Groundwater Protection Legislation in Slovenia: Theory and Practice

As an EU member, Slovenia implemented the Water Framework Directive (WFD) guidelines into national legislation quite successfully, but in many parts of the country, groundwater is still under threat, mainly from nitrate. The problematic areas, as is the case in many other EU countries, are mostly shallow-soiled alluvial plains. Their groundwater is the country’s biggest source of drinking water, but at the same time, the fertile soil on their flat surface is considered to be the most suitable for agricultural activities. We are aiming to provide an overview of groundwater protection practices in Slovenia. To evaluate the “theory,” we will take a close look at the national legislation concerning the subject. From the “practical” perspective, we will research what guidelines and solutions were drawn from legislation to comply with WFD objectives. Furthermore, we will also discuss the current activities aimed at improving Slovenia’s groundwater status

Perspectives of Hydrologic Modeling in Agricultural Research

For decades agricultural research was done in the field or laboratories, but with the rise of computer science, hydrologic modeling became another essential tool for environmental impact studies. Many types of models can be used, each with its strengths and weaknesses in terms of accuracy, speed, and amount of input data needed. Models can be used on different scales and simulate very different processes. Based on a literature review, APEX (Agricultural Policy Extender) and SWAT (Soil and Water Assessment Tool) models are the most popular for environmental research in agronomy. An important share of modeling work in agronomic studies is focused on pollution research, mainly nutrient and pesticide leaching and soil erosion processes. Other topics include simulating the effects of irrigation and other agricultural practices and studying the impact of extreme weather events and climate change. When working with model results, it is crucial to be mindful of inevitable uncertainties and consider them during interpretation. Modeling is gaining importance in agronomic research in Slovenia, with many studies done in the recent decade and more underway

Assessing and mapping the environmental impacts of best management practices in nitrate-vulnerable areas

This investigation explores the impact of various management practices on nitrate leaching and crop yield in two specific areas in Slovenia. The issue of nitrate leaching from agricultural land is a worldwide threat to drinking water, and despite years of research efforts, universal solutions are still unknown. The two chosen study sites are significant because of their importance for agricultural production and because groundwater aquifers beneath are main sources of drinking water, which makes imposing mitigation measures challenging. One of the areas was reported to be of “bad” status according to the Water Framework Directive criteria, while the other is at risk of reaching this status if nitrate concentrations in groundwater continue to rise. This research used the SWAT model to simulate nitrate leaching and crop yield changes under different agricultural scenarios on different soil types. It aimed to accomplish two objectives: first, to identify parts of the case study areas where the existing combination of soil conditions and agricultural practices enables a high potential for nitrate leachingsecond, to identify agricultural practices that decrease nitrate leaching from various soil types while maintaining crop yields in each area. By identifying the most vulnerable locations and the most promising practices, we generated a chart of best management practices for specific soil types as a guide that extension services can use to advise farmers on potential management improvements. The main findings demonstrate that reducing fertilizer application, both organic and inorganic, in areas where the rates exceed crop requirements may not have a significant impact on crop production. However, these reductions often resulted in a noticeable decrease in nitrate exports. The results also showed that soil type is crucially important and should always be considered when evaluating the effects of agricultural management on crop yields and nitrate leaching

Analysis of nitrate pollution pathways on a vulnerable agricultural plain in Slovenia

Groundwater pollution with nitrate of agricultural origin is a major problem in many countries. A great deal of effort is focused on finding ways to reduce leaching from agricultural land. In this study, different land management scenarios were evaluated with the SWAT model in order to determine which are the most effective in reducing nitrate leaching on specific soil types in the Krška kotlina alluvial plain (Slovenia). The area is very important both for agriculture production and drinking water resources. The model was calibrated for three soil moisture field trial sites, each representing one major soil type of the area. Simulated soil moisture values were in good agreement with the observed values (PBIAS (percent bias) ±25%). Of the nine land management scenarios that were evaluated, vegetable rotation caused the most nitrate leaching on all soil types, but it fared better on Cambisol than on Fluvisol. Orchards on the other hand leached the least amount of nitrate, but also fared better on Cambisol. Presented studies should be considered as a preliminary stage in the study of nitrate pollution in the investigated area. Results show that nitrate leaching varies for different land management scenarios on different soil types. Further work should concentrate on field trials to evaluate the impacts of reduced fertilization on nitrate leaching and both crop yield and quality on different soil types

Modelling impacts of a municipal spatial plan of land-use changes on surface water quality—example from Goriška Brda in Slovenia

Intensive agriculture causes nutrient leaching and accelerates erosion processes, which threatens the good quality status of surface waters, as proposed by the European Union (EU) Water Framework Directive. The purpose of this study was to define the impact of two alternative agricultural land-use change scenarios defined in a Municipal Spatial Plan on surface water quality by using the Agricultural Policy/Environmental eXtender (APEX) model. As experimental area, we chose a small Kožbanjšček stream catchment (1464 ha) situated in the Goriška Brda region in Slovenia. The area, due to favorable conditions for vineyards, is facing increasing deforestation. The change of 66.3 ha of forests to vineyards would increase the sediment, nitrate, and phosphorus loads in the stream by 24.8%, 17.1%, and 10.7%, respectively. With the implementation of vegetative buffer strips as a mitigation measure of the current situation, we could reduce the sediment, nitrate, and phosphorus loads by 17.9%, 11.1%, and 3.1%, respectively, while a combination of the two land-use change scenarios would result in a slight increase of the above-mentioned loads, corresponding to 0.61%, 2.1%, and 6.6%, respectively, compared to the baseline situation. The results confirm that, as we can increase pollution levels with deforestation, we can also reduce water pollution by choosing proper types of land management measures

Cost optimisation of supermarket refrigeration system with hybrid model

Refrigeration systems based on vapour compression cycle are one of the largest energy consumers in supermarkets. In this paper a hybrid model of a refrigeration system is developed, in order to estimate the benefits of energy optimisation measures. The refrigeration model comprises the refrigerated display case dynamics, food products dynamics, evaporation model, and ice formation model, and is further extended with the discrete events that are typical for normal operation of a refrigeration system (i.e. customer interactions, product refilling, defrosting). Model parameters are identified from the measured data, equipment specifications and estimations of some conditions in a supermarket case study. The simulation software AnyLogic is used to realise an agent-based model of the display case that allows us to extend the model to the entire store-wide refrigeration system. The analysis demonstrates the use of the model for system optimisation purposes. The defrosting schedule of a single display case as well as for the complete store is optimised considering the overall running costs, food quality, and maximum peak power. Moreover, several energy optimisation measures are compared and evaluated in terms of their contribution to the overall savings and food quality degradation