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The glomalin content is generally considered an indicator of the soil organic matter (SOM) quality. The content of easily extractable glomalin (EEG) and the total glomalin (TG) content was investigated across 71 different sites in the Czech Republic with arable soil and crop production (12 chernozems, 30 luvisols, 17 cambisols, and 12 fluvisols). The majority of the crops in the crop rotation were cereals (45.5%—mainly winter wheat, winter barley, and spring barley). The proportion of winter canola within the crop rotation was 15.9%. The contribution of other crops was substantially smaller (alfalfa, clover, potatoes, beet, silage maize, grain maize). The representation of crops in the crop rotation is standard for conventional farming in the Czech Republic. Based on the results of long-term field monitoring at 71 sites in different soil–climate conditions, we can state the following. The TG content was significantly correlated with the soil organic matter carbon content (CSOM), as well as another important indicator of SOM quality (humic and fulvic acid carbon content ratio—CHA/CFA). A significant and positive correlation was also determined for the TG and clay content (size < 0.002 mm), as well as particles smaller than 0.01 mm. The easily extractable glomalin content (EEG) did not differ based on the reference soil group (RSG). On the other hand, the total glomalin content (TG) was significantly higher in the chernozem RSG in comparison with other RSGs (luvisols, cambisols, fluvisols). There was no relationship between the pHCaCl2 and glomalin (EEG; TG). The same can be said about the relationship between glomalin (EEG; TG) and the bulk density and porosity. No link was established between the glomalin content (EEG; TG) and phosphorus plant-available content. There was no relationship between the amount of applied organic matter (carbon inputs) and the soil glomalin content (EEG; TG). This relationship was not influenced by the type of applied organic fertilizer. No significant relationship was found for either straw, manure, or compost. The data on the glomalin content are significantly influenced by the site (soil type and soil texture). [ABSTRACT FROM AUTHOR]

In recent years, sulfur inputs into the soil have greatly diminished due to the significant decrease in SO2 emissions. Plant nutrients, like sulfur, can be released by the mineralisation of soil organic matter (SOM), which is a complicated mixture of substances (or fractions) like glomalin-related soil protein (GRSP) and fulvic acids (FA), humic acids (HA), humic substances (HS) and others. GRSP, FA, HA, and HS content, as well as the content of mineral and organic fractions of sulfur, was determined in different mineral and organic fertiliser treatments of the long-term field experiment. Using these results, the sulfur content in GRSP was calculated based on the soil's organic matter carbon and soil's organic bound sulfur (CSOM/SORG) ratio. Sulfur content in GRSP was 4.08-5.46 (easily extractable GRSP), 9.77-15.7 (difficultly extractable GRSP), and 13.9-21.1 (total GRSP) mg S/kg of soil. Overall, the application of the organic fertiliser caused an increase in S content bound to GRSP. A strong significant relationship was also observed between GRSP fractions and soil organic sulfur. A similar relationship was also observed for the HA and HS with organic sulfur.

In recent years, sulfur inputs into the soil have greatly diminished due to the significant decrease in SO2 emissions. Plant nutrients, like sulfur, can be released by the mineralisation of soil organic matter (SOM), which is a complicated mixture of substances (or fractions) like glomalin-related soil protein (GRSP) and fulvic acids (FA), humic acids (HA), humic substances (HS) and others. GRSP, FA, HA, and HS content, as well as the content of mineral and organic fractions of sulfur, was determined in different mineral and organic fertiliser treatments of the long-term field experiment. Using these results, the sulfur content in GRSP was calculated based on the soil's organic matter carbon and soil's organic bound sulfur (CSOM/SORG) ratio. Sulfur content in GRSP was 4.08-5.46 (easily extractable GRSP), 9.77-15.7 (difficultly extractable (GRSP), and 13.9-21.1 (total GRSP) mg S/kg of soil. Overall, the application of the organic fertiliser caused an increase in S content bound to GRSP. A strong significant relationship was also observed between GRSP fractions and soil organic sulfur. A similar relationship was also observed for the HA and HS with organic sulfur. [ABSTRACT FROM AUTHOR]

The glomalin content is generally considered an indicator of the soil organic matter (SOM) quality. The content of easily extractable glomalin (EEG) and the total glomalin (TG) content was investigated across 71 different sites in the Czech Republic with arable soil and crop production (12 chernozems, 30 luvisols, 17 cambisols, and 12 fluvisols). The majority of the crops in the crop rotation were cereals (45.5%—mainly winter wheat, winter barley, and spring barley). The proportion of winter canola within the crop rotation was 15.9%. The contribution of other crops was substantially smaller (alfalfa, clover, potatoes, beet, silage maize, grain maize). The representation of crops in the crop rotation is standard for conventional farming in the Czech Republic. Based on the results of long-term field monitoring at 71 sites in different soil–climate conditions, we can state the following. The TG content was significantly correlated with the soil organic matter carbon content (CSOM), as well as another important indicator of SOM quality (humic and fulvic acid carbon content ratio—CHA/CFA). A significant and positive correlation was also determined for the TG and clay content (size < 0.002 mm), as well as particles smaller than 0.01 mm. The easily extractable glomalin content (EEG) did not differ based on the reference soil group (RSG). On the other hand, the total glomalin content (TG) was significantly higher in the chernozem RSG in comparison with other RSGs (luvisols, cambisols, fluvisols). There was no relationship between the pHCaCl2 and glomalin (EEG; TG). The same can be said about the relationship between glomalin (EEG; TG) and the bulk density and porosity. No link was established between the glomalin content (EEG; TG) and phosphorus plant-available content. There was no relationship between the amount of applied organic matter (carbon inputs) and the soil glomalin content (EEG; TG). This relationship was not influenced by the type of applied organic fertilizer. No significant relationship was found for either straw, manure, or compost. The data on the glomalin content are significantly influenced by the site (soil type and soil texture).

Phosphorus (P) transformations and associated changes in soil chemistry following lime application in acidic soils are very determinant to enhance P use efficiency. Thus, this study was conducted to evaluate the effects of different rates of lime on soil P fractions and chemical properties in acidic Luvisols of southern Ethiopia. The lime rates were 0 t/ha (0%), 3.75 t/ha (50%), 7.5 t/ha (100%), and 11.25 t/ha (150%), and incubated for a month with three replications. The soil P fractions analyzed includes soluble P (P-sol), P associated with iron (Fe-P), aluminum (Al-P), calcium (Ca-P), organic part (Org-P) and residual (Res-P). The result indicated that liming significantly (p < 0.05) improved the release of P-sol, Ca-P, and Res-P, and reduced Fe-P, Al-P, and Org-P. The changes in soil chemical properties were also significant. For instance, increased rate of lime enhanced soil pH from 5.3 to 6.5, reduced exchangeable acidity from 1.47 to 0.15 cmol(+)/kg, and increased available P from 2.74 to 8.72 cmol(+)/kg. Yet, the amount of P-sol was found low for plant needs even at a 150% rate of lime. Thus, working on external P requirement to equilibrate the need for plants followed by crop response validation are suggested. [ABSTRACT FROM AUTHOR]

Erosion is a serious environmental problem that affects Brazilian agricultural soils, mainly those with medium and sandy texture, naturally very susceptible to erosion, such as those occurring in the northwest of the state of Paraná, that have been potentially degraded, especially when cultivated with sugarcane. This work presents the survey of a characteristic slope and a typical pedological system of sandstones in the Santo Anastácio Formation, in the hydrographic basin of the Pirapó River. It studies the vertical and lateral transformations of the pedological horizons and its physical-hydric functioning, associating them with the use and management of sugarcane. The survey of the soils along the slope followed the Structural Analysis of Pedological Cover methodology. The physical, hydric, and chemical attributes of soils were determined in the pedological horizons identified in the trenches. The results pointed to a changing pedological system, where e-iluviation mechanisms and surface runoff act, enhanced by the management of sugarcane. The natural dynamics of the pedological system and the type of management adopted contribute to the installation and evolution of laminar and furrow erosion processes in the study area. [ABSTRACT FROM AUTHOR]

A significant portion of the increase in atmospheric CO2 enters the environment through a decrease in the level of organic matter (SOM) in soils. One of the reasons for this is the cutting of forests and the conversion of growing areas into arable land, thus changing land use. As a result, SOM today only has approx. 70–80% of the period before the spread of intensive farming. For the long-term study of the effect of varying amounts of SOM, we set up experimental plots for litter manipulation in 2000. In the course of our investigations, we studied how changing the amount of organic matter input the soil affects the CO2 emissions of the soil and its closely related biological activity after five or ten years, in addition to the continuous maintenance of the treatments. According to our assumption, after 10 years, the biological activity of the soil will decrease as a result of the removal treatment of organic matter, and the biological activity will increase as a result of the doubling. The pH value of the soil shifted in the acidic direction over 10 years as a result of the removal of organic matter, while it did not change as a result of the increase. In the first year, we could not detect any significant differences in the enzyme activity values. From our later results, we found that a drastic reduction in the amount of leaf litter has a greater effect on soil enzyme activity and soil respiration to a greater extent than an increase in litter production above natural levels. The pH of the soil was as expected, with litter withdrawal shifting the pH towards acidic over the years. [ABSTRACT FROM AUTHOR]

The influence of different fertilizers (mineral/organic) on the quantity and quality of soil organic matter was monitored in long-term stationary experiments (27 years) with silage maize monoculture production on Luvisol. The main aim of this study was to investigate the relationship between easily extractable glomalin (EEG), total glomalin (TG), and parameters commonly used for the determination of soil organic matter quality, i.e., the content of humic acids (CHA), fulvic acids (CFA), and potential wettability index (PWI). A significant correlation was found between EEG content and CSOM content, humic acid content (CHA), humic acid/fulvic acid ratio (CHA/CFA), PWI, and index of aromaticity (IAR). Furthermore, the contents of EEG and TG correlated with soil organic carbon (CSOM). Periodical application of sewage sludge and cattle slurry increased the content of glomalin in soils. From the results, it is obvious that data about glomalin content can be used to study soil organic matter quality. A more sensitive method (a method that reacts more to changes in components of soil fertility) seems to be the determination of EEG rather than TG. The factors supporting use of EEG extraction in agronomic practice are mainly the substantially shorter time of analysis than TG, CHA, and CFA determination and lower chemical consumption. Furthermore, the PWI method is even suitable for studying soil organic matter quality. On the other hand, the humus quality ratio (E4/E6) does not provide relevant information about soil organic matter quality. [ABSTRACT FROM AUTHOR]

One of the challenges of harnessing higher productivity levels and sustainability of agriculture related to N fertilization is in expanding soil N2O emissions, which has become a serious issue in recent years. Recent studies suggest that biochar may be the solution to this problem, but there is still a knowledge gap related to biochar application rates and its reapplication in Central Europe; therefore, in this study, we investigated the effect of biochar (initial application and reapplication in 2014 and 2018, respectively, at rates of 0, 10 and 20 t ha−1) combined with N-fertilizer (N0—0 kg N ha−1; N1—108 kg N ha−1 and N2—162 kg N ha−1) during the growing season of maize in 2019 (warm temperature with normal precipitation) on the changes of soil properties and N2O emissions in the silty loam, Haplic Luvisol, in the temperate climate of Slovakia. The results showed that the application and reapplication of biochar proved to be an excellent tool for increasing soil pH (in the range 7–13%), soil organic carbon—Corg (2–212%), and reducing the soil's NH4+ (41–69%); however, there were more pronounced positive effects when biochar was combined with N-fertilizer at the higher level (N2). The same effects were found in the case of N2O emissions (reduction in the range 33–83%). Biochar applied without N-fertilizer and combined with the higher fertilizer level had a suppressive effect on N2O emissions. Biochar did not have any effect on maize yield in 2019. [ABSTRACT FROM AUTHOR]

Background: Although fertilization and crop rotation practices are commonly used worldwide in agriculture to maximize crop yields, their long-term effect on the structures of soil microorganisms is still poorly understood. This study investigated the long-term impact of fertilization and crop rotation on soil microbial diversity and the microbial community structure in four different locations with three soil types. Since 1996, manure (MF; 330 kg N/ha), sewage sludge (SF; 330 and SF3x; 990 kg N/ha), and NPK (NPK; 330 kg N/ha) fertilizers were periodically applied to the soils classified as chernozem, luvisol and cambisol, which are among the most abundant or fertile soils used for agricultural purposes in the world. In these soils, potato (Solanum tuberosum L.), winter wheat (Triticum aestivum L.), and spring barley (Hordeum vulgare L.) were rotated every three years. Results: Soil chemistry, which was significantly associated with location, fertilization, crop rotation, and the interaction of fertilization and location, was the dominant driver of soil microbial communities, both prokaryotic and fungal. A direct effect of long-term crop rotation and fertilization on the structure of their communities was confirmed, although there was no evidence of their influence on microbial diversity. Fungal and bacterial communities responded differently to fertilization treatments; prokaryotic communities were only significantly different from the control soil (CF) in soils treated with MF and SF3x, while fungal communities differed across all treatments. Indicator genera were identified for different treatments. These taxa were either specific for their decomposition activities or fungal plant pathogens. Sequential rotation of the three crops restricted the growth of several of the indicator plant pathogens. Conclusions: Long-term fertilization and crop rotation significantly altered microbial community structure in the soil. While fertilization affected soil microorganisms mainly through changes in nutrient profile, crop rotations lead to the attraction and repulsion of specific plant pathogens. Such changes in soil microbial communities need to be considered when planning soil management. [ABSTRACT FROM AUTHOR]

In the last decades, Poland has become the leader in mushroom Agaricus bisporus production in Europe. Mushroom production generates large amounts of spent substrate, which as a waste material must be recycled. Significant in this macronutrient content, inducing nitrogen, encourages the use of this organic waste material to fertilize, especially light soils. The aim of the study was to assess the effect of spent mushroom substrate fertilization on the properties of A horizon of the Stagnic Luvisol, especially for the variation in the nitrogen fraction, in the two-year cultivation period. The following laboratory analyses were performed: soil pH, organic carbon content, total content of nitrogen and sorption properties. The sequential extraction of nitrogen compounds was performed with a 0.25 M KCl solution (for the extraction of mineral nitrogen forms and the most labile organic nitrogen compounds) and with 0.25 and 2.5 M H2SO4 (hot hydrolysis for sequencing of organic nitrogen compounds that are easily hydrolysing and difficult to hydrolyse). The application of spent mushroom substrate to the A horizons of the experimental objects had an effect on differentiation of soil properties and increased their value (pH, Corg, N-tot, Hh, CEC) in comparison to the control object to a greater degree after the first, then after the second year of cultivation. As the content of nitrogen mineral forms was differentiated, more nitrogen was found in an ammonium form (N-NH4) than in a nitrate form (N-NOx). The organic nitrogen content formed the following series of increasing amounts: soluble organic nitrogen NOS < NOEH < NODH < NONH.

In agricultural land use, organic residues such as compost, digestate, and sewage sludge are discussed as costeffective soil conditioner that may improve the water holding capacity and crop available soil moisture. The objective of this study is to determine the effect of application of digestates with different compositions in maize, sugar beet and winter wheat, compost of shrub debris and sewage sludge on shrinkage behaviour and contact angle of till-derived loamy topsoil of a Haplic Luvisol under agricultural use. Novelty is the simultaneous determination of contact angle and shrinkage of soils amended with digestates composed of different composition in maize, sugar beet and winter wheat, compost of shrub debris and sewage sludge. The results suggest that the application of organic residues impacts the air capacity, while the contact angles remained in the subcritical range between > 0° and < 90°. The relationship between CA values and moisture ratios, ϑ, during proportional shrinkage was positive and linear (r2 of 0.98) and negative during residual- and zero-shrinkage (r2 of 0.93).

Improvement of carbon sequestration in soils for a more sustainable environment and prevention of climate change require not only knowledge about soil organic carbon (SOC) stocks, but also about interactions between land use and total amount and distribution of carbon. In North Germany (state: Schleswig-Holstein) about 925 soil profiles in the four dominant geological regions [Weichselian glacial region, the sandy outwash region (Lower ―Geest), the Saalian glacial region Higher ―Geest), and the marshland with alluvial deposits] were sampled down to at least the 90 cm depth. Carbon content, pH, bulk density, and grain size distribution were analyzed for the major characteristic soil horizons. The four dominant geological regions possess different SOC stocks as well as SOC contents. The total amount of SOC stored within the representative soil profiles down to the 90 cm depth was analyzed for three depths: 0 – 30, 30 – 60, 60 – 90 cm; for the total area of Schleswig Holstein (15.369 km²), they summed to 244 Mt. SOC stocks, however, differed depending on the land use management system and clay content. Arable soils were most sensitive to soil deformation and the higher the clay content the less rigid they were, if the SOC to clay ratio were used as an index for structural quality. Grassland topsoils showed the highest SOC stocks and a mediate structural quality. The latter was highest for forest soils, which, however, had a higher SOC content but, at the same time, a less fertile SOC composition (litter with high C: N ratio). Further research on the carbon composition (labile, active, intermediate, or passive pools) would help to get a better insight into the role of SOC on soil strength and soil functions.

A significant portion of the increase in atmospheric CO2 enters the environment through a decrease in the level of organic matter (SOM) in soils. One of the reasons for this is the cutting of forests and the conversion of growing areas into arable land, thus changing land use. As a result, SOM today only has approx. 70–80% of the period before the spread of intensive farming. For the long-term study of the effect of varying amounts of SOM, we set up experimental plots for litter manipulation in 2000. In the course of our investigations, we studied how changing the amount of organic matter input the soil affects the CO2 emissions of the soil and its closely related biological activity after five or ten years, in addition to the continuous maintenance of the treatments. According to our assumption, after 10 years, the biological activity of the soil will decrease as a result of the removal treatment of organic matter, and the biological activity will increase as a result of the doubling. The pH value of the soil shifted in the acidic direction over 10 years as a result of the removal of organic matter, while it did not change as a result of the increase. In the first year, we could not detect any significant differences in the enzyme activity values. From our later results, we found that a drastic reduction in the amount of leaf litter has a greater effect on soil enzyme activity and soil respiration to a greater extent than an increase in litter production above natural levels. The pH of the soil was as expected, with litter withdrawal shifting the pH towards acidic over the years.

The influence of different fertilizers (mineral/organic) on the quantity and quality of soil organic matter was monitored in long-term stationary experiments (27 years) with silage maize monoculture production on Luvisol. The main aim of this study was to investigate the relationship between easily extractable glomalin (EEG), total glomalin (TG), and parameters commonly used for the determination of soil organic matter quality, i.e., the content of humic acids (CHA), fulvic acids (CFA), and potential wettability index (PWI). A significant correlation was found between EEG content and CSOM content, humic acid content (CHA), humic acid/fulvic acid ratio (CHA/CFA), PWI, and index of aromaticity (IAR). Furthermore, the contents of EEG and TG correlated with soil organic carbon (CSOM). Periodical application of sewage sludge and cattle slurry increased the content of glomalin in soils. From the results, it is obvious that data about glomalin content can be used to study soil organic matter quality. A more sensitive method (a method that reacts more to changes in components of soil fertility) seems to be the determination of EEG rather than TG. The factors supporting use of EEG extraction in agronomic practice are mainly the substantially shorter time of analysis than TG, CHA, and CFA determination and lower chemical consumption. Furthermore, the PWI method is even suitable for studying soil organic matter quality. On the other hand, the humus quality ratio (E4/E6) does not provide relevant information about soil organic matter quality.

Agroecosystem crop residues are considered to be a primary resource of organic substances, and are subject to the different transformation processes in the soil environment. The decomposition processes of organic substance can be also regulated by the application of the different biopreparations. The decomposition of organic substances in soil also causes changes in nitrogen content and its forms. It is essential for farmers to know about these processes in order flexibly to regulate and affect the transformation processes of the applied crop residues via the biopreparations directly in the production conditions. The changes of content and forms of nitrogen and its calculated parameters in Haplic Luvisol influenced by the applied crop residues (wheat – WR, rape – RR) and biopreparations (Betaliq, Trichomil) were monitored in the small-pot experiment carried out at the Department of Soil Science (FAFR, SUA-Nitra). The laboratory experiments were established for the incubation period 4, 7, 14, 28, 60, 90 and 180 days. The applied crop residues had statistically significant impact on the contents of total nitrogen (Nt) and potentially mineralizable nitrogen (Npot) and inorganic forms N, similarly also the values of labile nitrogen (LN) and nitrogen pool index (NPI). The biopreparations affected statistically significantly the average values Npot, LN, nitrogen lability index (NLI) and nitrogen management index (NMI). During the incubation period, the contents Npot and values LN and other calculated indexes of nitrogen fluctuated significantly.

The character of parent material, organic matter and climatic conditions are the crucial factors of pedogenesis. They directly influence the intensity of weathering, transformation processes, elements release and geochemical cycles. The mineral transformation in a profile of the recent soil developed on loess (Haplic Luvisols, Siltic, Epidystric, Ochric) was studied. The land area Litovelské Pomoraví was chosen because of the stability of soil‐forming factors such as topography, relief, vegetation and climate. X‐ray diffraction (XRD) quantitative analysis of the fine earth (<2 mm) and XRD analysis of clay (<2 μm) and the fine clay fraction (<0.2 μm) were applied. The obtained results showed the most significant differences between the argic horizons (Bt1 and Bt2) and other soil horizons. The lower content of quartz and feldspars and higher content of dioctahedral micas and phyllosilicates in both Bt horizons was observed. It was assumed the clay illuviation/lessivage process was preceded by long‐term leaching of carbonate in humid continental conditions during almost the whole Holocene. The distribution of the clay fraction correlates with the distribution of phyllosilicates through the profile. Major clay minerals in the clay fraction (<2 μm) were illite and kaolinite, smectite, chlorite, vermiculite and several types of mixed‐layered phases. The analysis of the finer clay fraction (<0.2 μm) identified the new phase hydroxy‐interlayered minerals as the product of illite (vermiculite) weathering in humid continental conditions. Highlights: Clay mineralogy of Haplic Luvisols on loess was studied.XRD analysis identified the new phase of hydroxy‐interlayered minerals.Increasing of smectites, dioctahedral micas, and goethite as a result of clay illuviation/lessivage process was observed. [ABSTRACT FROM AUTHOR]

The present paper analyses forest soils from Satu Mare County based on their main chemical properties and by using data from forest management plans. The study follows the distribution of the main soil types, their development conditions as well as their evolution during three decades, starting with the year 1990. The research methodology is specific to studying forest ecosystem within projects specialized in forest fund characterization, whose result is represented by forest management plans. As such, analysis were realized for pH, humus content, exchange base capacity(Sb), hydrogen exchange capacity (Sh), total cationic exchange capacity (T), base saturation degree(V) and total nitrogen. Luvisol is the most widespread forest soil in this area while the lowest pH values in the first horizon were found for dystric cambisol (4.36), while the highest ones were for eutric cambisol (4.96); pH values increase in the second horizon. The lowest values for the basis degree saturation were also found for dystric cambisol (oligomesobasic soils), while the highest values were for eutric cambisol (eubasic soils). The humus content is high for luvisol and dystric cambysol, while stagnosol, preluvisol and eutric cambisol are moderately humiferous. Nitrogen supply is very good for dystric cambisol, good for eutric cambisol, preluvisol and luvisol and weak for stagnosols. Dystric cambisol has a very large total cationic exchange capacity, while all the other soil types have a large exchange capacity. As such, we can conclude that the values of the main analysed parameters are situated within the appropriate variation limits for Romania’s forest soils. [ABSTRACT FROM AUTHOR]

One of the challenges of harnessing higher productivity levels and sustainability of agriculture related to N fertilization is in expanding soil N2O emissions, which has become a serious issue in recent years. Recent studies suggest that biochar may be the solution to this problem, but there is still a knowledge gap related to biochar application rates and its reapplication in Central Europe; therefore, in this study, we investigated the effect of biochar (initial application and reapplication in 2014 and 2018, respectively, at rates of 0, 10 and 20 t ha−1) combined with N-fertilizer (N0—0 kg N ha−1; N1—108 kg N ha−1 and N2—162 kg N ha−1) during the growing season of maize in 2019 (warm temperature with normal precipitation) on the changes of soil properties and N2O emissions in the silty loam, Haplic Luvisol, in the temperate climate of Slovakia. The results showed that the application and reapplication of biochar proved to be an excellent tool for increasing soil pH (in the range 7–13%), soil organic carbon—Corg (2–212%), and reducing the soil’s NH4+ (41–69%); however, there were more pronounced positive effects when biochar was combined with N-fertilizer at the higher level (N2). The same effects were found in the case of N2O emissions (reduction in the range 33–83%). Biochar applied without N-fertilizer and combined with the higher fertilizer level had a suppressive effect on N2O emissions. Biochar did not have any effect on maize yield in 2019.

Over the period 2004-2018, on the luvisol from Șimnic were tested 394 varieties and lines of winter wheat of different origins, at least 3 years each, in order to identify those with high productive potential and a high degree of adaptability to the pedoclimatic conditions in the area. The analysis of the results was made in terms of average yields obtained from the varieties and lines of wheat tested. The registered values had extreme limits: 267 kg / ha for the Bancal variety in 2015 and 8420 kg/ha for the Gruia variety in 2004. The average preponderant classes were 4001-5000 kg/ha and 5001- 6000 kg/ha, with 25% of the results placed in each of them. The fact that the Glosa variety registered the highest average yield over a period of 15 years (5078 kg/ha) certifies the results of this research, knowing that this variety is the most cultivated and the most stable variety in Romania. [ABSTRACT FROM AUTHOR]

In the last decades, Poland has become the leader in mushroom Agaricus bisporus production in Europe. Mushroom production generates large amounts of spent substrate, which as a waste material must be recycled. Significant in this macronutrient content, inducing nitrogen, encourages the use of this organic waste material to fertilize, especially light soils. The aim of the study was to assess the effect of spent mushroom substrate fertilization on the properties of A horizon of the Stagnic Luvisol, especially for the variation in the nitrogen fraction, in the two-year cultivation period. The following laboratory analyses were performed: soil pH, organic carbon content, total content of nitrogen and sorption properties. The sequential extraction of nitrogen compounds was performed with a 0.25 M KCl solution (for the extraction of mineral nitrogen forms and the most labile organic nitrogen compounds) and with 0.25 and 2.5 M H2SO4 (hot hydrolysis for sequencing of organic nitrogen compounds that are easily hydrolysing and difficult to hydrolyse). The application of spent mushroom substrate to the A horizons of the experimental objects had an effect on differentiation of soil properties and increased their value (pH, Corg, N-tot, Hh, CEC) in comparison to the control object to a greater degree after the first, then after the second year of cultivation. As the content of nitrogen mineral forms was differentiated, more nitrogen was found in an ammonium form (N-NH4) than in a nitrate form (N-NOx). The organic nitrogen content formed the following series of increasing amounts: soluble organic nitrogen NOS < NOEH < NODH < NONH. [ABSTRACT FROM AUTHOR]

Potato cultivars have different strategies for dealing with potassium (K) deficiency in soil, and their response to different forms and rates of K fertilisation may vary because of differences in soil K availability. This study was performed to evaluate the effect of K fertilisation rates (0, 30, 60, 90, 120 and 150 kg K/ha) on tuber yield and quality (dry matter, starch, sugar and ascorbic acid content, taste) of two potato cultivars (Roco and Rosara) grown in the microplot field experiment on Luvisol in the forest-steppe zone in southern West Siberia, Russia (NL 54.422106, EL 83.160257). The tuber yield of both potato cultivars increased with increase in K application rate up to 2.1 and 2.9 kg/m2 for Roco and Rosara, respectively. Sugar content, averaging 3.5%, was mostly determined by cultivar; however, in both cultivars it tended to decrease with increasing K application rate. The application of K fertiliser in the form of sulphate as compared to chloride increased dry matter content from 22.4 to 23.8% and ascorbic acid content from 13.2 to 14.6 mg/100 g fresh mass. Starch content of potato tubers averaged 59.7 ± 4.8% over all K fertilisation variants, with cultivar responses being different. Potassium application rate did not affect Roco tubers’ taste, while improving Rosara tubers’ taste under moderate application rates. The results underscore the importance to adjust fertiliser recommendations concerning potassium application rates and source on the basis of biological requirements and intended utilization of individual potato cultivars

A comparative study of mountain-meadow and mountain-forest soils was performed within the entire Dolgorukovskaya Yayla—a plateau on the northern macroslope of the Main Ridge of the Crimean Mountains—in the altitudinal range from 560 to 975 m a.s.l. Soil morphology, texture, acidity, exchangeable cations, nonsilicate iron content, parameters of the humus status, and optical characteristics of soils were studied. Forest soils on the entire slope are assigned to acid and dark burozems (Cambisols, Luvisols); they are characterized by similar morphological properties and profile patterns of clay, humus, and nonsilicate iron. Mountain-meadow, mountain-meadow chernozem-like, and residual-carbonate soils (Phaeozems) are formed under meadow vegetation in the upper part of the plateau, and soils transitional to piedmont chernozems (Chernozems) are located in its lower part. Humus reserves in the 0- to 50-cm-thick soil layer varied from 16.6 to 42.2 kg/m2 under meadows and from 10.7 to 18.8 kg/m2 under forests. Soils under forest and meadow vegetation were characterized by an increase in acidity and a decrease in base saturation with the increase in the altitude. Acidity was generally higher in forest soils, while the difference in this parameter between forest and meadow soils in the upper part of the plateau was minimal. In soils under meadows, the content of oxalate-extractable iron also increased with the altitude, and its mean content in the A horizon (226 ± 67 mg/100) was higher than that in forest soils (183 ± 41 mg/100 g). More intense color of soils under grass vegetation as compared to soils under forests is mainly explained by the differences in the rate of organic matter humification and optical density of humic acids, the total humus content being similar in both groups of soils. [ABSTRACT FROM AUTHOR]

Forest soils from a certain geographic area can be studied based on the soil analyses realized during forest management activities. As such, based on the values of the main chemical parameters for the 1392 pedo-genetic horizons from the 10 forest districts from Sibiu County, relevant conclusions were obtained and statistically ensured regarding their characteristics. The main soils from Sibiu County are luvisol, eutric cambisol and dystric cambisol. Entic podzol and dystric cambisol are strongly acid and oligomesobasic, while eutric cambisol, luvisol and preluvisol are moderately acid and phaeozem is neutral and eubasic. All soils form this area have a high total cationic exchange capacity and are well supplied with nitrogen and humus, having a superior reliability for the forest vegetation. [ABSTRACT FROM AUTHOR]

Soil samples were taken in order to investigate the spatial soil water content changes at 40 points in a field of 675 m2 located on the old Istanbul-Izmit road in Kocaeli-Turkey. The water content values of soil samples collected were obtained using oven and Speedy Moisture Tester (SMT) in the laboratory to correlate with measured electrical conductivity of soil by electrical resistivity method with a 2-electrode system. The results showed a reasonably good correlation between electrical conductivity and water content. The determination coefficient between the water content and the electrical conductivity found by the oven method (R2 ≈ 0.8) was higher than that of the SMT (R2 ≈ 0.6). The correlation between the water content values of oven and SMT is quite affordable with the determination coefficient (R2 ≈ 0.7). Considering the results obtained from Oven and SMT method, it can be concluded that the resistivity method is also successful in measuring soil water content. It is foreseen that resistivity method can be preferred both because it is easy to use, and large areas are faster and economical in measuring soil water content. [ABSTRACT FROM AUTHOR]

An experiment of different application rates of biochar and biochar combined with nitrogen fertiliser was conducted at experimental field on a Haplic Luvisol located in Nitra region of Slovakia during the growing season of spring barley (2014). The aim of this study was to evaluate the effects of biochar and biochar combined with nitrogen fertilisation on the soil organic carbon (SOC). The treatments consisted of 0, 10 and 20 t/ha of biochar application (B0, B10 and B20) combined with 0, 40 and 80 kg/ha N of nitrogen fertiliser applied (N0, N40 and N80). The results showed that SOC content at the beginning and end of the trial was always higher at the plots amended with biochar as compared to control plots (B0N0, B0N40 and B0N80); however, statistically significant effects were observed only at the beginning of the trial as well as at the end of trial in B20N40 treatments. Overall, the highest values of SOC contents were obtained at the beginning as well as at the end of the trial when 10 and 20 t/ha of biochar was applied together with 40 kg/ha N.

Recent findings of changing climate, water scarcity, soil degradation, and greenhouse gas emissions have brought major challenges to sustainable agriculture worldwide. Biochar application to soil proves to be a suitable solution to these problems. Although the literature presents the pros and cons of biochar application, very little information is available on the impact of repeated application. In this study, we evaluate and discuss the effects of initial and reapplied biochar (both in rates of 0, 10, and 20 t ha−1) combined with N fertilization (at doses of 0, 40, and 80 kg ha−1) on soil properties and N2O emission from Haplic Luvisol in the temperate climate zone (Slovakia). Results showed that biochar generally improved the soil properties such as soil pH(KCl) (p ≤ 0.05; from acidic towards moderately acidic), soil organic carbon (p ≤ 0.05; an increase from 4% to over 100%), soil water availability (an increase from 1% to 15%), saturated hydraulic conductivity (an increase from 5% to 95%). The effects were more significant in the following cases: repeated rather than single biochar application, higher rather than lower biochar application rates, and higher rather than lower N fertilization levels. Initial and repeated biochar applications, leading to N2O emissions reduction, can be related to increased soil pH(KCl).

In a model laboratory experiment on gray forest soil, the succession of microbial communities during the decomposition of proteins, lipids, and polysaccharides was studied. Proteins were mineralized during the first three months; active decomposition of lipids started two months after the beginning of the experiment. Differences in the functional diversity of microbial communities during the succession were revealed using the method of multisubstrate testing of respiration activity. Microbial respiratory responses to introduction of nitrogen-containing compounds (amino acids) were the highest in variants with decomposition of nitrogen-free compounds and low in protein variants. The ratio of respiratory responses of microbial communities to introduction of carboxylic acids to that of amino acids characterized the nitrogen supply in the soil. This parameter may be useful for reconstruction of initial presence of organic materials in various archaeological contexts. [ABSTRACT FROM AUTHOR]

The dynamics of Cu and Pb were studied in eight soil profiles (Luvisols, Chernozems), located at various distances from the tailing dams near a closed Cu-Pb-(Zn)-Ag mine at Kombat (Namibia) by a combination of isotope and elemental studies, leaching techniques and speciation modelling. Tailings, soils and bedrocks were analyzed for the bulk Cu and Pb concentrations, for their chemical forms using the sequential extraction procedure and for the isotope compositions of Cu (δ65Cu) and Pb (206Pb/207Pb, 208Pb/206Pb). In spite of the differences in the contamination of the studied profiles by tailing dust, both soil types exhibit characteristic trends in the behaviour of metals and distribution of their isotopes. While most Luvisols exhibit an increase in the metal content towards depth in the profile, Chernozems exhibit the opposite trend (decrease in metal content with depth) or similar contents in the whole profile. Luvisols were mostly characterized by changing δ65Cu values as a function of depth. The value of δ65Cu decreases with depth to the Bt horizon and then the δ65Cu value increases with increasing depth. Chernozems mostly yielded uniform Cu concentrations and isotope compositions in all the soil horizons, clearly contrasting with the isotopically lighter compositions of the carbonate bedrocks. Positive δ65Cu values in the tailing material affect the surface of the soil, especially soil sampled in its vicinity. In most Luvisols and Chernozems, the isotope composition of Pb exhibits similar patterns with a low 206Pb/207Pb ratio on the surface of the profile and with a slight increase to depth. The low 206Pb/207Pb values at the surface of the profiles are caused by dust from the tailings. The elemental and isotopic patterns of both contaminated and uncontaminated soil types reflect not only the distance from the tailing dam but also pedogenetic processes in the profiles and geochemical behaviour of both contaminants. The copper elemental and isotope patterns reflect the formation of more mobile species in the surface environment and movement of solutions and colloids and precipitation onto secondary minerals in Luvisols. Plant uptake of lighter isotopes in Chernozems can influence the Cu isotope patterns in these soil types. The limited movement of colloids and higher sorption capacity of Chernozems is manifested in the isotope compositions of Cu and Pb in their profiles. Unlabelled Image • Cu and Pb dynamics in semi-arid soils were studied using isotope and elementary data and thermodynamic modelling. • Behaviour of metals differs in Luvisols and Chernozem. • Formation and transport of solutions and colloids influence metallic and isotope patterns in Luvisols. • While Pb isotopes reflect simple mixing, Cu isotopes are influenced by mixing and pedogenic fractionation. [ABSTRACT FROM AUTHOR]

Abstract—: A comparative analysis of organic matter in the mountainous soils under the main plant communities of the Crimea was performed. The humus state of burozems and mountainous meadow soils under natural meadow vegetation and planted forests was studied using traditional methods and 13C-NMR spectroscopy for the determination of the contents of total organic carbon, carbon of humic acids and optical density of humic acid solutions. The highest humus content in the A horizon was found in the dark burozem under the beech-hornbeam forest on the Chatyr-Dag Plateau. The meadow soils of the Ai-Petri Plateau were significantly inferior in terms of humus content than the dark burozem and meadow soils of other Crimean plateaus due to the intensive anthropogenic impact on these lands until the 1970s. The lowest humus content was found in the meadow soils of the forested Ai-Petri areas because of the strong degradation of the grass cover after planting trees. The investigation of humic acids using the 13C-NMR method showed that humic acids of Crimean mountainous soils were characterized by the elevated hydrogen content, which well agreed with the content of alkyl fragments. The structural molecular composition of humic acids was dominated by aliphatic components, aromatic components being weakly expressed. At the same time, the aromaticity was somewhat higher in the cases when the soil was formed in the meadow ecosystem; it was lower in the upper soil horizons of the forest ecosystems. The degree of aromaticity of humic acids is intermediate between that of podzolic and chernozem soils, which is typical for soils of semihumid regions. The substitution of herbaceous vegetation in the course of natural overgrowing or afforestation of areas with meadow soils has led to an increase in their acidity, but it had no noticeable effect on the elemental and structural composition of humic acids. [ABSTRACT FROM AUTHOR]

Abstract This chronosequential study focuses on the vegetation succession, Luvisol pedogenesis, and long-term carbon dynamics during post-agricultural restoration in the temperate broad-leaved forest of European Russia. The study comprises three chronosequences of 37 years (North), 120 years (Middle), and 42 years (South) to cover climatic differences within the study area. The sites of each catena were mostly comparable in terms of climate, soil texture, and land history, but the duration of agricultural abandonment differed between sites. Plant succession developed via a birch forest or a pear-ash woodland to a birch-oak forest with Aegopódium podagrária after 120 years, which indicates the plant association is near to a climax oak forest. Former homogenous plow horizons formed a new morphological stratification similar to natural Luvisols, due to the formation of a well rooted Ah horizon and an O horizon of mull; a change in soil structure from coarse blocky to granular; and decreasing bulk densities. However, plow features were identified even after 120 years of Luvisols restoration. During restoration, the former plow horizons showed minor changes of pH 5.4–5.6 (CaCl 2). However, a slightly increased pH value within the newly developed Ah and O horizons induced a new pH stratification of the former plow horizon, approaching the natural soils. Compared to the former plow horizons below, soil organic carbon (SOC) and plant available nutrients (P, K) enrichment was observed within the newly developed Ah horizons. The SOC stocks of the 5 cm mineral topsoil increased from 0.8 to 1.7 kg m−2 (North), from 1.3 to 1.7 kg m−2 (Middle), and from 1.4 to 2.3 kg m−2 (South) during restoration. The surface organic layers showed SOC stocks of 0.1–0.2 kg m−2. However, the levels of the near-natural soils were not reached after 37 years (North) and 42 years (South) of restoration. The model predicted a recovery time of about 150 years to achieve a comparatively steady state. A negative effect of mowing was observed for the modelled SOC accumulation. Despite all these alterations, the study showed no full restoration for many parameters within the chronosequential timescale of 120 years. Highlights • Post-agricultural restoration of Luvisols of European Russia was analysed with chronosequential approach. • Vegetation and soils developed towards their natural conditions • SOC accumulation was found. • A recovery of SOC stocks after 150 years was modelled. • No full restoration was found within the chronosequential timescale. [ABSTRACT FROM AUTHOR]

Con el objetivo de determinar la densidad de longitud de raíces (DLR) finas en una plantación de café variedad Catimor en la zona de Custepec en la Concordia, Chiapas, se ubicaron los suelos en función de la pendiente mediante tres perfiles en diferentes posiciones siográ cas de la pendiente. Los suelos se clasi caron y caracterizaron con la Base Referencial Mundial del Recurso Suelo y la NOM-021-RECNAT 2000. La DLR vertical y horizontal se determinó por medio de la selección aleatoria de tres plantas por cada posición fisiográfica, las cuales se distribuyeron bajo un diseño completamente al azar con arreglo factorial con tres niveles: posición de la pendiente (alta, media y baja), dos distancias al tronco (50 y 100 cm) y tres profundidades (0-20, 20-40 y 40-60 cm). En la posición alta, media y baja de la pendiente los suelos se clasificaron como Haplic Lixisol (Clayic, Cutanic, Hypereutric), Eutric Sideralic Cambisol (Clayic, Humic) y Haplic Luvisol (Loamic, Cutanic, Hypereutric, Humic), respectivamente. Las características del suelo en las tres posiciones di eren, debido a la erosión, lixiviación de bases, argilización e intemperismo de la arcilla. La DLR horizontal a las dos distancias evaluadas se comporta de forma homogénea; en cada sitio y cada tipo de suelo la DLR fue similar, solo presentó diferencias signi cativas en forma vertical entre sitios y tipos de suelo. La mayor concentración de raíces 89.95% se tuvo con DRL de 6.97 km m-3 en los primeros 20 cm de profundidad.

Chemical, physical and biological characteristics of forest soils are very important for foresters especially for assessing the capacity of forest sites for timber production. More and more foresters started to take into consideration the relation between the forest soils, the tree layer composition and the silvicultural measures in order to find the best combination from a sustainable development point of view. The aim of this study was to realize a description of the forest soils from Prahova County. The data for the timeframe 1988-2012 from the forest management plans of the eight state-owned forest districts within Prahova Forestry Directorate were taken into account. The most common forest soils across Prahova County were the eutric cambisol, the dystric cambisol and the luvisol. By taking into account the values of the pH and soil base saturation, two of the most relevant chemical characteristics of forest soils, we can say that the forest sites with eutric cambisols and luvisols provide the optimum conditions for the development of beech and Norway spruce. In order to conserve or to increase the chemical characteristics of the forest soils to an optimum level, future silvicultural measures should be focused on promoting the mixed stands, even if by doing this, the forests managers will have to face several challenges. [ABSTRACT FROM AUTHOR]

Abstract: Soil profiles keep records of the legacies of historical land uses on soil physicochemical properties with deep‐soil (3‐m depth) profiles providing information on centuries‐old dynamics. By combining geohistorical archives on past land uses and management practices together with soil pH data from 19 plots scattered across five study areas in North France, we analyzed the effect of two contrasting historical land‐use change trajectories (afforestation of former arable land vs. cultivation after deforestation) on the acidification and alkalinization dynamics along 3‐m‐depth loessic Luvisols profiles. An analysis of covariance and a generalized additive model were used to test the interaction effect between depth and the two studied chronosequences levels on soil pH. Results show two contrasting alkalinization dynamics for formerly acidic forest soils converted to arable land depending on past management practices. One century of liming practices based on hydrated lime is enough for a complete deprotonation, whereas alkalinization dynamic was much slower (two to four centuries are necessary to neutralize the relictual acidity below 2 m) under liming based on chalk‐blocks supply. Per contra, afforestation of former arable land cultivated and limed during at least 2–4 centuries keep an alkaline ‘memory’ effect over more than a millennium. The acidification process is progressive through time from the surface to deeper soil horizons. This suggests that soil pH profiles can be used to estimate time since afforestation of former arable land. Linking deep‐soil pH profiles with chronosequences is a powerful tool to understand the potential impact of future land‐use change trajectories on soil physicochemical properties. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) has the potential to supply substantial quantities of nutrients [ i.e nitrogen (N), phosphorus (P) and sulphur (S)] for plant uptake. Yet there is little understanding of the impact of management on the nutrient supply potential in soils (particularly, P and S). To quantify N, P and S availability from SOM, surface soils (0–10 cm) were collected from 14 management practices across three long-term (16–46 years) experimental sites under semi-arid (Luvisol), Mediterranean (Luvisol) and sub-tropical (Vertisol) environments in Australia. The practices comprised conventional (CT) and reduced tillage (RT) with mixed farming, no-till with continuous cropping (NT), and perennial pasture (PP) in the semi-arid Luvisol, while in a Mediterranean direct-drilled continuous cropping system, stubble was either retained (SR) or burnt (SB). Practices on the Vertisol comprised a factorial combination of CT, NT, SR, SB with either 0 (0N) or 90 kg urea-N ha −1 (90N) in a continuous cropping system. Soils were incubated under controlled soil moisture and temperature, and cumulative organic C mineralised (C min ), and net available N, P and S were measured over 126 days. In the semi-arid Luvisol, CT and/or RT showed significantly higher C min and net available N, P and S than NT and PP. In the Mediterranean Luvisol, C min and net available P were not influenced by stubble management. In the Vertisol, CT-SR ( cf. CT-SB and NT-SR/SB) with or without N fertilisation significantly increased C min , and CT-SR and/or -SB with N fertilisation ( cf. CT-SR/SB without N fertilisation and NT-SR and/or -SB with or without N fertilisation) significantly increased net available N and P. This study found a continuous release of net available N (11–49 kg N ha −1 over 126 days) across all management practices, whereas, the release of available P and S was evident only during the first 30 days (6–74 kg P ha −1 , −4 to 22 kg S ha −1 ), after which microbial immobilisation or clay fixation of P and S predominated, particularly in the Vertisol. In conclusion, the results indicate that SOM is a ready source of plant available P and S (in addition to N), and tillage and stubble retention generally enhanced SOM mineralisation and nutrient release, which varied with soil type. [ABSTRACT FROM AUTHOR]

The aim of this paper is to realize a description of forest soils from Arad County. The work material is represented by soil analysis data from forest management plans made in the period 1985-2015 from 22 forest districts, meaning 483 soil profiles and 1332 pedo-genetical horizons. The soils found in Arad are characteristic to the area of low hills (luvisols, preluvisols, eutric cambisols). However, field soils (phaeozems), mountain soils (dystric cambisols) and even azonal soils (fluvisols, gleysols) are present, in the order of their spreading: luvisol (moderately acid, mezobazic in Ao and Bt and oligomezobasic in El, with a high total cationic exchange capacity, well supplied with nitrogen and intensely humiferous), eutric cambisol (moderately acid, mezobazic, with a high total cationic exchange capacity, very well supplied with nitrogen and intensely humifeous), preluvisol (moderately acid, mezobazic, with a high total cationic exchange capacity, very well supplied with nitrogen and intensely humiferous), gleysol (eubazic, with a very high total cationic exchange capacity, very well supplied with nitrogen and moderately humiferous). [ABSTRACT FROM AUTHOR]

Soil respiration (Rs), or soil CO 2 efflux, is the largest carbon flux from ecosystems to the atmosphere; it is an order of magnitude greater than that released by human activity, and is a key process in CO 2 atmospheric accumulation and climate change. Due to its importance, many studies have investigated respiration in different ecosystems, with studies in tropical dry areas being more scarce. We measured the effects of soil temperature and moisture on respiration from Regosols and Luvisols under pasture and native deciduous forests in the Brazilian Northeast semiarid region. Respiration had a direct relationship with soil moisture and an inverse relationship with temperature in both soil classes and land covers. Respiration was higher under the forest than under the pasture (9.0 and 4.8 Mg C ha−1 y−1) in both wet and dry seasons, probably due to higher biomass incorporation and higher root respiration, but it did not differ between soil classes. These respirations corresponded to high proportions of the soil C contents in the 0–10 cm superficial layer (46.2% in Caatinga and 36.7% in pasture). In the Brazilian semiarid region, soil respiration was controlled by soil moisture (positively) and temperature (negatively), both of which were affected by land-use changes. • Soil respiration was similar in Regosols and Luvisols. • Soil respiration was higher under the forest than under the pasture. • Soil moisture was the main driver of soil respiration in both soil classes and land uses. [ABSTRACT FROM AUTHOR]

We studied Fe-Mn concentric nodules from Cutanic Luvisol in the northern part of Namibia, where agricultural fields are irrigated with the drainage water from the Kombat Cu-Pb-(Zn) mine (pH 7, metal concentrations in μg l − 1 : Fe 7, Mn 10, Zn 7, Cu 18). Concentric nodules (0.5–2 cm in size) were mostly found towards the bottom of the sampled soil profile (Btcg2 horizon, depth 100–120 cm). Comparisons with the bulk chemical composition of the soil matrix showed that Fe-Mn nodules were enriched in metals, metalloids and other trace elements (with a few exceptions, enrichment factors varied in the range 1.3–6.4). The concentrations of the elements of interest in the Fe-Mn nodules were as follows (mg kg − 1 ): As 23.1, Ba 3840, Cd 6.83, Cu 450, Pb 597, Zn 137. The X-ray diffraction analysis indicated that the nodules were composed of quartz, goethite, hematite, illite/mica, pyrochroite, lithiophorite and birnessite. The scanning electron microscopy (SEM) observations confirmed that the internal structure of the nodules with concentric rings reflected seasonal changes in the redox conditions. Spot analyses and X-ray elemental maps performed using energy/wavelength dispersion spectrometry (EDS/WDS) showed that the concentrations of metalloids were rather low except for the slightly elevated Ba concentrations, which were observed only within the Mn oxide-rich zones. Selective extractions were used to understand the partitioning of trace elements within the individual phases. Whereas Mn oxides sequestered the majority of the Cd (up to 98%), Ba, Pb and rare earth elements (REEs) (up to 78%), other metals such as Cu and Zn exhibited much lower values (47–65%) and, together with oxyanionic species (As, Cr, V), were also significantly bound to Fe oxides. The pH-static leaching test conducted in the pH range 2–12 indicated that the majority of the trace elements were mostly leached under acidic conditions with the exception of As, which was highly solubilized at pH 12 (up to 17%). Whereas Ba, Cd, Cu and Zn were significantly released under acidic conditions (up to 12%), the leaching of Pb was almost negligible over the entire pH range. Our results show that Fe-Mn nodules act as significant traps for trace metals in Luvisols irrigated by mine water. However, an abrupt decrease in the pH and changes in the redox conditions may cause the dissolution of Fe-Mn nodules and subsequent release of contaminants into the soil system. [ABSTRACT FROM AUTHOR]

Mineral N fertilizer application may have an effect on soil organic matter and other soil parameters. Therefore, we studied the effects of different doses of N fertilization on soil organic matter and chemical properties of Haplic Luvisol in the locality of Dolná Malanta (Slovakia) during 2014-2016. Soil samples were collected from the plots exposed to the following treatments: 1. N0 - no N fertilization as control during 2014-2016, 2. N40 - N fertilizer at the rate of 40 kg N ha-1 in 2014 and 2016, 3. N80 - N fertilizer at the rate of 80 kg N ha-1 in 2014 and 2016, 4. N160 - N fertilizer at the rate of 160 kg N ha-1 in 2015, and 5. N240 - N fertilizer at the rate of 240 kg N ha-1 in 2015. The results showed that in N80 the soil organic carbon (SOC) content increased by 32% in comparison to N0. The addition of 80 kg ha-1 of N significantly decreased the humic substances (HS) content in the soil by 16% compared to N0. The higher doses of N fertilization 80 rather than 40 kg ha-1 as well as 240 rather than 160 kg ha-1 significantly decreased humus stability. The addition of N fertilization decreased the average values of soil pH. Values of hydrolytic acidity (Ha) increased by 41% and 46% in N40 and N80, respectively than N0, but on the other hand, this one decreased by 36% and 27% in N160 and N240, respectively in comparison to N0. Positive statistically significant correlations were determined between soil pH and SOC in N40 and N80 treatments. The increase of soil pH was connected with higher humus quality in N160 and N240. Negative correlations between humic acids (HA) and sum of basic cations (SBC) and cation exchange capacity (CEC) were observed in N80 < N160 < N240 treatments. Higher values of fulvic acids corresponded with lesser CEC in N80 and N160 treatments. In N160, with increased humus quality, CEC significantly decreased. The same effect was observed in N240. In addition, in N240, we also observed that with increased HA:FA ratio SBC and base saturation significantly decreased. [ABSTRACT FROM AUTHOR]

The pressure to increase biomass production worldwide has pushed the boundaries of agricultural lands towards fragile soils. This process is particularly intense in Pernambuco State, NE Brazil. Pernambuco features a moisture gradient, with soils developed from similar gneisses. Resistant structures within the rock influenced the internal movement and distribution of water, consequently influencing regolith genesis. This paper presents the mineralogical characteristics of three regolith profiles with shallow soils (here assumed to be soils in which the top of the Cr horizon is at a depth of 1.5 m or less) along a transect at 8°S and discusses their weathering and pedogenetic processes. Samples were investigated via optical microscopy and scanning electron microscopy (SEM), X-ray diffraction (XRD) and total chemical analysis by inductively coupled plasma - atomic emission spectrometry (ICP-AES). The presence of weathering-resistant quartz veins and planes in the rock structure played a central role in controlling the water dynamics and the advancement of the weathering front. Therefore, desilication was dominantly controlled by the pore network. Hence, the weathering indexes did not differ appreciably among the climatic zones, and both 1:1- and 2:1-type clays were found in all profiles, although the amount of clay minerals that formed and the degree of dissolution of the primary minerals varied among the climate types. From an agricultural perspective, the thinness of these soil profiles and the presence of leucocratic layers are the main drawbacks of the regoliths, whereas the capacity to supply plant nutrients via primary mineral dissolution near the root zone can be an advantage. [ABSTRACT FROM AUTHOR]