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Possibilities of application of orthophoto maps in determination of land degradation
2016
Cintina, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Baumane, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
Aim of the paper is to explore the possibilities of application of orthophoto maps in determination of land degradation. One of the forms of remote sensing is aerial photography. Orthophoto maps are made from aerial photography with specialized software orthophoto maps were analysed in perspective for several years – from 2005 to 2011.The results are based on the expert. With each year possibilities of application of orthophoto maps are expanding. During the research, data of survey and SWOT analysis of determination of land degradation by orthophoto maps. The study results prove that based on orthophoto maps mainly, it can be detected the following land degradation processes – agricultural land overgrowing with bushes and abandonment of built-up areas.
显示更多 [+] 显示较少 [-]Scenic roads in Latvia
2016
Vugule, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Turlaja, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
United States of America and European countries like Great Britain, Germany, Norway have long traditions in the development of scenic roads, special scenic routes for tourists, National Scenic Byway Programs. They have set criteria for road landscape planning and design, discussed the economic value of scenic roads. Scenic roads are also important for tourism, as well as visual and cultural countryside development in Latvia. Planning regions and regional communities in Latvia have strategic development plans and spatial plans. All of them include high value landscapes and protected, scenic territories. Some scenic roads are defined in these documents, but criteria for scenic road designation are set in every region individually. There are unlisted roads with high aesthetic value which could be protected. Common methods, criteria for the assessment of road landscapes and scenic road designation in Latvia are not developed. The aim of the research was to evaluate and understand the present situation of scenic roads in Latvia. An online questionnaire was carried out in order to find out peoples’ opinion about the road landscape quality. Spatial plans of regional communities and planning regions were examined. A field study of two sections of scenic roads was carried out. The research project was carried out from December 2014 to December 2015. Results show that current road landscape has a potential for development, and it needs improvements. The study gives a general insight into the scenic road situation in Latvia and provides basis for further research on scenic road planning and management.
显示更多 [+] 显示较少 [-]The research of hydrodynamic processes in rehabilitating rivers of Lithuania
2016
Baublys, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Dumbrauskas, A., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Geguzis, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
From the 1920s through the 90s, most streams in Lithuania were channelized. Channelization is the deepening, clearing and straightening of meandering streambeds resulting increase of water flow velocity and the rate at which water drained away from agricultural land. Channelized and straightened streams have better hydrodynamic parameters and different morphological properties, but at the same time that caused more unfavourable conditions for natural biodiversity along stream beds and banks reducing the amount of vegetation which means less food and cover for wildlife. Most of West European countries have a good practice for restoring of channelized rivers. This experience is quite new in Lithuania and starting with pilot projects. The most important purpose of these projects is to choose the appropriate restoration measures and evaluate their effectiveness under conditions of dense channel network and tile drainage systems in Lithuania. Two channelized streams, selected for a pilot project are discussed in this paper. The main purpose is to restore stream meandering with minimal efforts allocating artificial obstructions at a right place and reach the necessary stream velocities to initiate the stream bed deformation. For this purpose detailed channel geometry data were collected and 1D hydrodynamic model applied. The results of different scenarios revealed that installed obstructions can accelerate deformations processes initiate the meandering process and at the same time it will not have any significant effect on the agricultural land along restored stream.
显示更多 [+] 显示较少 [-]The abandoned block-cut peat extraction field influence on the natural raised bog hydrological regime
2016
Purmalis, O., University of Latvia, Riga (Latvia);Institute for Environmental Solutions, Riga (Latvia) | Grinfelde, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Valujeva, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Burlakovs, J., University of Latvia, Riga (Latvia);Linnaeus Univ. (Sweden). Faculty of Health and Life Sciences
Peat is still mined in many parts of the world for production of peat substrates and energy. Many peatlands were affected by drainage in the past also for forestry and agricultural needs. Nowadays a raised attention to peatlands is focused, especially to drained peatlands due to their carbon reserves and their potential influence to the climate on the one hand, but on the other hand - due to raising awareness on protection of environment, habitats and biotopes. There are many examples on restoration activities in peatlands found worldwide, especially their water regime is the subject of regulation, which plays the major role to bring back original functions. In most cases in Latvia as the aim for protection and restoration of degraded peatlands was protection of EU biotopes and habitats. Of course, peatlands play an important role in emissions of the greenhouse gases CO2, CH4 and N2O, produced during mineralization of the drained peat organic matter. In literature, we can find only few cases where hydrological regimes are described for natural raised as well as restored block-cut peat extraction fields. This research analyses block-cut peat extraction field water level fluctuation influence on naturally raised bog hydrological regimes. Hourly data is analysed for six groundwater monitoring wells as well as for determination needs of water level fluctuations in excavated peat quarry as a response to precipitation.
显示更多 [+] 显示较少 [-]Weather impact on the household electric energy consumption
2016
Jakusenoks, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Laizans, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the article is to ascertain the interaction between weather conditions and electric energy consumption in the Latvia household. The electric energy consumption data in the Saurieši village, Riga region, Latvia, for the year 2012 were collected, and the climate data for the same period including the duration of the sun-shine, ambient air temperature, precipitation intensity, and wind speed were obtained. The research hypothesis that there is strong relation between weather conditions and electric energy consumption was proved partially – there is rather strong correlation between household electric energy consumption and air temperature (r = 0.91), and medium correlation between household electric energy consumption and precipitation (r = 0.61), as well as between household electric energy consumption and duration of the sunshine (r = 0.67). Correlation found between weather conditions and electric energy consumption in the household allows to forecast the trends in energy consumption based on weather measurements, and even to use the weather forecasts for electric energy future demand trends development. The equations developed explain the household energy consumption patterns in Latvia with its geographical location and economic conditions, but the methodology developed can be applied for any region if necessary data are available.
显示更多 [+] 显示较少 [-]Impact of agroecological conditions on the Hagberg falling number of winter wheat grain
2015
Linina, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ruza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Grain quality adversely affects price and consumer acceptance of finished products. Hagberg falling number (hereinafter falling number) is one of the most important grain quality indices of winter wheat (Triticum aestivum L.), especially in humid climate countries (Northern Europe). Field experiments with winter wheat cultivars ‘Bussard’ and ‘Zentos’ were conducted at the Latvia University of Agriculture, Study and Research farm ‘Peterlauki’ during a three year period (from 2009/2010 to 2011/2012). The aim of this investigation was to clarify variation of the falling number (FN) depending on cultivar, weather conditions and different rates of nitrogen (N) fertilizer applied (N 60, N 90, N 120, N 150) on fresh and stored grain (60, 120 and 360 days). During the investigation period, wheat ‘Zentos’ grain was characterised by a higher falling number compared with ‘Bussard’ grain. The falling number values for fresh grain for both wheat varieties studied were high: averagely 301 s for ‘Bussard’ and 359 s for ‘Zentos’, and reached demands set for grain suitable for bread baking. Differences in the falling number values were noted when freshly harvested winter wheat grain was compared with grain stored for 60 or 120 days and 360 days. During storage (60 – 360 days), α-amylase activity in winter wheat grain reduced and the FN increased on average up from 94 to 110 s. The falling number significantly depended on weather conditions, grain storage period and nitrogen fertilizer. The higher was the falling number of freshly harvested grain, the higher its increase during grain storage of compared to freshly harvested grain with a lower falling number value.
显示更多 [+] 显示较少 [-]The effect of planting density on potato (Solanum tuberosum L.) minituber number, weight and multiplication rate
2015
Dimante, I., State Priekuli Plant Breeding Inst., Priekuli, Priekuli parish, Priekuli Municipality (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
The study was aimed to investigate the effect of potato (Solanum tuberosum L.) in vitro plantlets planting density under greenhouse conditions on obtained minitubers number per unit area, multiplication rate and their weight distribution. Three cultivars of different maturity (‘Monta’ – early maturity, ‘Prelma’ – medium early and ‘Mandaga’ – medium late maturity) were used for the study. In vitro plantlets were planted in a greenhouse of State Priekuli Plant Breeding Institute, Latvia in 2014 at four planting densities (PDs) 63 plants per square m, 95 plants per square m, 142 plants per m2 and 184 plants per square m respectively. Fertilized peat was used as a substratum. Significant effect of planting density (p is less than 0.001) and cultivar (p is less than 0.01) was found on analyzed yield parameters. Increased planting densities resulted in increased minitubers number per square m (from 272 minutubers mE-2 at PD 63 plants mE-2 to 414 minutubers mE-2 at PD 184 plants mE-2), decreased multiplication rate (4.3 to 2.7 minitubers per planted plant) and mean fresh weight of minitubers (from 20.26. g to 12.11 g). The highest increase of minitubers number per m2 was observed within size (weight) range 3 to 5 g. Minitubers number per m2 increase within bigger size ranges (5 to 10 g, 10 to 20 g) was less pronounced. Slight insignificant (p=0.330) decrease of minitubers number is greater than 20 g was observed in relation of planting density increase (112 minitubers mE-2 at PD 95 plants mE-2 to 84 minitubers mE-2 at PD 184 plants mE-2).
显示更多 [+] 显示较少 [-]The effect of double inoculation on the broad beans (Vicia faba L.) yield quality
2015
Dubova, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Senberga, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Legumes (Leguminosae) are one of the most widely grown crops in the world after cereals (Poaceae). They are not only an important source of protein in food and feed, but also a significant component of different agrosystems. The N2 fixation by legumes is of great importance in nutrient management and sustainable economy of nitrogen. Legume productivity largely depends on a successful formation of symbiosis between the plant and soil microorganisms. The most important among those are rhizobia and mycorrhiza fungi. The field experiment was carried out at the Institute of Soil and Plant Sciences, Latvia University of Agriculture in 2014 to evaluate the influence of double inoculation using rhizobium leguminosarum and mycorrhiza fungi preparation on yield formation of broad bean V. faba L. var. major Harz ‘Bartek’. The bean seeds were treated with rhizobia and/or mycorrhiza fungi before sowing. Seeds were treated with rhizobia by soaking in bacteria suspension for 30 minutes directly before sowing. Mycorrhiza fungi preparation was added in soil under seeds before sowing. Plant height, fresh and dry weight and the weight of nodules were measured at the beginning of broad bean flowering (BBCH 60-61). rhizobium leguminosarum response to double inoculation differed between the strains. Rhizobium leguminosarum strain RL407, isolated from Vicia faba, was shown to be the most appropriate strain used for inoculation of broad bean seeds. Bean seed double inoculation increases the protein content significantly comparing to single inoculation using mycorrhiza fungi preparation.
显示更多 [+] 显示较少 [-]The changes in nitrogen content in soil depending on winter wheat (Triticum aestivum L.) fertilizing system
2015
Skudra, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian Rural Advisory and Training Centre, Ozolnieki parish, Ozolnieki Municipality (Latvia) | Ruza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The objective of this study was to evaluate the main plant nutrient: mineral nitrogen (NH4 + -N and NO3 -N) dynamic in soil under fertilizing for obtaining high grain yields of winter wheat (Triticum aestivum L.) and to determine relationships between nutrient uptake and winter wheat productivity. The field study was carried out at the Research and Study farm ‘Vecauce’ of the Latvia University of Agriculture for two years 2012/2013 and 2013/2014 with winter wheat variety ‘Kranich’. Different nitrogen application rates (0, 85, 153, 150, 175, 180 and 187 kg haE-1) and timing were used for winter wheat. The content of nitrates NO3 -N and ammonium nitrogen NH4 -N was determined in the soil layers 0-0.20 m, 0.20-0.40 m, 0.40-0.60 m. Nitrogen management strategy during the plant growth period based on soil Nmin evaluating can improve N use efficiency and reduce environmental contamination. The maximum of mineral nitrogen content in soil in the vegetation period was observed at the beginning of stem elongation with a tendency to decrease. A significant impact (p is less than 0.05) of nitrogen fertilizer application was noted on the mineral nitrogen content in soil layer 0-0.20 m deep in both trial years. The increasing doses of nitrogen fertilizer raised the amount of mineral N in the soil profile. The significant impact (p is less than 0.001) of nitrogen application and year conditions was observed on grain yield. Close positive correlation significant at 99% probability level was observed between the grain protein content and nitrogen concentration mostly in all soil layers, but it was not found between the grain yield and nitrogen content.
显示更多 [+] 显示较少 [-]Light - emitting diodes (LEDs) for higher nutritional quality of brassicaceae microgreens
2015
Vastakaite, V., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Virsile, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this study was to investigate the effect of industrially designed light-emitting diode (LED) lamp lighting on the nutritional quality of Brassicaceae microgreens. Red pak choi (Brassica rapa var. chinensis ‘Rubi F1 ’), tatsoi (Brassica rapa var. rosularis) and mustard (Brassica juncea L. ‘Red Lion’) were grown in a greenhouse (20±2/18±2 °C) during winter season, and the solar daily integral (DLI) was ~3.46±1.16 mol mE-2 dE-1. The light spectra of lamp consist of 8 violet (420-430), 16 blue (460-470 nm), 8 orange (610-615 nm), 3 red (620-630 nm), 56 red (660-670 nm), 8 white (contain blue (400-500 nm), green (500-600 nm) and red (600-700 nm)) LEDs. The treatments of ~150 and ~250 µmol m-2 sE-1 LED irradiance levels (LED 150 and LED 250) for 16 h dE-1 in comparison with high pressure sodium (HPS) lamps (~150 µmol mE-2 sE-1) as a control were performed. Photophysiological response to the artificial light varied among Brassicaceae species. Microgreens treated with LED 150 and LED 250 were significantly (P is less than or equal to 0.05) shorter and formed smaller hypocotyls. The photooxidative changes were evoked by both lighting treatments and led to higher phytochemical (phenols, ascorbic acid, flavonols, anthocyanins) and mineral element (Ca, K, Mg, Na, P, Fe, Zn) contents, and the DPPH and ABTS free radicals scavenging activities in all microgreens. Significantly lower content of nitrate was obtained with LED 150 treatment. Finally, LED lamps have the potential to be used as the main light source for growing high nutritional quality microgreens in greenhouses.
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