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Relationship of birch (Betula sp.) plywood bending properties determined according to the European standards EN 789 and EN 310
2007
Zudrags, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Tuherm, H., Latvia Univ. of Agriculture, Jelgava (Latvia)
The manufacturers of wood-based panels are interested to get easy and cheap method for determination of characteristic values of panels. The correlation between European standards EN 789 and EN 310 tests results can be used as an alternative procedure for determination of characteristic values of bending properties. The correlations between two results of bending properties determined by testing methods of European standards EN 789 and EN 310 are studied in this paper. The ratio of EN 789 test results divided with EN 310 test results (ratio of EN 789/EN 310), depending on panel thickness and glue type, was examined. Samples from 846 panels of birch (Betula sp.) plywood with thickness ranging from 6.5 to 30 mm and two glue types - phenol formaldehyde and melamine urea formaldehyde resin - were used for verification of the correlations. The results show that the panel thickness influences the ratio of EN 789/EN 310 and the highest ratio were found between 12 and 15 mm panels. When the panel thickness is increased or decreased, the ratio of EN 789/EN 310 decreases significantly. The regression equations for each thickness of plywood are presented. The difference between plywood glued with phenol formaldehyde and melamine urea formaldehyde resin glues was not found.
Показать больше [+] Меньше [-]The lichenoindicative evaluation of oak woodland key habitats
2007
Straupe, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Donis, J., Latvian State Forestry Research Inst. Silava, Salaspils (Latvia)
This article presents the description of oak woodland key habitats and their importance in the maintaining of biodiversity as well as a necessity of management and monitoring. The lichens Lichenes and its percental cover features have been described. The exposition of lichen species depending on the cardinal points has been analysed. The article presents the characteristics of ecological indicators of lichens in the objects. The lichenoindicative evaluation and comparison of oak woodland key habitats in Latvia have been carried out.
Показать больше [+] Меньше [-]Maintanance peculiarities of polder systems in Lithuania during the last decade
2007
Bastiene, N., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst. | Saulys, V., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
Basing on the economic, ecological and social points of view, the polder systems in the Nemunas lowland are considered as unique, requiring a great deal of annual state subsidies. According to the land-improvement programme, during the period of 2006-2008, Lithuanian polder system are planned to be yearly granted 2.15 million euro from the State budget, whereas the local administration of Silute district, which is exploiting the polders of the Lower Nemunas - more than half of the sum (63%). The article includes the analysis of exploitation expenses and statistical estimation of the Lower Nemunas' polders during the period of 1996-2006 as well as the investigation of the funds distribution on routine repairs, reconstruction and maintenance work. The average annual expenses on the pump stations, dikes, ditches and roads during the research period were determined. The analysis of the previous decade's expenses shows that the statistical average of the expenditure on the polder systems of Silute district amounts to 0.68+-0.13 million euro a year. The yearly renovation of polders depreciation should be obviously awarded a grant of the amount not less than 0.72 million euro.
Показать больше [+] Меньше [-]The effect of slurry application on the quality of ground water
2007
Miseviciene, S., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
The paper deals with the analysis of ground water quality when slurry is applied on crop rotation fields. The investigations were carried out in Juodkiskis study object of the Lithuanian Institute of Water Management in 1995-1998. According to the average concentrations, the quality of ground water samples taken from the borehole arranged in Juodkiskis test field was good compared with hygienic rates for drinking water. All samples taken for the estimation of ammonia and nitrate nitrogen amount were of good quality. However, nitrate-N concentration increased to 5.5-5.6 mg lE-1 in some periods. Having compared actual phosphate phosphorus concentrations with the allowable ones it may be confirmed that ground water is not polluted with phosphates as phosphate phosphorus concentrations did not reach P-load permissible for drinking water. Considering the correlation connection between ground water level and chemical compounds concentrations, it was determined that ammonia nitrogen and phosphorus compounds concentrations were influenced by ground water level fluctuations (correlation coefficient r = 0:54 and r = 0:62). (Given r values correspond to the reliability criterion tactual is greater than ttheor95%). Lower ground water levels in a borehole determine higher N - NH4**+, P - PO4**- and Ptotal concentrations. No relation between nitrate nitrogen (N - NO3**-), Ntotal and K**+ and ground water level fluctuations was determined.
Показать больше [+] Меньше [-]Social capital in Pieriga region, [Latvia]
2007
Igaune, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
At rural enterprises, besides the traditional resources - natural, financial, and human capital - there is some other kind of capital - it is social capital. Foreign scientists have done a lot of researches on it. The nature of social capital and its role in economics is not much studied in Latvia. The present scientific article reflects consumptions on social capital by different foreign scientists. The World Bank as an institution has also approached to the research of social capital. It studies social capital at institutions. The World Bank describes the social capital of two kinds. The scientific article characterizes Pieriga region. Rural enterprises and businessmen of agricultural, industrial and service branches in Pieriga region have been enquired. By the results of the enquiry, the presence of social capital in rural enterprises and its impact on their development have been analysed.
Показать больше [+] Меньше [-]Features and likenesses of information models of animals registration
2007
Smirnova, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Arhipovs, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The process of creation of the informative systems based on the account of such animals as horses, sheep and goats is analyzed in the work. Three structural models are created and their comparative analysis is conducted. As a result of analysis the general elements of structures, characteristic to each model were found. The Meta modelling approach to facilitate the system was used. The system has a more abstract structure and allows dynamically to adding not only the animal specimens but also new types of attributes in fly during runtime. Recompilation of the system is not required there is no necessity of the analytical restructuring of the model, the absence of type explosions is guaranteed in a database because not a new table-type, but a new record in one or two tables is added.
Показать больше [+] Меньше [-]Fungicide application effect on yield and quality formation of winter oil-seed rape (Brassica napus L.)
2007
Balodis, O., Latvia Univ. of Agriculture, Jelgava (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia) | Bankina, B., Latvia Univ. of Agriculture, Jelgava (Latvia) | Vitola, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
Sowing area under oil-seed rape (Brassica napus L.) has grown dramatically only during the last 10 years in Latvia. Lack of knowledge and research on different issues is observed. The aim of our research, started on season 2005/2006 in Research and Study farm Vecauce, was to investigate the influence of split fungicide (1st dose of fungicide Juventus 90 s.c. (Metconasol 90 g LE-1) used as growth regulator in autumn at the 4-6 leaf stage and the 2nd dose at the growth stage 63-64) application. Winter rape development in autumn, winterhardiness, disease incidence, and yield and its structure elements were estimated. Totally 13 cultivars were used in the trial, but several assessments were done for 5 cultivars. Additional objective was to evaluate economic effect of fungicide use. Winter rape biometrical indices were influenced by the fungicide application in autumn period and by used cultivar. Fungicide treatment in autumn increased also the rape winterhardiness. Our research for the first time indicated that Phoma stem canker could become a problem for rape growers in Latvia. Fungicide use (in growth stage 63-64) decreased incidence of this disease a little (on average by 5%). Fungicide treatment according to applied scheme increased the average seed yield (check 5.37 t haE-1, with fungicide 5.80 t haE-1; LSD0:05 = 0:18 t haE-1), but impact on yield structure elements was mainly non-essential. Despite agronomic improvements, economic calculation showed that on average fungicide use in 2006 was not pro table. Research should be continued for specification of conclusions.
Показать больше [+] Меньше [-]Spring barley yield, grain quality and factors affecting them
2007
Braziene, Z., Lithuanian Inst. of Agriculture, Rumokai, Vilkaviskio reg. (Lithuania). Rumokai Research Station | Kaunas, J., Lithuanian Inst. of Agriculture, Rumokai, Vilkaviskio reg. (Lithuania). Rumokai Research Station
Effects of nitrogen fertilizers and weather conditions on spring barley (Hordeum vulgare L.) yield and grain quality were investigated at the Rumokai Experimental Station of the Lithuanian Institute of Agriculture in the period of 1998-2000 and 2003-2004. The soil of the experimental site was Hapli Epihypogleyic Luvisol. Analyses were made with fertilisers rates of 0 and 90 kg haE-1. The data of analyses indicated a positive and reliable correlation between the yield of spring barley and the amount of precipitation in May (rate of correlation was 0.70**) and a negative and reliable correlation with the amount of precipitation in June and July (rates of correlation were -0.80** and -0.29* respectively). A reliable though weak correlation was found between the application of nitrogen fertilisers and the yield of grains. The amount of precipitation in April and the spring barley leaf diseases had a considerable negative effect on 1000 grain weight and grain size. Strong correlation was identified between the amount of precipitation in May and June and the protein content in grain. Nitrogen fertilisers promoted protein accumulation in grain.
Показать больше [+] Меньше [-]The evaluation of effectiveness of Rhizobium leguminosarum in field beans (Vicia faba)
2007
Ansevica, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dubova, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The vegetation pot experiment was conducted at the Institute of Soil and Plant Sciences of the Faculty of Agriculture of the Latvia University of Agriculture. The aim of the experiment was to investigate the effectiveness of five Rhizobium legumonosarum strains stored in the period from the 18th of August till the 20th of October 2006 in the collection of the Latvia University of Agriculture. Three of the five mentioned Rhizobium legumonosarum strains were included in the international Rhizobium database IBP World Catalogue of Rhizobium collections. Taking into consideration the results of the experiment it has been pointed out that all Rhizobium strains were active and inoculated plants formed nodules on the roots. Inoculation with Rhizobium strains increased the proportion between shoots and roots' weight. It has been found that the dry matter content of the inoculated plants increased in comparison with the untreated ones. In addition, negative correlation between the dry matter and the protein content has been observed.
Показать больше [+] Меньше [-]Variability of wild martagonlily (Lilium martagon L.) in the region of Kurzeme, [Latvia]
2007
Balode, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this research is to evaluate the variability of the martagonlily (Lilium martagon L.) found in the wild in the west of Latvia. Latvia is situated in a nature zone between the vegetation of Northern and Central Europe. The country distinguishes itself with a large variety of flora and fauna (total approx. 27, 7 thousand species). The genus Lilium L. includes approximately a hundred species, subspecies and varieties of species. In northern Europe, one of the best known and longest cultivated of lilies is L. martagon L. It is distributed across the largest growing area of most species - from western Portugal throughout Europe and Asia. To evaluate the survival potential of L. Martagon L. in Latvia, research was carried out in locations at Kurzeme - districts of Ventspils, Kuldiga, and Tukums. The results indicate that the diversity in genotypes varies according to location and distribution. There are differences in phenotypes and colour variability from pale to bright violet-pink. Diameter of flower varies between of 3.5 to 6.0 cm. The height of these plants varies up to 114 - 130 cm. The flowering time is in June and July. Wild martagonlily found in these regions is growing in calcareous soils among shrubs in river valleys and semi-shaded deciduous forests. This particular martagonlily is hardy and disease resistant and is recommended as a donor in breeding programs.
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