Mathematical approaches for assessment and classification of the European Union member states based on the average yield of vegetables for the period 1961-2014

N. Keranova*

Faculty of Economics, Agricultural University-Plovdiv, 4000 Plovdiv, Bulgaria (Manuscript received 30 May 2017; accepted for publication 27 July 2017)

Abstract. The objective of this work is to analyze the statistical data on the average yield of vegetables in the European Union member states for the period 1961 – 2014. The EU countries are classified and grouped through hierarchical cluster analysis based on the average yield of vegetables. A mathematical model for evaluation of the received data is composed through a single-factor analysis of variance (ANOVA). The results show that the countries with the highest yields are Belgium (33.81 t/ha), Austria (29.39 t/ha) and the Netherlands (27.76 t/ha), while the lowest yields are in Bulgaria (4.05 t/ha) and Luxembourg (0.19 t/ha). Dependencies have been identified between the change in the average yields in Bulgaria, Greece and Romania and time. It was found that they were modeled by polynomial regression models of second degree.

Justification of a method for determining the moment for switching on the level one signaling of filled grain harvester hoppers

G. Tihanov1*, B. Kolev2, K. Trendafilov3, N. Delchev1, Y. Stoyanov1

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Agricultural Machinery, Agrarian and Industrial Faculty, “Angel Kanchev” University of Ruse, 7017 Ruse, Bulgaria 3Department of Mechanical Engineering, Faculty of Technics and Technologies – Yambol, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 4 January 2017; accepted for publication 11 April 2017)

Abstract. The main issue in the joint operation of a grain harvester and a transport vehicle is determining the moment when the vehicle has to start travelling to the harvester, so that it will arrive at it when the hopper is full. The result of the incorrect determining of that moment is that the productivity of the transport vehicle is not efficiently used and in the case when the hopper is unloaded at a harvester stantstill position, the harvester productivity is also reduced due to more frequent stops. The article proposes a method for determining the part of the grain harvester hopper volume after the filling of which the signalling shall be switched on indicating to the vehicle driver when to start moving toward the harvester. The results of real measurements are shown on different farms of the time of movement of the vehicle to the harvester for unloading. An analysis of the results has been made on the basis of the developed method as well and recommendations have been made to regulate the time of switching on the signalling. A nomogram has been proposed for determining the part of the grain hopper volume after the filling of which the signalling is to be switched on depending on the ratio between the time for moving of the vehicle and the time for filling the grain harvester hopper to the top.

Reclamation of soil excavated from construction and mine searching areas in Turkey

F. Apaydın

Department of Business Administration, Faculty of Economics and Administrative Sciences, Yalova University, Çınarcık Yolu, Yalova, Turkey

(Manuscript received 20 April 2017; accepted for publication 02 June 2017)

Abstract. Soil fundamental for life is a strategic entity for our country like other countries and both the government and institutions and society should make an effort to protect it. On fertile lands for different purposes construction is made and mines are searched and soil on these lands are called excavated soil and in most times lost. In this paper, the main purpose is to analyze the situation of fertile excavation soil and develop suggestions which are believed to be bases for academicians and practitioners. Another significant purpose of this paper is to make suggestions for reclamation of excavated soil. Methods used are observation of construction areas, content analysis of legal arrangements and comprehensive literature review. As a conclusion it is suggested that the mentioned soil should be reclaimed and earned for agriculture by carrying it and spreading it over unfertile land in other parts. In order to put this into practice, it is suggested that “soil protection plan” should be made compulsory for the project owners before starting any kind of construction and mine searching activities to reclaim fertile excavated soil. Some amendments are needed to be done by the politicians.

Ecological characteristics of reclaimed areas in Pernik mines region, Bulgaria

I. Kirilov*, M. Banov

Nikola Poushkarov Institute of Soil Science, Agrotechnologies and Plant Protection, Sofia, Bulgaria

(Manuscript received 5 August 2016; accepted for publication 29 April 2017)

Abstract. A referential literary analysis of the reclaimed area around coal mines near the town of Pernik, Bulgaria, is made in this paper. Affected areas (damaged, altered, etc.) around mining companies in the country are a serious environmental problem, including the territory of coal mines of Pernik which is a problem for the country. The area affected by the mining industry around Pernik occupies a territory of about 30 000 ha. As a result of the natural factors and the anthropogenic impact this region is characterized by a rather complicated soil situation. There are markedly expressed erosion and land-sliding processes on the slopes as well as conditions for surface over-humidification, swamping and salinization in some land lowering and on separate sections of the terraces of the rivers. The situation has acquired an exceptionally technogenic character after the development of the mines, the enormous pits and heaps and the construction of the industrial pads and equipment. The reclamation of environment in industrial areas is closely connected above all with the reclamation of disturbed areas and materials and can be performed in different ways according to their properties and economic effect. In connection with the extremely unfavorable conditions of a significant proportion of disturbed technogenic areas one of the basic methods is planting forests of production character or for recreational purpose. The inevitable degradation of the landscape can be corrected mainly by technical and biological reclamation of the disturbed terrains. A large part of the green belt of the town of Pernik was constructed on former heaps – mainly by afforestation. These activities have solved the problem of the separation of the town from the mining sites by a noise-preventing and dust-stopping embankment especially when the prevailing northwestern and northeastern winds are considered. Our main goal is to analyze and suggest the appropriate methods for biological reclamation of territories degraded by mining activities in Pernik coal mines region. That all proves the relevance and necessity of fundamental research and experimental work to identify opportunities for its targeted guidance and acceleration of the process. It has been established that almost all lands provided for agricultural uses are not cultivated and enter the fund of deserted lands. The basic reason for that fact is the lack of projects for biological reclamation and the insufficient justification of technical reclamation.

Heavy metal pools in urban soils from city parks of Sofia, Bulgaria

V. G. Kachova1*, I. D. Atanassova2

1Forest Research Institute, Kliment Ohridski Blvd. 132, 1756 Sofia, Bulgaria

2Nikola Poushkarov Institute of Soil Science, Agrotechnology and Plant Protection, 1080 Sofia, Bulgaria

(Manuscript received 4 April 2017; accepted for publication 30 May 2017)

Abstract. With a population ~ 1 300 000 million and an area of 1344 km2, Sofia, Bulgaria is one of the most densely populated cities in Europe with registered contamination of the air, water and soils of the city including heavy metals. The purpose of the study is to analyze the different pools under which heavy metals in urban soils exist. The chosen sites are the largest forest parks in Sofia. Cu, Zn, Pb and Cd in soil of samples were sequentially extracted and separated soluble F1 (70% ethyl alcohol solution), liable F2 (1N CH3C00Na, pH = 7), carbonate bound F3 (1N CH3C00Na + 1N CH3C00H, pH = 3), soil organic matter bound F4 (30% H2O2), amorphous iron oxide bound F5 (0.5 M Na-citrate), total “aqua regia” content and residual fraction F6 (measured as a difference from total). These operationally defined fractions give estimates of available (F1, F2), potentially liable (F3, F4, F5) and pseudo-total contents in soils, respectively. Metals were manly concentrated in the “residual fraction” F6. Organic matter associated is manly Cu and Pb, while carbonates-bound and amorphous iron oxides-bound were Pb and Zn. The mobility of the studied metals decreased in the order: Cd > Zn > Cu ≥ Pb. The soils with high pH and Cation exchenge capacity measured at pH = 8.2 (CEC8.2) show lower amounts of mobile (easily-available) forms of heavy metals.

Floristic diversity of ‘Chinarite’ protected area – Rodopi municipality, Bulgaria

L. Dospatliev1*, M. Lacheva2

1Department of Pharmacology, Animal Physiology and Physiological Chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora,
2Department of Botany, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria
(Manuscript received 10 June 2016; accepted for publication 21 March 2017)

Abstract. Study on the species composition of vascular plants in ‘Chinarite’ protected area in Belashtitsa village, Rodopi Municipality, Bulgaria was conducted using the floristic analysis method. A total of 147 species of vascular plants were identified, belonging to 124 genera and 51 families. The families Poaceae, Asteraceae, Lamiaceae, Brassicaceae, Apiaceae, Rosaceae and Fabaceae are the most highly represented. The comparative analysis shows that the angiosperm taxa are dominating in the studied area. Dicotyledonous plants are prevailing among them, while monocotyledonous are significantly less in number. Molinia caerulea species, identified in the present study, has not been reported to have been found so far in the Thracian lowland floristic region.

Modeling and simulation of fuzzy logic controller for optimization of the greenhouse microclimate management

Didi Faouzi*1, N. Bibi-Triki1, B. Draoui2, A. Abene3

1Materials and Renewable Energy Research Unit M.R.E.R.U, University of Abou-bakr Belkaïd, B.P. 119Tlemcen, Algeria
2Energy Laboratory in Drylands, University of Bechar, Bechar Algeria
3Euro-Mediterranean Institute of Environment and Renewable Energies, University of Valenciennes, France

(Manuscript received 21 November 2016; accepted for publication 8 June 2017)
Abstract. Agricultural greenhouse is largely answered in the agricultural sphere, despite the shortcomings it has, including overheating during the day and night cooling which sometimes results in the thermal inversion mainly due to its low inertia. The glasshouse dressed chapel is relatively more efficient than the conventional tunnel greenhouse. Its proliferation on the ground is more or less timid because of its relatively high cost. Agricultural greenhouse aims to create a favorable microclimate to the requirements of growth and development of culture, from the surrounding weather conditions, produce according to the cropping calendars fruits, vegetables and flower species out of season and widely available along the year. It is defined by its structural and functional architecture, the quality thermal, mechanical and optical of its wall, with its sealing level and the technical and technological accompanying. The greenhouse is a very confined environment, where multiple components are exchanged between key stakeholders and the factors are light, temperature and relative humidity. This state of thermal evolution is the level sealing of the cover of its physical characteristics to be transparent to solar, absorbent and reflective of infrared radiation emitted by the enclosure where the solar radiation trapping effect otherwise called “greenhouse effect” and its technical and technological means of air that accompany. The socio-economic analysis of populations in the world leaves appear especially the last two decades of rapid and profound transformations These changes are accompanied by changes in eating habits, mainly characterized by rising consumption spread along the year. To effectively meet this demand, greenhouse systems have evolved, particularly towards greater control of production conditions (climate, irrigation, ventilation techniques, CO2 supply, etc.). Technological progress has allowed the development of greenhouses so that they become increasingly sophisticated and of an industrial nature (heating, air conditioning,
control, computer, regulation, etc.) New climate driving techniques have emerged, including the use of control devices from the classic to the use of artificial intelligence such as neural networks and / or fuzzy logic, etc. As a result, the greenhouse growers prefer these new technologies while optimizing the investment in the field to effectively meet the supply and demand of these fresh products cheaply and widely available throughout the year, The application of artificial intelligence in the industry known for considerable growth, which is not the case in the field of agricultural greenhouses, where enforcement remains timid. It is from this fact, we undertake research work in this area and conduct a simulation based on meteorological data through MATLAB Simulink to finally analyze the thermal behavior – greenhouse microclimate energy.

Study on the process of unloading grain harvesters at the end of the field

G. Tihanov

Department of Agricultural Engineering, Faculty of Agriculture, Trakia University,
6000 Stara Zagora, Bulgaria

(Manuscript received 4 January 2017; accepted for publication 11 April 2017)

Abstract. The paper analyses the cases of unloading harvester hoppers at the end of the field. A passive experiment was carried out in two agricultural farms while harvesting wheat and rice, and the times that affect the unloading of the grain hopper have been measured when the harvester moves to the end of the field to unload its hopper. In chronometering the operations it has been established that 63% of the time for unloading grain hoppers at the end of the field is used for auxiliary operations and only 37% of the time is related to proper unloading of the grain hopper. It has been found that the time for moving the harvester to the vehicle at the end of the field has longer duration (t = 127.72 s) than the time when the harvester goes back to the strip of land to continue harvesting (t = 1 780.36 s).

Effect of pre-sowing soil tillage for wheat on the crop structure and the yield components in Dobrudzha region

P. Yankov*, M. Drumeva

Department of Plant Production, Faculty of Shipbuilding, Technical University Varna, 1 Studentska, 9010 Varna, Bulgaria

(Manuscript received 6 March 2017; accepted for publication 15 May 2017)

Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute on slightly leached chernozem soil. In order to clarify the effect of some types of pre-sowing soil tillage for wheat on the crop structure and certain yield components, the following variants of a stationary field experiment were analyzed: double disking at depth 10-12 cm (check variant); ploughing at 14-16 cm + disking; no-tillage (direct sowing) – pre-sowing treatment of the area with total herbicides. Wheat was sown after previous crop grain maize and was fertilized with N140P120K80. Wheat cultivar Enola was planted at norm 550 germinating seeds/m2. The number of emerging wheat plants was read using square sampling frames sized 50 cm x 50 cm. Using the same sampling frames, the tillering in autumn prior to the wintering of the crops was followed, and in spring – prior to booting stage. The number of productive tillers was also read using these sampling frames. To determine the length of spike, the number of grains in it, and their weight, 30 spikes from 8 replications of each variant were analyzed. The emerging of the wheat plants, under the conditions of slightly leached chernozem soil in Dobrudzha region, was more uniform after sowing following disking, and after direct sowing. The minimal pre-sowing tillage and no-tillage for wheat ensured better autumn development of the crop and the plants. In these variants, higher number of overwintering plants and productive tillers per unit area were registered. Spike length was the highest after ploughing as pre-sowing tillage. Significant variations in the number of grains per spike of the investigated variants were not found. Grain weight per spike was the lowest under direct sowing.

Analysis of the technological dairy cows traffic “to and from” herringbone milking parlors

K. Peychev, D. Georgiev*, V. Dimova, V. Georgieva
Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 5 September 2016; accepted for publication 13 March 2017)

Abstract. The aim of this study was to analyze the behavioral responses of milked cows and throughput performance of a herringbone milking parlor of capacity 2×10. For this purpose, 120 cows, of which about 100 milked, housed in an existing undivided compost bedded-pack barn (manure with minimum straw tilled on a daily basis), were investigated. Cows were milked three times per day in a 30-degree 2 x 10 herringbone parlor. A real-time monitoring system was designed, developed and installed to obtain the required information. A steady trend of difference between entrance and exit routines in cows from the left and right platform of the milking parlor was found. The most likely reason is the difference in illumination between the two milking platforms, and also direction of the exit traffic. Groups of cows who turned at 180˚ had longer exit time, irrespective of the shorter distance covered. Milking duration within the range of the three milkings showed a clearly defined rate. Morning milking was of the shortest duration, although the one-time absolute milk yield is the highest in the morning. The most likely explanation for it is the higher oxytocin release in the early hours of the day as a result of the reduced impact of the surrounding stress factor. Often cows from the left platform would come into contact with those from the right platform and delay movement to the selection gate. Therefore, an optically impenetrable barrier would be required to be installed on the gate.