Current State and Development of the Soil Health Index in Localities with Various Soil-Climatic Conditions in the Slovak Republic

The aim of the study was to assess the current state and development of the Soil Health Index (SHI) at 13 localities with various soil-ecological conditions in the Slovak Republic. The SHI was developed using a minimum soil data set, physical and chemical soil parameters in combination with environmental parameters (land use, gradients). The SHI is one numerical value accumulates information about the state of soil health and its ability to provide soil functions and thus ecosystems in the optimal range. The highest SHI values were determined at model localities used as arable land (Haplic Chernozem, Fluvisol) located in a warm climate at altitudes up to 200 meters above sea level. Ecosystems with very low and low value are mostly grass-lands with mildly cold climate (Cambisol) and considerable slope, agroecosystem on low organic matter (Arenosol). Arable ecosystem SHI is also reduced in areas of geochemical anomalies and areas with anthropogenic load, where there is a higher content of risk elements. The SHI changes are mainly the result of changes in dynamic indicators such as soil response and soil bulk density.

support ecosystem services (Bonfante et al., 2020;Veerman et al., 2020). Kibblewhite et al. (2008) defined the healthy agricultural soil as soil that is able to support production of food together with continued delivery of the other ecosystem services essential for maintenance mankind life quality and conservation of biodiversity. The quality and health of soil determine agricultural sustainability as well as environmental quality which determine plant, animal and human health (Doran, 2002;Kobza, 2017). The new EU Soil Strategy 2030 calls for all land to be in good health by 2030 and for soil protection, sustainable use and restoration to become the new standard (EU, 2020;Wittkowski, 2020).
Defining soil health indicators is crucial for monitoring soil health (Arshad & Martin, 2002). Although a unique framework of indicators is needed, the reference values of soil health indicators must be context-specific (climate, soil type, land use). The soil health index compiled from soil indicators must respect knowledge of their critical limits (Laishram et al., 2012;Abbott & Manning, 2015). Karlen and Stott (1994) developed a soil quality index based on four soil functions (the ability of the soil to accommodate water entry, facilitate water movement, absorption, resist surface degradation and supply nutrients for plant growth).
Several methods of soil health evaluation have been developed, including soil card design and test kits, geostatistical method or soil quality index methods (Bünemann et al., 2018;Jian et al., 2020). Soil health assessment is carried out by selecting a minimum data set of soil properties that are considered to be indicators of soil health (Vasu et al., 2016). Recently, soil health assessment has become increasingly integrated into sustainable soil management, environmental risk assessment as well as environmental monitoring and soil restoration (Gelaw et al., 2015;Bünemann et al., 2018).
The aim of the study was: 1) to develop SHI based on soil functions, 2) to apply this method to assess the current state and development of the SHI in localities with various soil-ecological conditions in the Slovak Republic, 3) to evaluate the impact of soil types, climatic conditions and changes of land use on SHI.

SHI Evaluation
The calculation of the SHI included three steps: 1) selection of the appropriate indicators for a minimum data set (MDS), 2) score assignation for the selected indicators, and 3) the integration of the indicator scores into an overall SHI (Rahmanipour et al., 2014). In Slovakia, Bujnovský et al. (2011), Makovníková, Barančíková andPálka (2007), Barančíková and Makovníková (2003), Vilček and Koco (2018) define the MDS of soil indicators needed for sufficient assessment of soil functions. These indicators were used as a basis for composite SHI. The SHI was created using the MDS of physical and chemical soil indicators (direct indicators) combined with environmental parameters, land use and climatic region (Kibblewhite et al., 2008;Alam et al., 2016;Costanza et al., 2017). These soil in-Journal of Geoscience and Environment Protection dicators are included in the soil monitoring system in Slovakia (Kobza et al., 2014) according to the recommendation of the European Commission (EC) for comprehensive soil monitoring system in Europe (van Camp et al., 2004). All indicators are significant, representative and quantifiable. Each observed value was converted into a score (from −1 to 2) with respect to the knowledge concerning their critical limits (Table 1). Based on correlation analysis (Makovníková et al., 2019), the SHI is also a suitable comprehensive indicator for the evaluation of regulatory ecosystem services of agricultural land.
According to the results of SHI value, we classified model localities into 5 classes (

Model Localities
The model localities represent the main soil types of agriculturally used soils in various soil-ecological regions of the Slovak Republic ( Figure 1, Table 3).
We performed spring soil sampling at model localities during years 1995-2021 (we used four points sampling in the shape of the letter Z; Kobza et al., 2011).
We analysed potential static soil parameters (depth of humus horizon, soil texture, content and quality of organic matter in the soil, total content of inorganic pollutants), and potential dynamic soil parameters (bulk density, soil reaction value) that enter into the construction of the SHI.
Within model localities the values of soil reaction (pH in KCl) ranged from 3.95 to 7.30, the content of organic matter in the soil ranged from 0.79% to 3.37%, the values of bulk density ranged from 1.21 g·cm −3 to 1.78 g·cm −3 . Contamination level, exceeding the limit value of 4 elements was set at two localities (Dvorniky and Krompachy). In one locality (Nacina Ves) the values of 3 elements were exceeded and at 2 localities the limit for one (Ziar n/Hronom) or two elements (Raková) was exceeded.      as soil response and soil bulk density, similarly as in Bünemann et al. (2018). Soil properties, which can change rapidly in response to natural or anthropogenic effects, are considered as good indicators of soil health (Rahmanipour et al., 2014).

Results and Discussion
Land use change can be significant factor influencing SHI (Mukherjee & Lal, 2014). In localities, where there was a change in land use-alternating arable land to permanent grassland-the total content of organic matter in the soil in-

Conclusion
Soil health is the continuous ability of soil to function as a vital living ecosystem that supports plants, animals and humans, and connects agriculture and soil with policies, the needs of stakeholders through sustainable supply chain management.
The concept of soil health meets the important need of stakeholders in the field of sustainable development by increasing the recognition of the role of soil in modern society and creating a functional platform for farmers, land owners, local authorities and policy makers. The multi-composite SHI accumulates in one numerical value information on the state of soil health, and thus its ability to provide soil functions and regulatory ecosystem services to the optimal extent in a specific way of its use. Our results showed that monitoring of changes of SHI values represent the possibility of a comprehensive assessment of negative pressures on the soil eco-