2018, Vol. 16, No. 4

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5377

Sirvi

Nüüd näidatakse 1 - 20 33

Evaluation of greenhouse gas emissions and area of organic soils in cropland and grassland in Latvia – integrated National forest inventory data and soil maps approach
(2018) Petaja, G.; Okmanis, M.; Polmanis, K.; Stola, J.; Spalva, G.; Jansons, J.
The aim of the research was to assess distribution of organic soils in farmlands for the time period between 1990 and 2015, as well as to carry out a recalculation of GHG emissions from organic soils in grassland and cropland. We evaluated the area of typical organic soils using digitized soil maps created between 1960s and 1980s there were 183,000 ha of cropland and grassland on organic soils. A selected number of areas on organic soils intersecting with the National forest inventory (NFI) plots were surveyed. We found that 66 ± 10% of surveyed plots still conforms to criteria for organic soils according to Intergovernmental Panel on Climate Change (IPCC) guidelines; in the rest of plots soil organic matter has been mineralized and these areas do not conform to IPCC criteria of organic soils. The following distributionof organic soils was estimated in cropland – 6.3 ± 3.3% in 1990 and 4.1 ± 3.4% in 2015, but in grassland – 11.6 ± 3.6% in 1990 and 7.7 ± 3.9% in 2015. The annual reduction of GHG emissions due to reduction of area of organic soils in cropland in 2015 corresponds to 1,400,000 tonnes CO2 eq. in comparison to 1990 and in grassland – to 1,100,000 tonnes CO2 eq. The estimated reduction of the GHG emissions due to conversion of organic soils into mineral soils, comparing the average value in 2005–2009 with the projection for 2021–2030 on average will correspond to 313,000 tonnes CO2 eq. annually, however LULUCF sector still won’t become a net CO2 sink according to the GHG inventory data on other land use categories and carbon pools.
Modelling of operator’s focusing scheme along working hours: Windrowing and cultivating operations
(2018) Szabó, I.; Hushki, M.; Bártfai, Z.; Lágymányosi, A.; Kátai, L.
Enhancing productivity and cost reduction are two main targets for any production operation. In the agricultural field; It is the role of researchers to come out with reliable models and make it available to be used in m odern farming management organizations as well as to the rural farmers. When it comes to the Human Machine Interface it is essential to assess the system in term of the Human Cantered Design aspects. This research is focusing on the developing simple model s for the operator’s focusing scheme as a human behaviour inside an off - road vehicle cabin based on the operator’s focusing scheme measuring along working hours using proven and up to date technologies. The results of this research provide the decision mak ers with reliable inputs using proven methodology regarding the change of operator’s focusing scheme along working hours in two agricultural operations “windrowing and cultivating”. Both operations are requiring continuous physical involvement of the opera tor for checking the attached tool and steering of the vehicle in the planned track, which is directly related to the accumulated passive fatigue as a main contributor of resulted data.
Ergonomic modelling parameters and the influence of ergonomics on planning workplaces
(2018) Maksimov, D.G.; Kalkis, H.
Modern economic research divides all economics into structural levels: mega - economics, macroeconomics, meso - economics, micro - economics, and nano - economics. From the point of such traditional divisions, the research is topical in the primary economic struct ure of society – nano - economics – and thanks to this work operations can be subdivided into workplaces in the form of transformation processes. The aim of the research is to develop ergonomic modelling parameters and to discover the influence of ergonomics on the planning of workplaces ba sed on a case study. The research involved a study of workplace ergonomic planning methods and principles. Solutions for a series of problems which are related to the improvement of workplace ergonomics may be discovered in the following ways: improving wo rk organisation in every workplace by using work process - related micro - elemental methods and a determination of work expenditure, the levels of physical strenuousness involved in the work, the complexity of the work, and the social importance of the workpl ace. These parameters will allow the workplace quantity characteristics to be discovered, such as in terms of a generalised parameter which conforms to the requirements which describe a workplace, and in terms of operational management via the condition of workplaces and the salary systems being utilised. The research provides a case study in which ergonomic modelling parameters are developed and concrete workplace interventions are introduced.
The influence of drying method to the changes of bioactive compounds in lingonberry by-products
(2018) Ozola, L.; Kampuse, S.
The aim of this research was to evaluate the effect of different drying methods on industrially obtained lingonberry pulp juice by - products. For investigations, by - product was dried using hot air dryer (at temperatures 80 °C , 60 °C and 40 °C ), microwave - vacuum dryer and freeze - dryer. The freshly defrosted by - product was used as control. All samples were analysed on the basis of their moisture content, colourimetric attributes (CIE L*a*b* colour system), content of vitamin C (iodometric method), content of total carotenes (TC), total phenol content (TPC), total anthocyanin content (TA) and antiradical activity (DPPH, ABTS + ). The obtained data on content of vitamin C showed a 10% decrease between control and sample dried in hot air at 80 °C . Similar changes were noticed with total anthocyanin content, the lowest amount was also foun in this sample ( 306.72 ± 18.32 mg 100 g - 1 DW). Total carotenes content was higher in freeze - dried sample (5.61 ± 0.16 mg 100 g - 1 DW) which was very close to control sample. A significant loss of total phenol content was noticed after drying, up to 80%, similar ten dencies were noticed with changes of antiradical activity. After evaluating the obtained data, the use of hot air dryer at 80 °C temperature resulted in the lowest amount of vitamin C and anthocyanins in lingonberry by - products, which makes this method unsuitable for drying by - products of these berries. However, vacuum assisted microwave drying and freeze drying showed less damaging impact on dried material.
Assessment of Calotropis natural dye extracts on the efficiency of dye-sensitized solar cells
(2018) Alami, A.H.; Aokal, K.; Zhang, D.; Tawalbeh, M.; Alhammadi, A.; Taieb, A.
This work presents the construction and testing of solar cells sensitized with natural dyes extracted from plants indigenous to the desert. Calotropis plants are self - sufficient as they grow in very harsh environments, and yet are not consumed by humans or livestock due to their irritating agents to the skin and eyes. The energy generators of these plants are the leaves, which are crushed and processed to produce the dye solution. Also, the Calotropis leaves are covered in a white powder that is thought to aid in mitigating the heat by scattering incident radiation. This powder material is examined and added to the dye as it proved advantageous for the o verall cell efficiency, which reached 0.214% compared with 0.108% for cells with no powder. The produced cells are also compared with ones sensitized by spinach, another common natural sensitizer for dye - sensitized solar cells, and the performance proved t o be significantly better. The fact that Calotropis is a non - food plant is an added advantage to utilizing it as a dye source, along with its intrinsic heat resistance that allows it to survive the harsh desert conditions all year round.
Assessment of potato plant development from Minitubers
(2018) Dimante, I.; Gaile, Z.
In production of minitubers, mani pulation of their weight by modifying production method is common. Under field conditions plant development from minitubers can be affected by their weight, as well as cultivar. This objective of this study was to compare plant development from four minitu ber weight classes (MtC) (3 to 4.99 g, 5 to 9.99 g, 10 to 19.99 g, and > 20 g) with broken apical dominance of cultivars ‘Monta’, ‘Prelma’ and ‘Mandaga’. ‘Prelma’ and ‘Mandaga’ had a similar development pattern, and minitubers > 20 g required significantly less growing degree days (GDD) to emerge than minitubers from the lightest classes. The heaviest minitubers needed on average 176 GDD for 50% emergence and 207 GDD were needed for the lightest class. The difference in GDD between the marginal MtC was more pronounced in period between 50 and 80% emergence. MtC did not affect the final rate of emergence. Number of above ground stems (1.4 – 4.0) was significantly affected by MtC. ‘Monta’ had significantly different development – delayed emergence, lower emergen ce rate, less above ground stems, faster canopy closure. Our study showed that plant development was significantly affected by MtC and cultivar. Differences between MtC were more pronounced under adverse meteorological condi tions.
Importance of microclimate conditions and CO 2 control in educational buildings: a case study
(2018) Merisalu, Eda; Mugur, Danel; Kic, P.; Estonian University of Life Sciences. Institute of Technology
Current efforts to minimize energy losses and maximize energy savings for heating of all houses are most often gained by insulating facades and replacing windows. However, these measures can have a significant negative impact on human health and these problems can occur in buildings with a high concentration of people, such as school buildings. The aim of this paper is to analyse the results of measurements of air temperature, relative air humidity and carbon dioxide in winter period in the classrooms of two universities, Estonian University of Life Sciences (EULS) in Tartu and Czech University of Life Sciences (CULS) in Prague. The measurements have carried out in 2017  2018 in eight classrooms of the EULS and two classr ooms of the CULS. The external and internal temperature, relative humidity and concentration of carbon dioxide have measured in the classrooms during a few days in the winter period. In the lecture rooms of CULS, when the air conditioning was off, the leve ls of CO 2 exceeded the recommended levels about two times. The average internal temperature and CO 2 concentrations in the classrooms of EULS follows the norms and refers on good ventilation. The extremely low relative humidity in the classrooms of EULS at 17.1 ± 2.6% refers to a high risk of allostatic load and respiratory symptoms among students. It is important to pay attention on regular ventilation and relative air humidity control in the teaching rooms, especially with high number of students to preven t seasonal sickness of upper respiratory tract.
Field trajectories proposals as a tool for increasing work efficiency and sustainable land management
(2018) Kroulik, M.; Hula, J.; Brant, V.
Together with the requirement for higher productivity the average performance and the weight of agricultural machines are increasing. Agricultural land is increasingly exposed to pressures caused by agricultural machinery. The heavy agricultural machinery passes across a field are frequently associated with technogenic soil compaction. Soil compaction is one of the main problems of modern agriculture. From the previous measuring of the traffic intensity it was found 86.13 % of the total field area was run - o ver with a machine at least once a year, when using conventional tillage and 63.75 % of the total field area was run - over when using direct seeding technology, with dependence on the working width of the machines. Field passes are inevitable in present agri culture. As a result of the increase of total machines weight, it is necessary to optimize the traffic lines trajectories and limit the entries of the machines in the field. At present, the choice of traffic lines direction is based primarily on the experi ence of drivers or the practice of farmers. There are a number of influences that affect the machine work efficiency. Monitoring of the tractor, on an irregular 8 fields showed the following results. Eight - meter working width tiller or seeder brought short ening of total length of turns at headlands with the change in trajectory azimuth. For purposes of measuring the monitored tractors were equipped with monitoring units ITineris. An overview of the chosen directions of the trajectories and the lengths of wo rking and non - working passes was obtained. Based on the shape of the plot, the trajectory of the lines was also modelled. Suitable traffic lines directions in terms of the ratio of work and non - work passes were searched. Based on records of real trajectori es, the ratio of working and non - working path ranged between 6.3 and 15.2%. It was obvious from the results that the shortening of non - working passes and turns in comparison with the originally chosen trajectory directions was achieved by optimization. Thi s was especially valid for complex shapes of fields. Trajectory optimization leads to a reduction of total le n g th of path in all cases. The reduction in total length of path ranged from 69.7 m to 1 , 004.8 m. Changing the length of the working path ranged fr om 10.9 m to 264.9 m with the change in azimuth. The extension was observed in three cases. The highest part on the change of the overall length of the path presented nonworking rides.
Effect of PTO-driven tillage machines on soil particles transfer
(2018) Buřič, M.; Novák, P.; Hůla, J.
Displacement of soil particles by erosion can be seen as a major threat to the quali ty of agricultural land in the conditions of Czech Republic. While the effects of water and wind erosion have long been investigated and reported, the effect of soil tillage technology on soil particles translocation are relatively new area of agriculture research. Soil tillage may contribute to the undesirable translocation of soil particles towards lower - lying parts of fields especially on slopes. The effect of soil tillage implements on soil particle translocation has not been sufficiently explained yet. The object of this research was to assess the influence of PTO (power takeoff) - driven tillage machines on soil particle translocation during secondary tillage (soil preparation). Measurements to determine the displacement of soil particles were performed in location Nesperská Lhota in the Central Bohemia Region. Measurements were performed on a sandy loam cambisol after harvest winter cereals (winter wheat). To indicate displacement of soil particles was used grit of white limestone (size 10 – 16 mm). Limest one was put down into the trench with known position orthogonal to the direction of working operations. Subsequently were performed working operations in the specified sequence. Limestone particles were counted and weighed in each section. It was detected by measuring the different nature of displacement for each machine. Statistical significance of differences in the weight of translocated particles was evaluated for different type of machines.
Morphological and biochemical indicators of Fusarium oxysporum f sp. fragariae in strawberry crops (Fragaria x ananassa Duch) in the province of Pichincha, Ecuador
(2018) Salazar, S.; Bayas-Morejón, F.; Niño, Z.; Guevara, J.; Ruilova, M.; Merino, O.; Donato, W.; Guamán, J.
Fusarium oxysporum f. sp. fragariae is a fungal pathogen, transmitted by soil in crops of strawberry (Fragaria x ananassa Duch.), which causes wilt disease that, kill the strawberry cultivars. The disease caused by Fusarium oxysporum f. sp., fragariae is hard to detect as the of the symptoms are similar with other soil-borne diseases. In spite of detection methods targeted F. oxysporum using molecular criteria have been developed, they have not been shown to successfully identity the unique identity of F. oxysporum strain that causes this disease. In Ecuador, the cultivation of strawberry has acquired great importance for the consumption, promoting the increase of its production. However, the process of importing plant material from producing countries for the purpose of improving production has contributed to the spread of the fungus. The objective of this study was to identify the presence of the Fusarium oxysporum f. sp fragariae by means of morphometric identification and the application of biochemical methods (BIOLOG) in the province of Pichincha. Fifty-two diseased strawberry plants and 52 asymptomatic plants were analyzed. Of these, 13 isolates were identified by morphometry as F. oxysporum. However, through BIOLOG four strains were identified as F. oxysporum, 5 as Fusarium sp., 2 F. lateritium, 1 F. udum and 1 strain as F. sacchari. The results obtained through the identification and evaluation confirmed the presence of F. oxysporum f. sp., fragariae in evaluated strawberry cultivars, thus determining the high risk to exist if the pathogen spreads in new plantations in Ecuador.
Faults and the physical workload in sawing and packing-related woodworking processes when considering potential ergonomic solutions
(2018) Kalkis, H.; Roja, Z.; Babris, S.
The forest sector is a high - risk economic sector in Latvia, one in which manual work, awkward postures, the tightening up of individual muscle groups, and work monotony still exists. The aim of this study was to analyse the physical workload and fault modes, and their effects on the sawing and packing proce sses in woodworking when considering potential ergonomic solutions. Results show that packing operators and saw operators alike are exposed to severe loads, and these results coincide with survey results in which employees in these professions complain abo ut the physical load and mention lower back pain. Fault modes and their effects on the sawing and packing processes were analysed using Failure Mode and Effects Analysis, and the main errors which were revealed in packing operations were related to machine ry and lifting equipment, as well as to ergonomics and errors involving the human factor. The risk priority was calculated in terms of a figure. Financial indices were compared before and after any potential improvement in the sawing and packing processes. Analysis proves that investments in the improvement of ergonomics in relation to the automation of the production process saves human resources and is economically favourable when it comes to ensuring the sustainable development of the business in questio n.
Fodder beans and peas in the diet of dairy cows
(2018) Trūpa, A.; Ošmane, B.; Konošonoka, I.H.
The Holstein - Friesian Black - and - White cows were grouped into four treatments groups according to the analogue principle (n = 4 × 5). Lactating dairy cows were included in the trial in the initial lactation phase with the average milk yield of 23.00 kg per day, fat content 4.10% and 3.20% protein content in milk. The analyses of the chemical composition of legume grains show, that crude protein and undegraded intake protein (UIP) were higher in fodder beans than in peas, respectively 29.97% and 25.04% of dry matter but UIP content, respectively 40.51% and 39.69% of crude protein. There was a total of 17 amino acids detected in legume grains and soybean meal. The highest concentration of arginine, leucine, glutamic acid, aspartic acid and isoleucine was in fod der beans, respectively 0.76%, 0.58%, 0.67%, 0.42% and 0.29% more than in peas. Even though the daily milk yields decreased for all the cow groups during the experiment, which was normal during the lactation period, yet the milk yield decreases for the tri al groups. The highest total amount of amino acids in milk was detected in 3 rd and 2 nd trial cow groups, respectively, 4.00 g kg - 1 and 3.90 g kg - 1 which was fed fodder beans and peas. The milk sale and feed cost summary records for the trial that lasted 90 days show that economic efficency of peas plus beans has been positive.
POST herbicide programme for effective weed control in winter wheat (Triticum aestivum L.)
(2018) Pacanoski, Z.; Mehmeti, A.
Field experiments were conducted during two winter wheat - growing seasons to evaluate the efficacy of some new POST herbicides and herbicide combinations for those effective controls of weeds in winter wheat crops in the Republic of Macedonia. The weed population consisted mainly of annua l winter and spring and some perennial weeds. Weediness comprised 116 and 208 plants m - 2 in 2012 – 2013 and 2013 – 2014, respectively, in the Skopje region, and 93 and 114 plants m - 2 in 2012 – 2013 and 2013 – 2014, respectively, in the Probištip region. All POST h erbicides effectively reduced dominant weeds density ( > 93%) in the Skopje region in both years, as well as in the Probištip region in 2012 – 2013, but not in 2013 – 2014. In this year, lower temperature directly following application decreased efficacy of POS T applied herbicides, which provided control of Lolium perenne that was between 76 and 84%; control of A. ludoviciana was less than 85%; control of B. radians was no more than 83% and no one treatment controlled P. convolvulus more than 82%. Wheat yields i n the Skopje region were not significant among years for the different POST herbicide applications and ranged between 3,580 and 3,720 kg ha - 1 in 2012 – 2013, and between 3,760 and 3,910 kg ha - 1 in 2013 – 2014. A significant treatment by year interaction resulted in two distinct years for wheat yields in the Probištip region with POST herbicides. In 2012 – 2013, wheat yields were between 3,230 and 3,390 kg ha - 1 , but in 2013 – 2014, wheat yields ranged from 3,060 to 3,4 90 kg ha - 1 and weed - free control showed a significant higher wheat yield compared to all evaluated herbicides.
Analysis of indoor temperature in the workshop building during the summer: a pilot study
(2018) Cao, D.V.; Kic, P.
The aim of this paper is the presentation of measurements' results and the calculation method for analysis and evaluation of climate conditions as well for using of natural illuminance in two large simple buildings during summer which could be used to calc ulate power demand for the air cooling to reduce the indoor temperature caused by solar radiation. In this research, we carried out experiments of measuring the indoor temperature at level of working place which is 1.1 m, in two similar large workshops wit h floor area 260 m 2 and height 6.5 m, during several hot summer days. The indoor conditions were strongly influenced by the solar radiation as the buildings have large wall and roof windows. The indoor air temperatures in the first building achieved 39.5 ° C, which caused the heat stress for workers. The indoor air temperatures in the second building achieved only 29.5 °C. The calculated power demand for the air cooling to reduce the indoor temperature to 25 °C is 25 . 6 kW in the first building, the cooling p ower for second building is 14 . 9 kW. We investigated measured construction of the workshop and we set up the formula in order to calculate thermal balance. The measurement results and calculated results in two buildings are compared and summarized in the t ables and in the graphs for analysis. As a general conclusion, it must be said that solar radiation has a big influence on the air temperature and methods of passive air - conditioning should be more applied also on the production buildings in industry, agri culture and other branches of civil engineering to release heat increasing air temperature inside the building.
Concentration of air-borne microorganisms in sport facilities
(2018) Kic, P.; Ruzek, L.; Popelarova, E.
This paper is focused on the microclimatic research in several buildings and ro oms used for sport at the University. The attention is paid mainly to the problems of dimensions of space, capacity and activity of sportsmen, and influence of space ventilation. The air samples for microbiological analyses were taken by the microbial air sampler Merck Mas - 100 Eco and cultivated by potato - dextrose agar and nutrient agar. Captured microorganisms, are expressed as colony forming units per m 3 (CFU m - 3 ). Measurement results showed that bacteria average quantity was statistically significantly less without students (562 CFU m - 3 ) than with students (1,024 CFU m - 3 ). The students inside the rooms increased the bacteria concentration. From this point of view th e ventilation is not adequate for the removal of bacteria from ventilated spaces. From the results we can conclude that the great importance on the air quality in terms of a specific bacteria concentration has the specific volume of the room per one athlet e. The worst situation is in rooms with the smallest volume, which has the largest biological load of the space. The lowest quantity of bacteria was in the swimming pool all year round (152 to 300 CFU m - 3 ). The opposite situation was in average quantity of filamentous fungi, which was with students and ventilation (57 CFU m - 3 ) and without students but without ventilation (109 CFU m - 3 ). The pollution of air by fungi was higher without ventilation.
Application of conversion model for designing hydrodynamic pumps in turbine mode
(2018) Polák, M.
The use of the smallest water resources has been coming again to the centre of interest in recent years. A water engine – turbine, is the heart of these power plants. This is usually the highest expense for the investor, in terms of cost. The effort is therefore to seek investment less demanding alternatives. One of them is the use of hydrodynamic pumps in reverse turbine operation. This paper provides a methodology for conversion of parameters of the smallest power pumps (micro hydro sites) to turbine operation. The conversion model is based on the results of experimental research at the author's workplace and is suitable for pumps with low specific speeds and outputs. The pump design process for turbine mode is complemented by a practical example for a specific deployment site. This example also serves to verify the accuracy of the conversion model.
Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products
(2018) Kļava, D.; Kampuse, S.; Tomsone, L.; Kince, T.; Ozola, L.
During the pumpkin processing large amounts of waste material as a combination of pumpkin peel, seeds and the flesh between seeds has produced. Therefore it is important to investigate the possibilities for using the pumpkin residues. The aim of this resea rch was to investigate the effect of different drying technologies on maintenance of bioactive compounds in pumpkin by - products. Two pumpkin residue products of Hubard group pumpkins were used to obtain pumpkin powder: residue products formed in the proces s of extracting industrial pumpkin purée by heating it in a heat exchanger and treating through a sieve of pulpier; residues resulting from pumpkin juice extraction process mechanically pressed from fresh, chopped pumpkins. In order to be able to choose th e most suitable drying technology pumpkin by - products were dried in the microwave - vacuum, convective (at 40, 50, 70 and 80 °C ) and freeze - drying type dryers. For all samples total carotenes, the ascorbic acid, total phenols content (TPC) and antiradical ac tivity (DPPH ̇, ABTS ̇+ ) were determined by using standard methods. The highest total carotenes content was retained in freeze - dried pumpkin powders. The most suitable drying method for obtaining pumpkin powder with the highest ascorbic acid, total phenolic content and antiradical activity is drying in convective type drying at 80 °C temperature.
Efficiency of the use of field beans in fattening lambs
(2018) Kairisa, D.; Aplocina, E.
The breeding and feeding of self produced pulses to livestock is one of the important directions of research for reducing the production costs of livestock products. Experiment on the effective using of the field beans to lambs for fattening was arranged in three replications using the Latvian Da rk - headed breed male lambs. The mixture of concentrated feed consisted of 50% of bean and 50% of oat. Lambs were weighed at the starting and ending of the trial. Carcass quality was assessed according to the European standard for the classification of carc asses of sheep. The fattening period lasted from 37 to 94 days, on average 63 ± 3.6 days. The average live weight gain per day was 247.4 ± 13.85 g, and live weight increased on average by 15.3 ± 0.94 kg. Significantly higher ( P < 0.05) growth rate during fattening period reached lambs of 3rd group, where lambs started fattening above 27 kg of live weight, reaching a 276.8 ± 26.26 g daily live weight gain. The quality of the obtained carcasses was an average, and score for musculatu re was from R to O class, but the average score for fat deposition was from 3 to 4 points. The mixture of field beans and oats provided 19.3% of crude protein and 12.1 MJ of metabolizable energy per 1kg of dry matter, and its unlimited feeding provided med ium lamb's growth rate. The level of feed conversion was 7.56 kg of dry matter .
The impact of weather conditions on microclimate in storage facilities
(2018) Bradna, J.; Šimon, J.; Hájek, D.; Vejchar, D.
The key to maintaining good qualitative parameters of stored grain on farms is to achieve and maintain suitable storage temperatures relative to the outside temperature. In the framework of this research, the main focus was on typical representatives of grain storage facilities used in the Czech agriculture. In the post - harvest period after the crops were stored in the chosen storage facilities, the temperature of the material was monitored at 15 - minute intervals using an external temperature probe as well as the temperature and dew point of the outdoor air. A simple linear regression model was used for data analysis. The correlated temperature d ependence of the stored grain varies considerably in the monitored storage facilities. The storage halls were characterized by a low dependence (r = 0.2208) of the temperature of the material on the outside air temperature in the first 4 months following t he harvest when the grains were being stabilized by active aeration. In addition to the grain and the air temperature, the second focus was monitoring the dew point, i.e. assessing the risk of water vapour condensation on the surface in the upper layer of the stored grain, which is very undesirable for maintaining the quality of the stored grain. The results show that the monitored storage hall can be characterized by the ability to maintain the required climate due to outdoor climatic conditions. In genera l, this ability mainly depends on the type and design of the storage facility, the aeration system and also the storage capacity. Mainly during spring the dew point and water vapour condensation can often happen within the grain, therefore the need to focu s on appropriate measures such as reduced aeration or increased grain mixing, and thus avoiding the formation of critical spots.
The impact of the termination technology of agro-ecological service crops on soil properties in open field vegetable production
(2018) Tamm, Kalvi; Bender, Ingrid; Nugis, Edvin; Edesi, Liina; Võsa, Taavi
The agro - ecological service crops (ASC) are introduced in the agro - ecosystems to provide or enhance ecological services, thus promoting the whole soil - plant system equilibrium. To avoid competition with the subsequent cash crops, the growth of the interposed ASC is terminated in advance of the cash crop planting. The traditional, most widespread technique to terminate the ASC is incorporation as green manure into the soil by tillage (GM). However, since tillage includes energy and labour consuming and soil dis turbing operations, the use of no/reduced tillage techniques (as the roller crimping technology - RC) has received increasing interest. An international research consortium (SOILVEG) including Estonian Crop Research Institute, was established in 2015 with th e aim to study among others the impact of ASC termination on soil dry bulk density (BD), water content, soil structure and microbiological activity. Data are collected from Estonian tri als in 2016 and 2017 at Jõgeva. The physical properties of 0 – 40 cm soil layers were determined. Higher BD in soil layers (0 – 20 cm) of plots with ASC and RC was determined comparing to the GM and control plots. Bigger water content in same layer of plots with ASC and the RC was determined comparing to the GM plots. The use of the ASC - s helped to arise ratio of agronomically preferred soil particles. Microbial activity was estimated by assessing of enzyme dehydrogenase activity in 0 – 20 cm soil layer. There were no statistically relevant differences in soil dehydrogenase activit y (DHA) be tween the RC and GM treatments.

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