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Changes in weed flora of basket willow (Salix viminalis L.) under different soil nutrient supply
116-120Views:277The world is in a continuous progress, as a result of which energy consumption and with this the release of gases with adverse impact show rapid increase. As a result of the survey conducted by the International Energy Agency, if the major economic powers do not initiate a change in their energy policy, the increase of energy consumption may as well reach 40 % by 2030. This increased energy demand is getting more and more difficult to fulfill with the fossil energy resources, which is to lead to an increasing significance of renewable energy resources. In Hungary, these energy resources are the best to provide with biomass growth. Biomass growth for energetic purpose can mostly be provided by energy plants, out of which “energy willow” (Salix viminalis L.) is outstanding with its high yield and with its excellent burning technology characteristics of its timber. The willow’s cropping technology is being established in our country. One of our tasks is to work out an adequate weed control plan. The professional and safe use of herbicides can increase the success of production. In our paper, we discuss the weed flora data collected on treatments applied in the different fertilizer and compost. We started our survey in 2010. We examined twelve different fertilizer and compost treated areas. The dominant weeds were: Amaranthus retroflexus, Chenopodium album, Echinochloa crus-galli among annuals; Cirsium arvense and Agropyron repens among the perennials.
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Estimating the amount and heating value of wood waste burned in households based on FICM HWP model output data
79-84Views:471A 2009 study published by the Regional Centre for Energy Policy Research (RCEPR) sparked significant debate within the Hungarian forestry and wood industry sectors. The study suggested a substantial shortfall in the balance of solid bioenergy biomass usage and sources, which it attributed to large-scale illegal logging. The Bio Screen CCE Project updated this analysis and quantified a 37.2 PJ (43%) deficit in the solid bioenergy biomass balance for 2019. This study investigates the extent to which household wood waste burning could account for this shortfall. Using the Forest Industry Carbon Model (FICM) HWP submodel, the authors estimate that over 1.2 million m³ of wood waste may be burned annually in households. The heating value of this burned wood waste for 2019 is estimated at 14 PJ, explaining 39% of the shortfall identified in the Bio Screen CCE Project’s 2021 report.
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Objectives of the EU in the field of biomass use and utilisation
9-12Views:287The energy independence very important for the European Union, while simultaneously sparing the natural environment in order to increase the use of renewable energy sources . A further development is the key issue of how renewable energy sources available can be better utilized to improve the efficiency of economic competitiveness. EU renewable energy policy is determined by five principles : The first is the environment, including the carbon dioxide and other pollutants to reduce emissions . The second increase energy security and at the same time reducing dependence on imports. The third aspect of local and regional development. With this realignment of economic and social development levels of different areas they want to achieve. This point is closely related to rural development and create new jobs . The transformation of the agricultural structure is an important aspect , which is that they can reduce the overproduction of food by providing alternative land use options , such as the cultivation of energy crops.
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Meat meal and industrial fat as alternative fuels in agriculture
220-222Views:173I study new energy sources which can replace fossil fuels. As I deal with the burning processes, I have analyzed several kinds of wastes. I think one solution for replacing fossil fuels would be to burn regenerated energy sources in agriculture. For example, oil, industrial fat and meat meal from processing plants are treated as hazardous wastes. There exist non-hazardous wastes for energy recovery, as by-products e.g. sawdust, wood shavings, vegetable oils, stems of plants or poultry manure.
We should produce energy from the outsides of vegetables and juices, and should produce bioethanol by fermenting vegetable wastes. We could treat the used vegetable oil to make bio-diesel fuel. Meat meal and fat are good alternative energy forms, if burnt in incineration plants. These materials are new renewable sources of energy.
There are some problems in the use of biomass for energy sources. We have to look for the best loading device and burning processes. -
The effect of dissolved oxygen on common carp (Cyprinus carpio) and basil (Ocimum basilicum) in the aquaponics system
89-96Views:1170Aquaponics is an integrated system that combines fish farming (aquaculture) and hydroponic plant production. The objective of this study was to examine how the level of dissolved oxygen with or without an air pump affects water quality, fish output and plant growth parameters for common carp (Cyprinus carpio) and basil (Ocimum basilicum).
Ebb – and flood aquaponics systems (with automatic syphon) was used. Two treatments were set in this experiment, one of which was the aquaponics system without air pump (unit I), where water of the plant bed was pumped two directions, one falling back to the fish tank oxygenating the water the other was pumped to the hydroponics unit. The other system (unit II) was designed with an air pump.
In the course of the study, water quality parameters, such as oxygen saturation, dissolved oxygen (DO), electrical conductivity (EC) and nitrite were significantly different (p<0.05). Total basil biomass was higher in unit II. (5367.41 g). The final biomass of common carp were
2829.45 g ± 79.24 and 2980.6 g ± 64.13 g in unit I and unit II respectively. Weight gain (WG) and specific growth rate (SGR) showed no significant differences (p>0.05) between the treatments. -
Changes of some soil chemical and microbiological characteristics in a long-term fertilization experiment in Hungary
253-265Views:707Agricultural management practices – directly or indirectly – influence soil properties.
Fertilization rates and crop rotation can strongly affect soil pH, soil nutrient supply and soil organic matter content due to the changes of microbial processes. The objective of this study was to compare the effects of different fertilization doses in monoculture and tri-culture of maize (monoculture: only maize grown since 1983, tri-culture: it is a three-year crop rotation system: pea – winter wheat – maize) on selected soil characteristics. The long-term fertilization experiments were set up in 1983 in Eastern Hungary. These experiments are situated west of Debrecen in Hajdúság loess region, on calcareous chernozem (according to WRB: Chernozems).
The test plant was maize (Zea mays L.). One-one pilot blocks were selected from monoculture and tri-culture of the long-term experiments. The observed soil samples were taken in the 30th year of the experiment, in 2013. The doses of NPK fertilizers increased parallel together, so the effects of N-, P- and K-fertilizers cannot be separated.
With the increasing fertilizer doses, the soil pH has decreased in both crop production systems and, in parallel, the hydrolytic acidity has significantly increased. A close negative correlation was proved between the pHH2O, pHKCl and hydrolytic acidity. An increased nutrient content in soil was recorded in every NPK treatment and the available phosphorus and nitrate content increased in higher proportion than that of potassium. Of the measured parameters of C-and N-cycles, fertilization has mostly had a positive effect on the microbial activity of soils. Besides the effects of fertilizer doses, correlation were looked for between soil microbiological properties. Evaluating the ratios among the measured parameters (organic carbon and microbial biomass carbon, OC/MBC ratio; carbon-dioxide and microbial biomass carbon; CO2/MBC proportion), the fertilization rate seems to be favoured by the increase of amounts of organic compounds
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Sewage sludge compost as an alternative source of phosphorus to rye in acidic sandy soil
11-18Views:467Today, the use of chemical fertilisers is significantly determined by their production and purchase costs, which are high. In contrast, phosphorus (P) is present in sewage sludge in a form that is easy for plants to absorb. Good quality sewage sludge compost (SSC) could contain a high quantity of P, together with other macro- and microelements and organic matter. The effect of regular SSC application on soil characteristics as well as plant parameters has been studied since 2003 in Nyíregyháza in a small plot experiment. Focusing on the P in the soil-plant system, our hypothesis was that SSC covers plants’ P demand through enhancing soil P content and its plant availability in the acidic sandy soil. The effect of the SSC was examined at the doses of 0, 9, 18, and 27 t ha-1 on rye as a test crop. Some soil chemical parameters (pH, soil organic matter - SOM, ammonium lactate (AL) extractable P2O5), and the relationship between plant development (green weight, shoot length), physiological parameters (SPAD index), plant shoot P content, and soil available P content were studied. The obtained data indicated that the SOM content, pH, and available P content of the treated plots increased as a result of the long-term applied SSC compared to the control. Measurement of the relative chlorophyll content showed a strong correlation with the available P content of the soil, but surprisingly less correlation with shoot P content was found. The results of plant biomass and soil P content proved that SSC could be used as a low-cost and good source of P for plants.
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Soil Biological Activity within Integrated and Ecological Management of Soil
47-52Views:194The effects of the integrated (IS) and ecological (ES) management of soil on chosen parameters of soil biological activity were investigated in the period 1999-2000. The following characteristics were determined: biomass of microorganisms (Cmic), dehydrogenase activity (DHA), an amount of potentially mineralizable nitrogen (Nbiol), and nitrification intensity. Soil samples were collected from a stationary field experiment established in 1990 on gley brown soil at the Experimental Station of Slovak Agricultural University, Nitra. For each field with a different crop rotations two fertilization treatments were selected: (a) no fertilization and (b) use of manure for silage maize and, within IS, also mineral fertilizers. There was a statistically significant difference at α = 0.05 in the amount of biologically released nitrogen (Nbiol) between both systems and in the nitrification intensity in favour of ES. A higher amount of microbial biomass (Cmic) was noted for ES but without statistical significance. Cultivated crops and the timing of soil sampling were found to have the greatest effect on all the parameters observed in individual experimental years and within the two systems of soil management.
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Extras of the rural system of areas
271-273Views:228The essay describes the rural system of areas as a system unit of mutually necessitating natural, social, economic and human environments. A new rural developmental model has been developed to achieve the effects that strengthen this system. The taxonomically interpreted effects are achieved through guiding projects. The author presents the connections of biomass – bioenergy generation to covey the message in practice.
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Energy forests or vineyards?
237-240Views:200This paper primarily aims at giving an introduction to an alternative opportunity for vineyards owners many of whom have come to a
decision about elimination of their vineyards. The paper is focusing on the Mátra wine-region as a study area, which is the largest mountain
wine region in Hungary where more than one third of supported clearing of vineyards have been implemented in the last few years. The
abandoning of vineyards is explicable in more than one way such as very small average size of land or the increasing mean age of owners
etc. The fundamental reason is the chronic doubtfulness of the grape and wine market and the low level of overall profitability of production.
Grape production has a long tradition in this region, thus the disappearance of vineyards caused serious problems in land use through the
absolute lack of plans for the future. The popularity of biomass production in the press and the biofuel resultant from vine stocks raise
interest for short rotation forestry within a group of farmers. Short rotation forestry offers a new chance for some farmers to cut oneself adrift
from the harmful effects of the market of agricultural products. -
Survey on energetic short rotation forestry systems – Possibilities of spatial development and job creation
7-11Views:202Both the European and the Hungarian rural areas suffer multi dimensional problems. Beside infrastructural under development the most important difficulty is employment. Unemployment is significant in the rural areas, while other structural characteristics like education, profession, work circumstances and seasonality worsen this unfavourable situation. It can be stated that the challenge with the highest priority in rural and spatial
development is to create jobs and to strengthen local employment. The authors examine the job generating possibilities of energetic biomass of agricultural origin in a structural point of view. The aim is to develop spatial biomass product line models that permanently support the raise of employment by utilizing the possibilities of the European Union support policy and the popularity of this branch. -
Influences of different organic fertilizers on nutrients of humic sandy soil and on the growth of Spinach (Spinacia oleracea L.)
23-28Views:682A greenhouse pot experiment was conducted to compare the effects of manure with different origin (horse, cattle), various bedding materials (straw, sawdust) and diverse doses (30 t ha-1, 60 t ha-1) and the impact of food waste compost on the plant growth and the available plant nutrient content of soil. The study was conducted on humic sandy soil and consisted of 9 treatments in a randomized complete block design with four replications. Spinach (Spinacia oleracea L.) was grown as the test crop. The treatments were: 1. unfertilized control; 2. horse manure with straw (30 t ha-1); 3. horse manure with sawdust (30 t ha-1); 4. cattle manure (30 t ha-1); 5 food waste compost (30 t ha-1); 6. horse manure with straw (60 t ha-1); 7. horse manure with sawdust (60 t ha-1); 8. cattle manure (60 t ha-1); 9. food waste compost (60 t ha-1). Plant growth was monitored for 4 weeks. Shoot and root weights per pot were measured, total biomass weight per pot were counted.
On the basis of the results it can be concluded, that among treatments the application of horse manure with straw enhanced spinach growth most significantly compared to other treatments and to the non-treated control, resulted the highest weights of leaves and roots of spinach. At the same time even small dose (30 t ha-1) of this fertilizer caused increased plant available nitrogen and phosphorus of soil and the higher dosage further increased these values. The horse manure with sawdust applied in lower dose did not alter the leaves and roots weights, but higher portion (60 t ha-1) caused significantly decreased plant biomass. The results proved that the bedding material may significantly alter the composition of manure and may change the plant nutrition effect of organic fertilizer. Cattle manure and food waste compost in both applied doses enhanced plant growth. Both fertilizers increased the plant available nitrogen forms and phosphorus content of soil, but cattle manure caused higher increase.
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Plant production possibilities on a heavy metal contaminated soil with the purpose of biorefinery
215-222Views:278Significant part of not cultivated area of Hungary is not suitable for agricultural utilization because of industrial
pollution. Technologies of biorefinery make reutilization of contaminated areas possible. Biomass of plants
produced on polluted soils can be raw material of valuable products. Applicability of biorefinery was tested on a
heavy metal polluted soil, where the contamination originated from previous mining activity. Complete biomass
utilization was aimed to obtain cosmetic ingredients, pharmaceutical agents, and precursors. During our research
work 88 plant species and varieties were produced and tested for potential utilizable components. Levels of
possible contaminants in these plants were monitored, and amounts of carbohydrates, protein, organic acid and
cellulose were determined as well. Different plant extracts were tested as potential sources of biologically effective
components or as raw materials for lactic acid fermentation. Our results show that biorefinery is a real possibility
for utilization of polluted areas. Numerous plants could be cultivated on contaminated areas without increased
levels of contaminants in their tissues, thus they can be sources of valuable compounds. -
Regional interactions of bioenergy utilization
159-162Views:163The backwardness of the rural areas compared to the cities poses a problem all over Europe. In Hungary, a relatively small size of the population lives in the capital, more than 80% of Hungarians live in rural cities or villages. The tension between the countryside and the cities is rather intensified and the symbiotic correlation would need to be restored. Many people migrate from the countryside, especially young adults, as they have no opportunities to find a job in their hometowns. This phenomenon poses big risks because getting a job is usually difficult everywhere and because fitting into a new environment always involves a lot of difficulties.
Non-renewable energies are restricted and they will not be accessible after reaching a certain limit. People’s everyday activities and the functioning of the economy presuppose the availability of the necessary amount of energy. In the future, a solution that provides the longterm stability of energy for the world will become increasingly necessary. There is a huge potential in bioenergy, more specifically in biomass. The building of biomass plants and putting them into operation creates jobs in the rural spatial environments: a locally available resource that can help in creating the energy safety of the country and the reduction of the dependence on import. The production of energy crops or the crops whose purpose of use is energy could help in strengthening the multifunctional character of agriculture and it can represent a source of income for those living off agriculture under the current uncertain conditions.
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Effects of some herbicides on the microbiological characteristics of soil nitrogen cycle under maize plantation
93-100Views:345Nitrogen is a key element for the living organisms and influence not only for the quantity but for the quality of the yield, considerable. Availability of nitrogen from the soil is influenced by several microbiological processes of the Nitrogen-cycle. Among the intensive agricultural production the herbicide application cannot be omitted more information needs therefore about the inhibitor effect of herbicides on the different microorganisms.
An experiment was set up on calcareous chernozem soil under maize culture. Effect of four different herbicides (Acenit, Frontier, Merlin, and Wing) was investigated. The effect of herbicides was measured to four microbiological parameters of the Nitrogencycle (abundance of nitrifying bacteria, nitrate solubilisation, biomass nitrogen and urease enzyme activity). There were singledouble- and five times of recommended doses of herbicides applied for two onsecutive vegetation periods.
From the results of the different doses of herbicides, the following can be stated:
– The Acenit has a stimulating effect on nitrifying bacteria in general. The Frontier and Merlin also influenced the quantity of nitrifyers, however in certain cases decreased in another cases increased the number of bacteria.
– The double doses and five times doses of herbicides was found to be increasing the nitrate content of soil, -especially in 2006.
– The quantity of microbial biomass nitrogen increased in the 60% of treatments and decreased in the 40% of the treatments.
– Except of the result of Wing in 2006 and Merlin in 2005, the effect of simple dose herbicides was the smallest on the urease enzyme activity. According to the results the effect of Merlin was positive; the effect of Wing was negative on the soil enzyme’s activity.
Regarding the application of four different herbicides in three different doses on the microbiological parameters of soil (at two consecutive years-) in 39% of the treatments has resulted a significant inhibitory effect, 28% of the treatments, however have significant stimulating effect on the parameters measured. More than 50% of the inhibitory effect was measured in case of the Wing, at more than 50% of the Frontier the microbiological parameters have not changed. -
Deproteinized plant juice as part of circular economy: A short review and brief experimental data
23-26Views:1922As the population of the Earth is constantly growing it generates an unmet demand for protein, which is an urgent problem. The protein extraction process is a potential solution, which offers high-quality plant protein suitable for animal and human nutrition at a favorable price. The process used within our project produces green juice from the green alfalfa biomass through pressing. After the coagulation of protein from this green juice, the by-product is called DPJ (Deproteinized Plant Juices) or brown juice. Our preliminary results match the international literature, namely that brown juice take up as much as 50% of the fresh biomass in weight. To utilize this by-product is a crucial part of the process to make it environmental-friendly and financially viable as well. The examined brown juice samples came from a small-scale experiment of alfalfa varieties carried out in the experimental farm at the University of Debrecen. According to our preliminary results, brown juice has high macro- and micronutrient values, furthermore, it has a potentially high amount of antioxidant compounds. The study highlights that brown juice is suitable as an ingredient in microbiological media, in plant nutrition as a supplementary solution, for feedstock and for preparing human food supplements or functional foods. The potential utilization of all biorefinery products makes it a very appropriate technology for today’s challenges.
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Impact of ammonium nitrate and Microbion UNC bacterial fertilizer on dry matter accumulation of ryegrass (Lolium perenne L.)
35-39Views:215Pot experiment was performed to investigate the effects of increasing NH4NO3 doses with or without Microbion UNC bacterial fertilizer
application on dry matter production of ryegrass (Lolium perenne L.). Experiment was set up on calcareous chernozem soil of Debrecen-Látókép and on humus sandy soil of Őrbottyán. The bi-factorial trials were arranged in a randomized complete block design with four replications. Grass was cut three times. Dry matter production was determined and the sum of biomass of cuts was calculated as cumulated dry weights. Analysis of variance was carried out on the data in order to provide a statistical comparison between the treatment means. The least significant difference (LSD5%) test was used to detect differences between means. On the basis of our results it can be concluded, that the dry weights of ryegrass cultivated on chernozem soil were higher than on sandy soil. With increasing nitrogen supply the dry matter production of grass significantly increased in both types of soils. In case of sandy soil the increasing effect was more expressed, but dry weights of this soil never reached the appropriate values of chernozem soil. Application of Microbion UNC had positive effect on dry matter production of ryegrass grown on both two types of soils but the effect was more expressed on chernozem soil. Finally it can be concluded that the increasing effect of NH4NO3 on biomass weights was more expressed in both types of soils, the biofertilizer application also increased the dry weights of plant in a small degree. -
The use of renewable resources is an opportunity and an obligation
13-17Views:237The renewable energy sources could be used in energy production, while no or only very slightly emit harmful substances to the environment. The solar, wind, hydropower, biomass and heat rational utilization of land contributes to greenhouse gas emissions.
Renewable energy sources also reduces the dependence on fossil fuels, thus contributing to increase security of supply. The creation of local jobs to strengthen the area's population retaining ability. -
Comparison of the technological background of aquaponic systems
47-52Views:898Aquaponics is the combined culture of fish and plants in recirculating aquaculture systems, an ecologically sustainable horticultural production technique with long traditions.
The objective of this study is to compare flood-and- drain, and the water crossflow system and examine the differences in the water quality, fish yield and plant growth parameters for Common carp (Cyprinus carpio) and basil (Ocimum basilicum). During the study, water quality parameters of two treatments were compared in temperatures, pH, EC and NO3¯N were significantly different (p <0.05). Leaf area of the basil plants grew to an average of 20.37 cm2 (± 9.02 cm2). The plants’ biomass production was significantly different (p< 0.05) in the two systems. The biomass production showed lower yield, 458.22 g (± 214.59 g) in the constant flow system that in the flood- and- drain system 692.9 g (± 175.82 g). Fish Growth parameters were better in constant flow system (FCR 5.48 g/g ± 0.19). However, the specific growth rate (SGR) demonstrated that fish grew faster in flood- and- drain system 1.38 %/day (± 0.29).
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Spatial environment analisys of the bioenergy production and utilization
235-240Views:247The backwardness of the rural areas compared to the cities poses a problem all over Europe. Rural development and the reduction of differences between the development levels of the regions have expressed roles among the programs of the European Union. Member States are even entitled to subsidisation, they just need to manage subsidies economically. In Hungary, a relatively small amount of the population lives in the capital, more than 80% of Hungarians live in rural cities or villages. The opposition between the countryside and the cities is rather intensified and the symbiotic correlation would need to be restored. Many people migrate from the countryside, especially youngsters, as they have no opportunities to find any job. This phenomenon poses big risks because getting a job is usually difficult everywhere and because fitting into a new environment always involves a lot of difficulties. Also from the aspect of the national economy, migration from the rural areas to the cities is a problem. The state budget will face significant excess costs if someone moves from a village to the city. It could cause unpredictable consequences if people leave the villages, as the maintenance and development of the village living space will face a hopeless situation.
Non-renewable energies are restricted and they will not be accessible after reaching a certain limit. People’s everyday activities and the functioning of the economy presupposes the availabilty of the necessary amount of energy. In the future, solution that provide the longterm stability of energy for the world will become increasingly necessary. There is a huge potential in bioenergy, more specifically in biomass. The building of biomass plants and putting them into operation creates jobs in the rural spatial environments. A locally available resource that can help in creating the energy safety of the country and the reduction of the dependence on import. The production of energy crops or the crops whose purpose of use is energy could help in strengthening the multifunctional character of agriculture and it can represent a source of income for those living off of agriculture under the current uncertain conditions. -
Potential use of bamboo in the phytoremediation in of heavy metals: A review
91-97Views:992There are many literature sources focusing on the phytoremediation of woody plants, but there are only few dealing with the phytoremediation of bamboo plants. Phytoremediation technology has the advantages of little disturbance to the environment and low remediation cost. Bamboo mainly exists in tropical and subtropical regions. As an energy plant, bamboo has a fast growth cycle, large biomass, simple cultivation, high economic efficiency, and convenient harvesting, which highlights the advantages of bamboo in phytoremediation. In addition, bamboo plants have good tolerance and uptake ability to heavy metals and have high application potential and development value in uptaking heavy metal contaminated soil. However, due to climate, temperature and other reasons, bamboo cannot be widely planted in most countries. Research status of remediation of heavy metal contaminated soil by bamboo plants is summarized. The feasibility of its application in heavy metal contaminated soil is discussed in this paper. Aiming at the shortcomings of existing research, bamboo plants have a prospect in the field of plant phytoremediation for the future.
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Agricultural biogas plants in Eastern Hungary
79-81Views:289In the scope of the article, agricultural biogas plants which operate within the region have been analysed together with their linked livestock plants. The study attempts to describe the current condition and future opportunities of the sites. It also covers the description of energy production/use efficiency. The study contains the list of factors determining the economic operation of biogas plants. In the course of the analysis, types, amount and quality of energy produced of different raw materials have been determined within the decentralised energy production.
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Tools of promoting „energy-crops”
47-52Views:191The utilisation of renewable energy sources have come to front with the decreasing fossil fuel stocks, the unsolved problems and fears of nuclear energy and so the cumulating energy dependence. In Hungary the potential of biomass is the largest in renewable energy sources.
During our examinations, we analysed the promotion of producing energy crops in Szabolcs-Szatmár-Bereg county. With the examination of the territories involved in energy crop subsidies it can be stated that the energy crop subsidy had its promoting role only on those areas where because of the bad soil conditions the energy crop producing is more profitable than other alternative (non energy) crops.
The expected growth rate of energy plantations will be low, according to the low rate of subsidy intensity (40-60%). The uncertainty of direct area payments decreases the calculability that cuts back the favour of investment in short rotation forestry planting. -
Study of factors controlling the amount of 0.01 M CaCl2 extractable Norg fraction
437-449Views:360The use of new methods describing the “readily available” nutrient content of the soil is spreading on a global scale. The 0.01 M CaCl2 extractant is a dilute salt solution in which the easily soluble inorganic (nitrate-N and ammonium-N) and organic N fractions, P, K and micronutrients are also measurable. The 0.01 M CaCl2 has been tested in the University of Debrecen, Institute of Agricultural Chemistry and Soil Sciences since the 90’s. The results of the researches related to organic N fraction, performed in the last decades, and the results of the present study (originating from the long-term experiment of Karcag, 2007–2009) can be concluded as follows:The measurement of easily soluble and oxidizable organic nitrogen (Norg), besides inorganic fractions, could improve the nutrient management.The amount of the Norg fraction is determined by the soil conditions, therefore it is considered to be a site-specific parameter.Management practices and cropyear affect the amount of Norg as well. The present research confirmed that, the effect of fertilization on the amount of Norg can be explained by the changing of the yield (related to total biomass production), while the effect of cropyear is related to the differences in mineralization circumstances and yield as well.The measurement of the Norg fraction is increases the accuracy of N-supply, therefore it could prevent the environmentally harmful excess N application as well. -
Preliminary results on Siberian sterlet (Acipenser ruthenus marsiglii) fries rearing under intensive conditions
27-31Views:266In our experiments production performances of Siberian sterlet were tested under intensive tank conditions. During the 25 days long experiment effectiveness of weaning to artificial diet of the fish was investigated. Production performances of fish fed on exclusively dry diet from the beginnings were lower than the other two groups. Between the values of sterlets fed on live food also then suddenly vs. continuously were weaned to dry diet there were no significant differences. Based on our results live food feeding could be suggested for the Siberian sterlet larvae for some days but the method of the weaning to dry diet has no significant influence to the production performances.
In 21 days long experiment four different feeding frequencies were tested in Siberian sterlet (~13 g) fingerlings. Dry feed was offered for the fish continuously, 2, 3 and 4 times per day. There were no significant differences between the values of the four treatments. Based on our results there is no high influence of feeding frequency in case of this size group of Siberian sterlet.
During the nursing in two different size groups of Siberian sterlet the optimal daily amounts of feed were aimed to determine. In case of growth values of the group fed at 7% of the total biomass were higher than the other two groups (3 and 5%). Feeding performances of fish fed at 5% were significantly better than fish fed at 7%. Based on our results for ~20 g size of the subspecies at least 5% of total body weight could be suggested.
In case of ~150 g size of the fish the production performances of fish fed at 1% were lower than the other two groups (2 and 3%). Between the values of stocks fed at 2 and 3% there were no significant differences. Based on these results 2% of total body weight of dry feed could be suggested for the Siberian sterlet with ~150 g body weight.