兰州市生态农业旅游开发

系统分析了兰州市发展生态农业旅游的有利条件、开发现状和存在问题,提出了发展兰州市生态农业旅游的建议。     

维生素B1和B2的萤光光度同时测定法

探讨了用同步荧光法测定维生素Ｂ１和Ｂ２的操作步骤和条件。维生素Ｂ１和Ｂ２的测定范围分别为质量浓度０．００１￣４．０００ｍｇ／Ｌ，０．０００５￣５．０００ｍｇ／Ｌ。该方法维生素Ｂ１的回收率在１０２％￣１０６％之间，维生素Ｂ２在８５．５％￣１０３．１％之间。     

Aesthetic preferences of non-farmers and farmers for different land-use types and proportions of ecological compensation areas in the Swiss lowlands

Beyond its traditional function of food production, agricultural land offers public amenities such as the protection of natural resources and landscape scenery. This study investigates the preferences of non-farmers and farmers for nine landscape scenarios in the Swiss lowlands. The nine landscapes were the result of a photo editing process combining three land-use types (arable crops, grassland and a mixture of both) and three proportions of ecological compensation areas (0%, 10% and 30%). The landscape photographs were randomly arranged on one page of a paper-based questionnaire which was sent to a random sample of 4000 Swiss households (non-farmers) and 500 farmers. The respondents (1376 non-farmers and 276 farmers) rated each landscape by attractiveness. Both non-farmers and farmers preferred a mixed land-use type or one dominated by arable crops over one dominated by grassland. Non-farmers’ preference ratings were highly influenced by the proportion of ecological compensation areas (ECAs) in the rated landscape: Non-farmers rated a landscape with a mixed land-use type and 30% ECAs highest, whereas farmers rated a landscape dominated by arable crops and 10% ECAs highest. The results indicate that heterogeneous landscapes (mixed land use, high proportion of ECAs) influence scenic beauty positively. Thus, farming practices and agro-environment schemes such as ECAs can have an impact on the visual attractiveness of a landscape.     

Amikacin therapy for Pseudomonas cellulitis in an Amazon parrot

Amikacin sulfate, an aminoglycoside antibiotic, was used successfully to treat a case of severe Pseudomonas cellulitus in an Amazon parrot. Side effects of polyuria and polydipsia occurred, but resolved without treatment 3 weeks after the antibiotic regimen. Amikacin sulfate was given at a dosage of 0.04 mg/g of body weight, IM, twice a day, based on antimicrobial sensitivity results. Amikacin sulfate is indicated for P aeruginosa cellulitis that is resistant to gentamicin sulfate. Although it is potentially nephrotoxic, it can be used successfully in birds without permanent clinically evident renal effects.     

Estimate of digestibility in dairy cows using an indicator method in comparison to the Hohenheimer feed value test

In order to measure the digestibility of feed with an indicator method two trials were realized on the dairy research farm "Karkendamm". The first trial was to test the suitability of TiO2 as an indicator to determine the digestibility in cows. The rate of recovery of the indicator was 98.8% (95.5%-101.9%). The concentration of TiO2 of the rectal samples in the morning (daily or every second day) corresponded very well with the values from total faeces collection. The samples taken in the evening showed lower concentrations. The estimation of digestibility of organic matter led to the same values with the total collection or the indicator method with morning samples. The digestibility derived from evening samples were 1.7-2.3%-units digestibility derived from evening samples were 1.7-2.3%-units lower in comparison to total collection. In the second trial the digestibility derived from the in vitro method "Hohenheimer-Futterwert-Test" and from a digestion trial with 30 cows using the indicator method were compared. The digestibility calculated from the date of the in vivo trial was 9.9%-units lower than the one from the "Hohenheimer-Futterwert-Test". The depression of digestibility was due to the variation in concentrate feeding between cows. If the cows got less than 8 kg concentrates the depression in digestibility was 1.9% when increasing the level of feeding one unit of maintenance requirement. If the cows got more than 8 kg concentrates the depression was 3.1%-units. It could be concluded that the "Hohenheimer-Futterwert-Test" underestimates the digestibility if the level of feeding is increased to a certain extent.     

基于机载LiDAR数据的农作物叶面积指数估算方法研究

叶面积指数(LAI)是农作物长势监测及估产的重要参数,激光雷达能够提供精确的农作物冠层结构信息,可弥补光学遥感在提取冠层结构信息方面的不足。因此,本文旨在挖掘激光雷达所能提取的农作物垂直结构信息,并研究冠层结构参数与农作物叶面积指数之间的关系,从而估算整个研究区的叶面积指数。首先,基于机载激光雷达数据提取平均高度(Hmean)、最大高度(H_(max))、最小高度(H_(min))、高度百分位数(H_(25th)、H_(50th)、H_(75th)、H_(90th))、激光穿透力指数(LPI)、回波点云密度、孔隙率(fgap)、叶倾角(MTA)等结构参数;然后,利用Pearson相关性分析法对以上参数与地面实测LAI进行相关性分析,并选择与LAI相关性高的参数;最后,对选择的敏感性参数进行回归分析,构建激光雷达参数与实测LAI的LiDAR-LAI估算模型,估算整个研究区的农作物冠层LAI。精度评价结果表明:预测LAI与实测LAI之间的相关系数为0.79,均方根误差为0.47,说明激光雷达所提取的农作物冠层结构参数可用于估算空间上连续、大面积的农作物LAI。     

Einfluss des Porenwasserdruckes auf die Zugfestigkeit von Bodenproben

Effect of pore water pressure on tensile strength Direct tensile testing with measurements of the pore water suction was used to investigate the relationship between tensile strength and suction. The tests were conducted on a till and a clayey soil, both homogenized. A closer view is focused on the relationship between material strain and the development of suction. Beyond, the factor χ of the effective stress equation for unsaturated soils by Bishop (1959), which was calculated by the data of tensile strength and corresponding matric suction is compared to the volumetric χ of the tested soil specimens. It could be shown, that the pore water pressure changes with strain. Therefore, not the initial suction of a soil is relevant for its failure but the actual one that can be measured in the failure zone at the moment of fracture. In addition the application of the volumetric χ in the effective stress equation compared to the χ derived from tensile testing leads to an 1.6 to 2.8 fold overestimation of the contribution of matric suction to soil tensile strength.     

马家塔露天矿生态复垦区土壤养分状况研究

本文系统研究了神东矿区马家塔露天采坑复垦区土壤养分状况,结果显示:复垦区土壤基本上为原始回填土,剖面层次不发育,成土程度很低;土壤机械组成以砾石、粗沙为主,含量高达90%。有机质、含碱解氮含量略高于未受扰动的原状土壤,但速磷、速钾含量均低于原状土壤,总体评价土壤属于养分贫乏型;成土程度低、养分含量少是农林业生产水平不高的主要原因。研究表明通过改良复垦工艺以及提高复垦区生产管理水平是提高土地生产力的主要措施。     

乳酸菌添加剂对青藏高原燕麦青贮品质的影响

[目的]研究乳酸菌添加剂对青贮燕麦发酵品质的影响,为燕麦的青贮提供技术条件。[方法]按0．005g／kg燕麦的添加量,将乳酸菌粉剂直接加入燕麦,采用捆裹青贮系统进行青贮。处理80d后,观察其感官特征并测定品质,与普通青贮燕麦和青刈燕麦进行比较。[结果]乳酸菌青贮燕麦的气味、色泽和手感均优于普通青贮燕麦,其pH值低于3．8,乳酸与乙酸的比值下降,乳酸占总酸的比例增加,DM、CP和Ash含量增加,NDF、ADF含量降低。[结论]乳酸菌添加剂改善了青贮燕麦的品质,所得燕麦属于优质青贮料。