Sándor Koós

Carbon-dioxide emission measurements in a tillage experiment on chernozem soil

Introductions The terrestrial ecosystems are the biggest carbon reservoirs on the earth and soils, as part of these ecosystems, play a very important role in the global carbon cycle. Globally, in the upper one meter of minerals soils 1300-1500 Gt carbon is stored, which is twice more than the amount stored in terrestrial vegetation (Neill et al. 1998). Therefore a considerable part of the atmospheric carbon pool came from the terrestrial ecosystems, especially from soils (Lai, R et al. 1998). The atmospheric carbon dioxide concentration was approximately 280 mg/kg in 1850 and 365mg/kg in 1996, so it has been increasing at a rate of 0.5 % per year. Now, this rate has reached the 1.5% per year, so if this trend does not change, the COj concentration of the atmosphere can be about 600mg/kg during the 21st century. (Lai R. et al. 1999) Globally, the agricultural originated carbon getting into the atmosphere is estimated at 2.5xlOlsg. This loss has an effect not only on the global warming, but plays an important role in the long-term quality of soils (Bloodworth and Uri, 2002). The balance must be found between the highly disturbed and the non-tillage cropping systems applied in agriculture to ensure the least possible carbon losses from soils. (Nemeth et al. 1998)

Relation between carbon-dioxide fluxes and nitrogen content of soil in a long-term fertilization experiment

Introduction The fast-growing Earth population necessitated harvesting of greater productivity plants, which brings on the increasing of the nutrient supplying (manure and chemical fertilizer). The CO2 emission from natural origins has always existed, so the increased atmospheric concentration is due to the anthropogenic sources. The main human activities which influence the CO2 concentration in the atmosphere are the following: the chemical industry, the fossil fuel combustion and agricultural and land use changes. The agricultural sector contributes to the emission of greenhouse-gases in 25,6 percentage. The atmospheric concentration of the CO2 was approximately 280 mg kg -1 in the middle of 19 th century and 365 mg kg -1 at the end of 20 th century. If this tendency continues, the CO2 concentration will be above 600 mg kg -1 during the 21 st century (Lal et al., 1999). In point of view of the sustainable development and agriculture as well as the aspect of global warming this quantity is huge. Land use, land use changes and forestry are some of the important factors controlling or affecting the carbon cycle and have a great impact on the exchange of CO2 between terrestrial ecological systems and the atmosphere. Until the 1950’s 75% of the annual increase in atmospheric CO2 concentration came from changes in land use, agricultural expansion and soil cultivation. With the application of the good agricultural practices, the soil carbon sequestration can be increased with the result of reduced loss of soil organic carbon and increased humification rate, so it can be lead to the increased organic content of the soil (Nemeth, 2004).Due to the facts mentioned above, it is important to examine the CO2 emission among different field circumstances and to work out such management system, which can mitigate the emissions, improve soil carbon sequestration and increase the soil carbon content. Hence, we examined the CO2 emission in a long-term fertilization experiment.

Seasonal dynamics of mineral nitrogen in the 10th and 30th years of a long-term field experiment in Hungary

Abstract Long‐term field experiments are the most suitable tools for determining the optimal nutrient‐supplying technologies that contribute to sustainable agriculture. Under certain environmental conditions (low precipitation, deep groundwater table, negative water balance), part of the applied nitrogen (N) can be found in the soil profile for a longer period and provide N nutrition for crops. A long‐term field experiment has been running at Nagyhörcsök in Hungary since 1973. The nitrogen–phosphorus–potassium (NPK) application rates follow the overall nutrient‐supplying categories (weak, medium, adequate, excessive) by the main nutrients and their combinations. The seasonal dynamics of exchangeable NH4 and NO3 were followed in 1983 and 2003. From certain treatments, two parallel average samples (20–20 subsamples were mixed to get average composite samples by plots) were collected 19 times from March through November from three soil layers. There was no difference in NH4‐N between years, and its seasonal fluctuation was slight in both years, whereas there was an increase in NO3‐N in accordance with the applied N rates. No significant difference occurred in the NO3‐N of the N0P0K0 and the N1P1K1 treatments during both years. A significantly higher NO3‐N content was observed in the higher rate nutrient treatments. Both soil N forms were higher in 1983 than in 2003. Based on the experimental results, the fate and behavior of the surplus N in the soil can be characterized and the residual amount can be taken into account during the calculation of the N‐fertilization demand of arable crops in relation to the N‐fertilizer advisory system.

Soil carbon dioxide efflux determined from large undisturbed soil cores collected in different soil management systems

The aim of this study was to evaluate a measuring technique for determining soil CO2 efflux from large soil samples having undisturbed structure under controlled laboratory conditions. Further objectives were to use the developed measuring method for comparing soil CO2 efflux from samples, collected in three different soil management systems at various soil water content values. The experimental technique was tested and optimised for timing of sampling by taking air samples after 1, 3 and 6 hours of incubation. Based on the results, the incubation time was set to three hours. The CO2 efflux measured for different soil management systems was the highest in the no-till and the lowest in the ploughing treatment, which was in accordance with measurements on accessible organic carbon for microbes. An increase in CO2 efflux with increasing soil water content was found in the studied soil water content range. Our results indicate that soil respiration rates, measured directly after tillage operations, can highly differ from those measured long after.

Modelling of seasonal dynamics of nitrogen, phosphorus and potassium in the rooted zone

Our objectives were to assess and rank 3 soil condition variants - root zone improving (RI), mulch leaving (NIL) and minimum disturbing (MD) - suitability to soil quality improvement and demonstrate the plant responses to different soil state and rind a possible relation between soil condition and plant growth under extreme climate. To rank the soil-plant interrelations twelve soil and plant factors were assessed; quality and depth of loosening state, surface protection by plants and stubble residues, soil aggregation, earthworm number, water supply in the root zone, tillage-induced C-flux, rooting depth of plants, yield, dry biomass and biomass recycling. Finally, seven fundamental requirements were selected to mitigate climate-stress and to improve plant resistance to the heat damage. A climate damage mitigation soil tillage strategy can establish a harmony between soil conservation and the demands of crop production.The results of a small-pot experiment of cadmium-loading (5 mgkg) with the addition of zinc (5 mgkg) carried out are introduced in this paper. For this, soil samples were taken from 4 sites of plough-land, grassland and forest land-use types. Accumulation characteristics of the two metals as well as their interaction with the soil properties were analysed. The results show that land-use has significant effect on zinc uptake. There is close correlation between the zinc and cadmium uptake of plants as well as that cadmium concentration of soils plays an important role in it. Zinc shows positive correlation while cadmium shows negative correlation with organic matter. Beside organic colloids, inorganic colloids i.e. clay fraction also showed close correlation.The effects of soil and climatic properties was studied on the winter wheat (Triticum aestivum L.) concerning on the heavy metal content of the plants. During this study the distribution of cobalt, copper, iron, manganese, nickel, and zinc was studied within a plant. Sampling was carried out in the same period of subsequent three years between 1995 and 1997. Our hypothesis was that the individuals of the same species has similar physiological answer for the same environmental properties. In this study we found no significant differences among the different plant’s parts and years. Our results can reveal that the ecological indication of plants could be major driver of agro-environmental studies to recognize unusual patterns of soil attributes.

Evaluating the sustainability of different soil tillage practices using field measured electrical properties

Introduction Sustainable and soil conserving utilization of soils require knowledge of soil physical, chemical and biological properties affecting soil water, heat and nutrition regime. In Hungary soil moisture control prevention, elimination or moderation of extreme moisture situations is essential for sustainable land use and site-specific soil management (Varallyay, 2004). Soil tillage may play an important role in these actions (Soane & Ouwerkerk, 1994), especially under rainfed conditions, as in Hungary. Soils under tillage, however, have been found to be generally less stable than those under forest or grassland (Low, 1972). Soil physical degradation, reflected by changes in the shape of the soil water retention curve has harmful effects on soil water regime and on aeration (Stekauerova et al. 2006). When soil is degraded, the value of the soil water content at saturation becomes smaller and the slope of the retention curve at the inflection point, S also becomes smaller (Dexter, 2004). S has been found to be a useful measure of soil physical quality (Birkas et al., 2006). Soil properties vary strongly in space and time, thus, their determination is costly and time consuming. The need for more detailed information on spatial and temporal variation of soil properties (e.g. for precision agricultural utilisation) (Jolankai & Nemeth, 2002) lead to increasing interest over indirect methods for mapping soil properties. These methods allow overcoming the costs of detailed soil mapping based on traditional sampling. In-situ measurement of bulk soil electrical conductivity (ECa) is a quick and relatively easy method. The instrument readings show correlation with a number of soil properties that affect yield potential and environmental factors. This is why ECa measurements have been seen as one of the most promising methods. Several investigations have been carried out to study the relationship between the field measured ECa values (indirect measurements) and soil water, salt and humus contents, pH, mechanical composition and other soil properties. However, the relationship between data, obtained by indirect measurement techniques and soil hydraulic properties and soil quality indicators has not been widely examined yet. This paper studies the relationship between certain soil hydraulic properties, the soil quality indicator S and data, obtained from indirect field measurements in a long-term tillage experiment.

Evaluation of three semi-distributed hydrological models in simulating discharge from a small forest and arable dominated catchment

Abstract Catchment scale hydrological models are promising tools for simulating the effect of catchment-specific processes and management on soil and water resources. Here, we present a model intercomparison study of runoff simulations using three different semi-distributed rainfall-runoff catchment models. The objective of this study was to demonstrate the applicability of the Hydrologiska Byrans Vattenavdelning (HBV-Light); Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport (PERSiST); and INtegrated CAtchment (INCA) models on Somogybabod Catchment, near Lake Balaton, Hungary. The models were calibrated and validated against observed discharge data at the outlet of the catchment for the period of January 1, 2006 –July 12, 2015. Model performance was evaluated using graphical representations, e.g. daily and monthly hydrographs and Flow Duration Curves (FDC) and model evaluation statistic; Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2). The simulation results showed that the models provided good estimates of monthly average discharge (0.60–0.90 NSE; 0.60–0.91 R2) and satisfactory results for daily discharge (0.46–0.62 NSE; 0.50–0.67 R2). We found that the application of hydrological models serves as a powerful basis for ensemble modelling of average runoff and could enhance our understanding of the eco-hydrological and transport processes within catchments. On the other hand, it can highlight the uncertainty of model forecasts and the importance of goal specific evaluation.

Riolittufa mállásának hatása a talajok vízvezető képességére

A kovaval atitatott, alig mallott riolittufat feltaro furasban elenk vizmozgas volt megfigyelhető a fizikai aprozodas soran felnyilt kőzetrepedeseknek koszonhetően, a meresek alapjan szamolt hidraulikus vezetőkepessege a valyog–homokos valyog fizikai talajfelesegű szintekehez hasonlo. A megjelenese alapjan „vulkani homok”-kent aposztrofalt, mallott riolittufa viz-vezető kepessege az előzetesen vartnal kisebb volt, nagysagrendekkel maradt el a „tenyleges” homok vezetőkepessegetől, megjelenese jelentősen lelassitotta a szel-venyekben tapasztalt vizmozgast; szamolt hidraulikus vezetőkepessege nagysag-rendileg az agyagos valyogehoz all kozel. A tapasztalt jelenseg oka egyreszt az, hogy a mallas soran a kőzetrepedesek eltomődtek, eltűntek, masreszt pedig az, hogy a mallott agyagos resz a durvabb szemcsejű „mallasi maradek” porusterebe uleped-ve a nedvessegmozgas szamara rendelkezesre allo porusteret jelentősen lecsokken-tette. Az eredmenyek azt jelzik, hogy a szőlőteruletek termőhelyi adottsagait meghata-rozo ...