Andmebaasi logo

2018, Vol. 16, No. 5

Selle kollektsiooni püsiv URI


Viimati lisatud

Nüüd näidatakse 1 - 20 32
  • Kirje
    The effect of herbicides on seed productivity of Festulolium
    (2018) Obraztsov, V.; Shchedrina, D.; Kadyrov, S.
    An artificially developed intergeneric hybrid Festulolium (+Festulolium F. Aschers, et Graebn.) is the best forage crop with high energy and protein nutrition value which can be used for green fodder when creating cultural haylands and pastures. The advantages of this crop are high regrow capacity, high content of sugars and good winter hardiness. Wide use of this new crop in fodder production is constrained, firstly, because the crop is yet new and little known and, secondly, because there is a lack of seeds due to imperfections in the production technology. There are still very few scientific studies on the biology and technology of Festulolium cultivation in the forest-steppe of the Central Chernozem Region of Russia. In our works we were the first to study the biological features of Festulolium and develop the main technological methods of growing and harvesting its seeds. The work was carried out in long-term studies of the Department of Crop Science, Forage Production and Agricultural Technologies of Voronezh State Agrarian University in 2009 2011. The soil in the experimental plot was leached medium loamy chernozem. The experiments involved the VIK-90 Festulolium variety with the preceding crop being the vetch-oat mixture harvested for green fodder. The soil preparation was conventional for seed herbage of perennial grasses in the Central Chernozem Region. The associated records and observations were made according to conventional methods adopted in the seed production of perennial grasses. A high efficiency of the Aurorex (0.55 L ha -1 ) and the Dicamba (0.15 L ha -1 ) herbicides in the suppression of annual and perennial dicotyledonous weed plants has been identified. The application of these herbicides has significantly reduced (by 40-73%) the weed infestation of seed herbage in the first year of vegetation and, as a result, has improved its structure and crop quality. The use of the developed agricultural techniques allows reducing the energy costs and receiving an average of 433 496 kg ha -1 of certified seeds.
  • Kirje
    Analysis and forecast of performance characteristics of combine harvesters
    (2018) Zubko, V.; Roubik, H.; Zamora, O.; Khvorost, T.
    This article presents results of an experimental research of qualitative indicators of the modern combine harvesters (Case IH Axil Flow 8230, MasseyFergusonMFT7, JohnDeereS680i, ClaasLexion760, NewHolland CR9.80) used for winter wheat harvesting. Based on the results obtained, determination was made regarding the productivity of combine harvesters on the field, fuel consumption, and field conditions influence the grain loss and grain damage caused by a harvester. When conducting the experimental research of a combine's performance on the field a study of the effectiveness of the combine JohnDeereS680i was made on different modes. A program 'Machine Unit', designed by the authors, was used for the determination of productivity, fuel consumption and quality indicator for harvesting.
  • Kirje
    The theory of cleaning the crowns of standing beet roots with the use of elastic blades
    (2018) Bulgakov, V.; Adamchuk, V.; Arak, Margus; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
    A standing beet root crown cleaner has been designed. The design comprises the vertical drive shaft that carries two flat elastic cleaning blades installed on axes and connected through the articulated connection. The aim of the study was to develop the new theory of cleaning the crowns of standing roots with the use of an elastic blade installed on the vertical drive shaft in order to determine its optimal design and kinematic parameters. The first step was to design an equivalent schematic model of the interaction between the elastic cleaning blade installed on the vertical drive shaft and the spherical surface of the beet root fixed in the soil. The interaction between the blade and the root's crown took place at the point, where all the forces that can arise during such interaction are applied. A three-dimensional coordinate system was set and the design and kinematic parameters of the considered interaction were designated. Using the original differential equations projected on the set coordinate axes, the system of four nonlinear differential equations of the three-dimensional motion of the elastic cleaning blade on the spherical surface of the root crown was set up, then it was transformed into the system of two differential equations in the normal form. Further, to determine the force that strips off the remaining haulm, which is part of the obtained system of differential equations, the problem of its analytical determination was solved separately. Also, the additional equivalent schematic model of the interaction between the elastic blade as a cantilever beam and the root's crown was designed, the differential equation of the beam's deflection curve (taking into account the beam's simultaneous bending and twisting) was set up and, on the basis of it, the projections of the stripping force on the coordinate axes were found. The values of the force were substituted in the earlier obtained system of differential equations.
  • Kirje
    Air-conditioning in the cabins of passenger cars
    (2018) Kumar, S.; Cerny, J.; Kic, P.
    The objective of this paper is to analyse the current state of the constructional design and operational conditions of air - conditioning device in passenger cars. The research was focused on the function of air - conditioning equipment of passenger cars Skoda and KIA in various modes of operation during the winter, spring and summer season at different levels of air conditioning (without air - conditioning, minimum, medium and maximum level). Air temperature, air humidity, globe temperature, CO 2 concentration, dust concentration and noise inside the cabin w ere measured. Solar radiation plays a big role to rise up temperature inside the cabin. It resulted in the higher values of globe temperature than temperature of the air. The results of the measurements showed that CO 2 values were significantly lower than 2,500 ppm at minimum air - conditioning, lower than 600 ppm at medium and lower than 500 ppm at maximum level of air - conditioning. For all vehicles, dust concentration was greater when it measured with the air conditioning switched off than with the air con ditioning system turned on. The measurements confirmed that the total dust concentration was not more than 47 μg m - 3 , PM 10 lower than 28 μg m - 3 and PM 1 lower than 27 μg m - 3 . The noise levels ranged from 49.1 to 68.7 dB(A). The air - conditioning had very positive impact on the inside comfort in car cabins from all points of view during all periods of the year.
  • Kirje
    Identification of yeast species involved in fermentation of the Kazakh camel dairy product–shubat
    (2018) Nadtochii, L.; Orazov, A.; Kuznetsova, L.; Pinaev, A.; Weihong, L.; Garbuz, S.; Muradova, M.
    In certain countries of the world, camel's milk is used for food on a level with cow's milk. Shubat is a traditional food product based on camel milk in Kazakhstan. It is a fermented milk product obtained as a result of spontaneous fermentation of camel's milk under the influence of native microflora. Received dairy product from the southern region of K azakhstan became the object of the investigation of the microflora of the fermented milk product shubat . The aim of the research was to study the microflora of camel milk, which causes its spontaneous fermentation. During the experiment, the dynamics of ac id accumulation by the change in active acidity (pH) and titratable acidity (°T) was studied. In addition to lactic fermentation fermented product ( shubat ), alcoholic fermentation was noted, which has given the finished product an increased acidity and a h igh degree of gassing. To enumerate and identify microorganisms, shubat was sown to the following nutrient media: MRS, Malt wort - agar medium at 36 °C and 30 °C respectively both for 3 days. We suppose that the dominant component of the shubat ’ s microflora was yeasts: Brettanomyces anomalus, Naumovozyma castellii . Pathogenic microorganisms, such as Salmonella, Shigella , were not detected during the research, considering that the shubat is formed as a result of spontaneous fermentation and has poor hygienic c haracteristics in comparison with pasteurized milk. Identification of individual strains of bacteria allows us to simulate a starter microflora for the production of a safe fermented product based on camel milk on an industrial scale in Kazakhstan. The ide ntified microflora, which causes spontaneous fermentation of camel milk and isolated strains of lactic acid bacteria, will make a significant contribution to the improvement of food safety in arid regions.
  • Kirje
    A comparative analysis of functional traits in semi-natural grasslands under different grazing intensities
    (2018) Targetti, S.; Messeri, A.; Argenti, G.; Staglianò, N.
    The reduction of traditional management practices is a major threat for the conservation of permanent grasslands in many European marginal areas. The ecological importance of grasslands is acknowledged by the European Habitats Directive 92/43/EEC (1992) which includes many natural or semi-natural grassland types, and by the growing attention of society towards functions and services provided by these ecosystems. Nonetheless, the efficiency of conservation policies is questioned also for the lack of local-scale information on trends and state of grasslands hampers the definition of local-tailored schemes. The main objective of this work is to assess the potential of a set of functional traits in discriminating between different management intensities and their capacity to describe the dynamics occurring in semi-natural grasslands. The research was carried out in a hilly area of Tuscany (Italy) on four grassland sites characterized by similar environmental features (soil, climate, topography), and by different management practices for 10 or more years. The survey concerned collection and analysis of different functional traits related to foliar features, litter and botanical composition. The functional traits were able to differentiate the four sites under different management practices, but their effectiveness was different. Results support the possibility to perform a rapid appraisal of grassland successional stages based on leaf functional traits of dominant species and by the assessment of presence of a reduced number of species among those occurring in the community.
  • Kirje
    Model for cost calculation and sensitivity analysis of forest operations
    (2018) Kalēja, S.; Lazdiņš, A.; Zimelis, A.; Spalva, G.
    Forest operations include logging, off-road and road transport of round wood, harvesting residues and wood chips, soil scarification and pre-commercial thinning, as well as other less conventional operations like stump extraction and undergrowth removal before felling. The process of harvesting can involve different interfering phases with specific productivity parameters, which will have impact on the productivity of harvesting and delivery, as well on the prime cost of logs and forest biofuel. Detailed prime cost calculation allows to assess the impact of various factors on costs of the products, as well as to define threshold values for certain parameters affecting the productivity. The base model elaborated within the COST action FP0902 is complemented with standard economic methods and adopted to the harvesting process or any other forest or farming operation including systems consisting from several machines. The model is designed in a way, which is simple in use, easily extensible with additional parameters and machines and with possibility to change individual input data. The cost calculation section of the model consists from investments (base machines and equipment), labor costs (salaries, social charges, insurance and other payments) and operational costs (fuel, lubricants, maintenance, repair and other consumables). The average hourly cost is calculated according to forecast of number of working hours per year. Engine hours are used in calculation to synchronize input data with service statistics from dealers’ centers. The parameters of the forest stands affecting productivity, like diameter or volume of an average extracted tree, number of relocations per year, average off-road transport distance, driving speed and other parameters are defined in the calculation. Productivity and load size can be set as fixed values or equations (in case if the sensitivity analysis should be done). The model calculates the hourly cost (productive, engine and proposed working hours) and the unit price for each phase of the work process. The sensitivity analysis demonstrates impact of various factors, like number of working hours per year, dimensions of the average extracted tree, forwarding and road transport distance, fuel price and fuel consumption as a default parameters or any other indicator, which can be added to the sensitivity analysis. The model is validated against the actual harvesting contracts and hourly cost of rental machines. Default parameters in the calculation are summaries of information provided by contractors or service companies.
  • Kirje
    Determination of the tension limit forces of a barley malt and a malt crush in correlation with a load size
    (2018) Hromasova, M.; Vagova, A.; Linda, M.; Vaculik, P.
    This article deals with determination of selected parameters of barley malt (whole grain and crushed grain). The barley malt is besides water, hops and brewer's yeast, one of the basic ingredients necessary for the production of traditional Czech pilsner type of beer. The aim of this research is to determine limit force and internal friction angle with depending on the size of the load. The assessed malt crush was produced using a 2-roller malt mill. The 2-roller malt mill is based on the principle of grinding the material in a milling gap between two milling rollers, which is a very commonly used production of the malt crush. By determining the tension limits of the barley malt and the malt crush in correlation with the load, we can obtain very important parameters that inform us of the bulk material behavior, particularly with respect to the storage method (storage shape, height of the stored material layer, and the removal method from the storage, etc.), and to the transport (route gradient, transport speed, etc.). The determination of the tension limits has a direct link with cohesion of the bulk material and thereby contributes to establishing of the basic parameters of the bulk material, such as - the friction angle. The measurement for the angle of internal friction determination were performed on a prototype device. The principle of measurement on a mobile prototype devices is, the upper square chamber slides down the lower square chamber. Barley malt (whole grain and crushed grain) were loaded from 100 g to 5,000 g. The results of measuring were statistically analyzed with software Statistica 12.
  • Kirje
    Productivity, quality and economics of four spring wheat (Triticum aestivum L.) cultivars as affected by three cultivation technologies
    (2018) Zargar, M.; Polityko, P.; Pakina, E.; Bayat, M.; Vandyshev, V.; Kavhiza, N.; Kiselev, E.
    Managing farming inputs in wheat production technologies is an issue of paramount importance to attain optimum profitable production. To examine how varying the farming inputs affects the nutrients uptake and productivity of spring wheat (Triticum aestivum L.) cultivars and to determine the economic efficiency of various cultivation technologies, three-year field experiments were laid out at the Russian Research Institute of Agriculture, during the 2015–2017 growing seasons. Experiments were conducted once a year using randomized complete block arranged in a split plot experimental design with three replications, with the cultivation technology treatments (basic, intensive and high intensive technology) as the main plots, and spring wheat cultivars (Zelata, Lubova, Liza and Ester) as the sub-main plots. The highest grain yield (10.8 t ha-1), harvest index (42.9%), gluten content (39.45%) and gluten index (71.17%) observed for spring wheat cultivar Lubova with the moderate application of farming inputs as an intensive cultivation technology. Highest protein content (18.02%) was attained for both intensive and high intensive cultivation technology with the cultivar Lubova, and the highest 1,000 grains weight (46.32 g) was recorded by cultivar Lubova in basic cultivation technology. Applying moderate amount of inputs as an intensive cultivation technology resulted in highest wheat yield and net income.
  • Kirje
    Comparative characteristics of antioxidant capacity of some forage plants of the Baltic Sea Region (a case study of the Kaliningrad Region and Estonia)
    (2018) Chupakhina, G.N.; Shansky, Merrit; Parol, Argaadi; Chupakhina, N.Y.; Feduraev, P.V.; Skrypnik, L.N.; Maslennikov, P.V.
    In this paper, we investigate changes in the antioxidant levels (anthocyanins, leucoanthocyanins, catechins) and the total water-soluble antioxidants capacity in forage plants in relation to their geography, i.e. proximity to northern or coastal areas. We demonstrate that the antioxidant content increases in unfavorable conditions, being higher in plants growing closer to the sea and in northernmost plants. Thus, since the total water-soluble antioxidants capacity is influenced by ecological factors, it may be used as one of the indicators in complex environmental assessment.
  • Kirje
    Analysis of gamma rays induced variability in lentil (Lens culinaris Medik.)
    (2018) Tabti, D.; Laouar, M.; Rajendran, K.; Kumar, S.; Abdelguerfi, A.
    In this study, a lentil variety, Idlib-3, was subjected to 100 Gy (LD50) gamma-ray irradiation. At M2, mutant families were characterized for the most beneficial agronomic traits. High genotypic coefficient of variation, broad sense heritability and genetic advance of the traits such as seed yield per plant and hundred-seed weight indicated expression of additive gene action and confirmed the response at early generation selection. Total number of pods per plant had positive correlation and the highest positive direct effect on seed yield per plant and hence the preference should be given for this trait during selection. The novel mutant families identified with early flowering, early maturity (families 5 and 90) in cluster I, and more first pod height (families 10,70 and 82) in cluster II could be utilized to breed short duration lentil varieties suitable for machine harvest.
  • Kirje
    Volatile combustible release in biofuels
    (2018) Vitázek, I.; Majdan, R.; Mojžiš, M.
    Plant biomass consists of varied materials. Biomass is used for different purposes, but it is most frequently burnt in modern combustion devices for heat production. The quality of solid biofuels depends on the total content of combustibles while the volatile combustible content affects the combustion process. The aim of the paper is to determine the exact content of the biofuel components by the means of the gravimetric method – namely volatile combustible, ash and moisture content – and to evaluate the process of volatile combustible release as a function of temperature during the experiment. The device Nabertherm L9/11/SW/P330 type with accessory was used to carry out the experiments. Various biofuel samples were examined, namely wood (9 kinds), wood cuttings and wood chips (2 kinds), pellets (4 kinds), sawdust (1 kind), compared to less traditional fuels (DDGS and RME – 2 kinds) and wood coal (1 kind). The tables and graphs present the experimental results, which allow evaluation of the components content in different biofuels and provide characteristics of the process of volatile combustible release in analysed fuels. Spruce wood without bark showed the highest content of combustible (99.89%). Sawdust of fruit trees contains the highest proportion of volatile combustible (93.978%) and releases the combustible at the highest rate (15.25 mg h-1).
  • Kirje
    Film agents as an effective means of reducing seed shattering in Festulolium
    (2018) Obraztsov, V.; Shchedrina, D.; Kadyrov, S.
    In the conditions of the forest steppe of the Central Chernozem region, methods were studied to reduce shatter losses in the pre-harvesting period for Festulolium during the period 2009–2011, applying the film forming agents, Elastik (0.8–1.2 L ha-1), Bifaktor (0.8–1.2 L ha-1), and Metylan Universal Premium (1.4–3.8 kg ha-1). The agents were used at seed humidity levels of between 60–65%. Following anti-shattering treatment, seed moisture content gradually decreased. The application of film forming agents prevented seed shattering, and seeds were harvested by direct combining at a humidity of between 20–25% without heavy losses being suffered. Moreover, decreased seed losses due to film forming agents significantly reduced the cost of seed heap drying. In the control treatment, the seed yield amounted to 214.8 kg ha-1, and 360.7 kg ha-1 was lost as a result of natural seed shattering in the process of ripening. The Elastik and Bifaktor preparations prevented seed shattering and contributed to the preservation of a seed yield of between 522.1–563.5 kg ha-1. The application of film forming agents contributed to a reduction in losses during harvesting within the range of 9.7–16.8%. Application of the Metylan Universal Premium glue in the studied doses provided a significant increase of seed yield. The highest seed yield (490.1–495.2 kg ha-1) was obtained in the treatment which used a Metylan application at a dose of 3.0–3.4 kg ha-1, where seed shattering was reduced by 14.8–17.6%.
  • Kirje
    The effect of starter cultures on the qualitative indicators of dry fermented sausages made from poultry meat
    (2018) Zinina, O.; Merenkova, S.; Soloveva, A.; Savostina, T.; Sayfulmulyukov, E.; Lykasova, I.; Mizhevikina, A.
    Changes in physicochemical, rheological and microbiological properties occurring throughout the ripening (on days 0, 7, 14, 21, and 28) of dry fermented sausages made from poultry meat were studied. The effect of starter bacteria on the microstructure and sensory attributes of dry fermented sausages has also been determined. The results of physicochemical analysis of dry fermented sausage shows no significant difference (P < 0.05) between the test (inoculated) and the control sausages in the protein, fat, moisture, salt, ash and nitrite content. However, the significant difference (P > 0.05) between the control and inoculated batches in lowering the pH level, changing the critical shear stress, growth of viable microorganisms, accumulation of amine nitrogen during ripening was established. The results show, that inculcation of starter cultures accelerates biochemical processes during fermentation and thereby provides the necessary functional and technological properties of minced meat. Sensory profiling showed a more significant (P < 0.05) acidic and spicy flavour and intensity of acidic and smoked meat aroma; and increased firmness and cohesiveness in inoculated sausage. The results of microstructural analysis showed that the dry fermented sausages that ripened with the starter bacteria (Lactobacillus curvatus, Staphylococcus carnosus, Pediococcus pentosaceus), differ from the control sample compacted as a thin surface layer which is formed during the drying, smoking and maturation, and that indicates more uniform moisture removal.
  • Kirje
    The application of micro-wave treatment to reduce barley contamination
    (2018) Kretova, Y.; Tsirulnichenko, L.; Naumemko, N.; Popova, N.; Kalinina, I.
    The goal of this work is to study the applicability of ultra high frequency electromagnetic field treatment for decontaminating barley grain used in brewing while preserving its technological properties. The germination rates and/or yield of the treated sample seed were compared with those of the untreated seed germinated under normal conditions. To determine optimal treatment conditions, a two-factor analysis was carried out, taking the mycological state of the grain into account. The heating rate and the duration of electromagnetic exposure were chosen as variables; these values varied from 0.4 to 0.8 °C s-1 and from 30 to 90 s, respectively. It was found that germination of the treated barley seed was increased about 10.1–15.7% compared with that of the untreated seed. The microbial load decreased up to 80%. A heating rate of 0.4 °C s-1 and treatment exposure time of 30 s showed the strongest effect of decontamination while preserving the viability of the barley grain.
  • Kirje
    Evaluation of rice by-products, incubation time, and photoperiod for solid state mass multiplication of the biocontrol agents Beauveria bassiana and Metarhizium anisopliae
    (2018) Bich, G.A.; Castrillo, M.L.; Villalba, L.L.; Zapata, P.D.
    The success of biological control of insect pests depends not only on the isolation, characterization, and pathogenicity, but also on the success of the mass production of the microbial agents. The biological control strategy using entomopathogenic fungi like B. bassiana and M. anisopliae can only be useful if practical and economic methods of mass multiplication are available. Rice by-products like broken rice grains, rice hulls and their combination was evaluated for solid state multiplication of B. bassiana and M. anisopliae. The influence of photoperiod and incubation time in the production of conidia was also evaluated. This study showed that, broken rice was the most productive substrate for conidial production of both fungal genera, with a yield of 4.62 x 107 and 2.22 x 106 conidia g-1 respectively. Also, under the evaluated solid state multiplication conditions, the best conidia production was achieved with a photoperiod of 24 h of light for B. bassiana (with 4.43 x 107 conidia g-1) and M. anisopliae (with 1.35 x 106 conidia g-1). The results here demonstrated that these two fungal species could viably be multiplied with good yields of conidia on agro-industrial by-products using solid-state culture and regulating some culture conditions.
  • Kirje
    Fatty acid composition in pork fat: De-novo synthesis, fatty acid sources and influencing factors – a review
    (2018) Vehovský, K.; Zadinová, K.; Stupka, R.; Čítek, J.; Lebedová, N.; Okrouhlá, M.; Šprysl, M.
    Fats are among the basic nutrients the human organism needs as a source of energy, as well as to grow and regenerate cells, tissues, and organs. Particularly animal fats, with their higher proportion of saturated fatty acids and low content of n-3 fatty acids, are often seen by the public as relatively undesirable food components. Fatty acid (FA) composition of pork is affected by many factors: genotype, breeding, gender and feeding methods. Numerous research teams, therefore, have searched for means of effectively manipulating the chemical composition of animal fats. This paper reviews existing knowledge and means of effectively influencing the fatty acid composition in pig fat, which is a significant component of human food in European countries due to their high consumption of pork. The findings of various authors demonstrate that not only altering of fatty acids sources in animal diets but a range of other factors as well can significantly influence the composition of fatty acids in pig fat and consequently pork quality.
  • Kirje
    Impact of faba bean (Vicia faba L.) cultivation on soil microbiological activity
    (2018) Dubova, L.; Alsiņa, I.; Ruža, A.; Šenberga, A.
    Faba bean (Vicia faba L.) is widely grown not only as an important protein source for food and feed, but as a component in different cropping systems to improve soil quality. Beans are grown using different soil management practices, moreover, legume seeds often are inoculated before sowing. Microorganisms, introduced in the soil as an inoculum, affect not only inoculated plants, but these microorganisms can remain in the soil for the next growing season and can also affect the subsequent crops. Seed inoculation can stimulate production of root exudates as well as change microbial diversity and structure. The aim of the present study was to estimate the soil microbiological activity in soils where faba beans were cultivated with different rhizobia inoculants obtained from collection of Latvia University of Life Sciences and Technologies. Another trial was established where faba beans were included in different crop rotations under two tillage systems. During both trials, soil microbiological activity was analysed. Soil respiration intensity was measured by changes of carbon dioxide. Soil enzymatic activity was assessed by dehydrogenase activity and fluorescein diacetate (FDA) hydrolysis intensity. The total number of bacteria, fungi and rhizobia was expressed as colony forming units (CFU) g-1 dry soil. Soil microbiological activity depended on the cultivated crop and the crop rotation. Faba bean inoculation method had less impact on the ratio between analysed microorganism groups than on the activity of soil enzymes.
  • Kirje
    Split water application for a water supply reduction in Callistemon Citrinus pot plant
    (2018) Militello, M.; Sortino, G.; Talluto, G.; Gugliuzza, G.
    Irrigation management in Greenhouse Nursery Production (GNP) is based on empiric methods based on farmer personal experiences with over-irrigation results. The effects of irrigation volume and daily application were studied in a pot experiment carried out on rooted cuttings in a greenhouse The irrigation volume treatment was performed on Full and reduced Treatment. The treatment of water application was carried out with split supply and unsplit supply. The effects of the treatments were evaluated in terms of biomass accumulation and partitioning, leaf area, photosynthesis and stomatal response, chlorophyll content, and water productivity. Callistemon showed a good adaptation to the different treatments tested during the experiment. A positive relation was found between biomass accumulation and irrigation volume, moreover split water application increased plant Dry Weight. Therefore, the highest biomass accumulation was registered in full irrigation volume in split application treatment, and this behavior was confirmed by the photosynthetic rate. No statistical differences were found, in terms of Relative Water Content (RWC), between the treatments. Stem water potential and stomatal conductance values suggest in Callistemon an anysohidric water stress response behavior. Our results evidenced that, in Callistemon potted plants, an irrigation volume reduction is possible when a split application occurs during the daytime. A full irrigation volume amounts to10.8 L per plant during the trial period of 90 days while the reduced volume amounts to 8.2 L per plant. Therefore, an increased water productivity can be obtained if the daily water requirement is split on two applications during the daytime. Our results highlighted a possible reduction in environmental impact of Callistemon greenhouse pot production, through the 25% reduction of the volume irrigation.
  • Kirje
    Identification of wet areas in forest using remote sensing data
    (2018) Ivanovs, J.; Lupikis, A.
    Aim of this study is to evaluate different remote sensing indices to detect spatial distribution of wet soils using GIS based algorithms. Ar ea of this study represents different soil types on various quaternary deposits as well as different forest types. We analyzed 25 sites with the area of 1 km 2 each in central and western part of Latvia. Data about soil characteristics like thickness of pea t layer and presence of reductimorphic colors in soil was collected during field surveys in 228 random points within study sites. ANOVA test for comparing means of different soil wetness classes and binary logistic regression analysis for evaluating the ac curacy of different remote sensing indices to model spatial distribution of wet areas are used for analysis. Main conclusion of this study is that for different quaternary deposits and soil texture classes different algorithms for soil wetness prediction s hould be used. Data layers for predicting soil wetness in this study are various modifications and resolutions of digital elevation model like depressions, slope and SAGA wetness index as well as Sentinel - 2 multispectral satellite imagery. Accuracy of soil wetness classification of soils on moraine, fluvial and eolian sediments exceeds 94%, whereas on the clayey sediments it is close to 80%.