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Methodology adaptation and development to assess salt content dynamics and salt balance of soils under secondary salinization
Published June 1, 2021
199-206

The effect of irrigation with saline water (above 500 mg L-1) is considered a problem of small-scale farmers growing vegetable crops with high water demand in the hobby gardens characteristic of the Hungarian Great Plain. In order to simulate the circumstances of such hobby garden, we set up an experiment including five simple dr...ainage lysimeters irrigated with saline water in the Research Institute of Karcag IAREF UD in 2019. We regularly measured the electric conductivity (EC) of the soil referring to its salt content and the soil moisture content with mobile sensors. Before and after the irrigation season, soil samples from the upper soil layer (0-0.6 m) were taken for laboratory analysis and the soil salt balance (SB) was calculated. The actual salt balance (SBact) was calculated of the upper soil layer (0-0.6 m) based on the salt content of the obtained soil samples. The theoretical salt balance (SBth) was calculated by the total soluble salt content of the irrigation water and leachates. During the irrigation season, we experienced fluctuating EC in the topsoil in close correlation with the soil moisture content. Based on the performed in-situ EC measurements, salts were leached from the upper soil layer resulting in a negative SB. Combining SBact and SBth of the soil columns of the lysimeters, we estimated the SB of the deeper (0.6-1.0 m) soil layer. We quantified 12% increase of the initial salt mass due to accumulation. We consider this methodology to be suitable for deeper understanding secondary salinization, which can contribute to mitigating its harmful effect. By repeating our measurements, we expect similar results proving that saline irrigation waters gained from the aquifers through drilled wells in Karcag are potentially suitable for irrigation if proper irrigation and soil management are applied.

 

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The influence of channel network silting up at Žitný Ostrov to range of interaction between surface and groundwater
Published May 20, 2020
23-31

The movement of water resources, especially the possibilities of their regulation by interaction between surface and groundwaters are the subject matter of attention particularly during the occurrence of extreme hydrologic situation. This work presents the overview of knowledge and results which were achieved at IH SAS in this question. It ...can show the ways how to optimize the adjudicated processes which emerge during the requirement of emergency intervention. The solution of this task was located at the Žitný Ostrov area because this territory with their existence of channel network is suitable for studying the surface and groundwater interaction. The channel network at Žitný Ostrov was built up for drainage and also to safeguard irrigation water. The water level in the whole channel network system has an effect on groundwater level on the Žitný Ostrov and vice versa. It was been necessary to judge the impact of the channel network silting up by bed silts on the interaction between channel network and groundwater on the Žitný Ostrov. The aim was to evaluate the changes of bed silt state of Žitný Ostrov channel network and consecutively their influence on interaction processes between groundwater and surface water along the channels in the period from 1993 to present. The measurements of bed silt thickness in Žitný ostrov channel network had been started from1993, later they continued at selected profiles of three main channels – channel Gabčíkovo-Topoľníky, Chotárny channel and Komárňanský channel (for checking of the silting up variability). From 2008 the detailed field measurements of cross-section profiles aggradations along these selected three channels have been started. The objective of detailed field measurements was the determination of the silt permeability which is expressed by parameter of saturated hydraulic conductivity. This parameter was determined by two ways – as the saturated hydraulic conductivity obtained from disturbed samples of silt Kp and as the saturated hydraulic conductivity obtained from undisturbed samples of silt Kn. In the first case the granularity of silts was determined as a first step and then was computed their Kp from the empirical formulas according Bayer-Schweiger and Spacek. From undisturbed samples of silts which were extracted along the channels from top, middle and bottom layer of silts, were determined the values Kn by the laboratory falling head method. The valid values Kp on channel Gabčíkovo-Topoľníky ranged from
4,33 10-7 to 4,46.10-5 m s-1, on Chotárny channel from 5.98 10-5 to 2.14 10-6 m s-1 and on Komárňanský channel fluctuated from 1.93 10-6 – 6.09 10-5 m s-1. The valid values Kn on on channel Gabčíkovo-Topoľníky ranged from 5.21 10-8 – 4.18 10-3 m s-1 , on Chotárny channel ranged from 8.54 10-8 – 2.70 10-4 m s-1 and on Komárňanský channel fluctuated from 4.72 10-7 – 1.26 10-5 m s-1. The remarkable results were noticed by comparison of values of saturated hydraulic conductivity from disturbed and undisturbed samples Kp and Kn. On Chotárny channel the values of silt saturated hydraulic conductivity from undisturbed samples Kn approximately hundredfold decreased (from 10-6 to 10-8 m s-1). On Komárňanský channel the comparison of values Kp and Kn shown that the values Kn from undisturbed samples approximately tenfold descended against Kp.

Simultaneously, the bed silts‘ impact on the groundwater recharge (saturated hydraulic conductivity of silt) was also examined. Determination of the total recharge amount was done by numerical simulation (model SKOKY) and by the so-called method of interaction formulas. These two approaches were applied at the Žitný Ostrov channel network. There were field measurements performed in monitored three main channels and adjacent to obtain correct input data. These characteristics were used for simulation and computation of total recharge along the channels. The total recharge amount was calculated for four alternatives of the surface water levels in the channel and the surroundings groundwater respectively. We chose four simplified variants with the same geological conditions in surroundings area of channels, only water levels of groundwater and in channels were modified. The results of the simulations seem to show greater impact of the silt in the case of outflow from the channels to the surroundings than the inflow into the channel from the surroundings.

 

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Evaluation of nutrient conditions in open hydroponic system based on tomato production
Published November 15, 2007
116-119

Monoculture caused a gradual decline of soil conditions, while nematodes and salt accumulation stimulated the growers to choose alternative practices, such as soilless cultures, which proved their value in Western Europe. Exact statistics are lacking, but estimates deal with approximately 300-400 hectares of vegetable on rock wool, whereas othe...r substrates of soilless culture may multiply this number. Real perspectives are attributed to the forced production of pepper, tomato and cucumber.
Vegetable production in greenhouses may impair the ecological balance of the environment substantially as far as being uncontrolled. Soilless cultures especially should be handled thoughtfully. A fraction of the nutrients administered, more than 25-30%, is doomed to be lost in an open system, and the resulting ecological risk is accompanied with increasing costs of the production.
In Hungary, the quantity of nutrient elements in drainage water is unknown, et all. Connecting the production results with chemical analysis, we gain more information about it.
You can see a mathematical method for evaluation of nutrient and water conditions in tomato hydroponics production.

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Mitigation of the effect of secondary salinization by micro soil conditioning
Published May 20, 2020
115-119

This research has the general goal to meet the customization of agriculture in small scale farming. We are developing a technique using micro doses of soil conditioners and organic material applied in the root zone of vegetable crops. We expected to change the physical and chemical properties of the affected soil, which has been irrigated w...ith salty water. Two different soil conditioners were tested. A lysimeter experiment including 8 simple drainage lysimeters was set up in the Research Institute of Karcag IAREF University of Debrecen in 2017. The main goal was to study the effect of different soil conditioners on the soil endangered by secondary salinization induced by irrigation with saline water. In order to compare the difference between the treatments, we collected soil samples, water samples, and determined the yields. Chili pepper (Capsicum annuum) was used as an indicator crop during one specific agricultural season. The technique called micro soil conditioning is rational because several reasons. The roles of the technique are various, for example it can serve as a source of carbon or a container for soil amendments and can minimize evaporation. We found this technique not to interfere with the chemical reaction or the interaction with the plants. However, the micro doses of soil amendments had the role to minimize the risk of soil degradation and do not significantly influence soil respiration. In addition, by improving soil properties, soil conditioning increases the leaching of the excess of salts from the root zone. In fact, this technique can decrease the cost of the inputs and improves the production of vegetables, and at the same time mitigates the effect of secondary salinization.

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Amelioration and arable land-use possibilities of Solonetz soils in the Trans-Tisza region of Hungary
Published September 5, 2018
107-117

Salt affected soils cover about 1 million hectares in Hungary. This paper is based on the research results obtained at the Karcag-puszta long-term experimental site, where, depending on the catena, crusty (A horizon=0–7 cm), medium (A hor.=8– 20 cm) and deep (A hor.>20 cm) subtypes of the Meadow Solonetz soil could be found. The chemical... reclamation was made specifically for the given site. Lime was applied on the soils with neutral or slightly acidic top layer, while on the soils with alkaline top layer, gypsum was applied. As regards internal drainage, a tube system with an average depth of 1 m and 5, 10 and 15 m drain spacing was constructed. Decreasing salt and sodium content could be measured both in drained and non-drained soils. The advantage of drainage was that the leachingout extended to the whole layer above the drain pipes, while without drainage, the Na ions exchanged from the upper layers still accumulated at a depth of 60– 100 cm. In the first two decades, the groundwater level was deeper and leaching was the dominant process. Since 2004, due to the frequently high groundwater level, the leaching and deepening of the fertile top layer has been slower.

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Influence of Hydrological Parameters on the Biodiversity of the BerettyóRiver I.
Published December 6, 2005
215-229

The DIRECTIVE 2000/60/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL orders the measurement of the state of natural and artifical waters. We therefore applied environmental qualification methods, which allow inductions of the searched area in environmental management, conservation and water quality protection points of view. These methods are... accepted in interdisciplinary sciences, and are in use in Hungarian and international practice. We applied the range data measured along the Berettyó River, and ratified by the remote sensing, to count hydrological-hydraulical attributes of the stream, by the framework of the Hec-Ras programme. We processed the physical, chemical and biochemical water qualifications, determined the MMCP-index (the point-system of the Hungarian macrozoobenthos taxons), and estimated the Spencer index-numbers, which were based on complex environmental qualification and bioindication. Appointed, that the different results of researches are not inconsistent. This results together the spatial analysis reveal the natural and anthroponetic specialities of the river and the landscape, which determine the environmental flavours and biodiversity. The bioindicators represent better environmental status, than the physical, chemical and biochemical parameters. The natural conservationist importance of drainage canal network of Bihari-Plain is appreciated by these facts.

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The importance of millet production in regional production, with special emphasis on climate change
Published June 30, 2018
141-146
Regional production is a traditional production structure developed adjusting to the geographical, climatic, biological and soil conditions in given production regions, a certain territorial specification of agricultural production, and a type of farming that best fits the natural conditions and takes the biologic...al needs of plant and animal species into account as fully as possible. The most probable element of risk in plant production is the changeable, extreme weather. That is the reason why the specific characteristics of the place of production and the characteristics of regional production should be considered to a greater extent. The establishment of the range of varieties appropriate for the place of production is the key issue in regional production. One of our historically grown cereal plants that perfectly fits regional production is millet. Due to its short growing season, favourable reproduction ratio and the fact that it is relatively undemanding, it used to be grown in larger quantities in the middle ages. Its good nutritional values made it an important food item, but over time, as a result of industrialisation and technological progress; it has been eclipsed by other cereal crops. In our country it is mainly used to cook porridge, but it is also used in the form of flour and as a base material in the spirit drinks sector. In the recent decades, millet has been applied only in a small area, mostly as a secondary crop in areas that dried out from drainage water in late spring, or as a replacement of extinct sowings due to its late sowing time. Water will be the most significant factor for the future of agriculture, especially considering climate change.
My examinations took place in the area of the Institutes for Agricultural Research and Educational Farm of University of Debrecen, in the Research Institute of Nyíregyháza, in a small-plot experiment with four replications in 2016.
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