Ágota Horel

Impact of expected climate change on soil water regime under different vegetation conditions

A mathematical model was applied for the Bükk Mountains (Hungary) to evaluate the effects of climate change on soil water balance elements and soil water regime. Model runs using SWAP model were performed for combinations of four distinctive soil types and three land use systems of arable land, grassland, and forest. The temporal variation of soil water regime under changing climatic conditions was examined considering no land cover change occurring in the future. The climate data consisted of the predictions of two regional climate models, the Swiss CLM and the Swedish RCA. The RCA results showed 45% to 50% and the CLM showed 5% to 14% higher future precipitation outlook compared to present conditions. Considering different land use types, the projected number of days with soil moisture deficit was the highest in forest ecosystems for both the upper 50 cm soil layer and the whole soil profile, which could be as high as 61% of days below optimal soil water content range. Our results showed increased water fluxes, especially in deep percolation in far future period and a strong influence of soil properties on the changes in the climate model results, indicating significant long-term effects of climate change on soil water regime.

Effects of vegetation at different succession stages on soil properties and water flow in sandy soil

Abstract The effects of vegetation at different succession stages on soil properties and water flow were assessed in sandy soil at 3 experimental sites near Sekule village (southwest Slovakia). Site S1 was a pioneer site dominated by mosses, site S2 was an early successional stage with a thin stand of grasses, and site S3 was an early successional stage (more advanced compared to the previous), richer in species, with a denser stand of grasses. It was found that vegetation at different succession stages affected soil properties and water flow in sandy soil, but the order of changes in some soil properties and water penetration depths were different from the order of succession stages.

Effects of Land Use and Management on Soil Hydraulic Properties

Abstract Soil hydraulic properties are among the most important parameters that determine soil quality and its capability to serve the ecosystem. Land use can significantly influence soil properties, including its hydraulic conditions; however, additional factors, such as changes in climate (temperature and precipitation), can further influence the land use effects on soil hydraulic properties. In order to develop possible adaptation measures and mitigate any negative effects of land use and climatic changes, it is important to study the impact of land use and changes in land use on soil hydraulic properties. In this paper, we summarize recent studies examining the effect of land use/land cover and the associated changes in soil hydraulic properties, mainly focusing on agricultural scenarios of cultivated croplands and different tillage systems.

Transport of iodide in structured clay-loam soil under maize during irrigation experiments analyzed using HYDRUS model

Transport of radioactive iodide 131I− in a structured clay loam soil under maize in a final growing phase was monitored during five consecutive irrigation experiments under ponding. Each time, 27 mm of water were applied. The water of the second experiment was spiked with 200 MBq of 131I− tracer. Its activity was monitored as functions of depth and time with Geiger-Müller (G-M) detectors in 11 vertically installed access tubes. The aim of the study was to widen our current knowledge of water and solute transport in unsaturated soil under different agriculturally cultivated settings. It was supposed that the change in 131I− activity (or counting rate) is proportional to the change in soil water content. Rapid increase followed by a gradual decrease in 131I− activity occurred at all depths and was attributed to preferential flow. The iodide transport through structured soil profile was simulated by the HYDRUS 1D model. The model predicted relatively deep percolation of iodide within a short time, in a good agreement with the observed vertical iodide distribution in soil. We found that the top 30 cm of the soil profile is the most vulnerable layer in terms of water and solute movement, which is the same depth where the root structure of maize can extend.

A hőmérséklet és a bioszén típusának, valamint mennyiségének hatása a talaj nettó nitrifikációjára

A vizsgalat celja kulonboző bioszeneknek a talaj nitrifikacios folyamataira gyakorolt hatasanak tanulmanyozasa volt. Kiserleteink soran elterő mennyisegű es tipusu bioszennel kevert talajt kulonboző hőmersekleten vizsgaltunk. Az eredmenyeink alapjan a legnagyobb kulonbsegeket a nitrifikacios potencialban a hőmerseklet eredmenyezte. Az alacsony hőmerseklet gatolta vagy nagymertekben lelassitotta a nitrifikacios folyamatokat. 20 °C valamint 30 °C hőmersekleten a nitrat kepződes hasonloan alakult, kiemelve a nyari időszakban tortenő minimalis bioszen hatast a nitrifikalo mikroorganizmusokra. igy elmondhato, hogy tavaszi időszakban a bioszen hatasa a nitrifikalo bakteriumokra a legkiemelkedőbb, 10 es 20 °C kozott. Magas hőmerseklet (30 °C) eseteben a netto nitrifikacios potencial akar haromszorosara is megnőtt a 20 °C-os hőmerseklethez kepest. Ugyanakkor elmondhato, hogy a magas hőmerseklet negativan befolyasolta a talajban levő mikrobialis kozosseget, kiemelkedően a CT bioszen eseteben. A kulonbsegeket a nit...

Soil CO2 Emissions in a Long-Term Tillage Treatment Experiment

Abstract The aim of our study was to investigate the effect of plowing (P) and no-tillage (NT) management on soil CO2 emissions from an arable field (i.e., winter wheat) in a 13-year-old experiment. In 2015, CO2 measurements were taken weekly in P and NT during the growing season and biweekly during the dormant season using the static chamber technique. Measurements were more frequent in a 7-day campaign scheduled right before and immediately after a soil disturbance caused by plowing to detect the short-term effects of soil management on CO2 emissions. We investigated the relationship among soil CO2 emissions, soil temperature, and soil water content. Soil CO2 emissions increased during the vegetation period and were higher in NT than P, although they were only significant from jointing to maturity stages. In contrast, CO2 emissions were higher in P compared to NT at a relatively short but well-monitored measurement interval just after plowing. Long-term systematic plowing resulted in lower CO2 emissions than that in NT during vegetation season, but a sudden pulse in CO2 emissions were detected in P directly after soil disturbance caused by plowing. These observations indicate that plowing can temporarily have a major effect on soil CO2 emissions.

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.