Modelling carbon dynamics in mixed grass–red clover swards

Growth and carbon dynamics in mixed grass–red clover leys were simulated using a growth model for pure stands based on radiation use, allocation within plant and loss of biomass. The model and its parameter values were taken from previous applications of the model to pure swards of grass and red clover grown in the same experiment at the same sites and years.     

Earthworm biomass response to soil management in semi-arid tropical Alfisol agroecosystems

Earthworms recorded during 1989–1993 across 15 soil management treatments, comprising three different tillagexthree organic amendments (bare, farmyard manure, and rice straw) and six perennial ley treatments, belonged to two endogeic species, Octochaetona phillotti (Michaelsen) and Lampito mauritii Kinberg, while in a nearby undisturbed natural revegetation area three species were found, including the above two and Octonochaeta rosea (Stephenson). The earthworm biomass showed significant temporal and spatial variations and was higher during the post monsoon period than in the early rainy season. No worm biomass was recorded during the dry season. In the tillage and organic amendment treatments, the biomass was drastically reduced from September 1989 to September 1991 after the application of carbofuran and some herbicides, and was significantly reduced during these two years compared to that of 1992. The maximum monthly earthworm biomass ranged between 2.5 and 17.9 g m^-2 across the treatments and increased several-fold in the nearby natural revegetation area (75.9 g m^-2). It significantly increased in perennial ley treatments compared to annual treatments with organic amendments. Thus the earthworm biomass varied significantly (P<0.01) across the 15 treatments, indicating discernible effects of soil management.Visiting Scientist (under the Rockefeller Foundation Environmental Research Fellowship in International Agriculture)     

怀山药—怀地黄对药多糖对小鼠淋巴细胞增殖的影响

探讨怀山药—怀地黄对药多糖对小鼠脾脏淋巴细胞增殖功能的影响。首先采用MTT法测定怀山药—怀地黄多糖、怀山药多糖、怀地黄多糖对小鼠脾脏淋巴细胞的安全浓度,然后,在各多糖安全浓度范围内,用MTT法测定三种多糖对健康和免疫抑制小鼠脾脏淋巴细胞增殖的影响。结果表明,怀山药-怀地黄多糖、怀山药多糖、怀地黄多糖均具有一定的促进淋巴细胞增殖作用,具有一定的浓度依赖性,综合比较,三种多糖增强小鼠脾脏淋巴细胞增殖功能的作用顺序为:怀山药—怀地黄多糖怀山药多糖怀地黄多糖。结论,怀山药—怀地黄对药多糖增强小鼠脾脏淋巴细胞增殖功能的作用优于其单一中药。     

红花石蒜的组织培养

选用双鳞片法切割红花石蒜鳞茎为外植体,采用MS基本培养基,以两种植物生长调节剂NAA和6-BA不同浓度配伍,研究了不同消毒时间和不同激素浓度对小植株诱导和不定芽诱导的影响。结果表明:利用0.1%升汞溶液浸泡石蒜鳞茎10~15min消毒效果最好;MS+2mg/L 6-BA+0.2mg/L NAA是小植株诱导的最佳培养基;MS+NAA 2mg/L+6-BA2mg/L是不定芽诱导的最佳培养基;MS+2mg/L NAA对于小鳞茎的生根效果最好。     

不同产地瓦松活性成分初步研究

目的:讨论不同产地瓦松提取物活性成分差异,以期为瓦松应用开发提供理论基础。方法:采用系统化学检测法研究瓦松水提物及醇提取物成分差异;采用HPLC法,对水提物正丁醇萃取相进行了讨论,研究其差异。结果:不同产地瓦松水提物及醇提物存在一定差异。结论:相对来说辽宁、黑龙江所产瓦松活性成分较为丰富,相对含量较高。     

太原城市生态廊道草本植被调查及其分布格局分析

对太原市河流生态廊道和道路生态廊道的草本植被进行调查,分析其植物种类构成和分布格局,探讨城市生态廊道植物多样性及景观效益。结果表明,太原城市生态廊道草本植物有 174 种,隶属于 41 科 20 属,其中乡土植物 107 种,所占比例 61.49%;外来植物 48 种,所占比例 27.59%;入侵植物 19 种,所占比例 10.92%。相关分析表明,距离城市中心越远,调查样点草本植物多样性越高,可见城市化进程降低了城市生态廊道的植物丰富度。总体来看,道路生态廊道草本植被多样性高于河流生态廊道。不同廊道中入侵种占比的分布规律并不一致,河流生态廊道入侵种比例随着城市中心距离的增加而增加;而道路生态廊道恰恰相反,距城市中心越近,入侵种占比反而越大。     

正交试验优选地锦草颗粒成型工艺

为优选地锦草颗粒成型工艺,以可溶性淀粉用量、乙醇浓度、阿司帕坦用量为考察因素,以制粒难易程度、外观、粒度、溶化性、口感及其综合评分为指标,采用L9（34）正交试验优选成型工艺。最佳成型工艺是可溶性淀粉用量为70%,乙醇浓度为75%,阿司帕坦用量为0.50%,测得临界相对湿度为65%。     

Reduced tillage in temperate organic farming: implications for crop management and forage production

To promote conservation tillage in organic farming systems, weed control and ley removal within arable-ley rotations need to be optimized. A long-term field trial was thus established in Frick, Switzerland in 2002 on a clayey soil and with a mean precipitation of 1000 mm/year. The tillage experiment distinguished between conventional tillage with mouldboard ploughing (CT, 15 cm depth) and reduced tillage (RT), including a chisel plough (15 cm) and a stubble cleaner (5 cm). Results of a 2-year grass-clover ley (2006/2007) and silage maize (2008) are presented. Due to dry conditions, mean grass-clover yields were 25% higher in RT than in CT, indicating better water retention of RT soils. Clover cover and mineral contents of the fodder mixture were also higher in RT. The ley was successfully removed in autumn 2007 in RT plots, and a winter pea catch crop was sown before maize. In CT, ploughing took place in spring 2008. Maize yields were 34% higher in RT than in CT, despite a two- to three-fold higher but still tolerable weed infestation. Maize in RT plots benefited from an additional 61.5 kg of easily decomposable organic N/ha incorporated into the soil via the pea mulch. Measurement of arbuscular mycorrhizal colonization of maize roots indicated a similar mechanical disturbance of the topsoil through the reduced ley removal system compared with ploughing. It is suggested that RT is applicable in organic farming, even in arable-ley rotations, but long-term effects need further assessment.     

中药渣及添加剂对幼兔增重效果的研究

本试验利用药厂生产“增长乐”取汁后的中药渣，配合于家兔日粮中并对其生长效果进行观察研究。在小白鼠预试的基础上，添加３％的中药渣并配合２００ｐｐｍ铜、７５ｐｐｍ喹乙醇，２００ｐｐｍ铜＋０．３克四环素于幼兔日粮中。结果表明；添加３％中药渣较对照组提高日增重９．６％，节料７％；配合使用２００ｐｐｍ铜，则效果更佳。总的结果表明：中药渣及添加剂作为一种促生长剂增加到家兔日粮中是可行的