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The application of biochar is considered to be a beneficial strategy for improving soil ecosystem services. The objectives of this study are to evaluate the differences in the soil erosion of silt loam soil with or without the application of biochar and to compare the impact of the application of biochar on soil erosion for different agricultural practices, namely, bare soil, silage corn, and sown peas. Specifically, the physically-based EROSION 3D model was used to estimate the soil erosion of small plots of sloping agricultural land. In considering various combinations of agricultural practices and rainfalls with different durations and intensities, several scenarios were used to assess the impact of the application of biochar on soil erosion.

Abandonment of agricultural fields triggers the ecosystem recovery in the process referred to as secondary succession. The objective of this study was to find the impact of secondary succession during 12 years lasting abandonment of agricultural fields with loamy sand and sandy loam soils on soil properties, namely soil organic carbon content, pH, water and ethanol sorptivity, hydraulic conductivity, water drop penetration time (WDPT), and repellency index (RI). The method of space-for-time substitution was used so that the fields abandoned at different times were treated as a homogeneous chronosequence. The studied soils showed a permanent increase in WDPT and a monotonous decrease in pH and water sorptivity with the duration of field abandonment. The dependence of the other characteristics on the duration of field abandonment was not unambiguous. The ethanol sorptivity decreased between 0 and 8 years of field abandonment, and increased between 8 and 12 years, when it copied a similar course of sand content during abandonment. The hydraulic conductivity halved within the first eight years of field abandonment and then increased statistically insignificantly between 8 and 12 years of abandonment. The repellency index decreased statistically insignificantly between 0 and 8 years of abandonment and then increased between 8 and 12 years.

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Pines are widely planted for sand dune stabilization and their cultivation results in the changes in physical, chemical, hydro-physical and water repellency properties. Soil properties were evaluated at three Scots pine plantations (PF1, PF2 and PF3) close to Studienka village, Borská nížina lowland (southwestern Slovakia) during hot and dry summer period. The PF1 site is a newly established plantation, the PF2 site is about 30 years old plantation, and the PF3 site is about 100 years old plantation. Here, we estimated the differences in pH, soil organic carbon content, Cox, particle size distribution, PSD, saturated, ks, and unsaturated, k(–2 cm), hydraulic conductivity, water, Sw, and ethanol, Se, sorptivity, water drop penetration time, WDPT, and repellency index, RI. It was found that Cox varies most significantly with plantation age, and relative differences in PSD and pH were lower than the relative difference in Cox. The PF3 site differs the most from the other two, especially in Cox and in the content of sand fraction. It can be attributed to the older age of the plantation, which represents a more advanced stage of succession accompanied by an accumulation of soil organic matter. Relationships between Cox, k(–2 cm), RI, and WDPT and pine forest age were described by appropriate mathematical models. We found a similarity between k(–2 cm) and RI relationships vs. pine forest age (exponential models), and between Cox and WDPT relationships vs. pine forest age (first and second-order polynomial models). The latter similarity can be supported by the fact that soil water repellency is induced by the hydrophobic and amphiphilic components of soil organic matter.

Current biochar application in the global agronomic practice focuses firstly on economic profits. In this paper, we would like to draw attention to our results and experience from the economic assessment of the agronomic effect of applied biochar through the generated crop yields. The results come from a field experiment (locality Dolná Malanta, Slovakia, silt loam Haplic Luvisol – the most intensively used soil in the Slovak Republic for agricultural purposes), where a biochar experiment was established in 2014. Based on our data, it is evident that both the application of biochar and its application in combination with N-fertilisation in field conditions at current realization prices of commodities in individual years and high input costs are still unprofitable. However, we emphasize that from an economic point of view of the stand ard agronomic practice.

The objectives of the study were to: (1) assess the strength of associations of direct CO2 and N2O emissions with the seasonal variations in the relevant soil properties under both tillage systems; 2) evaluate how CT and RT affect magnitudes of seasonal CO2 and N2O fluxes from soil. Field studies were carried out on plots for conventional tillage (up to 0.22–0.25 m) and reduced tillage (up to 0.10–0.12 m) during the growing season and post-harvest period of red clover. The results showed that daily CO2 emissions significantly correlated only with soil temperature during the growing season under conventional and reduced tillage. Soil temperature demonstrated its highest influence on daily N2O emissions only at the beginning of the growing season in both tillage systems. There were no significant inter-system differences in daily CO2 and N2O emissions from soil during the entire period of observations. Over the duration of post-harvest period, water-filled pore space was a better predictor of daily CO2 emissions from soils under CT and RT. The conventional and reduced tillage did not cause significant differences in cumulative N2O and CO2 fluxes from soil.

The paper presents evaluation of the calibration method using side-by-side direct gravimetric and indirect time domain reflectometry (TDR) for soil moisture measurements to improve TDR measurement accuracy. Measurements were carried out at the experimental site Dolná Malanta (Slovakia) in 2017. Two non-fertilized treatments – without biochar (B0 + N0) and with biochar at 20 t·ha−1 (B20 + N0) – and two fertilized treatments – with biochar at 20 t·ha−1 and N fertilizer at dosages of 160 kg·ha−1 (B20 + N160) and 240 kg·ha−1 (B20 + N240) – were used in this study. The study also investigates the relationship between both used methods of soil water content determination. A strong correlation between both methods was observed. In case of (B0 + N0); (B20 + N0); (B20 + N160); and (B20 + N240), it was 0.93; 0.97; 0.97; and 0.98, respectively. However, it is assumed that the TDR probe may show errors in the results without prior calibration. It was observed that the accuracy of TDR device was lower for fertilized treatments in contrast to the gravimetric method and non-fertilized treatments. It is assumed that the higher measurement inaccuracy might be increased by salt concentration in the soil as a result of applied N fertilizer.

Snow production results in high volume of snow that is remaining on the low-elevation ski pistes after snowmelt of natural snow on the off-piste sites. The aim of this study was to identify snow/ice depth, snow density, and snow water equivalent of remaining ski piste snowpack to calculate and to compare snow ablation water volume with potential infiltration on the ski piste area at South-Central Slovak ski center Košútka (Inner Western Carpathians; temperate zone). Snow ablation water volume was calculated from manual snow depth and density measurements, which were performed at the end of five winter seasons 2010–2011 to 2015–2016, except for season 2013–2014. The laser diffraction analyzes were carried out to identify soil grain size and subsequently the hydraulic conductivity of soil to calculate the infiltration. The average rate of water movement through soil was seven times as high as five seasons’ average ablation rate of ski piste snowpack; nevertheless, the ski piste area was potentially able to infiltrate only 47% of snow ablation water volume on average. Limitation for infiltration was frozen soil and ice layers below the ski piste snowpack and low snow-free area at the beginning of the studied ablation period.

During the last decade, biochar has captured the attention of agriculturalists worldwide due to its positive effect on the environment. To verify the biochar effects on organic carbon content, soil sorption, and soil physical properties under the mild climate of Central Europe, we established a field experiment. This was carried out on a silty loam Haplic Luvisol at the Malanta experimental site of the Slovak Agricultural University in Nitra with five treatments: Control (biochar 0 t ha−1, nitrogen 0 kg ha−1); B10 (biochar 10 t ha−1, nitrogen 0 kg ha−1); B20 (biochar 20 t ha−1, nitrogen 0 kg ha−1); B10+N (biochar 10 t ha−1, nitrogen 160 kg ha−1) and B20+N (biochar 20 t ha−1, nitrogen 160 kg ha−1). Applied biochar increased total and available soil water content in all fertilized treatments. Based on the results from the spring soil sampling (porosity and water retention curves), we found a statistically significant increase in the soil water content for all fertilized treatments. Furthermore, biochar (with or without N fertilization) significantly decreased hydrolytic acidity and increased total organic carbon. After biochar amendment, the soil sorption complex became fully saturated mainly by the basic cations. Statistically significant linear relationships were observed between the porosity and (A) sum of base cations, (B) cation exchange capacity, (C) base saturation.

Recent studies show that biochar improves physical properties of soils and contributes to the carbon sequestration. In contrast to most other studies on biochar, the present study comprise a long-term field experiment with a special focus on the simultaneous impact of N-fertilizer to soil structure parameters and content of soil organic carbon (SOC) since SOC has been linked to improved aggregate stability. However, the question remains: how does the content of water-stable aggregates change with the content of organic matter? In this paper we investigate the effects of biochar alone and in a combination with N-fertilizer (i) on the content of water-stable macro- (WSAma) and micro-aggregates (WSAmi) as well as soil structure parameters; and (ii) on the contents of SOC and labile carbon (CL) in water-stable aggregates (WSA).

An experiment of different management practices in a commercial vineyard, which was established in 2006 in the locality of Nitra-Dražovce, Slovakia on Rendzic Leptosol, was used to evaluate the dynamics of soil organic-matter parameters during the years 2008–2015. The following treatments were established: 1. G (grass without fertilisation as control), 2. T (tillage), 3. T+FYM (tillage + farmyard manure), 4. G+NPK3 (grass + 3rd intensity of fertilisation for vineyards: it means 125 kg/ha N, 50 kg/ha P, 185 kg/ha K), and 5. G+NPK1 (grass + 1st intensity of fertilisation for vineyards: it means 100 kg/ha N, 30 kg/ha P, 120 kg/ha K). The results showed that the soil-management practices in the vineyard significantly influenced the soil organic carbon in water-stable aggregates (SOC in WSA). The content of SOC in WSAma increased on average in the following order: T < G < G+NPK1 < G+NPK3 < T+FYM. Intensive soil cultivation in the T treatment resulted in a statistically significant build-up of SOC in WSAma at an average rate of 1.33, 1.18, 0.97, 1.22 and 0.76 g/kg/y across the size fractions > 5 mm, 5‒3 mm, 2–1 mm, 1–0.5 mm and 0.5–0.25 mm, respectively. The content of non-labile carbon reflected the contents of SOC in WSA. The highest labile carbon (CL) in WSAma, as compared to others, was found in T+FYM. Overall, application of higher NPK doses resulted in higher content of CL in WSAma compared with the lower applications of NPK. On the other hand, lower applications of NPK to soil increased the content of CL in WSAmi, as compared to G+NPK3.

Laser diffraction analysis is an alternative to standard sedimentation methods designed to determine particle size distribution. In this article, five samples from the forested part of the floodplain of the Svitava River in the Czech Republic were analyzed. Laser diffraction analysis and sedimentation hydrometer method were performed for each sample. The samples were divided according to soil classification into two groups depending on their classification–group A and group B. The results of laser diffraction analysis and hydrometer method were compared. Correlation relationships between both methods were established, and values were recalculated from laser diffraction analysis to the hydrometer method according to correlation equations. The article is a part of the methodology under preparation, which will include the most common soil types in the Czech Republic. This methodology focuses on the use of laser diffraction for the establishment of structures in forest environments using the regional specific standards for particle size distribution determination. [ABSTRACT FROM AUTHOR]

The objectives of the study were to: (1) assess the strength of associations of direct CO2 and N2O emissions with the seasonal variations in the relevant soil properties under both tillage systems; 2) evaluate how CT and RT affect magnitudes of seasonal CO2 and N2O fluxes from soil. Field studies were carried out on plots for conventional tillage (up to 0.22-0.25 m) and reduced tillage (up to 0.10-0.12 m) during the growing season and post-harvest period of red clover. The results showed that daily CO2 emissions significantly correlated only with soil temperature during the growing season under conventional and reduced tillage. Soil temperature demonstrated its highest influence on daily N2O emissions only at the beginning of the growing season in both tillage systems. There were no significant inter-system differences in daily CO2 and N2O emissions from soil during the entire period of observations. Over the duration of postharvest period, water-filled pore space was a better predictor of daily CO2 emissions from soils under CT and RT. The conventional and reduced tillage did not cause significant differences in cumulative N2O and CO2 fluxes from soil. [ABSTRACT FROM AUTHOR]

Greenhouse gases such as N2O and CO2 are formed in microbiological processes of nitrification and denitrification and also governed by microbial decomposition of soil organic matter (SOM) plant residues. A key factors influencing these processes are temperature and soil moisture. Therefore the objectives of this study were to: (1) evaluate the seasonal variations in SOM content, temperature, water-filled pore space (WFPS) and mineral nitrogen content under conventional tillage (CT) and reduced tillage (RT) system, and (2) assess the direct CO2 and N2O emissions associated with the seasonal variations in the soil properties under both tillage systems. An experiment was carried out in a randomized blocks with two different tillage system: CT and RT in a Haplic Luvisol (loamy) covering the growing season of spring barley. Each block included treatments: no mineral fertilizers; mineral fertilizers; mineral fertilizers plus plant residues. Overall, the SOM content and temperatures were insignificantly higher in the plough layers of RT than CT during the entire period of study. Soil moisture content (SMC) and WFPS were insignificantly higher in CT than RT. The application of mineral fertilizers resulted in a significant increase of mean NO3− concentrations only in the plough layers of CT. SMC was a stronger driving factor of mean daily CO2 emissions in all treatments, while variations in soil temperatures and SMC were jointly responsible for changes in mean daily N2O emissions in all the treatments of CT and RT. The postponed highest peaks of mean daily N2O emissions from RT were observed under aerobic soil conditions several days after the heavy rainstorm. The cumulative CO2 and N2O fluxes were insignificantly higher from CT than RT over the entire period of study. [ABSTRACT FROM AUTHOR]

The benefits of biochar application are well described in tropical soils, however there is a dearth of information on its effects in agricultural temperate soils. An interesting and little explored interaction may occur in an intensive agriculture setting; biochar addition may modify the effect of commonplace N-fertilization. We conducted a field experiment to study the effects of biochar application at the rate of 0, 10 and 20 t ha-1 (B0, B10 and B20) in combination with 0, 40 and 80 kg N ha-1 of N-fertilizer (N0, N40, N80). We followed nitrous oxide (N2O) emissions, analysed a series of soil physicochemical properties and measured barley yield in a Haplic Luvisol in Central Europe. Seasonal cumulative N2O emissions from B10N0 and B20N0 treatments decreased by 27 and 25% respectively, when compared to B0N0. Cumulative N2O emissions from N40 and N80 combined with B10 and B20 were also lower by 21, 19 and 25, 32%, respectively compared to controls B0N40 and B0N80. Average pH was significantly increased by biochar addition. Increased soil pH and reduces NO-3 content seen in biochar treatments could be the two possible mechanisms responsible for reduced N2O emissions. There was a statistically significant increase of soil water content in B20N0 treatment compared to B0N0 control, possibly as a result of larger surface area and the presence of microspores having altered pore size distribution and water-holding capacity of the soil. Application of biochar at the rate of 10 t ha-1 had a positive effect on spring barley grain yield. [ABSTRACT FROM AUTHOR]