Long-term analysis of soil water regime and nitrate dynamics at agricultural experimental site : field-scale monitoring and numerical modeling using HYDRUS-1D
- Authors: Krevh, Vedran , Filipović, Lana , Petošić, Dragutin , Mustać, Ivica , Bogunović, Igor , Butorac, Jaminka , Kisić, Ivica , Defterdarović, Jasmina , Nakić, Zoran , Kovač, Zoran , Pereira, Paulo , He, Hailong , Chen, Rui , Toor, Gurpal , Versini, Antoine , Baumgartl, Thomas , Filipović, Vilim
- Date: 2023
- Type: Text , Journal article
- Relation: Agricultural Water Management Vol. 275, no. (2023), p.
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- Description: Intensive agricultural practices increase agrochemical pollution, particularly nitrogen (N) based fertilizers, which present an environmental risk. This study aims to evaluate long-term (2009–2020) data on soil water regime and nitrate dynamics at an agricultural experimental site on fine-textured soils and to better understand the implications of N management in relation to groundwater pollution. The field site is located in the Biđ field (eastern Croatia), in the proximity of the Sava river. Zero-tension lysimeters were installed at six selected locations. Lysimeters were used to monitor the water regime, i.e., outflows in which nitrate concentration was measured, while additional soil-water samples were collected via 4 and 15-meter-deep monitoring wells. Soil hydraulic parameters were estimated by combining the laboratory measurements, and estimation in RETC software. Water regime and nitrate leaching in lysimeters were simulated using HYDRUS-1D for each year to allow crop rotation and to evaluate their effects individually. The HYDRUS-1D model successfully reproduced lysimeter outflows and nitrate dynamics, which was confirmed with high R2 values (water: 93% above 0.7, and nitrate: 73% above 0.7) indicating the good performance of the model simulating nitrification chain reactions. Principal component analysis (PCA) was performed to identify the relationships among all soil properties and environmental characteristics. The results showed the complex interaction of soil hydraulic properties, precipitation patterns, plant uptake, and N application. All locations have a decreasing trend of nitrate leaching over the investigation period. Most of the lysimeter outflows and elevated nitrate concentrations were connected to the wet period of the year when the soil was saturated, and evapotranspiration was low. The results of this study show that it is important to optimize N fertilizer applications for each particular environmental condition to reduce nitrate loss. The study indicates the importance of long-term field studies, key for agro-hydrological modeling and the improvement of agricultural practices. © 2022 The Authors
Characterising soil physical properties of selected temperate highland peat swamps on sandstone in the Sydney basin bioregion
- Authors: Shaygan, Mandana , Baumgartl, Thomas , McIntyre, Neil
- Date: 2022
- Type: Text , Journal article
- Relation: Journal of Hydrology: Regional Studies Vol. 40, no. (2022), p.
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- Description: Study region: Sydney Basin, New South Wales, Australia. Study focus: Some of Temperate Highland Peat Swamps on Sandstone of Sydney Basin overlie existing underground mining areas, which may impact the hydrological fluxes into and out of the swamps. Understanding and predicting these potential impacts and their consequences for swamps’ vegetation requires knowledge of the relevant physical properties of the soil, however such knowledge is almost completely absent from the literature. This study addresses this gap, and provides new insight into the degree and nature of variability between swamp sites, and between groups of swamps, the soil properties controlling these variabilities and the classification of these swamps in the context of peatland. Soil samples were collected up to a depth of 750 mm from ten sites in Upper Nepean and Newnes Plateau swamps. Samples were analysed for organic matter, bulk density, texture, saturated hydraulic conductivity and water retention characteristics. New hydrological insights: Not only the organic matter, but also bulk density and sand content control soil physical properties of the swamps. Soil properties vary between swamps; however, the variabilities were not large relative to those found in peatlands globally. These THPSS of the Sydney Basin cannot be classified as peatland and so their soil parameters cannot be estimated through the generalisation of peatland soil physical properties. It is concluded that the insights into soil properties provide new scope for developing hydrological models to assist in hydrological and ecological impacts analysis of the swamps. © 2022 The Authors
A small-scale test for rapid assessment of the soil development potential in post-mining soils
- Authors: Bucka, Franziska , Pihlap, Evelin , Kaiser, Jara , Baumgartl, Thomas , Kögel-Knabner, Ingrid
- Date: 2021
- Type: Text , Journal article
- Relation: Soil and Tillage Research Vol. 211, no. (2021), p.
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- Description: When ceasing brown coal mining activities, the restoration of the disturbed landscape is required, and a rapid development of functional soils is of utter importance for the rehabilitation of these areas. In order to accelerate soil development and rehabilitation, soils are designed or engineered by applying alternative approaches in order to construct a soil-like substrate, e.g., by mixing different substrates and organic carbon (OC) sources. We used a rapid and easy to perform laboratory approach to simulate the initial steps of soil development. We investigated the mixtures’ properties and the initial development of soil structure, in order to identify suitable soil mixtures for subsequent field trials. We tested six different mixtures composed of increasing complexity, based on the mixture used for a rehabilitation program at a coal mine in southern Australia. The components were overburden, fly ash, paper mulch, brown coal and plant litter. We performed a short-term laboratory incubation in regularly irrigated microcosms for forty days at constant water tension. Our results showed that the addition of fly ash to the overburden led to a higher moisture content. Fly ash together with paper mulch and brown coal improved nutrient supply and OC content, but led also to a very wide C/N ratio >95. The molecular composition of the paper mulch and brown coal OC shows the potential for long-term OC storage because of slow microbial degradation. Microbial activity, as measured by CO2 release, was high in all mixtures with litter addition, but only the additional presence of fly ash, brown coal and paper mulch led to a higher microbial carbon use efficiency (CUE). Soil structure formation, as measured by isolating water-stable aggregates, was induced in all mixtures and intensified in the presence of litter. In the mixtures with litter, there was a predominant formation of large macroaggregates (0.63−30 mm) which stored >80 % of the total OC. We suggest that the complex rehabilitation mixture indicates the potential for soil structure development within a short timeframe also in field scale, because the tested substrates are known to store moisture, deliver nutrients and OC for sustainable microbial growth. © 2021 Elsevier B.V.
Mapping the cumulative impacts of long-term mining disturbance and progressive rehabilitation on ecosystem services
- Authors: Wang, Zhenyu , Lechner, Alex , Yang, Yongjun , Baumgartl, Thomas , Wu, Jiansheng
- Date: 2020
- Type: Text , Journal article
- Relation: Science of the Total Environment Vol. 717, no. (2020), p.
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- Description: Open-cut coal mining can seriously disturb and reshape natural landscapes which results in a range of impacts on local ecosystems and the services they provide. To address the negative impacts of disturbance, progressive rehabilitation is commonly advocated. However, there is little research focusing on how these impacts affect ecosystem services within mine sites and changes over time. The aim of this study was to assess the cumulative impacts of mining disturbance and rehabilitation on ecosystem services through mapping and quantifying changes at multiple spatial and temporal scales. Four ecosystem services including carbon sequestration, air quality regulation, soil conservation and water yield were assessed in 1989, 1997, 2005 and 2013. Disturbance and rehabilitation was mapped using LandTrendr algorithm with Landsat. We mapped spatial patterns and pixel values for each ecosystem service with corresponding model and the landscape changes were analyzed with landscape metrics. In addition, we assessed synergies and trade-offs using Spearman's correlation coefficient for different landscape classes and scales. The results showed that carbon sequestration, air quality regulation and water yield services were both positively and negatively affected by vegetation cover changes due to mined land disturbance and rehabilitation, while soil conservation service were mainly influenced by topographic changes. There were strong interactions between carbon sequestration, air quality regulation and water yield, which were steady among different spatial scales and landscape types. Soil conservation correlations were weak and changed substantially due to differences of spatial scales and landscape types. Although there are limitations associated with data accessibility, this study provides a new research method for mapping impacts of mining on ecosystem services, which offer spatially explicit information for decision-makers and environmental regulators to carry out feasible policies, balancing mining development with ecosystem services provision. © 2020 Elsevier B.V.