ,90 %以上可当年育成一级壮苗 ,造林后速生杨、柳幼树初期生长量显著快于对照 ;引进的美国紫花苜蓿品种在林草复合经营中的品质和产量与对照相比有明显优势 ;林草间作的经济效益远远高于普通农作物种植 ,林草复合系统中草的收益完全可以保证林木成材前幼林的抚育费用 ,并可实现盈利 90 0～ 15 0 0元 /hm2 。     

闽南地区草本花卉的配置应用——以厦门植物园花卉园为例

草本花卉种类丰富、适应性强、栽培容易、便于管理,是园林绿化中的重要材料。针对其园林特色,结合厦门地区的资源情况,探讨草本花卉在不同的园林环境中的植物配置与应用,并以厦门植物园草本花卉园的建设为例,阐述其植物配置,营造色彩绚丽、种类丰富、风格各异的园林植物景观。     

草本植物中总黄酮提取工艺研究

[目的]探讨常压下水煎煮法提取草本植物中总黄酮的工艺。[方法]采用料液比、煎煮温度和煎煮时间为主要因素进行正交试验,以确定总黄酮的最佳提取工艺。[结果]草本植物中总黄酮的最佳提取条件为料液比1∶5 g/L,煮沸,煎煮时间75 min,在此条件下总黄酮得率约为0.734%。[结论]为后续草本植物饮料产品的研发提供了相关资料。     

金属冶炼厂对周边植物物种多样性的影响

[目的]揭示距离厂区不同距离植物物种多样性的变化规律和原因。[方法1利用物种丰富度指数（S）、Simpson多样性指数（D）、Shannon—wiener多样性指数（H）和Pielou均匀度指数（J）研究了距离厂区不同距离样地的植物和草本植物物种多样性。[结果]厂区周边植物中综合优势比较大的植物为大籽蒿、芨芨草、画眉草、狗尾草、小草、四方蒿、臭蒿、清明草、野菊、齿冠草、川西小黄菊、滇川唐松草、黄花莱等。种数较少的科（18科）总种数（25种）占所有总种数的17．48％。S和H随距离的增加而显著增加,100m区域内S和H显著较小,100～300m区域内S和D略高一些。D只在100m区域内显著较小．其他距离该参数无显著差异;J在所有距离问无显著差异。[结论]该研究为金属冶炼厂污染情况的监测及周边地区的植物多样性保护提供了参考。     

Effect of three contrasting onion (Allium cepa L.) production systems on nitrous oxide emissions from soil

 N₂O emissions were measured from three contrasting onion (Allium cepa L.) production systems over an 8.5-month period. One system was established on soil where a clover sward had 3 months earlier been ploughed in (ploughed clover site). This production system followed conventional production management practices. The other two systems were established on soil where a mixed herb ley had 3 months earlier been either ploughed or rotovated. These last two production systems followed the guidelines of the International Federation of Organic Agriculture Movements (IFOAM). Cumulative N₂O emissions were significantly greater from the ploughed clover site compared to the ploughed ley site (3.8 and 1.6 kg N₂O-N ha^–1, respectively), while cumulative N₂O emissions from the ploughed ley and rotovated ley sites were not significantly different from each other. Emissions from all sites were dominated by episodes of high N₂O flux activity following seedbed preparation and drilling, when soil water suction (SWS) was shown to be the rate-controlling variable. The decline in the N₂O fluxes after these peak emissions followed clear exponential relationships of the form F=Ae^{– kt} (r≥0.91), where F is the daily flux and A is the y-intercept. First-order decay constants (k) during these periods of declining N₂O fluxes (corresponding to half-lives of 2.6–3.0 days) were not significantly different in magnitude from the first-order rate constants that characterised the increasing SWS. Gross differences in cumulative emissions between the clover and ley sites were attributed to the influence of differing soil pHs at the two sites on the N₂O:(N₂O+N₂) ratio in the denitrification products. It also appeared that fertiliser applications to the clover site had both direct and indirect effects on N₂O emissions by: (1) enhancing N₂O emissions via potential nitrification, (2) increasing the NO₃ ^– supply for enhanced N₂O emissions via denitrification, and (3) influencing the N₂O:(N₂O+N₂) ratio by lowering soil pH and increasing NO₃ ^– concentrations. Onion crop yields were greater at the clover site, mainly due to the higher density of planting made possible under a conventional production philosophy. Expressing the yield on the basis of net N₂O emissions, 23 t onions kg^–1 N₂O-N was obtained from the ploughed clover, which was double that obtained for the two systems based on the ley site. However, when the N₂O emissions from the cultivation of the soils prior to the sowing of the onions was included, all three systems produced a similar yield per kilogram of N₂O-N emitted, averaging 10 t kg^–1. Received: 6 January 1999     

广东重要农林有害外来生物飞机草入侵的历史阶段与特点

飞机草是世界上危害严重的100种有害外来入侵物种之一,是我国公布的第一批入侵植物之一,也是广东主要的入侵植物之一。本文介绍了飞机草对入侵地农田、牧草、生态等会造成严重危害,归纳了飞机草入侵广东的3个历史阶段,从防治和利用两方面总结了飞机草入侵广东的历史特点,指出了飞机草的入侵应引起社会的广泛关注,政府的高度重视,防止进一步扩散蔓延。