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2018, Vol. 16, No. 3

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Nüüd näidatakse 1 - 20 31
  • Kirje
    Changes in composition and spatial distribution of knowledge-based economy in rural areas of Latvia
    (2018) Rivza, B.; Kruzmetra, M.; Sunina, L.
    One of the features in the 21st century is growth of knowledge - based economic sector, which is referred as n ew growth theory. New growth theory reflects the attempt to understand the role of knowledge and technology in driving productivity and economic gr owth. In this view, key factors are investments in research and development, education and training and new managerial work structures. The aim of research is to estimate the composition and geographic location of knowledge economy and its perspectives in rural areas of Latvia in post - crisis stage. A special focus was placed on the mentioned processes in territorial units of the regions – municipalities , as the life of residents is influenced not only by national policies, but also by on - going processes in the administrative territories of local governments. The Eurostat classification of industries was used for the analysis of c hanges in composition and spatial distribution of knowledge - based economy. D ata were processed by quantitative and qualitative stat istical analysis, as well as grouping methods. The analysis of the information allows concluding that: municipalities with high and medium - high business is increasing and the business directions with bioeconomic features are the fastest growing ones in ter ms of composition. It must be stated that the economic growth in the rural territories was greatly affected by the quality of local governance and the fact that local community residents’ readiness for active, innovative and inclusive action is strengthene d.
  • Kirje
    Effect of alternative sources of input substrates on biogas production and its quality from anaerobic digestion by using wet fermentation
    (2018) Krištof, K.; Gaduš, J.
    The aim of the study was to confirm the suitability of alternative input substrates for production of biogas in order to decrese the need of utilization of high quality maize silage. All of the experiments were conducted by employement of wet fermentation process in mesophilic conditions (temperature in fermentor 40 ± 1 °C ) in experimental fermentor with volume 5 m 3 . The exp eriments were realised in operating conditions of biogas station designed for utilization of agricultural biowaste. The experiments were divided into two alternatives (I and II cycle) and one controle input substates. In the first alternative (I cycle) was daily dosage formed by 33 kg of Amaranth and 250 L of controle manure mixture. In this cycle, more than 3 – times greater specific production of biogas was observed with average methan content 63.9% in comparison with controle manure mixture (80 : 20%, liquid manure and manure). In the second alternative (II cycle) was daily dosage formed by 19.5 kg of sugar beer cuts, 3.3 kg of maize silage, 1.9 kg of oil - seed rape moldings, 2.5 kg of glycerine and 250 L of controle manure mixture. In this cycle, more than 5. 9 – times greater specific production of biogas was observed. The decrease in averare methan content 55.1% however also decrease in average content of hydrogen sulphide (128 ppm ) was observed as well. An unquestionable advantage for both tested alternative m ixed substrates was increase in biogas production and its quality in comparison with control substrate based on manure. At the basis of these findings can be concluded that both tested alternative input substrate mixtures are suitable as co – fermentation su bstances with great potential to increase the biogas production and its quality in case of wet fermentation processes.
  • Kirje
    Optimising cold compressive recovery of oil from the seeds of Sesame (Sesamum indicum L.)
    (2018) Akangbe, O.L.; Adamovský, R.; Mošna, F.
    Effects of the time rate of deformation and aspect ratio on mechanical response and performance in single cycle cold compression scheme were investigated for bulk sesame seeds and response forms fitted using forward stepwise multiple regression technique. The degree of deform ation was dependent on the time rate of its induction and the equipment’s aspect ratio. Energy requirement correlated positively with deformation rate and aspect ratio. Energy expenditure was however more efficient with larger aspect ratios than with small er ones, given the associated volume energy demands. Strain resistance correlated positively with each of the two influence factors. The time rate of deformation was the most important predictor of oil yield and performance. All the fitted forms had highly significant effects in predicting the responses investigated with 76.7 – 99.6% of the behaviours of the system explained. The results are valid within the ranges of the influence parameters investigated.
  • Kirje
    Evaluation of the fuel commercial additives effect on exhaust gas emissions, fuel consumption and performance in diesel and petrol engine
    (2018) Janoško, I.; Kuchar, P.
    The paper deals with the impact assessment of the additives used in diesel and petrol fuel to improve the power and emission parameters of the vehicle and its consumption. The usage of additives in engine fuels have an increasing tendency. The manufacturers claim that ad ditives have positive impact on engine operating parameters, cleaning the fuel supply system and decreasing fuel consumption by improving the engine combustion process. Based on the above statements, measurements were performed to determine change in the e ngine parameters utilising additives. Measurements were performed under laboratory conditions on the MAHA MSR 500 test bench (dynamometer) to simulate free driving cycle selected by authors, which were carried out at constant engine speeds and constant loa d. Focus have been given on tracking of the vehicle's external speed characteristic and measurement of selected parameters: CO, HC, O 2 , fuel consumption (petrol engine) and smoke, fuel consumption (diesel engine). Resulting values of the driving cycles mea sured before and after additives application have been then compared. The result of experiment confirmed that tested fuel additives improved performance and torque depending on engine mileage and fuel type. Tested diesel engine with the higher mileage (app rox. 388 k km ) showed significant increase in power (cca 3 . 57 % ) and torque while in newer petrol engine (approx. 73 k km ) improvement has not been measured. Emissions were improved in both engines. Difference has been also measured in fuel economy as in pe trol engine consumption insignificant increased while in the diesel engine it decreased. This paper brings new complex view on energetical and emission changes in internal combustion engines.
  • Kirje
    Comparison of consumption of tractor at three different driving wheels on grass surface
    (2018) Abrahám, R.; Majdan, R.; Drlička, R.
    The paper deals with possibility of reduction of tractor fuel consumption when working on grass surface, and compares use of two versions of spike devices embedded to the original tyre body. The device was designed at Department Transport and Handling (Slovak University of Agriculture in Nitra). Older as well as newer system proposed in 2017 comprises spikes and it is assembled to common tractor tyre tread pattern with auxiliary grooves cut in. Same device can be set to two positions, allowing to work as 8 - spikes and 16 - spikes system. The spikes are tilted in grooves when moving on paved road. The spikes are ejected out to reduce wh eels slip when operated in field. Remaining eight spikes are tilted in case of 8 - spikes system. Measurements were realised on grass surface. Tractor Mini 070 type was loaded with heavier tractor MT8 - 065 type in tests with 3 different driving wheels, balanc ing the actual weight in all cases. Drawbar pull and fuel consumption were measured in tests, allowing to compute specific drawbar consumption and fuel consumption per hour for three different loads. The results pointed out a fact the tyre slip loss and en ergy consumption of tractor movement increase at the soil humidity 19.45%. It follows from results achieved that use of both 8 - and 16 - spikes wheel device versions reduced fuel consumption when cultivating higher humidity soil, preferable for tillage. Eigh t spikes system with semi - tilted remaining spikes is the most efficient method.
  • Kirje
    Irradiation level affects fluctuating asymmetry value of bilateral traits of cucumber in juvenile phase
    (2018) Rakutko, S.; Rakutko, E.; Avotins, A.; Berzina, K.
    Light is an important factor of the plant's environment. The aim of research was to confirm the hypothesis on the influence of different irradiation levels on the fluctuating asymmetry (FA) value of bilateral traits of plants cultivated in the indoor plant lighting. The object of research was the plants of cucumber ( Cucumis sativus L ) as one of the main glasshouse crops. Young 14 - day - old cucumber plants in the first true leaf phase were studied. Different irradiation levels (15.0, 22.5 and 30 W m - 2 ) were maintained by fluorescent lamps. An essential asymmetry of bilateral structures in plants grown under different irradiation levels was observed. It was found that statistically significant lower values of FA, that is greater stability of plant development, correspond to increased plant performance. When the irradiation level was switched from 15 to 30 W m - 2 (by 100%), the FA index for different bilateral structures varied by dif ferent amount: in terms of cotyledons mass it decreased from 0.046 to 0.032 relative units (by 30.2%), in terms of chlorophyll content in cotyledons it increased from 0.038 to 0.073 relative units (by 88.6%). In some bilateral structures the FA index varia tion was rather small: in terms of the cotyledon area it was zero, in terms of the cotyledon thickness – by 1.8%. I t was experimentally prove through the example of cucumber plants that FA index could be used as an indicator of plant developmental stability, characterizing the deviations of the growing environment parameters from the normal state in the indoor cultivating.
  • Kirje
    Soil sampling automation using mobile robotic platform
    (2018) Väljaots, Eero; Lehiste, H.; Kiik, M.; Leemet, Tõnu; Estonian University of Life Sciences. Institute of Technology. Chair of Bioengineering Technologies
    Land based drone technology has considerable potential for usage in different areas of agriculture. Here a novel robotic soil sampling device is being introduced. Unmanned mobile technology implementation for soil sampling automation is significantly increasing the efficiency of the process. This automated and remotely controlled technology is enabling more frequent sample collection than traditional human operated manual methods. In this publication universal mobile robotic platform is adapted and modified to collect and store soil s amples from fields and measure soil parameters simultaneously. The platform navigates and operates autonomously with dedicated software and remote server connection. Mechanical design of the soil sampling device and control software is introduced and discu ssed.
  • Kirje
    Odour reduction of manure through addition of boracic charcoal
    (2018) Hampejs, G.; Jäger, A.; Steiner, S.; Steiner, K.
    Odours released during the land application of manure results from different gases released from the liquid phase. These gases do create objectionable odours in the vicinity of the land - applied manure. In order to reduce the intensity of odour durin g manure application, we investigated the effectiveness of combining Borkohle with manure during land application. Boracic acid is widely used as a flame retardant in cellulose insulation. During demolition of existing buildings, this insulation is sorted into its own residual waste fraction. The cellulose fibres are extracted and pelletized on site. Subsequently, the pellets are charred in a pyrolysis furnace. The resulting Borkohle – charcoal containing boron in various compounds - can be used as a soil e nhancer and provides the trace element Boron to the fields. Furthermore, Borkohle provides long - term storage of carbon in the soil. Initial trials of combining boracic charcoal with manure additionally showed that odour emissions seemed to be significantly lower when manure was combined with Borkohle. This work presents methods to quantify the odour reductions resulting from the addition of Borkohle to manure as well as first results. Parameters like the influence of the amount of charcoal added and exposur e time have been investigated. Charcoal was added at concentrations between 5 and 250 g L - 1 . While applying typical amounts of charcoal, a reduction of odour concentration of up to 85% was observed . A positive correlation between odour reduction and the amount of charcoal added was observed. Charcoal has a negligible effect when exposure times are less than 30 minutes.
  • Kirje
    Evaluation of the RTK receiver’s capability of determination the accurate position
    (2018) Kadeřábek, J.; Shapoval, V.; Matějka, P.
    The main aim of this experiment was to compare low - cost RTK receiver, that possible can be used for precise agricultural application, another that is currently used for these applications and the third one that suits for static measurement the most and gives the reference point for results comparison. The main idea of this research was to compare the measured positions during static measurement of RTK receivers. Were discovered that the receiver Trimble 750 was not able to work in fix mode (mode when the RTK receivers are capable to measure the most accurately) for the whole time. This fact affects the results from whole measurement and showed th at errors were a little higher than producers specifies. The low - cost receiver u - Blox C94 - M8P showed satisfying results when in most cases it was capable to solve the problem of ambiguity integer phases. The main parameters in this work that were counted a nd summarized were: accuracy, precision, RMS error, system status ratio and number of satellites.
  • Kirje
    Evaluation of different lighting sources on the growth and chemical composition of lettuce
    (2018) Sergejeva, D.; Alsina, I.; Duma, M.; Dubova, L.; Augspole, I.; Erdberga, I.; Berzina, K.
    Experiment were carried out in Latvia University of Agriculture in plant growth room. Lettuce Lactuca sativa L. var foliosum cv. ‘Dubacek’ and L . sativa L. cv. ‘Michalina’ were grown under 4 types of lights (luminescence lamps, commercial light emitting diodes (LED) lamps (V - TAC premium series – for plant growing) and two different Lumigrow LED strips - dominant wavelength - blue or red with 14 h ph otoperiod and total photosynthetic active radiation (PAR) 100 μmol m - 2 s - 1 in all variants. Plant weight, length, amount of leaves were measured. Content of chlorophylls, carotenoids, phenols, flavonoids in lettuce was determined three times per vegetation period. In experiments were found that higher lettuce yield was under commercial LED (V - TAC premium series), but these plants contain less soluble sugars, pigments and phenols. Better plant quality was obtained with luminescence lamps. These lettuces have higher sugar, phenols and flavonoids content. Lettuce growth under blue dominate LED (LEDb) was delayed, but these plants contain higher chlorophylls content. The differences in plant growth, response to light and biochemical content b etween cultivars wer e detected.
  • Kirje
    Effect of Automatic Feeding Station use on fattening performance in lambs and intake activity periods
    (2018) Šenfelde, L.; Kairiša, D.
    Implementation of precise farming technology is v ery important for productivity increasing of livestock. One of the highest components of the production costs is feeding expenses. An automatic concentrate feeding stations (AFS) can ensure economic feed distribution and intake registration for animals ind ividually. The aim of this research was to study the possibility and benefits of using AFS in fattening of lambs. Results show that during all the research average number of daily visits to AFS per lamb were 13 ± 0.2 visits, average daily live weight gain per lamb was 254 ± 15.7 g. For 1 kg lamb live weight gain 5.35 kg concentrate was used. More intesively acitivity periods of lambs was noted during following hours of day time: 02:00 – 02:59 , 08:00 – 09:59 and 19:00 – 20:59. Significant ( P ≤ 0.05) moderate positive correlation (r = 0.470) was found between average daily number of visits to the AFS per lamb and total amount of concentrate consumed during the research per lamb. Significant ( P ≤ 0.05) strong negative correlation (r = - 0.806) was found between a verage daily number of visits to the AFS per lamb and average amount of concentrate consumed during one visit.
  • Kirje
    Using the FEM model for design the heat treatment of an agricultural tools
    (2018) Kešner, A.; Chotěborský, R.; Linda, M.; Hromasová, M.
    Agricultural tools need mechanical properties such as abrasive wear, hardness and toughness. These mechanical properties are achieved by choosing a suitable steel and subsequent heat treatment of the steel. Phases of the microstructure affects the final steel properties. The phase composition in the steel is influenced with the designing of the heat treatment. 25C rMo4 steel was investigated for the production of agricultural tools. The heat treatments ware designed for different cooling conditions. The salt bath was used to cooling as a medium with subsequent cooling on the water or in the air. The FEM method was u sed to designing the heat treatment conditions. The Johnson - Mehl - Avrami - Kolmogorov equation and the Koistinen - Marburger equations were used to prediction the microstructure phases. The microstructures were verified with experimental measurements. The ASTM G65 method was using for abrasion resistance tests. The results show that this procedure can be used to designing parameters of heat treatment of agricultural tools.
  • Kirje
    Festulolium seed production dependence on fertilizer application system
    (2018) Obraztsov, V.; Shchedrina, D.; Kadyrov, S.
    Festulolium ( × Festulolium F. Aschers. et Graebn.) is a new perennial grass Роасеае family. The benefits of this culture are good regrow capacity, increased sugars content and higher winter hardiness. It can be used as a green feed when c reating cultivated hayfields and pastures. Widespread application of this new culture for forage production is constrained by the shortage of seeds, due to the imperfection of their production technologies. There are still very few of studies on the biolog y and technology of Festulolium cultivation in the forest - steppe of the Central Chernozem Region of Russia (CCR). The experiments involved the VIC - 90 Festulolium variety with the first crop being the vetch - oat mixture harvested for green fodder. The soil in the experimental plots was leached medium thick medium loamy chernozem. The humus content in the arable horizon was 4.56%, pH was 4.9, degree of base saturatio n was 74‒86%, P 2 O 5 content was 129 mg kg - 1 , K 2 O content was 115 mg kg - 1 (according to Chirikov) and the hydrothermal index was 1.13. The experiment included the following variants: no fertilizer application (control) and application of mineral fertilizers (ammonium nitrate and ammonium nitrate phosphate fertilizer) at different doses. Soil preparation was conventional for seed swards of perennial grasses in the CCR. Festulolium was sown in broad drills by coverless sowing to the depth of 0.5 – 1.0 cm at the s eeding rate of 6.0 kg ha - 1 . Experiments, records, observations and determination of economic and bioenergetic efficiency were carried out according to conventional procedures. It was found that the climatic conditions in the forest steppe of the CCR were f avorable for Festulolium seed cultivation. Application of mineral nitrogen fertilizers in autumn at a dose of 60 kg ha - 1 of active ingredient (AI) ensures the formation of high yielding erect seed - producing sward, and can increase harvest energy efficiency an average by 1.45‒1.82 times and obtain 591‒620 kg ha - 1 of certified seeds. The greatest profitability of production (179%) and the highest notional farm net income (RUB 43,000 per hectare) are provided by a single application of ammonium nitrate fertili zer at a dose of 60 kg ha - 1 of active ingredient in autumn (after vegetative mass topping).
  • Kirje
    Air flow conditions in workspace of mulcher
    (2018) Čedík, J.; Chyba, J.; Pexa, M.; Petrásek, S.; Jedelský, J.; Malý, M.
    Currently, there has been a great effort on increasing the efficiency of agricultural machinery. The energy demands of mulching with the vertical axis of rotation depends on the amount of pr ocessed material per unit of time, its properties and efficiency of material processing. Another important factor that is affecting the overall energy demands is the energy losses, which can be even higher than energy, required for the processing of materi al. The efficiency of the material processing and the energy losses are influenced to a large extent by the air flow inside the mulcher workspace, which is created by the movement of working tools. The air flow ensures the repeated contact of the processed material with the working tools, affects the energy losses and the quality of work. The contribution deals with the air flow conditions inside the workspace of mulcher with the vertical axis of rotation. The velocity of the air flow was measured my means of LDA (Laser Doppler Anemometry) method in three planes above the surface (180, 100 and 20 mm ) and in two directions (peripheral and radial). The laboratory model of one mulcher rotor from mulcher MZ 6000 made by BEDNAR Ltd. company was used for the measu rement. From the results it is evident that the maximum values of peripheral velocity of the air flow reach approx. 50% of the velocity of the tools. In the radial plane an air vortex is created between 20 and 100 mm planes above the surface around the tip of the blade.
  • Kirje
    Sunlight potential for microalgae cultivation in the mid-latitude region – the Baltic states
    (2018) Stunda-Zujeva, A.; Zuteris, M.; Rugele, K.
    Products, e.g. food and feed from microalgae are a promising part of bioeconomy. One of the most investigated and highly demanded microalgae is Spirulina . Light is one of limi ting factors for biomass cultivation by photosynthesis. Sunlight is cheap and climate friendly light source. The aim of this study was to evaluate available sunlight potential in the mid - latitude region - the Baltic states (Europe, 55 – 60 °N ) for microalgae, e.g. Spirulina growth. The data of Climate atlas based on satellites of EUMETSAT and data from an observation station in Riga were analyzed. The latitude and climate (cloudiness) were main parameters affecting the total solar radiation re ceived by Earth’s surface. The sunlight potential in the Baltic states was higher than in most of Europe in similar latitude. Multi - year mean daylight intensity in the Baltic states was slightly less than in Southern France or Bulgaria, (26 klux and 30 klu x , respectively, in summer) where Spirulina is commercially produced. Hourly solar radiation varied a lot in the Baltic states – from 880 W m - 2 to 200 W m - 2 , sunny and overcasted noon of summer day , respectively; average value (8 a.m. – 4p.m.) was 450 W m - 2 . Summer days are longer than 12 h, reaching 18 h in midsummer. The sunlight potential is suitable for microalgae, e.g. Spirulina cultivation in this period. From November till February days are shorter than 10 h and solar radiation is less than 300 W m - 2 e ven in noon of sunny days.
  • Kirje
    Performance evaluation of rural areas: the case of Estonian rural municipalities before the administrative reform
    (2018) Luik-Lindsaar, Helis; Põldaru, Reet; Põder, Anne; Roots, Jüri; Estonian University of Life Sciences. Institute of Economics and Social Sciences
    Estonian municipalities have recently pa ssed an administrative reform that has resulted in the reorganisation of municipal management and decreased the number of municipalities. Unfortunately, no thorough scientific research has been done to find out whether the emerging helps to increase the ef ficiency. The aim of this paper is to estimate the efficiency of Estonian rural municipalities and to identify the factors that influence their efficiency. In this study we use a two stage analysis. In the first stage, we use the DEA Slacks - Based Model’s ( SBM) output - oriented approach. In the second stage, we use the Fractional Regression Model (FRM) to determine relevant exogenous factors that are associated with efficiency. 170 Estonian rural municipalities have been analysed. According to the DEA results , 28% of municipalities (48) are efficient, the average efficiency of municipalities is 0.762. The analysis implies that there are considerable differences between smaller and larger rural municipalities. FRM results revealed that larger share of subsidies characterize inefficient municipalities. The weaker the municipality, the more state support the municipality must receive. A larger share of people with a higher education increases the efficiency, it is related to higher salaries and therefore higher re venue to the municipality. Elderly residents in the population increases the efficiency, however it isn’t sustainable in the long - run because more inputs are needed to offer various public services. The results indicate that the further away a municipality is from the capital, the more inefficient the municipality becomes.
  • Kirje
    Comparison between different types of bedding materials for horses
    (2018) Bambi, G.; Rossi, G.; Barbari, M.
    The sports horse lives a large part of the time inside the pen in constant contact with the bedding. Therefore the bedding material can deeply affect the welfare and health of horses kept in pens. The materials have to ensure the realization of a double aim: to create a comforta ble and soft surface on which the animal can stand and relax; to give appropriate hygienic and sanitary conditions. Other important factors influence the choice, such as: the material must not be appetizing for the horse; the litter has to maintain a prope r level of moisture, so that the hoof is kept healthy, elastic and hydrated. Also the costs for material and litter management have to be taken into account. In the present study, different organic materials are compared: wood chips, hemp, rice, flax and c oconut. The trials took place in five box stalls, with square plan of 3 x 3 m. Environmental data were collected during the trials (air temperature and humidity, ammonia concentration, litter moisture). Management data were also collected, regarding the us e of bedding materials, working time, costs. In the paper the main results of the comparison between the different litter materials used in horses pens are presented.
  • Kirje
    On the degradation of metformin and carbamazepine residues in sewage sludge compost
    (2018) Haiba, Egge; Nei, Lembit; Herodes, Koit; Ivask, Mari; Lillenberg, Merike; Estonian University of Life Sciences
    Recent decades have shown intensive studies devoted to the fate of pharmaceuticals in the environment. These studies have involved the development of analytical tools, determination of pharmaceuticals in different compartments, composting technologies, and plant uptake of pharmaceuticals. The presence of organic pollutants in sewage sludge, including pharmaceuticals, is a problem of major concern. The r e - use of sewage sludge should be encouraged since it represents a long - term solution provided that the quality of the sludge re - used is compatible with public health and environmental protection requirements. Composting is a widely recognized way of making the soil application of sewage sludge safer. In this study, the impact of sewage sludge composting on the degradation of metformin (MET), by far the most often prescribed antidiabetic drug worldwide, and carbamazepine (CBZ), a poorly biodegradable but wid ely used as an anticonvulsant drug to cure depression and seizures, were analysed. The anaerobically digested and dewatered sewage sludge samples were collected from municipal wastewater treatment plant. Composting experiments were performed under fixed co nditions during 30 days. The results of the experiment showed that during a 1 - month composting period more than 90% of MET residues degraded, but no degradation of CBZ took place during the composting period. The half - life of MET was 3 days for the compost mixture with the ratios of 1:3 and 1:2 (v:v). The results of this study show that composting maylead to the efficient degradation of MET, whereas for the elimination of CBZ from sewage sludge different means should be used.
  • Kirje
    Agricultural residues in Indonesia and Vietnam and their potential for direct combustion: with a focus on fruit processing and plantation crops
    (2018) Brunerová, A.; Roubík, H.; Brožek, M.; Velebil, J.
    Energy consumption in Indonesia and Vietnam has grown rapidly in recent decades. To meet the energy needs of both countries, a higher utilisation of waste biomass sources may represent an adequate solution. Investigated samples represent major crop residues (waste biomass) originating mainly from the agriculture sector of the selected countries. Herbaceous waste biomass from Indonesia is, namely, cassava stems and root peelings ( Manihot esculenta ), coffee leaves ( Coffea arabica ), cacao leaves ( Theobroma cacao ), banana leaves ( Musa acuminata ), bamboo leaves ( Bambusoideae spp.) and aloe vera leaves ( Aloe vera ). Furthermore, fruit and aquatic waste biomass originating from Vietnam is, specifically, sugarcane bagasse ( Saccharum officinarum ), durian peelings ( Durio zibethinus ), rambutan peelings ( Nephelium lappaceum ), banana peelings ( Musa acuminata ), water milfoil ( Myriophyllum spicatum ) and water hyacinth ( Eichhornia crassipes ). All mentioned types of waste biomass were subjected to proximate and calorimetric analysis: moisture, ash and volatile matter contents (%) and higher and lower heating values (MJ kg – 1 ). Obtained values indicated the highest level of ash content in fruit bioma ss samples in the case of sugarcane bagasse (0.84%), in herbaceous biomass in the case of cassava stems (3.14%) and in aquatic biomass in the case of water hyacinth (14.16%). The highest levels of lower heating values were achieved by following samples (be st samples from each biomass type): cassava stems (17.5 MJ kg – 1 ); banana peelings (17.3 MJ kg – 1 ) and water hyacinth (12.8 MJ kg – 1 ). The overall evaluation of all observed samples indicated that the best suitability for energy utilisation by direct combusti on of investigated representatives is fruit waste biomass, followed by herbaceous waste biomass and then aquatic waste biomass.
  • Kirje
    Assessment of soil electrical conductivity using remotely sensed thermal data
    (2018) Křížová, K.; Haberle, J.; Kroulík, M.; Kumhálová, J.; Lukáš, J.
    Detection of heterogeneity (crop, soil, etc.) gained a lot of importance in the field of site - specific farming in recent years and became possible to be measured by different sensors. The therma l spectrum of electromagnetic radiation has a great potential today and experiments focused on describing a relation between canopy temperature and various vegetation characteristics are conducted. This paper was aimed to examine the relation between canop y temperature and electrical conductivity as one of staple soil characteristics. The related experiment was undertaken in Sojovice, Czech Republic, within an agricultural plot where winter wheat was grown in 2017 growing season. The examined plot was compo sed of three sub plots and 35 control points were selected within this area which the data were related to. A canopy was sensed by UAV (eBee carrying thermoMAP (FLIR TAU2) camera). Soil conductivity data were collected by terrestrial sampling using EM38 - MK 2 Ground Conductivity Meter in 1 m depth and 2 m sampling point distance. This dataset was later interpolated using the kriging method. The correlation analysis results showed a strong negative correlation between conductivity and thermal data ( - 0.82; p < 0.001 ). When comparing conductivity with NDVI representing the aboveground biomass, there was an opposite trend but also strong result (0.86; p < 0.001 ). Correlation coefficient of thermal data and NDVI comparison was - 0.86; ( p < 0.001 ). These preliminary results have a potential for further research in terms of soil characteristics studies.