خيارات البحث
النتائج 391 - 400 من 2,098
Potassium balance in crop rotation fields where slurry was applied
2011
Miseviciene, S., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst.
In this article, the results of research on WRI of LUA Juodkiškiai experiment field (1999 – 2003) are discussed. Fertilization and other factors influence over potassium fluctuation, its balance and leaching into drainage water during crop rotation are analysed. In order to evaluate the potassium balance and its quantity passed together with rainfall, seeds, fertilizers and take with the yield (secondary and primary production) was established in plant residues and drainage water. When fertilizing with liquid manure, potassium balance was negative while growing perennial grasses as much potassium was needed to mature their yield. The investigations established that potassium concentration in drainage water and its leaching was increased by precipitation during the research period, and it was reduced by the amount of this element taking out with yield. Soil geochemical environment had influence on the increase of potassium supply in soil. It was established that long-term fertilization with liquid manure had raised the potassium supply in soil. However, from an ecological point of view, potassium leaching did not cause any problems. In all treatments the potassium concentration in drainage water did not exceed permissible concentration.
اظهر المزيد [+] اقل [-]Laboratory-scale investigation of wastewater purification in filters with dolomite chippings media
2011
Kazakeviciene, J., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst. | Askinis, S.
The article explores the possibility of the vertical filter instead of sand used for more coarse media for recharging, which would reduce the risk of freezing and clogging and ensure the cleaning of wastewater up to the limits. For this purpose the dolomite chippings have been chosen for research. It was equipped with two 0.2 m2 filters area: one of their models was 0.4 m dolomite chippings layer, the other 0.8 m. They have been loaded by the wastewater after the primary cleaning in the septic system. Medium contamination in organic pollutants have been 358 mg O2 LE-1, Ptotal 14.6 mg LE-1, Ntotal 108.5 mg LE-1, suspended solids 161.1 mg LE-1, pH 7.8. Hydraulic load of the filters was 0.03 m3 mE-2 dE-1. Wastewater flowing through a vertical sand layer by an average of 98.2% of the organic pollutants to be detained. The average of effluent wastewater contamination of the filter was 22 mg O2 LE-1. In the filter with dolomite chippings media can be cleaned wastewater with pollution reaches 500 mg O2 LE-1. The maximum load of organic pollutants is 14 mg O2 LE-1. The filtration path length to ensure wastewater cleaning up tolerance 0.8 m. In the filter with dolomite chippings media Ptotal is cleaned even 87.0%, Ntotal only 13.0% efficiency.
اظهر المزيد [+] اقل [-]Influence of the vertical filter media on phosphorus removal from the domestic wastewater
2011
Kazakeviciene, J., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst. | Askinis, S., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst.
Modelling of the domestic wastewater treatment and removal of the Ptotal in the vertical filters with the sand, dolomite powder and dolomite chippings each separately used as a filter media was performed. Six filter models taking 0.2 m2 each were installed. The length of the filtration path was equal to 0.8 m in three of these models and 0.4 m in the other three models. The hydraulic load on the filters was equal to 0.03 m3 mE-2 dE-1 in 2008, and it was equal to 0.06 m3 mE-2 dE-1 in 2009. The domestic wastewater which had undergone the pre-cleaning in the septic systems was poured into the models. Their average pollution with the Ptotal reached 14.6 mg LE-1 in the first year and 9.2 mg LE-1 in the second year. When the filtration path was equal to 0.8 m and the hydraulic load was equal to 0.03 m3 mE-2 dE-1, the Ptotal was removed from the wastewater with the efficiency of 99.9% in the dolomite powder filter. In the filter models with the sand and dolomite chippings, the Ptotal was removed with the same efficiency of 87.7%. When the hydraulic load doubled, the efficiency of P removal decreased to 59.8% in the sand filter and down to 45.7% in the dolomite chippings filter. When the hydraulic load reached 0.06 m3 mE-2 dE-1, only the dolomite powder filter could ensure the adequate cleaning of the domestic wastewater up to the allowable norms.
اظهر المزيد [+] اقل [-]Visual quality evaluation approaches of sacral landscape of Latgale
2011
Pidza, M., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aesthetic quality of landscape is one of the most threatened values in our environment. The methodology chosen to evaluate the landscape for the first time has to be precise and effective. The objective of this study was to find the most appropriate method for the first time evaluation of sacral landscapes. The paper compares two methods – the Scenic beauty estimation method, and the Q sorting method for evaluating the scenic beauty. Comparison of the two methods was made in the winter of 2010 – 2011. The Scenic beauty estimation method is effective for getting a quick estimation of general scenic beauty. The Q method gives the estimation of general scenic beauty and the explanation of perception priority. The visual quality is deeply connected with perception. Placing perception in numbers leaves some doubt, but it is quite an effective way of observing the main visual qualities in the perception of spectators. Both methods give the first impression of the landscape elements. But Q method gives more significant results than the Scenic beauty estimation method.
اظهر المزيد [+] اقل [-]Evaluation of art interventions for the public space in Latvia since the 1980'ies
2011
Alle, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The main aim of this paper was to investigate the development of art for the public space as a result of the historical impact through which the artworks have been evaluated. The context of social, ideological and economical changes is related. The author examined principal art practices in the public domain and discussed the main types of artworks created for the public space in Latvia in the period between 1980 and 2010. Seven art events were selected to analyze the main occurrence of historic periods as certain paradigms. Empirical and qualitative data collection methods were used to clarify the development of art for the public space in the Latvian landscape taking into account the historical point of view. According to the typology of artworks the following features were investigated: the aim, the location, the form and the size, and the function of artworks. The majority of art for the public space occurred in the city environment and the financial support of the project played an important role.
اظهر المزيد [+] اقل [-]Review of the pear scab caused by Venturia pyrina
2014
Sokolova, O., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia State Inst. of Fruit-Growing, Dobele (Latvia) | Morocko-Bicevska, I., Latvia State Inst. of Fruit-Growing, Dobele (Latvia) | Bankina, B., Latvia Univ. of Agriculture, Jelgava (Latvia)
European pear scab (Venturia pyrina Aderh.) is common and economically important disease in commercial orchards in most of the pear (Pyrus communis L.) growing areas worldwide. Studies on pear scab pathogen V. pyrina diversity in general and among different geographical regions are scars at an early stage. In the limited number of studies reported so far, some attempts have been made to characterize and define races or biotypes of V. pyrina and new biotypes co-adapteted to specific cultivars have been recorded recently. Despite the long history, worldwide distribution and increasing economic significance of the European pear scab, the research on control methods, and pathogen biology and disease epidemiology that could aid to develop more effective and also alternative to fungicide application control methods are still limited. Mechanisms of European pear resistance to scab remains uncertain and currently only one major resistance gene Rvp1 has been identified and characterised. Although the disease is important in many European countries, breeding programs of pear scab-resistant varieties are still under development. In this paper we provide an overview on V. pyrina, its significance and distribution, control methods and current scientific progress in understanding of the pathogen and the disease. Overview of literature on V. pyrina characterization, ecology, biology and diseases epidemiology from Latvia and other countries has been used for the study.
اظهر المزيد [+] اقل [-]Agrobiological estimation of introduced grape varieties in the conditions of the South-East of Kazakhstan
2014
Manarova, D., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Kazybaeva, S., Kazakh Scientific Research Inst. of Fruit Growing and Viticulture, Almaty, Kazahkstan
Assortment improvement is a natural process of updating varieties and improving the quality of variety assortment. The article presents the results of studying the introduced grape (Vitis vinifera) varieties in the conditions of the southeast of Kazakhstan, in particular in the bottom-mountain area of Almaty region. The beginning and the end of the main phenological phases passing for the vegetative period in a grape plant directly depended on climatic and weather conditions of this district. It is established that varieties ‘Kuibyshevsk early-maturing’, ‘Iyulsky’ and ‘Priusadebny’ have a good degree of eyes wintering buds and are able to give a yield of high quality in this area in comparison with recognized variety ‘Almaty early-maturing’.
اظهر المزيد [+] اقل [-]Potato minitubers technology – its development and diversity: a review
2014
Dimante, I., Latvia Univ. of Agriculture, Jelgava (Latvia);State Priekuli Plant Breeding Inst., Priekuli, Priekuli parish, Priekuli municipality (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
The study consists of literature review on potato (Solanum tuberosum L.) initial seed material – minitubers production. This paper covers aspects of healthy potato microplants production techniques and subsequent greenhouse minitubers production methods. The diversity of conventional minituber growing techniques (on solid medium in greenhouses) is discussed. Review showed that obtained minitubers number depends on growing methods and variety. Physical manipulation during in vitro phase could have positive effects on minitubers yielding capacities.
اظهر المزيد [+] اقل [-]Table potato variety 'Teele' with high yielding and late blight resistance
2014
Taehtjaerv, T., Estonian Crop Research Inst., Jogeva, Jogeva vad. (Estonia);Estonian Univ. of Life Sciences, Tartu (Estonia) | Tsahkna, A., Estonian Crop Research Inst., Jogeva, Jogeva vad. (Estonia) | Runno-Paurson, E., Estonian Univ. of Life Sciences, Tartu (Estonia) | Maend, M., Estonian Univ. of Life Sciences, Tartu (Estonia) | Tamm, S., Estonian Crop Research Inst., Jogeva, Jogeva vad. (Estonia)
The characteristics of the new potato cyst nematode (Globodera rostochiensis, pathotype RO1) resistant, medium ripening potato variety ‘Teele’ (‘Cinja’ ´ ‘Paola’) developed at the Estonian Crop Research Institute (ECRI) is discussed in this paper. The variety ‘Teele’ was included in Estonian and European Variety List in 2013.The variety ‘Teele’ passed the preliminary, dynamic and final trials in 2008 - 2012 at the ECRI, where it was compared with standard varieties ‘Maret’ (early), ‘Piret’ (medium) and ‘Anti’ (late). The official trials in Estonia and the technical examination (DUS test) in Czech Republic were carried out in 2011 – 2012. Potato cyst nematode (Ro1) and wart (Synchytrium endobioticum (Schilbersky) pathotype 1 (D 1)) resistance of the new variety were determined in Poland in the Plant Breeding and Acclimatization Institute. Tuber yield and tuber weight of the variety ‘Teele’ were equal to ‘Maret’ and ‘Anti’ but higher than ‘Piret’. The number of tubers per plant was equal in all standard varieties. Tuber yield and yield of marketable tubers of dynamic trials present the medium ripening of the variety ‘Teele’. The potato variety ‘Teele’ had good quality characteristics (shallow eyes, regular shape) and good culinary traits of table potato variety. It had a relatively good resistance to late blight (Phytophthora infestans) (field resistance), overcoming standard varieties ‘Maret’ and ‘Piret’.
اظهر المزيد [+] اقل [-]Relationship between body condition score, milk productivity and live weight of dairy cows
2014
Petrovska, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Live weight and body condition are indicators for dairy cow’s (Bos taurus) health, milk productivity and reproduction. Live weight and body condition are defined by genetic and non-genetic factors. These factors are dependent on dairy cows growing and welfare. The aim of research was to analyze body condition relationship with milk productivity and live weight. Data were collected from 49 different breed and lactation dairy cows. Research location was Latvia University of Agriculture Research and Study farm ‘Vecauce’. Data were collected from October 2013 to January 2014. Body condition score of all cows decreased from 2.8 ± 0.05 to 2.5 ± 0.04 points in research period. Milk yield increased from 35.6 ± 0.79 kg in the 1st recording to 40.9 ± 1.12 kg in the 2nd recording. Milk yield decreased in the 3rd recording (p is less than 0.05). Fat content was the lowest in the 2nd recording (35.5 ± 0.09 g kgE-1). Protein content was significantly different in the 1st and 2nd recordings (p is less than 0.05). Somatic cell changes were not significant. Body condition decreased of older lactation cows, but milk yield increased at the same time. Milk yield was significantly the greatest in red breed group, compared with Holstein black and white cows (51.1 ± 3.21 kg vs. 41.4 ± 0.78 kg; p is less than 0.05). Body condition score significantly affected live weight in such body condition score groups: less than 2.5 points, 2.75 to 3.0 points. Effect was not significant on live weight in body condition score 3.25 less than group. Milk productivity and quality traits were not affected by the body condition score (p is less than 0.05).
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