密度与施肥对高山反季节花椰菜产量影响研究

本试验研究了四种种植密度及四种施肥水平对花椰菜产量的影响,得出高山反季节花椰菜高产的适宜种植密度和施肥水平。结果表明：四种不同的种植密度之间存在显著差异,理想的种植密度为667m2植2400株;四种不同的施肥水平之间也存在显著差异,理想的施肥水平为667m2施78kg;理想的组合是667m2植2400株,施肥78kg。     

Using farmers' criteria to assess profitability of fodder shrubs in the desert margins of West Africa

This paper presents the results of a study carried out in the Ségou region of Northern Mali to analyse the use of fodder shrubs. The farmer‐level fodder banks consisted of three perennial legumes (Gliricidia sepium, Pterocarpus erinaceus and Pterocarpus lucens). The main question addressed is whether this new type of fodder was more profitable for smallholder farmers compared to alternative fodder options. To test hypotheses for profitability, farmers were grouped in two different ways. The first grouping was based on the different village communities the farmers belonged to. The second grouping consisted of three user groups based on individual (non‐) use patterns of the fodder banks. ‘Passives’ were non‐users because of apparent disinterest. ‘Actives’ were the group of users whose fodder banks performed well and who harvested in time while ‘Unfortunates’ were non‐users unable to harvest fodder mostly through high mortality rates of the shrubs. Profitability was measured by increases in income or increases in the productivity of labour spent on feeding livestock. Profitability was shown to be dependent on the use pattern of the fodder shrubs. In the actual situation no user group had gained any concrete financial benefits. The several scenarios in which other use modalities were modelled, did show gains of using fodder shrubs, but only under conditions where alternative options were expensive. The perceived value of this technology was high. The use patterns indicated that this did not necessarily reflect farmers' long term interest in the technology itself. Rather, farmers were motivated by perceived opportunities to gain short term material and social benefits from the project promoting the shrubs. Copyright © 2007 John Wiley & Sons, Ltd.     

高寒区施肥和混播对燕麦人工草地土壤碳氮储量及垂直分布特征的影响

了解高寒地区燕麦人工草地在燕麦品种、施肥措施和混播水平下土壤碳氮储量潜力及垂直分布动态,为高寒地区燕麦人工草地建植提供理论依据。采用4个燕麦品种（A1：青燕1号,Avena sativa cv. Qingyan No.1;A2：林纳,A. sativa cv. Lena;A3：青海444,A. sativa cv. Qinghai 444;A4：青海甜燕麦,A. sativa cv. Qinghai）、4个施肥水平（B1：不施任何肥料,CK0;B2：尿素75kg/hm2+磷酸二铵150kg/hm2,IM;B3：有机肥1500 kg/hm2,OM;B4：尿素37.5 kg/hm2+磷酸二铵75 kg/hm2+有机肥750 kg/hm2,IM+OM）和4个箭筈豌豆混播水平（C1：0 kg/hm2;C2：45 kg/hm2;C3：60 kg/hm2;C4：75 kg/hm2）的三因素四水平正交试验设计[L16(45)],在燕麦拔节期、抽穗期、开花期、乳熟期和收获后期研究了3个因素对高寒区燕麦人工草地土壤C、N储量的影响极其垂直分布特征,为高寒区燕麦人工草地土壤固C、固N潜力评估提供理论依据。品种、施肥和混播均显著影响了燕麦人工草地土壤C、N储量。3个因素在作物生长期对土壤C储量的积累的影响大小表现为施肥＞混播＞品种,收获后期表现为混播＞施肥＞品种;各时期对土壤N储量的影响大小均表现为施肥＞混播＞品种。采用尿素37.5 kg/hm2+磷酸二铵75 kg/hm2+有机肥750 kg/hm2的施肥处理,混播75 kg/hm2箭筈豌豆建植的燕麦人工草地土壤C、N储量最高。施肥措施造成燕麦人工草地各时期不同土层间土壤C、N储量的差异。在3种措施影响下燕麦人工草地0~50cm土层土壤C、N储量潜力分别为176.78 t/hm2和11.78 t/hm2。土壤C、N随着土层的加深而逐渐下降,0~20cm土层土壤C、N储量显著高于其它土层。     

五泉山公园部分木本观赏植物真菌病害调查及防治

于2008-2009年对兰州市五泉山公园部分木本观赏植物真菌病害进行了调查,共发现木本观赏植物真菌病害32种,危害部位以叶部为主。寄主植物以杨柳科和蔷薇科为主。引起病害的病原真菌隶属21属32种,以半知茵和子囊菌为主。同时,根据病害的种类及发生特点提出加强植物检疫、适地适树、正确养护管理、强化园林技术措施及尝试利用生物...     

天然草地放牧牦牛采食行为及食性选择的研究

对青南地区玉树县境内2牧场的草地植被及成年母牦牛的采食行为和选择性采食习性及其关系进行了探讨,结果表明：B牧场禁牧区的生物量显著高于A牧场的禁牧区及A,B牧场的放牧区（P〈0.05）,B牧场的可食植物量显著高于A牧场（P〈0.05）,A牧场的可食植物量只占地上生物量的一半以下;B牧场分别以小嵩草,矮嵩草,披碱草,针茅,蒲公英等优良牧草为优势种,次优势种,而A牧场以线叶嵩草为优势种,凤毛菊,狼毒,黄帚橐吾等毒杂草及早熟禾等为次优势种;B牧场以小嵩草、矮嵩草等莎草科和为主要采食植物,而在A牧场除以莎草科植物为主要采食植物外,由于可食牧草量的不足,还采食一些本不喜食的植物。矮嵩草和小嵩草是牦牛最喜食,选择性最高的植物;斑块内采食口数A牧场为50.6 bite/patch显著少于B牧场的81.1 bite/patch（P〈0.01）;斑块内采食站数A牧场为8.4 FS/patch显著多于B牧场的5.2 FS/patch（P〈0.001）;采食站内采食口数A牧场为6.6 bite/FS显著少于B牧场的17.4 bite/FS（P〈0.001）;采食速度A牧场为1.32 bites/sec显著慢于B牧场的1.46 bites/sec（P〈0.01）。放牧草地的食物资源的匮乏,使放牧牦牛的食物选择性降低,采食行为的内容变劣,A牧场草地处于严重退化状态;牦牛处于缺营养状态,草地的退化对牦牛的生产性能有很大的影响。     

返青期休牧对退化高寒草地植被特征及优势种光合生理的影响

为探讨返青期休牧对退化高寒草地植被特征及优势种光合生理的影响,本研究在祁连山区选择已实施返青期休牧6年的高寒草甸开展了植被特征及优势种光合生理相关指标的调查研究.结果表明:返青期休牧6年后,高寒草甸的植被盖度、地上生物量、地下生物量和土壤含水量较未休牧区分别增加了38.44％,985.00％,209.56％和62.62...     

青海冷地早熟禾在青藏高寒地区的生产性能

研究了青海冷地早熟禾(Poa crymophila cv. Qinghai)在青藏高寒地区的生产性能, 结果表明, 在高寒地区旱作条件下, 青海冷地早熟禾种植当年生长缓慢, 第2和第3年生长迅速, 整个生育期为106～110 d。从开花期到乳熟期生物量增长最快, 进入完熟期后生长缓慢。粗蛋白含量随生育期的推进呈下降趋势, 抽穗期含量最高;粗纤维含量随牧草生育期的推进呈逐渐增高的趋势;粗脂肪、无氮浸出物和粗灰分含量在整个生育期内无明显变化。     

Clipping by Plateau Pikas and Impacts to Plant Community

Plateau pikas (Ochotona curzoniae) often clip tall plants near active burrow entrances to detect and avoid predators. This clipping behavior influencing plant communities near active burrow entrances has not been well documented. A field experiment was conducted to investigate the effects of this clipping behavior on plant communities across three sites in the Qinghai-Tibetan Plateau by comparing plant communities near active burrow entrances with communities near abandoned burrow entrances. This study showed that the clipping behavior decreased plant community height and increased plant cover and species richness of the community and had no effect on plant community biomass across three sites or at each site. This study further showed that clipping behavior decreased the plant biomass of the graminoid group and had no effect on the plant species richness of the graminoid group, whereas it increased the plant biomass and plant species richness of the forb group across the three sites or at each site. These findings suggest that a general pattern concerning the effect of the clipping behavior can increase plant species richness and decrease the grazing quality of alpine meadows near active burrow entrances.     

高寒草甸优势物种饲用品质对短期放牧的响应

为了解放牧强度对高寒草甸牧草饲用品质的影响,以青藏高原东北边缘高寒草甸为对象,研究了轻度(0.75牦牛单位·hm-2)、中度(1.00牦牛单位·hm-2)和重度(1.25牦牛单位·hm-2)放牧下优势植物珠芽蓼(Polygonum viviparum)和线叶嵩草(Kobresia capillifolia)的全氮、酸性洗涤纤维、中性洗涤纤维含量以及牧草的可吸收营养物质总量和相对饲喂价值等的变化。在放牧末期,中度放牧下牧草的植株高度显著高于其他放牧强度(P0.05)。在整个放牧期,中度放牧下牧草的全氮含量高于其他放牧强度,其中珠芽蓼的全氮含量在放牧末期显著高于重度放牧(P0.05);各放牧强度间植物的酸性和中性洗涤纤维含量在放牧末期无显著差异;中度放牧下牧草的营养价值指数整体呈上升趋势或保持稳定。在青藏高原东北边缘,3年的短期中度放牧利用有利于高寒草甸主要优势物种珠芽蓼和线叶嵩草保持较高而稳定的饲用品质。     

高山马铃薯脱毒苗DNA甲基化的MSAP分析

为了解脱毒对高山马铃薯试管苗DNA甲基化水平的影响,探究DNA 甲基化在高山马铃薯脱毒后的作用,结合毛细管电泳检测技术对怀玉山高山马铃薯脱毒苗的基因组DNA甲基化进行MSAP分析。结果表明,怀玉山高山马铃薯常温继代带毒苗甲基化水平较高,经过玻璃化法超低温保存处理但未能脱毒时其甲基化水平有所下降,但甲基化仍处于较高水平,而常规茎尖培养脱毒和玻璃化法超低温疗法脱毒可明显降低试管苗的甲基化水平,且玻璃化法超低温疗法脱毒苗的甲基化水平更低。在怀玉山高山马铃薯超低温保存(未能脱毒)、茎尖常规培养脱毒和超低温疗法脱毒3个处理方式中,去甲基化模式和甲基化模式并存,但均以去甲基化模式为主要趋势,且在去甲基化模式的强弱依次为超低温疗法脱毒>茎尖常规培养脱毒>超低温保存(未脱毒)。本研究结果为怀玉山高山马铃薯脱毒苗的种质保存和规模化生产提供了一定的理论依据。