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Practical experiences of a designing and operating a pilot aquaponic system
27-32Views:239Aquaponics is the combination of fish farming (aquaculture) and the soilless cultivation of plants (hydroponics). The aquaponics system is an artificial, recirculating ecosystem, in which bacterial processes convert the waste materials in the water used for fish rearing into plant nutrients, and therefore with the generated heat it is suitable for culturing economically valuable plants, and thus it mitigates the nutrient laden and quantity of the intensive fish producing systems’ effluent water.
The primary goal of our 12 separate unit’s aquaponics system was to gain experience. We would like to find the right plant species, which are fit for that medium, and their crop can be sold. Besides the plants, our attention focused on the fish. Two fish species were included in the experiments, the common carp and barramundi. It was difficult to create them a perfect living space, besides a constantly changing conditions temperature. Apart the above mentioned we had a problem with the number of individuals per tank, the deformity of the fish body and the too high volume of pH (we registered continuous values above 8.4). We get by carps 4.7 grams of weight gain during 15 weeks, because of the bad conditions.
The main problems at the plants are caused by aphesis and protection against sunburn. Even so we have got the multiples of field yields for each plant species. At salad has grown twice of field yields, tomatoes one and half, kohlrabi than 3.5 times more. The causes of multiple yields are the continuous balanced water and the nutrient uptake of plants. Each plant species fit for cultivating in aquaponics and their crops are delicious, chemical -free, safe and marketable. The plants should be more concentrated. After the experiment, it has been determinated that the carp is suitable for aquaponics, but greater weight gain could be achieved with optimal selection of size of rearing units.
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Determining elements of variety-specific maize production technology
157-161Views:62Our aim was to work out such new maize fertilizer methods and models which can reduce the harmful effects of fertilization, can
maintain the soil fertility and can moderate the yield fluctuation (nowadays 50-60 %).
The soil of our experimental projects was meadow soil. The soil could be characterized by high clay content and pour phosphorus and
medium potassium contents. In the last decade, out of ten years six years were dry and hot in our region. So the importance of crop-rotation
is increasing and we have to strive for using the appropriate crop rotation.
The yields of maize in monoculture crop rotation decreased by 1-3 t ha-1 in each dry year during the experiment (1983, 1990, 1992,
1993, 1994, 1995, 1998, 2000, 2003, and 2007). The most favourable forecrop of maize was wheat, medium was the biculture crop rotation
and the worst crop rotation was the monoculture.
There is a strong correlation between the sowing time and the yield of maize hybrids, but this interactive effect can be modified by the
amount and distribution of precipitation in the vegetation period. At the early sowing time, the grain moistures were 5-12 % lower compared
to the late sowing time and 4-5 % lower compared to the optimum sowing treatment.
There are great differences among the plant density of different maize hybrids. There are hybrids sensitive to higher plant density and
there are hybrids with wide and narrow optimum plant densities.
The agro-ecological optimum fertilizer dosage of hybrids with a longer season (FAO 400-500) was N 30-40 kg ha-1 higher in favourable
years as compared to early hybrids.
We can summarize our results by saying that we have to use hybrid-specific technologies in maize production. In the future, we have to
increase the level of inputs and have to apply the best appropriate hybrids and with respect to the agroecologial conditions, we can better
utilize the genetic yield potential. -
Improved soil and tomato quality by some biofertilizer products
93-105Views:237The use of microbial inoculums is a part of sustainable agricultural practices. Among various bioeffectors, the phosphorus-mobilizing bacteria are frequently used.
The objective of this study is to investigate the effect of some industrial biofertilizer inoculums, of containing P-mobilizing bacteria on the quantity and some quality parameters of tomato fruits. Spore-forming industrial Bacillus amyloliquefaciens FZB42 (Rhizovital) as single inoculums and combinations with other Bacillus strains (Biorex) were applied on Solanum lycopersicon Mill. var. Mobil test plant. Soil microbial counts, phosphorus availability, yield and fruit quality, such as total soluble solids (TSS) content and sugars (glucose, fructose) were assessed. The results found that single industrial inoculums of FZB42 product had positive effect on P-availability and fruit quality in the pots. Fruit quality parameters, TSS content, soluble sugars were significantly improved (p<0.05). Such better fruit taste was correlated significantly by the most probable number (MPN) microbial counts. Use of such bioeffector products is supported by the positive interrelation among measured soil characteristics and inside healthy quality parameters of tomato fruits.
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Microbiological preparations affecting the soil nutrient availability and growth of ryegrass in a pot experiment
49-53Views:136The 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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Effect of Irrigation on Maize Yield (Zea mays L.)
30-35Views:296We have been continually examining the fertilizer and irrigation reaction of commonly cultivated maize hybrids for nearly twenty years at the Látókép experimental station of the Center for Agricultural Sciences, Debrecen University.
Upon evaluating the results, it can be established that year significantly influences the size of yield. Between the years of 1999 and 2002, in the average of applied fertilizers the difference is 3,4 t/ha, but even in irrigated treatments it reaches 3 t/ha. This is more than the effect of irrigation. Of the applied agrotechnical elements, the yield increasing effect of fertilization is the greatest and can even be greater than the effect of year. The yield increasing effect of fertilization can be reliably detected with small and medium doses, but at higher doses a plateau section is reached, where it is not worth applying more nutrients. Cultivation with irrigation can only be done with appropriate nutrient supply, due to the positive correlation of the two factors. The positive correlation also means that if the water supply of the plant declines, less fertilizer is needed for safe production. The two factors (irrigation and fertilization) have to be increased or decreased at the same time.
According to the experiment, in unirrigated treatments, 90 kg/ha nitrogen and the related phosphorus and potassium are enough, while in irrigated treatments this was 120 kg. -
The effect of long-term fertilization on the 0.01 M CaCl2 extractable nutrient content of a meadow soil
73-79Views:93During my research, I studied the 0.01 M CaCl2 extractable NO3--N, NH4+-N, Norg, P and K contents of the soil samples originated from a long term fertilisation trial in the experimental site Hajdúböszörmény. Relationships among the soil nutrient contents, the agronomic nutrient balances of the 2009 year, and fertilization were studied.
From the results of the study it was concluded as follows:
– Fertilization significantly increased the CaCl2 extractable NO3--N, NH4+-N, and K contents of soil.
– Norg fraction increased as a function of the increasing yield. Hence, it can be assumed that the greater the produced yield, the more the stubble and root residues remain on the arable land. These organic residues can result significant increase in the Norg content of soils.
– The CaCl2 extractable P and K contents were compared with the calculated P and K limit values. According to these, the experimental soil has a good phosphorus and lower potassium supply capacity. These results are in accordance with the results of the conventional Hungarian fertilization recommendation system.
– It can be stated that the 0.01 M CaCl2 is able to determine not just inorganic N forms but Norg fraction as well that characterize the easily mineralizable nitrogen reserves. The results proved that AL-P and -K (ammonium lactate acetic acid, traditional Hungarian extractant) are in good agreement with the P and K reserves, but it is important from the aspect of environmental protection and plant nutrition to measure the easily soluble and exchangeable K-, and P-contents of soil. 0.01 M CaCl2 method is recommended for this. -
Effect of N, P and K fertilisers and their interactions in a long-term experiment on winter barley (Hordeum vulgare L.)
87-92Views:165The aim of this work was to analyse the effect of K, P and N supplies on the yield of winter barley in a long-term mineral fertilisation experiment with clearly distinct soil nutrient supply levels in order to develop fertilisation guidelines for winter barley growers. The experiment was set up in 1989 on a chernozem meadow soil calcareous in the deeper layers, applying all possible combinations of 4 levels each of N, P and K fertiliser, giving a total of 64 treatments.
The results of analyses performed in 2011 and 2012 can be summarised as follows:
- In 2011, when rainfall supplies were deficient in the shooting phase, improved K supplies (324 mg kg-1 AL-K2O) increased the grain yield, but in 2012, when rainfall supplies were more evenly distributed, K supply levels in the range 210–335 mg kg-1 AL-K2O had no significant influence on the yield of winter barley.
- An analysis of the P treatments revealed that, compared to the 119–133 mg kg-1 AL-P2O5 level (P0), better P supplies (186–251 mg kg-1) led to a significant increase in the grain yield.
- In both years rising N rates significantly increased the yield up to an annual N rate of 160 kg ha-1.
4. A K×N interaction could only be detected in the nutrient supplies of winter barley in 2011. The yield-increasing effect of N fertiliser was more pronounced at better K supply levels, while K fertiliser led to higher yields in the case of better N supplies.
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Changes of Quality of Winter Wheat During Maturing
105-112Views:84We analysed the flour of two winter wheat varieties to determine the effect of maturity state and grain position in the ear on the element composition of flour. Samples were taken from the 14th to the 42th day of anthesis. Ear samples were cut into three (basal, central and apical) parts, the trashed grains were milled, and the element compositions of the flours were determined.
We found that the grain position within the ear has an effect on flour element content. Flours of apical grains had lower nitrogen, phosphorus and sulphur contents than flours of central and basal grains. The nutrients can be divided into two parts, based on the formation of element content during maturation. Nitrogen, sulphur and copper contents changed continuously during maturity, while the P, K, Ca, Mg, Mn, Sr and Zn contents decreased until a specific value and became nearly constant in the second half of maturity. We found that – although the nitrogen concentration of flours changed continuously – the amount of nitrogen in the flours reached a constant value for the second half of maturity. -
The effect of compost made of sheep manure on the first cut of a semi-natural grassland
25-29Views:187In an experiment, two types of compost were tested on natural grassland in order to improve the productivity of a natural sward on solonetz soil. Both composts were made of on-farm produced sheep manure, but the second one was enriched in phosphorus. These fertilizers/composts are officially authorized and can be applied in organic farming. Zero application and three rates of fertilizer were tested (10 t ha-1, 20 t ha-1, 30 t ha-1) on 30 m2 experimental plots wit four replications. Dry matter, crude protein and net energy content for maintenance were measured and determined and their yields per unit area were calculated. We found that all the treated plots produced significantly higher yield than the control ones, and in some cases the yields were almost three times higher. However, the optimal compost dose varied, depending on the examined parameter. Based on the evaluation of the experiment results along with rainfall data, it was concluded that, with higher precipitation, the positive effect of the compost application was bigger. The difference between the natural and enriched compost is remarkable, but it has to be mentioned that even the natural compost showed good results; therefore, it is also effective in improving the fertility of grassland.
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Yield and sward composition responses of a native grassland to compost application
35-38Views:170A major part of the animal products are based on the grasslands, due to the fact that the grassland ecosystems can be found all over the globe. In places where economical and successful crop production cannot be realized, the grassland based animal husbandry can be an efficient way of food production. In addition these ecosystems have an important role in carbon sequestration, and with their rich flora – and the fauna connected to it – in conservation of biodiversity. The protection of nature, and the sustainable agriculture is getting more and more attention in the European Union, but looking at the consumers’ needs, the production of healthy food cannot be neglected either. Because of these facts, the effects of two specific composts - which are officially authorized in organic farming, in Agri-environment Schemes and Natura 2000 programs – on grass yields and sward compositions were investigated in a field trial. The investigation took place in Hungary, on a natural grassland based on solonetz soil. The first type of compost was a natural one (N) without any additional material and the other one was enriched in phosphorus (E). Both was produced by the research institute, made of sheep manure. Three rates of compost (10 t ha-1, 20 t ha-1,30 t ha-1) were tested on 3 m×10 m experimental plots. Every treatments had four replications and both type of compost had four-four control plots too, this way 32 experimental plots were included in the investigations. The yield of the pasture was harvested two-times (in May and in September) and before cutting the plots measurements on botanical compositions were made. Samples for laboratory analysis were also taken. Dry matter yield and crude protein content was measured in laboratory and with the received data the yield per unit area was calculated. Based on the research results we can say that the application of compost in any dose inflicts higher dry material and crude protein yield. The changes were partly due to some positive changes in sward composition, because of the better nutrient conditions. The research results indicate, that use of organic compost can be an efficient way to increase grass yields in a sustainable way.
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Comparative examination of a mineral fertiliser and a bacterial fertilizer on humic sandy soil
111-116Views:79In our pot experiment, the impact of a bacterial fertilizer, Bactofil® A10 and a mineral fertilizer Ca(NO3)2 applied in different rates was studied on some soil chemical and microbiological characteristics of a humic sandy soil (Pallag). Perennial rye-grass (Lolium perenne L.) was used as a test-plant. Samples were collected four and eight weeks after sowing in each year. The experiment was set up in 2007-2009 in the greenhouse of
the UD CASE Department of Agrochemistry and Soil Science. The available (AL-extractable) nutrient contents of soil, among the microbial parameters the total number of bacteria, the number of microscopic fungi, cellulose-decomposing and nitrifying bacteria, the sacharase and urease enzyme activity, as well as the soil respiration rate were measured.
Statistical analyses were made by means of the measurements deviation, LSD values at the P=0.05 level and correlation coefficients were calculated. Results of our experiment were summarised as follows:
− The readily available nutrient content of humic sandy soil increased as affected by the treatments, in case of the available (AL-extractable) phosphorus and potassium content the higher value was measured in high-dosage artificial fertilizer treatment.
− The treatments had also positive effect on several soil microbial parameters studied. The higher-dosage mineral fertilizer treatments had a beneficial effect on the total number of bacteria, cellulose-decomposing and nitrifying bacteria. No significant differences were obtained between the effect of treatment in case of the total-number of bacteria, the number of microscopic fungi and nitrifying bacteria.
− On the sacharase enzyme activity the artificial fertiliser treatments proved to be unambiguously stimulating, the urease activity significantly increased on the effect of the lower-dosage Ca(NO3)2 artificial fertilizer treatment.
− The soil respiration increased in all treatments in related to the amounts applied, significantly increased in the highest rate of Ca(NO3)2 fertilizer addition.
− Some medium and tight positive correlations were observed between the soil chemical and microbiological parameters studied in case of both nutrient sources.
Summarizing our results, it was established that the organic and all the mineral fertilizer treatments had beneficial effects on the major soil characteristics from the aspect of nutrient supply. In majority of the examined soil parameters (AL-extractable phosphorus- and potassium, total number of bacteria, number of cellulose-decomposing and nitrifying bacteria, activity of sacharase enzyme) the high rate of Ca(NO3)2 mineral fertilizer treatment proved to be more stimulating, but at the same time the high rate bacterium fertilizer resulted in significant increases in
the nitrate-N content, the AL-potassium content of soil, the total number of bacteria, the number of cellulose-decomposing and nitrifying bacteria and the urease enyme activity.
Our examinations showed that the mineral fertilizer treatments proved to be more stimulating on most of the soil parameters studied but according to our results, it was established that Bactofil is efficiently applicable in the maintenance of soil fertility and the combined application of
mineral fertilizer and bacterium fertilizer may be a favourable opportunity – also in aspect of the environmental protection – in maintaining soil fertility. -
Effect of Silver willow “Russian olive” (Elaeagnus angustifolia) on extensive sheep management
157-162Views:43We carried out a study in the Karcag Research Institute, which affected the areas of narrow-leaved silver willow. In the framework of this research, we performed Balázs's coenology, and thus established the degree of Borhidi degradation, which resulted in the fact that the areas of the silver willow were degraded practically irreversibly, the diversity of the grassland has decreased. We consider it very important to study these grassland areas of silver willows, as they can provide an additional fodder base for sheep grazing, which will also increase the sustainability of the grassland. The obtained soil analysis results show that the soil samples of the silver willow areas are richer in nitrogen (p-value: 0.006) and phosphorus (p-value: 0.003) than the examined control area.
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Study regarding the influence of the nPK fertilizers use in long term trial on heavy metals concentration in wheat grains
107-109Views:107The paper presents research results obtained in stationary experiments, carried out at Agricultural Research and Development Station Oradea, regarding the influence of nitrogen, phosphorus and potassium fertilizers, on Cd, Pb, Cu, Zn and Ni concentration on wheat grains.
The minimum concentration of cadmium in wheat grains was recorded in the case of the unfertilized plot N0P0K0, 0.12 mg kg-1, and maximum value 0.22 mg kg-1, was registered at the fertilized plot with N160P80K120, relative difference relative to control was 84.2%.
Lead concentration had the lowest value in the unfertilized plot, the value (0.4 mg kg-1) being under the maximum allowed (1.0 mg kg-1). In case of the fertilized plot with N160P80K120, the lead concentration had the highest value, 0.47 mg kg-1, but even in this case it was located beneath the maximum limit allowed.
In all four systems of fertilization, copper has not exceeded the maximum allowed limit (5 mg kg-1), the values have been comprised between 1.68 mg kg-1 at the unfertilized plot and 2.81 mg kg-1 at the fertilized plot with N160P80K120. In other plots of fertilization copper had concentrations of 1.97 mg kg-1, at the fertilized plot with N80P40K40, and 2.78 at the fertilized plot with N80P80K80.
The lowest concentration of zinc, 26.47 mg kg-1, has been registered in the control N0P0K0. In the other fertilization plots studied, the zinc concentrations had the following values: 27.66 mg kg-1 (N80P40K40), (N80P80K80) 29.87 mg kg-1 and 33.62 mg kg-1 (N160P80K120).
Nickel has registered the lowest value in the unfertilized plot, 3.47 mg kg-1. The fertilized plot with N160P80K120 had the highest value 4.94 mg kg-1, with 42.39% higher compared to the control N0P0K0.
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Examination of nutrient leaching dynamics of Solidago virgaurea in Hévíz Lake and Hévíz canal
207-211Views:92The different nitrogen and phosphorus elements are prime constituents of the ecosystem and can exert a major effect on aquatic species and the overall ecological cycle. During our investigation we examined the nutrient leaching dynamics in decomposing leaf litter (stem and leaf blades) of Solidago virgaurea. We chose four different sampling sites during the winter period with different water temperatures in the Hévíz Lake and Hévíz canal. The bottles containing the plant material and water were incubated at natural temperatures and the fluid was removed at particular times. Water parameters such as pH level, conductivity, nutrients (ammonium and phosphates) were measured. In the case of Solidago leaf, we obtained higher values for all parameters compared to the stem ones.