160 JOZEF VARGA, RADOSLAVA KANIANSKA, JÁN SPIŠIAKSOIL SCIENCE ANNUAL Vol. 69 No. 3/2018: 160–168 DOI: 10.2478/ssa-2018-0016 JOZEF VARGA*, RADOSLAVA KANIANSKA, JÁN SPIŠIAK Matej Bel University Banská Bystrica, Faculty of Natural Sciences Tajovského 40, 974 01 Banská Bystrica, Slovakia Impact of land use and geological conditions on selected physical soil properties in relation to the earthworm abundance and biomass along an altitudinal gradient in Slovakia Abstract: The aim of the study was to analyse the impact of land use and altitudinal gradient including geological conditions on selected soil physical properties with subsequent effect on earthworms as important soil organisms. The research was conducted at three study sites (Oèová – OC, Tajov – TA, Liptovská Teplièka – LT) situated in the different climatic and natural conditions of Slovakia each with 3 plots differing in land use (arable land - AL, permanent grasslands – PG, forest land – FL). During 2014 over two periods, we measured soil penetration resistance (PR) with total depth of the measurement (DP) and soil moisture (SM). Earth- worms were hand sorted counted and weighed. We found out high variability of measured parameters conditioned by time, space (altitudinal gradient) and land use. PR values of all measurements ranged from 0.19 to 5.00 MPa, DP values from 0.02 to 0.80 m and soil moisture from 2 to 50%. Paired samples test confirmed differences between different land use types mainly between AL and FL plots. There were confirmed significant differences between three ecological gradients in all observed properties with one exception. Correlations among observed variables under different altitudinal gradients and land use types were found. The earthworm density and biomass was significantly higher in permanent grasslands compared to forest and arable land. In arable land, the earthworm density and biomass negatively correlated with the penetration resistance and positively with the depth of the total measurements. In permanent grasslands earthworm biomass positively correlated with soil moisture. Keywords: Penetration resistance, soil moisture, soil depth, land use change, earthworms INTRODUCTION by forest. The dominant rocks include sedimentary formations, but with granite and metamorphite Natural conditions and land use has permanent mountain cores. Among the causes of landscape influence on soil properties and vegetation cover change are urbanization, agricultural intensification, (Dupouey et al. 2002). Any change can affect the land abandonment and forest expansion, international aboveground and belowground part of ecosystems commerce and trade, new demands of land for nature including soil. The duration and land use type deter- conservation and development of renewable energy mines the soil physical and chemical properties with uses (Plieninger and Bieling 2012). Nowadays, land subsequent effect on soil biota. A large part of European abandonment is becoming a serious trend in Slovakia, land is currently devoted to agricultural activities Poland and other parts of Europe accelerated by the (Vliet et al. 2015). Twenty-five per cent of Europe´s retirement of the older generation of farmers and the land is covered by arable land and permanent crops, significant migration of young people to urban areas 17% by pastures and mixed mosaics and 35% by (Kanianska et al. 2014, Bucala-Hrabia 2017). forests (European Environment Agency 2010). Simi- Land use changes driven by intensification of larly, about 50% of the present Slovak land territory agriculture over the past century have resulted in is agricultural land even though Slovakia is a predo- widespread deterioration of many soil properties minantly mountainous country situated in the western influencing abundance and diversity of soil biota. Soil Carpathian arch. Only a small part of Eastern Slovakia compaction is a physical form of soil degradation that belongs to the eastern Carpathian region and the west- alters soil structure, limits water and air infiltration southern and east-southern part to the Panonian and reduces root penetration in the soil. The conse- lowland. Communities vary from thermophilous in quences of soil compaction are still underestimated southern parts of the country, to mountainous in the (Nawaz et al. 2013). Soil compaction has direct higher altitude. Mountain regions cover more than effects on physical soil properties and can be measured 55% of the total land territory. The climate is temperate. by penetration resistance. Soil compaction is mostly Thus most of the Slovak territory should be covered affected by water content, bulk density, soil texture * MSc. J. Varga, [email protected] http://ssa.ptg.sggw.pl/issues/2018/693 Impact of land use on physical soil properties in relation to soil biota 161 and porosity. Soil susceptibility to compaction is the and an integrated approach of the evaluation of abiotic probability that soil becomes compacted when exposed and biotic parameters is required. Because of the to compaction risk. It can be low, medium, high and abovementioned, the objective of this research was very high in dependence of soil properties and the set to analyse of the impact of land use type and altitudinal of external factors like, e.g. climate, soil use, etc. gradient on the soil physical properties related to soil (Houšková and Montanarella 2008). Soil compaction compaction having an impact on the earthworm abun- influences soil productivity (Mueller et al. 2010) often dance and biomass. resulting in yield reduction of most crops and decrease of soil fauna diversity and abundance. Earthworms STUDY AREA are very sensitive to physical soil parameters thus they are used as good bioindicators of microclimate and The research was conducted at three study sites, physical status of soil. Soil compaction in cultivated situated in the different climatic and natural condi- lands affects mostly the upper layer of soil but tions of Slovakia, each with 3 plots differing in land so-called subsoil compaction is also observed. use (arable land – AL, permanent grasslands – PG, Subsoil compaction is a serious problem because it is forest land – FL) and altitudinal gradient. Oèová expensive and difficult to alleviate and it has been study site (OC) is situated in Po¾ana Mountain from acknowledged as a serious form of soil degradation 418 to 422 m a.s.l. with Haplic Planosol developed by the European Union (Jones et al. 2003). There are on polygenic sediments. Tajov study site (TA) is about 200 000 hectares of compacted agricultural soils situated at Kremnica Mountain from 580 to 595 m and about 500 000 hectares potentially compacted a.s.l. with Haplic Cambisol developed on slope agricultural soils in Slovakia (Kobza 2014). deposits. Liptovská Teplièka study site (LT) is Earthworms are exposed to a range of natural and situated in Low Tatras Mountain from 931 to 950 m human induced disturbances including land use and a.s.l. with Rendzic Leptosol developed on dolomitic management. Assessment of this impact is difficult limestones (Fig. 1, Table 1, 2, and 3) (MESR, 2002). FIGURE 1. Location of the study sites in Slovakia. Abbreviations: OC – Oèová, TA – Tajov, LT – Liptovská Teplièka 162 JOZEF VARGA, RADOSLAVA KANIANSKA, JÁN SPIŠIAK TABLE 1. Geographic characteristics and land management at 3 study TABLE 2. Climatic characteristics from the metero- site under different land use logical stations nearest to the 3 study sites (according to Slovak Hydrometeorological Study Geographical Soil Substrate Soil Altitude – Land Institute) site location type texture AL (m) management OC Po¾ ana Haplic Polygenic Loamy AL-418 AL-intensive Study Meteorological Long-term Long-term Mountain Planosol sediments PG-420 farming site station average air average FL-422 PG-meadow temperature rainfall (°C) (mm) TA Kremnica Haplic Slope Loamy AL-595 AL-extensive Mountain Cambisol deposits PG-597 farming OC Víg¾aš 7.7 669 FL-580 PG-sheep TA Banská 8.1 795 pasture Bystrica LT Low Tatras Rendzic Dolomitic Loamy AL-950 AL-organic Leptosol limestone PG-931 farming LT Poprad 6.2 950 FL-945 PG-meadow Abbreviations: OC – Oèová, TA – Tajov, LT – Liptovská Abbreviations: OC – Oèová, TA – Tajov, LT – Liptovská Teplièka, AL – Ara- Teplièka. ble land, PG – Permanent grasslands, FL – Forest land. TABLE 3. Soil chemical properties at 3 study sites under different land use METHODS Study Land pH KCl TOC Nt P K Mg site use (g⋅kg–1) (mg⋅kg–1) During 2014 over two periods (summer – OC AL 4.90 17.27 1.86 13.88 171.75 602.25 beginning of June, autumn – end of Septem- PG 6.24 51.81 6.09 223.01 329.74 632.49 ber, and beginning of October), we measured FL 3.89 65.75 3.84 2.76 171.75 759.30 penetration resistance of soil (PR) total depth of the penetration resistance measurement TA AL 4.84 15.45 1.62 33.56 221.90 127.36 (DP), and soil moisture (SM) at each study PG 4.19 42.30 4.14 0.52 136.22 631.80 sites and plots in 10 replications. Soil mo- FL 5.06 145.44 7.38 13.49 329.74 717.57 isture level (SM) was measured at 0.05 m LT AL 6.70 34.50 3.05 38.23 199.36 949.12 depth by soil moisture sensor (ThetaProbe) PG 6.94 51.30 5.16 3.82 300.33 1233.15 in the soil moisture volume percentage by FL 7.12 30.00 4.21 11.09 119.22 1273.57 measuring the changes in the dielectric con- Abbreviations: OC – Oèová, TA – Tajov, LT – Liptovská Teplièka, TOC – Total stant. Penetration resistance (PR) was organic carbon, Nt – Total nitrogen, P – Available phosphorus, K – Available potassium, measured with an electronic penetrometer Mg – Available magnesium. (Eijkelkamp Penetrologger) with a cone dia- meter of 1 cm2 and a 60° top angle cone with the We used a paired samples test to examine the maximum operational depth of 0.80 m. Cone resistance differences in physical properties between the three land was recorded in MPa per 0.00–0.80, and sub use types (arable land, permanent grasslands and sequently recalculated per layers of 0.00–0.20, and forest land) and the three altitudinal gradients.