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Open access

Ladislav Kováč and Jana Jakubová

Abstract

The experiments aimed at the comparison of the growth and production parameters of sorghum with other field crops were established in the experimental workplaces CVRV-VÚA in Milhostov. In the course of favourable meteorological factors, the slowest initial development of vegetation height and dynamics of biomass accretion was observed in sorghum. From 15th August, however, sorghum accretion intensity significantly exceeded all the monitored field crops. The total cost of the cultivation of sorghum for silage accounted for 870.34 € ha-1 and of maize for silage 861.36 € ha-1. The difference resulted from different levels of material costs. In the experiment, the harvested amount reached 62.70 t ha-1 for sorghum silage and 54.20 t ha-1 for maize (33% moisture). At these yield and silage costs 33 € t-1, sorghum achieved a profit of 1198.76 € ha-1 without subsidy, while maize achieved a profit of 927.24 € ha-1. The yields exceeding 26.37 t ha-1 for sorghum and 26.10 t ha-1 for maize would be sufficient to achieve profits.

Open access

Ladislav Kováč, Jana Jakubová and Dana Kotorová

The Cost and The Economic Effectiveness Analysis of the Winter Rape Production Technologies (Brassica Napus L. SSP. Oleifera) on Heavy Soils

Winter rape farming practices were carried out between 2007 and 2009 on heavy soils under the conditions of the East Slovak Lowland. The influence of two levels of nitrogen fertilizers and three soil tillage technologies on winter rape seed yields was monitored. The costs of growing and the growing technology cost effectiveness were evaluated.

The influence of production year 2009 on winter rape seed yield was statistically significant. The effect of conventional tillage variant on rape seed yields was more significant compared with the variant with minimum tillage. The lowest yield of oilseed rape was obtained in a non-tillage variant. Higher dose of nitrogen fertilizers had higher statistically significant effect on winter rape yield compared with lower dose of nitrogen fertilizers.

The total cost of one ton of winter rape seed varied within the monitored years, different soil tillage technologies and levels of fertilization. In average of monitored years, the lowest costs of winter rape seed production were at minimum tillage (258.37 € t-1 for variant N150; 259.81 € t-1 for variant N200). At direct sowing, the costs were 400.14 € (variant N150), and 372.41 € (variant N200), however, the yields were very low.

Economic effectiveness evaluation showed that the winter rape produced by direct sowing was unprofitable, either with or without subsidy. The highest economic effectiveness was achieved at the minimum tillage variant. This variant was profitable even without subsidies, using both fertilization levels, but it was more profitable at the lower level of nitrogen fertilization. The profitability of conventional tillage variant was smaller.

Open access

Dana Kotorová, Jana Jakubová and Ladislav Kováč

Dependence of Heavy Soil Transport Function on Soil Profile Depth

The aim of this work was to quantify the effect of soil profile depth on the transport function of heavy soils. Treatments were carried out between 2006 and 2009 in Milhostov. Two variants were examined : the (conventional soil tillage and long-time no-tilled variant). Soil samples were taken in spring and autumn from soil profile depth of 0.00-0.60 m from each 0.10 m. For further evaluation the average values were used. Particle size composition, bulk density, total porosity and maximum capillary capacity were determined. Content of clay particles in soil profile was in interval 59.64-68.53% and such soils are characterised in the range from clay-loamy soil to clayey soil. The bulk density increased with the depth of soil profile and its values reached 1 184-1 646 kg m-3. The total porosity was in range 37.68-55.17% and it decreased with the depth of soil profile. The values of maximum capillary capacity were characterised for heavy soils with high content of clay particles. The depth had statistically significant effect on all observed parameters. In average, on both variants the bulk density was higher than 1 400 kg m-3, the total porosity was lower than 47% and the content of clay was higher than 30%, pointing to the possibility of soil compaction, which will result in reduced transport function of heavy soils.

Open access

Ladislav Kováč, Jana Jakubová and Danica Šariková

Abstract

Experiments with soybean on heavy soils of East Slovak Lowlands were established in the years 2010–2012. The effect of mineral fertilisers and soil conditioner application on soybean’s yield using three tillage systems (minimum tillage (MT), conventional tillage (CT) and no tillage (NT)) was studied. Production costs and economic efficiency of crop management practices were evaluated. The influence of production year on soybean crop was significant in the order of 2011, 2010 and 2012. Statistical evaluation confirmed that the effects of CT and MT systems were more significant compared with NT system. No significant differences were found between the variants of the mineral fertiliser and conditioner application. Differences in the total cost of soybean cultivation, as measured between years, were not significant. Fertilisation variants with application of HUMAC agro and NPK generated the highest costs. On the other hand, the lowest costs were achieved at fertilisation variants with application of NPK alone. Comparing tillage variants, the CT system had the highest costs each year. Significant savings were achieved on MT and NT variants. During the experimental period, a profit was reached on all variants. Applying NPK alone, the highest profit was achieved in 2010 and 2012 using MT system and in 2011 with CT tillage. The variant b2 with PRP sol in the years 2010 and 2011 was the most profitable using NT system and in 2012 using MT. Variant with HUMAC agro was the most profitable in each year using MT. The lowest income threshold for zero profitability was calculated in 2012. Using CT farming techniques at NPK fertilisation variant b1 in 2012, the income threshold was 1.85 t/ha, at variant b2 PRP sol it was 2.10 t/ha and at variant b3 HUMAC agro it was 2.42 t/ha. At MT and NT systems, the income threshold values for zero profitability were lower.

Open access

Božena Šoltysová, Ján Hecl, Ladislav Kováč and Martin Danilovič

Abstract

Three plots in Dry Polder Beša in Slovakia (E) and 3 plots in no flooded area (R) were chosen to assess the Cd, Pb and Ni contamination in the soil by using geo-accumulation index (Igeo) and anthropogenic contribution rate (ACR). Heavy metals content was measured at three depths (0‒0.2 m, 0.2‒0.4 m and 0.4‒0.6 m). It was found that the average content of Pb was 1.4 times higher and content of Ni 2.3 times higher at experimental area than at reference area. The average content of Cd were on the same level (E - 0.040 mg/kg, R - 0.041 mg/kg). The variability of heavy metals content in the soil was significantly influenced by soil depth and sampling plot and concentrations significantly correlated with soil organic carbon content (r - in the range of 0.41 to 0.65, p < 0.05). Geo-accumulation index indicates that the soils in the all of studied plots were polluted with respect to Ni, while were unpolluted with respect to Cd and Pb. Cd and Pb occurrence in these soils may be associated to the geochemical weathering. The value of the ACR indicate that anthropogenic input of Ni was 1.331 times higher in flooded area than in reference no flooded area. Different soil types can be arranged in descending Igeo values for Ni as follows: Luvisols ˃ Regosols ˃ Gleysols ˃ Chernozems. It was found that the content of Ni and Pb exceeded the critical values, in relation to transfer of contaminants from the soil to the plant , only at flooded area.

Open access

Miroslav Mikolášek, Michal Nemec, Jaroslav Kováč, Ladislav Harmatha and Lukáš Minařík

Abstract

In this paper we present the utilization of capacitance and current-voltage diagnostic techniques to analyse silicon heterojunction solar cell structures properties, particularly focused on the inspection of the amorphous emitter and amorphous silicon/crystalline silicon hetero-interface. The capacitance characterization of investigated samples have revealed the need for improvement of the a-Si:H/c-Si heterointerface quality as a main direction to obtain superior output performance of heterojunction cells. In addition, current-voltage characterization emphasized importance for enhancement of the light management in the structure. The obtained results demonstrate that electrical and capacitance diagnostic techniques can represents important diagnostic tools in the process of optimization of solar cells.

Open access

Arád Kósa, L’ubica Stuchlíková, Wojciech Dawidowski, Juraj Jakuš, Beata Sciana, Damian Radziewicz, Damian Pucicki, Ladislav Harmatha, Jaroslav Kováč and Marek Tłaczala

Abstract

In this paper authors present the results of identification of emission and capture processes in tandem solar cell structures based on quaternary InGaAsN semiconductor alloys by DLTFS (Deep Level Transient Fourier Spectroscopy) and by ana- lytical evaluation processes. The energies of five trap levels ET1=0.77 eV, ET2=0.47 eV, ET3=0.64 eV, HT1=0.62 eV and HT2=0.53 eV were identified with reliable accuracy. These values were obtained by available analytical procedures, verified by simulations and confirmed by reference structures with basic layer types and compared with possible reference trap data. Native structural defects in GaAs were stated as the origin of these deep energy levels