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Preliminary results of the combined production of duckweed Spirodela polyrhiza and common carp (Cyprinus carpio) in an aquaponic system
83-89Views:94As a result of population growth, increasin amount of food is needed, and agriculture is under an increasing burden to meet these needs. Traditional agriculture is often attacked due to its environmental impact. We must find alternative, environmentally friendly ways to produce more food. Aquaponics is a closed system in which we can produce both fish and plants at the same time. Duckweed species are small, aquatic, floating plants belonging to angiosperms. It can potentially be an alternative protein source, due to its high protein content, good amino acid supply, and rapid growth. Under suitable conditions, it doubles its weight in 2–4 days, and can reach a yield of 30 t ha-1 year-1in dry matter. It forms a carpet on top of the water and can be found in slow-moving or still waters. Since they are resistant to a wide range of nutrient concentrations, they are also suitable for cleaning wastewater (such as eutrophicated lakes, sewage reservoirs, liquid manure storage). Fish feed is the primary nutrient source for aquaponic systems, which usually contains fishmeal. If duckweed can be used as an alternative for fishmeal in the feed, it could improve the sustainability of the aquaponic and aquaculture systems. In this study, the aim was to develop an optimal harvesting protocol for duckweed Spirodela polyrhiza under aquaponic conditions. In a four weeks experiments, four harvesting protocols were set up, a control where only biomass measurements were made, a 25% group where 25% of the biomass at the time of measurement was harvested, and a 50% and a 75% group where at the time of measurement 50% and 75% of the biomass was harvested. Three replicates were used per treatment. We weighed the biomass every week and removed the amount corresponding to the group. Based on the preliminary results, it can be said that more biomass was obtained in the groups with the 25% harvesting protocol and the control group.
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Microbiological preparations affecting the soil nutrient availability and growth of ryegrass in a pot experiment
49-53Views:138The effects of different bacterial fertilizers and their combinations with NPK fertilizer and wheat straw were investigated on some soil properties (chemical parameters) and on the biomass production of testplant. The applied quantities of the bacterial fertilizers were the double of the recommended dose. The experiment was set up in 2013 at the Institute of Agricultural Chemistry and Soil Science, in a three replications, in a random block design. Calcareous chernozem soil; originating from Debrecen (Látókép) was used with ryegrass (Lolium perenne L.) test plant. At the end of the experiment (after 8 week) the samples of soil and plants were determined for nitrate-nitrogen, ALsoluble phosphorus and potassium content of soil, the weight of green biomass of ryegrass per pot, the dry matter and moisture content of ryegrass. Straw treatment resulted better water and available nutrient content of soil in general. Inoculation however was not improving the biomass production over the fertilizer treatment. Interrelation with the recommended dose could be further studied.
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Evaluation of water balance in apple and pear trees
193-198Views:124A significant proportion of the aboveground green and dry weight of the plant constitutes the foliage. The canopy is an important factor
of plant growth. On one hand the canopy absorbs the solar energy, which is necessary for the photosynthesis, on the other hand accumulates
the absorbed nutrients by the roots, and the most of the water-loss happens through the foliages. The determination of the full canopy is not
an easy target. In our research we developed a measurement method to determine the leaf area. With the parameters of the examined tree
(leaf length and maximum width) and the data of ADC AM 100 leaf area scanner we determined the k-value, with which we can easily and
fast evaluate the leaf surface. Furthermore we defined from the water balance of compensation lysimeters the cumulative transpiration of
fruit trees and the efficiency of water use of trees. -
The effect of different bacterial fertilizers on the AL-soluble P2O5 content of soil, and the biomass of the rye-grass (Lolium perenne, L)
93-98Views:204In pot experiment the effect of different bacterial fertilizers on some soil properties, and the amount of plant biomass were studied. The
experiment was set up in 2010 at the Department of Soil Science and Agricultural Chemistry, in a three replications in a random block design. The ryegrass (Lolium perenne, L.) was used as a test plant. The studied soil type was calcareous chernosem soil from Látókép. In our laboratory AL-soluble P2O5 content of soil, the phosphatase enzyme activityof soil, the dry weight of rye-grass, and the phosphorus content of rye-grass were determined.
The results of the study were the following:
– The bacterial fertilizers - by basic treatments NPK - had significant positive effect on the AL- soluble phosphorus content of the soil.
– The soil phosphatase enzyme activity was increased in all cases strongly by the microbial preparations used, the greatest impact was the Bactofil A bacterial fertilizer.
– The plant educed P values significantly increased by the effect of microbial products, in addition to the fund NPK. In this case, the EM-1 and Microbion UNC bacterial fertilizer were the effective.
– In case of the rye-grass biomass none of the bacterial preparations used caused any significant changes, either alone or when used them with straw treatment. -
Impact of chronic heat stress on digestibility of nutrients and performance of meat type ducks
51-55Views:191The aim of the study is to determine the effect of vitamin and mineral supplement under permanently high environmental temperature (30±1 °C) on the digestibility of nutrients, performance and furthermore the composition of duck meat in the growing period. A total of four hundred mixed sex 14 days old Cherry Valley type hybrid ducks were used for the study. Two experimental diets were formulated in the study (control and vitamin E, C and zinc supplemented diet). Based on the results the following conclusions were drown: the antioxidant defence system plays an important role in the reduction of heat stress generated lipid peroxidation process. Feed additives which have direct or indirect antioxidant effects can reduce the negative effects of heat stress on the ducks performance and meat composition. Digestibility of nutrients (Dry Matter, Crude Protein, Crude Fat) was not affected by antioxidant supplementation under chronic heat stress (30±1 °C). The performance was affected significantly by Vitamin C and E and zinc supplementation under heat stress (P<0.05). In the treated group the daily weight gain (dWG) increased and the feed conversion ratio (FCR) was improved significantly (P<0.05). The energy and protein conversion was decreased also significantly (P<0.05).
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Water managed properties of apple and pear trees based on lysimeters
129-132Views:162A significant proportion of the aboveground green and dry weight of the plant is constituted by foliage. The canopy is an important factor of plant growth. On the one hand, the canopy absorbs solar energy, which is necessary for photosynthesis; on the other hand, it accumulates the nutrients absorbed by the roots, and most of the water-loss occurs through the foliage. The determination of the full canopy is not an easy target. In our research, we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of the ADC AM 100 leaf area scanner, we determined the k-value, with which we can easily and fast evaluate the leaf surface. Furthermore, we defined from the water balance of compensation lysimeters the cumulative transpiration of fruit trees and the efficiency of water use of trees. From the examined trees were made a 3D depiction, which show the shape, branching and the location of trees.
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The effect of different fat content fish feed on the production parameters and meat quality of the hybrid striped bass
33-37Views:181The interspecific ’hybrid striped bass’ is the result of cross breeding. Their offspring have got good chances of growth and tolerate extreme water temperatures and the content of dissolute oxygen more than their parents. Furthermore, they are more resistant to diseases. Therefore, the hybrid is perfectly suitable for intensive fishery production.
Our experiment lasted for seven weeks. We analysed the indices of growth and production of the hybrid as the consequence of nurturing them with two feeds of high nutritive value during this period. We examined the content of fat and of fatty acids in the flesh of these fish. There were no considerable differences in terms of weight gain, feed conversion ratio and uneven growth between the two groups, while survival was less likely among the the fish which had consumed more fat. We demonstrated, examining the flesh of the individuals which had consumed feed containing lower fat content, that it was fattier and contained more dry matter than those that had been fed of higher fat content. Besides, the content of omega-3 and omega-6 fatty acids was higher in the fish that had consumed less lipids.
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Calculating possibility of the leaf area index of apple and pear trees
229-233Views:128A significant proportion of the aboveground green and dry weight of the plant constitutes the foliage. The canopy is an important factor of plant growth. On one hand the canopy absorbs the solar energy, which is necessary for the photosynthesis, on the other hand accumulates the absorbed nutrients by the roots, and the most of the water-loss happens through the foliages. The determination of the full canopy is not an easy target. In our research we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of ADC AM 100 leaf area scanner we determined the k-value, with which we can easily and fast evaluate the leaf surface.