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The study aimed to assess the impact of different investment strategies on agronomic parameters, specifically soil chemical composition and forage mass (FM), in a loamy-sandy Cambisol within the Brazilian Cerrado, following three cultivation cycles. High-investment (HI) included various crop-livestock integration strategies with soil management (harrowing/fertilisation) for intercrops: CG (corn with Paiaguas grass); GPP (Paiaguas grass with pigeon pea); CGPP (corn, Paiaguas grass, pigeon pea). After livestock farming, HI transitioned to soybean cultivation. Low-investment (LI) included other systems: CF (Decumbens grass monoculture with P2O5 fertilisation); PPCF (Decumbens grass with pigeon pea and P2O5); MC (Decumbens monoculture without fertilisation). In the third year (2016/2017), triple intercropping with Xaraes grass, corn, and pigeon pea was sown. In the HI, the highest base saturation (55.90%) values were obtained, which favoured increases in corn FM (2016/2017: 5181 kg/ha). In this investment model, high values of cation exchange capacity, calcium, and magnesium were observed. In the LI condition, the absence of mechanical soil management and the combination of legume and fertilisation promoted higher soil phosphorus (PPCF: 14.20 mg/dm3). When analysing corn FM and soil parameters, HI is the best option for sustainable production in agricultural areas (loamy-sandy) of the Brazilian Cerrado. [ABSTRACT FROM AUTHOR]

Acid tropical soils may become more productive when treated with agricultural lime, but optimal lime rates have yet to be determined in many tropical regions. In these regions, lime rates can be estimated with lime requirement models based on widely available soil data. We reviewed seven of these models and introduced a new model (LiTAS). We evaluated the models' ability to predict the amount of lime needed to reach a target change in soil chemical properties with data from four soil incubation studies covering 31 soil types. Two foundational models, one targeting acidity saturation and the other targeting base saturation, were more accurate than the five models that were derived from them, while the LiTAS model was the most accurate. The models were used to estimate lime requirements for 303 African soil samples. We found large differences in the estimated lime rates depending on the target soil chemical property of the model. Therefore, an important first step in formulating liming recommendations is to clearly identify the soil property of interest and the target value that needs to be reached. While the LiTAS model can be useful for strategic research, more information on acidity-related problems other than aluminum toxicity is needed to comprehensively assess the benefits of liming.

The cagaiteira (Eugenia dysenterica DC.) is an important fruit species native from Brazilian Cerrado that has economic potential for food and pharmaceutical sectors and the recovery of degraded areas. Knowledge about crop management is still limited, including fertilization methods. This study aimed to evaluate the effect of lime and phosphorus (P) application on nutrition, growth, dry matter production and physiological aspects of cagaiteira seedlings. The experiment was conducted in a greenhouse, using a randomized block design with three replications, in a 5x4 factorial scheme, five base saturation levels (24.5, 40.0, 60.0, 80.0 and 100.0%) and four P rates (0, 100, 200 and 400 mg dm-3). At 180 days after transplanting, gas exchange, biometrics (diameter, height and leaf area), dry mass production, seedling quality (Dickson Quality Index - DQI) and nutrient content were evaluated. The results were subjected to analysis of variance (p<0.05) and regression model adjustments. The growth and physiology of Eugenia dysenterica DC seedlings are not influenced by liming; however, the application of lime positively influences the B content in the plants. Phosphate fertilization increases growth in height, with an estimated rate of 245 mg dm-3 of P indicated to produce cagaiteira seedlings, since at this dose is estimated that the plant will be taller. In general, cagaiteira proves to be a species that develops well in acid soil conditions and with low availability of P. [ABSTRACT FROM AUTHOR]

Soil acidity correction aims to neutralize Al3+ and H+ and supply Ca and Mg for the development of crops, such as soybean. However, there is no consensus on the optimum lime rates and application methods for sandy soils, especially in no-till, given their increased susceptibility to leaching of water and nutrients as well as the reduced capacity of soil colloids. Thus, the aim of this study was to compare the efficiency of lime rates and application methods and establish liming criteria for soybean production in a sandy Latosol in Northwestern Paraná. The experimental soil was a typical dystrophic Red Latosol of sandy texture. Treatments consisted of surface and incorporated application of lime to achieve 50%, 60%, 70%, and 80% base saturation and an untreated control (without lime). Soybean was grown in undeformed soil columns. After 114 days, plants were evaluated for height, stem diameter, shoot fresh weight, and shoot dry weight. The soil was analyzed for pH H2O, pH CaCl2, Al3+, exchangeable calcium, exchangeable magnesium, available phosphorus and potassium. The liming criteria that resulted in the maximum development of soybean crops in sandy soil were base saturation of 60%, pH H2O of 6.1, 3.20 cmolc kg-1 calcium, and 1.89 cmolc kg-1 magnesium. [ABSTRACT FROM AUTHOR]

Cation exchange capacity and base saturation are of crucial importance for soil characterisation and classification; however, the interchangeability of soil data for international assessment of soil productivity, soil classification, mapping, and modelling is limited due to the lacking comparisons between results obtained using different analytical methods in particular regions of the world. The aim of the present study was to analyse the relationships between cation exchange capacity and base saturation measured using the methods adopted in Central and East Europe, and ‘standard’ techniques required for soil classification suggested by World Reference Base (WRB). This study was carried out using 183 soil samples collected from Luvisols, Retisols, Planosols, Chernozems, Phaeozems, Cambisols, and Arenosols in Poland, representing a wide range of texture, pH, and organic carbon content. A close comparability was found in noncalcareous soils between the ‘total sorption capacity’ (T) measured in Central and East Europe as the sum of base cations and ‘total’ (‘hydrolytic’) acidity, with the ‘standard’ cation exchange capacity (CEC) measured using 1 M ammonium acetate buffered at pH 7. The close correlation between T and CEC values (in noncalcareous soils) facilitates reliable data recalculation and its application in global modelling, soil classification and mapping. For soils containing carbonates, CEC must be measured using reference methods, because no relationship exists between T and CEC. The ‘potential’ base saturation (V) derived on the basis of T may be reliably recalculated to ‘standard’ base saturation (BS), allowing a retrieval of archival data from Central and East European regional databases and published reports. Similarities between the values of cation exchange capacity and base saturation, whether measured or calculated using the local and standard methods, allow a positive verification of previously proposed correlations between the local soil taxa and the reference soil groups of the WRB classification and soil orders defined by USDA Soil Taxonomy. The pH values corresponding to 50 % of ‘standard’, ‘potential’, and ‘effective’ base saturation were estimated at 5.5, 5.2, and 4.8, respectively. Irrespective of the differences between current estimates and previously reported pH threshold values corresponding to 50 % base saturation, the obtained results confirm that field measurements of soil pH may be considered a substitute for laboratory-measured base saturation for some purposes, such as soil classification.

The evaluation of Hadejia-Nguru wetland soils was carried out for two consecutive dry seasons. Standard analytical techniques were adopted to analyze the samples and statistical models were used to assess the spatial and temporal distribution of the parameters selected. The average pH values of the soil samples were mostly alkaline, and all the measured values were also within the approved standards. Experimental results revealed a significantly positive correlation between Ca and Mg for both seasons as indicated by the p-values and a high coefficient of determination (R2) for both metals with cation exchange capacity (CEC) values as the predictors. The regression analysis showed that the changes in CEC and pH levels in the soil were dependent on changes in Ca and Mg content of the soil. The data obtained showed that the increase in pH is directly proportional to the CEC and base saturation of the soils. A higher percentage of Ca than other cations (Mg, K and Na) was observed from the base saturation of the soils. The pH, base saturation, and CEC levels in the soils are suitable for most crops grown in the area, which has the potential to support a wide range of crops with further exploration. HIGHLIGHTS The physicochemical characteristics of Hadejia-Nguru wetlands soils were investigated.; Statistical models were used to assess the spatial and temporal distribution of the parameters.; Metals play a crucial role in determining the soil quality.; Investigations indicated that the study area is suitable for the farming of vegetables and cereal crops.;

This study aimed to assess the nutritional status of soybean and wheat and the relationship with grain yield and biometric components after lime and phosphogypsum (GY) reapplication. Treatments consisted of two lime application methods, surface liming and incorporated liming, to different levels of base saturation (BS) (44, 70, and 90%), in addition to surface liming to 70% BS associated with a standard dose (70GY1) or double dose (70GY2) of GY. Treatments were applied in 2012 and reapplied in 2016. The results refer to the 2018/2019 soybean season and the 2019 wheat season. Lime + GY treatment increased leaf area, plant height, leaf dry matter, and stem dry matter in soybean but had no effect on specific leaf area (235.4 cm2 g−1), stem diameter (6.08 mm), number of pods per plant (71.7), grain number per plant (165), or thousand grain weight (117 g). Liming to 90% BS reduced leaf manganese contents in both crops and leaf iron content in soybean. GY application improved the calcium status of both crops and the sulfur status of soybean. However, 70GY2 reduced leaf magnesium contents in soybean and wheat. Soil tillage without lime reduced wheat yield by 12% compared with no-till. Soybean yield correlated positively with leaf nitrogen (0.79), leaf phosphorus (0.91), leaf area (0.62), and thousand grain weight (0.65), whereas wheat yield correlated with leaf phosphorus (0.83), calcium (0.75), and sulfur (0.74). For improved soybean and wheat performance, it is preferable to apply lime and GY to the soil surface (70GY1), permanently maintaining no-till practices. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to determine the acidity levels to obtain adequate soil chemical attributes for the maximum fruit yield of blackberry trees grown in acidic soils subjected to increasing limestone rates. The BRS Tupy, Brazos, Guarani, and BRS Xavante blackberry cultivars were evaluated on the Typic Hapludox (LVdf) and Rhodic Hapludox (LVd) soils, to which four rates of dolomitic limestone were applied (0, 1.5, 3.0, and 6.0 Mg ha-1). The effect of liming on soil chemical attributes, in a 2×4 factorial arrangement (soils and limestone rates), as well as leaf nutrient content and fruit yield, in a 2×4×4 factorial arrangement (soils, limestone rates, and cultivars), were evaluated. The maximum fruit yield was obtained with 3.3 Mg ha-1 dolomitic limestone. The blackberry cultivars showed a high demand for Ca, Mg, and base saturation and a low tolerance to aluminum in the soils. From 3.3 Mg ha-1 dolomitic limestone, the maximum fruit yield of blackberry trees grown in acidic soils is obtained with pH 5.6, maximum tolerated aluminum saturation of 6%, Ca and Mg concentration of 45.3 mmolc kg-1, and base saturation of 48.3%.

The sorption capacity and nutrient regime under different soil management practices (C – control, T – tillage and PM – tillage + poultry manure) in productive vineyard soil (Rendzic Leptosol) in the Nitra vineyard region (Nitra-Dražovce, Slovakia, Central Europe) were studied for the years 2013–2022. With T and PM, the soil pH was significantly lower than with C. The soil sorption capacity for both studied depths (0–30 and 30–60 cm) increased in the following order: T < PM < C. For all the soil management practices and soil depths, the soil sorption complex was fully saturated with basic cations. With T, in the 0–30 cm layer, the total nitrogen (Nt) content was lower by 218 and 292 mg kg−1, respectively, than with C and PM. However, in the period 2013–2022, the Nt increased statistically significantly, by 50.9, 87.6 and 97.8 mg kg−1 year−1 with T, C and PM, respectively. The application of PM had a positive effect on the increase in available phosphorus (P) – there was an increase with C and T of 96 and 112%, respectively. The content of available P increased linearly with all soil management practices. However, in the case of T, it was statistically significant (increase of 23.2 mg kg−1 year−1) over the period of 10 years. With PM, at 0–30 cm, the content of available potassium was significantly higher, by 29 and 91%, than with treatments C and T. [ABSTRACT FROM AUTHOR]

We present a review of the life and scientific legacy of the founder of soil colloid chemistry Konstantin Gedroiz. The phenomenon of absorption was first studied in the mid-1800s, and Gedroiz started working on base exchange and absorption in soils in 1906. Based on the general pattern of cation exchange reactions, he proposed the concept of "absorption capacity" and "soil absorption complex", developed ideas about exchange acidity and the rate of exchange reactions, revealed the unique role of absorbed sodium and potassium in soil processes, and proposed the theory of the accumulation of sodium due to exchange reactions. He was one of the first to classify soil on the basis of the absorbing complexes and cations, which was a new approach in pedology. He used the climate classification of soils, and described Podzols, Laterites, and Chernozems in terms of their absorbing complexes and cations. The system of classification worked for mature soils in which pedogenic processes had proceeded to such an extent that the profile characteristics reflected a climatic region, but was less effective in alluvial soils and eroded soils. His studies established the connections between chemical and physical processes and the morphology of soils. He studied the evolution of saline soils from a chemical point of view, which led to the practical recommendations for chemical reclamation of Solonetz and liming of acidic soils. Gedroiz's work was groundbreaking but insufficiently known outside Russia until his books have been translated into English and German in the late 1920s. The soil microbiologist Selman Waksman in the 1925 translated 11 of his papers into English, and the United State Department of Agriculture distributed copies of these translations. In 1927 a textbook on chemical analysis, "Die chemische Bodenanalyse", was published; in 1930 the books "Der adsorbierende Bodenkomplex und die adsorbierten Bodenkationen als Grundlage der genetischen Bodenklassification" and "On the Problem of exchangeable Hydrogen and exchangeable Aluminium in acid soils", a 1931 – "Die Lehre vom Adsorptionsvermögen der Böden". [ABSTRACT FROM AUTHOR]

The Arenosols of Western Rhodopes Mountain are spread on soft, unconsolidated Neogene and Quateranry modern sediments with a sandy texture and weak structure. New research on their genesis, properties, diagnosis and classification were made on their major diagnostic features. Arenosols profile is typical A-AC-C type with low humus content and relatively lower values of CEC compared with other sandy soils in Bulgaria. Content of the soil particles of sandy fraction is above 80 % and soil texture is sandy or loamy sandy, which is main diagnostic feature for Arenosols classification. The research confirms the criteria for their terrain recognition and new additional data for mountainous sandy soils were established. [ABSTRACT FROM AUTHOR]

Cedro-rosa (Cedrela fissilis) is native to Brazil with great potential for seedling production. However, soil correction is necessary to improve its performance, due to the edaphoclimatic conditions in Brazil, where soils have a high weathering degree and large amounts of Fe and Al oxides. Here, we evaluated the combined effect of soil acidity correction by liming and phosphate fertilization using single superphosphate on the growth and development of cedro-rosa seedlings cultivated in Amazonian soil. The study was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA) - Campus Capitão Poço, between July and December 2019. Different levels of base saturation (V%) showed no influence on the variables analyzed. On the other hand, phosphorus (P), calcium (Ca), and sulfur (S) supplied by single superphosphate significantly influenced growth and development of cedro-rosa seedlings. The optimum P levels for stem diameter (SD), leaves number (LN), root dry matter (RDM), stem dry matter (StDM), leaf dry matter (LDM), total dry matter (TDM) were 405, 286, 385, 421.87, 393.75, 445 mg dm-3 of P, respectively. Seedling quality (DQI) showed a positive linear response to levels of P, Ca, and S in single superphosphate. Thus, fertilization with P was necessary at the nursery stage for the cultivation of the species in soil of low chemical fertility. For better quality of cedro-rosa seedlings grown in pots, the application of 400 mg dm-3 of P is recommended. [ABSTRACT FROM AUTHOR]

ABSTRACT Cedro-rosa (Cedrela fissilis) is native to Brazil with great potential for seedling production. However, soil correction is necessary to improve its performance, due to the edaphoclimatic conditions in Brazil, where soils have a high weathering degree and large amounts of Fe and Al oxides. Here, we evaluated the combined effect of soil acidity correction by liming and phosphate fertilization using single superphosphate on the growth and development of cedro-rosa seedlings cultivated in Amazonian soil. The study was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA) – Campus Capitão Poço, between July and December 2019. Different levels of base saturation (V%) showed no influence on the variables analyzed. On the other hand, phosphorus (P), calcium (Ca), and sulfur (S) supplied by single superphosphate significantly influenced growth and development of cedro-rosa seedlings. The optimum P levels for stem diameter (SD), leaves number (LN), root dry matter (RDM), stem dry matter (StDM), leaf dry matter (LDM), total dry matter (TDM) were 405, 286, 385, 421.87, 393.75, 445 mg dm-3 of P, respectively. Seedling quality (DQI) showed a positive linear response to levels of P, Ca, and S in single superphosphate. Thus, fertilization with P was necessary at the nursery stage for the cultivation of the species in soil of low chemical fertility. For better quality of cedro-rosa seedlings grown in pots, the application of 400 mg dm-3 of P is recommended.

Acidic deposition has been well studied for its impacts on forest soils and plants and is thought to detrimentally affect sugar maple (Acer saccharum) in northeastern North America. The physiological mechanism driving reduced tree growth on acid impaired sites is not well understood, but has been suggested to involve increased autotrophic respiration rates. We measured foliar respiration and leaf elemental composition on two species with contrasting acid tolerances (sugar maple and American beech, Fagus grandifolia) across a naturally occurring soil base saturation (BS) gradient in the Adirondack Mountains of New York. Foliar chemistry varied strongly as anticipated across the BS gradient, with decreases in base cations and increases in phytotoxic metals (e.g., Mn) on sites with highly acidified soils. However, foliar respiration rates were not correlated with most measures of acidity (e.g., BS, foliar concentrations of Ca, Mg, Al content). Respiration rates did correlate with other leaf traits (N content, leaf mass per unit area) reflective of leaf morphological variation in response to variable light availability. After accounting for multivariate trait covariation, mass-based respiration rates were associated with foliar Mn content, suggesting a positive relationship between the concentration of this phytotoxic metal and foliar respiration rates. Soluble foliar Ca, Mg, and Mn were closely correlated with total foliar concentrations of these elements. Overall these results demonstrate that soil acidification and loss of base cations is largely unrelated to foliar respiration rates, although the accumulation of foliar Mn on acidified soils may contribute to the metabolic burden of both sugar maple and American beech trees. [ABSTRACT FROM AUTHOR]

Ultic is the soil characteristics in soil taxonomy when argillic or kandic horizon is found within the depth of 125 cm with the base saturation of less than 35 % on the overall of upper 50 cm. The purpose of this research is to investigate whether ultic horizon was found in the soil developing from the Pleistocene eruption of Mount Tilu (basaltic parent materials), in West Java, Indonesia. The method used was descriptive and comparative surveys of three profiles in the area around Mount Tilu, including the investigation of andic soil properties and the formation of argillic or kandic horizon. The result showed that the soils fulfilled the requirements of andic soil properties to be classified as Andisols. Soil never dried for ninety days cumulative (udic) to be classified as Udands. There were Fulvudands and Hapludands in this location. Accumulation of clays was more than 1.2% higher than the overlying horizon found at the depth of 90, 79, and 51 cm in those three profiles. Base saturation in upper 50 cm ranged from 1.07 to 6.86 cmol kg-1 or less than 35 %, making the soils were classified as Ultic Fulvudands and Ultic Hapludands. The high rainfall in the tropics and Pleistocene age led to the leaching of clays for a long period to form the argillic horizon. The influence of rain was stronger than the basaltic parent materials in forming Ultic Hapludands. Basaltic parent material was not strong enough to produce base saturation of more than 35 %. [ABSTRACT FROM AUTHOR]

Atmospheric acid deposition has increased sharply since the beginning of industrialization but has decreased considerably since the 1980s owing to clean-air policies. Soil acidification induced by an input of acidity has been demonstrated in numerous studies using repeated forest-soil inventories. So far, relatively few data have been sampled to analyze long-term soil trends and only a few studies show the recovery of forest soils from acidification, whereas the recovery of surface waters following declining acid deposition is a widespread phenomenon. To assess a possible recovery from acid deposition, soil resampling data from 21 forested permanent soil-monitoring sites in Lower Saxony (Germany) were evaluated. For most sites, at least three repetitions of inventories from a period of 30 to 50 years were available. Trend analyses of indicators for the acid-base status of unlimed forest soils using generalized additive mixed models (GAMM) show either a trend reversal or a stagnation of the acid-base status at a strong acidification level. The recovery, if indicated by an increase of soil pH and base saturation, of soils from plots with deciduous trees appears to have occurred faster than in coniferous forest stands. This observation may be attributed to a larger amount of temporarily stored sulfur in the soil because of the higher atmospheric input into coniferous forests. As indicators for the acid-base status still show considerable soil acidification, mitigation measures such as forest liming still appear to be necessary for accelerating the regeneration process. [ABSTRACT FROM AUTHOR]

The impact of long-term (> 100 yr) irrigation on soil chemical properties was studied on eight plots in the Beli Drim river valley in Kosovo and Metohija near Klina, Serbia. For these studies, soil samples from shallow profiles were collected from only one or two depth zones of the Ah horizon; and from moderately deep and deep profiles, from two to three depth zones for the purpose of comparing irrigated field and non-irrigated meadow lands. Water from the Beli Drim River and surface gravity systems (irrigation furrows or border strip irrigation) were used for irrigation. Chemical variables included determination of pH-H2O, content of CaCO3, content of humus, hydrolytic acidity, sum of basic cations, cation exchange capacity, and base saturation. On irrigated soils, the results of chemical analysis showed on average a small increase in pH-H2O (0.07 pH units), as well as a significant decrease in humus content (2.00-4.75%), sum of basic cations (4.98-12.98%) and cation exchange capacity (12.8%) compared to the non-irrigated land of the study area. Long-term irrigation had no effect on hydrolytic acidity and base saturation in the Ah horizon of the investigated lands. Namely, the mentioned variations in the chemical properties of the investigated soils show that slight processes of reduction in the humus content and reduction of the content of base cations occured. Data on the chemical properties of the investigated soils indicate that the destructive processes of reduction in the humus content and leaching of base cations must be controlled in order to achieve a stable sustainable system of high productivity and prevent their further deterioration.

Arnica montana L. (AM, Asteraceae) is a perennial, herbaceous vascular plant species of commercial importance. The flower heads’ pharmacological properties are attributed mainly to sesquiterpene lactones (SLs), with phenolic acids and flavonoids also considered of relevance. The botanical drug is still partly collected in different European mountain regions. The SL content can be influenced by genetic factors and environmental conditions (altitude, temperature and rainfall). Surprisingly, the influence of the soil on SL-content have rarely been investigated. However, the soil determines the occurrence, distribution and overall fitness of AM. Equally, environmental factors are crucial determinants for the biosynthesis and fluctuations in plant secondary metabolites. Therefore, different abiotic (pH, C/N ratio, base saturation, cation exchange capacity) and biotic (species richness, vegetation cover) parameters need to be assessed as potential drivers of the variable content of AM’s secondary metabolites. Consequently, we developed an in situ experimental design aiming to cover a wide range of soil pH conditions. We detected and investigated different AM populations growing in grassland on acidic soils, on siliceous as well as calcareous geologies within the same geographical region and altitudinal belt. The total SL content and most single SL contents of the AM flower heads differed significantly between the two geologies. AM flower heads of plants growing on loam on limestone showed a significant higher total SL content than the flower heads of plants growing in siliceous grasslands. Furthermore, the SL contents were significantly correlated with geobotanical species richness and vegetation cover pointing toward an effect of species interactions on the production of SLs. Moreover, the ratios of the main SLs helenalin to dihydrohelenalin esters were significantly correlated to environmental parameters indicating that SL composition might be a function of habitat conditions. The findings of this study shed light upon the often ignored, complex interactions between environmental conditions and plant secondary metabolites. We highlight the importance of both abiotic and biotic habitat parameters for SLs in AM.

Arnica montana L. (AM , Asteraceae) is a perennial, herbaceous vascular plant species of commercial importance. The flower heads' pharmacological properties are attributed mainly to sesquiterpene lactones (SLs), with phenolic acids and flavonoids also considered of relevance. The botanical drug is still partly collected in different European mountain regions. The SL content can be influenced by genetic factors and environmental conditions (altitude, temperature and rainfall). Surprisingly, the influence of the soil on SL-content have rarely been investigated. However, the soil determines the occurrence, distribution and overall fitness of AM. Equally, environmental factors are crucial determinants for the biosynthesis and fluctuations in plant secondary metabolites. Therefore, different abiotic (pH, C/N ratio, base saturation, cation exchange capacity) and biotic (species richness, vegetation cover) parameters need to be assessed as potential drivers of the variable content of A M's secondary metabolites. Consequently, we developed an in situ experimental design aiming to cover a wide range of soil pH conditions. We detected and investigated different AM populations growing in grassland on acidic soils, on siliceous as well as calcareous geologies within the same geographical region and altitudinal belt. The total SL content and most single SL contents of the AM flower heads differed significantly between the two geologies. AM flower heads of plants growing on loam on limestone showed a significant higher total SL content than the flower heads of plants growing in siliceous grasslands. Furthermore, the SL contents were significantly correlated with geobotanical species richness and vegetation cover pointing toward an effect of species interactions on the production of SLs. Moreover, the ratios of the main SLs helenalin to dihydrohelenalin esters were significantly correlated to environmental parameters indicating that SL composition might be a function of habitat conditions. The findings of this study shed light upon the often ignored, complex interactions between environmental conditions and plant secondary metabolites. We highlight the importance of both abiotic and biotic habitat parameters for SLs in AM. [ABSTRACT FROM AUTHOR]

ABSTRACT Brazil is currently the leading country in no-till (NT) farming, particularly on Ferralsols (Latossolos), the most abundant soil type. These soils are characterized by subsurface acidity that cannot be effectively corrected by surface application of additives. In this situation, the use of phosphogypsum can be advantageous. This study aimed to assess the residual effects of lime and phosphogypsum application on a clayey Ferralsol, and four soybean and two wheat yields in southern Brazil. The area has been cultivated under no-till since 1975. The soil was limed to different base saturation (BS) levels (50, 60, 70, and 90 %) by surface application (SL) or lime incorporation (IL). Three combined treatments were also studied: (i) surface liming to 60 % BS plus standard (3.71 Mg ha-1) phosphogypsum dose (60G1), (ii) surface liming to 70 % BS + standard phosphogypsum dose (70G1); and (iii) surface liming to 70 % BS + double (7.42 Mg ha-1) phosphogypsum dose (70G2). Soil samples were collected 48 months after treatment. Soybean and wheat yield was not influenced by BS levels, however IL increased soybean yield in 2012/13, but reduced soybean and wheat yield in later crops. Phosphogypsum increased wheat yield by up to 12.8 % (2012 season) and 5.2 % (2015 season), but soybean was not influenced. Incorporated liming caused a decrease in soil Al3+ levels until 0.60 m depth, whereas SL decreased Al3+ levels until 0.30 m depth. Surface liming increased Mg2+ levels in the 0.40-0.60 m layer. Incorporated liming reduced soil organic matter in the surface layer. A double dose of phosphogypsum (7.42 Mg ha-1) had a greater residual effect in subsurface layers but caused a decrease in Mg2+ and K+ levels. Therefore, the standard phosphogypsum dose provided the best results. In the very clayey soil in subtropical environment, the effects of SL extend beyond surface layers and are preferable to those of IL, although production was not influenced by BS.

Lime (L) and phosphogypsum (GY) are indispensable inputs in acidic soils that can alter the nutritional status of crops. The objective of this study was to evaluate the nutritional status and productivity of maize and wheat after the application of L and GY. The treatments consisted of a 2 x 4 + 3 factorial, with two forms of L application: surface (SL) and incorporated (IL) to obtain different levels of base saturation (BS%): 44, 60, 70 and 90; additionally three treatments involving the use of GY were evaluated: BS% 60 + 3.71 Mg ha−1; BS% 70 + 3.71 Mg ha−1 and BS% 70 + 7.42 Mg ha−1 of GY. The increase in BS% favored the absorption of magnesium (Mg) (SL and IL) and phosphorus (P) (IL) content in maize. IL increased the contents of nitrogen (N) and sulfur (S) and maize yield compared with SL. GY increased the maize yield by 7.6% compared with the control (BS 44%). Maize productivity correlated positively with calcium (Ca) (0.65), S (0.78) and N (0.54) leaf contents. In wheat, the increase in BS% reduced absorption of potassium (K) (SL and IL) and increased leaf Ca and Mg (IL) contents. Wheat yield correlated positively to leaf Ca (0.61) and S (0.62). Lime incorporation decreased wheat yield. High doses of GY (7.42 Mg ha−1) reduced absorption of Mg (maize and wheat) and K (maize). It is better to apply GY than to till the soil, thus maintaining uninterrupted no-till. [ABSTRACT FROM AUTHOR]

In this paper, the results of an investigation of the effects of particle-size distribution, soil organic matter content and its parameters on soil sorption capacity are presented and their mutual relationships in sandy soils under long-term fertilisation experiments are determined. Soil samples were taken at the experimental station of Warsaw University of Life Sciences located in Skierniewice, (Poland) in spring 2017. The study included 94- and 41-year-old experiments with mineral fertilisation (no fertilisation, NPK, CaNPK) and 25-year-old experiment with mineral fertilisation + farmyard manure (FYM) in 4-year cycle: FYM, FYM+NPK and FYM+CaNPK. The results show that in the 94-year-old experiment in NPK and CaNPK treatments, hydrolytic acidity (Ha) decreased in comparison with the control by 30% and 88%, respectively, while in 25- and 41-year-old experiments only the application of NPK significantly increased Ha values. The sum of basic cations increased by a factor of 10 at the most in the CaNPK treatment in the 94-year-old experiment. The same effect was also observed in the 25-year-old experiment. On the one hand, the sorption complex gradually became fully saturated as a result of fertilisation in the 94-year-old experiment. On the other hand, in the 25- and 41-year-old experiments, base saturation was substantially reduced. A higher humus stability was an important agent for improving soil sorption capacity in 41- and 94-year old experiments.

Land-use change and specifically a change in the type of vegetation cover affects soil morphology, chemistry, biology, and nutrient regimes. Numerous studies have documented that in land-use conversions from agricultural land to forest, or from plantations to restored natural savanna most soil attributes and functions undergo changes. The purpose of the present study was to evaluate the changes brought about by afforestation of degraded croplands and to understand the impact of forest vegetation on soil evolution in a semiarid region where soils originally co-evolved with a savanna biotope. We used long-term experiments (>40 years) of five tree species: Pinus halepensis (PH), Pinus halepensis inoculated with ecto-mycorrhiza at planting (PM), Pinus pinea (PP), Eucalyptus spp. (E), and Gleditsia triacanthos (G) and compared these to an agricultural soil (A) at the same site near Santa Rosa, La Pampa in the semiarid center of Argentina. Soil profiles were described, and samples taken for chemical and physical analyses of soil properties [organic matter (OM), pH, cation exchange capacity (CEC) and exchangeable cations, particle size distribution (texture), aggregate stability (MWD), bulk density (BD), porosity (TP), and water holding capacity (WHC)]. We found a strong effect of tree species on soil profile morphology, even taxonomy, and on all studied variables. PM and G had highest OM, CEC, neutral pH, higher TP, WHC, while PH, PP, and E had acid pH, lower base saturation, OM, TP, and WHC. The effect of tree species on the soil profile was noticeable a depth of about 40 cm, comprising the A and AC, but not the C horizons. The results showed that to obtain reasonable results of OM sequestration under forest systems, tree species should be chosen to include legumes to improve C/N stoichiometry for C fixation, or inoculation with mycorrhiza to promote microbial transformation of forest litter.

ABSTRACT Oxisols ( Latossolos ) are widely distributed in tropical zones and generally characterized by high levels of surface and subsurface acidity. In Brazil, most Oxisols are managed under no-till conditions with surface application of acidity amendments. This study aimed to evaluate lime application strategies (incorporated and surface) for achieving the desired soil base saturation (BS%) levels (44, 60, 70, and 90 %) and the effect of phosphogypsum + lime application on soil chemical properties as well as wheat and corn yield in southern Brazil. Lime incorporation was more effective in reducing the soil acidity and increasing Ca2+ and Mg2+ despite a decrease in organic matter at the soil surface. Phosphogypsum application increased S-SO42- and Ca2+ availability throughout the deeper soil layers and reduced the Mg2+ content in the surface layer. Wheat yield under incorporated lime conditions increased with BS% up to 75, but there was no response to surface application. When phosphogypsum was applied, the wheat yield increased by 8.4 %. For corn, incorporated lime increased the yield up to 445 kg ha-1, which was equivalent to the yield after phosphogypsum application. An increase in the S-SO42- level was the main factor related to the increase in crop yields. In the short term, our results suggest that phosphogypsum applied along with lime is more appropriate than incorporating lime under no-till management conditions.

Questions: Vegetation in forest understories is determined by a complex interplay of many different environmental factors, including light, water and nutrient availability. Changes in these conditions, especially changes in nitrogen (N) availability, have been widely discussed to cause shifts in species composition and loss of oligotrophic species. We examined whether nitrogen is the most important factor for the decline of nitrogen-sensitive species in understorey communities, as measured by average Ellenberg N values and the share and number of nitrogen-sensitive character species. Location: Nine different oligo-mesotrophic types of temperate forest in southwest Germany. Methods: We combined understorey vegetation and soil data from 135 forest stands. To study the importance of variables in explaining the vegetation gradients, we used random forest analyses and non-metric multidimensional scaling (NMDS) ordinations combined with fitting of environmental vectors. Results: We detected strong differences between three examined forest type groups: eutrophication in the understorey vegetation of broad-leaved forests on carbonate soils was strongly related to high canopy closure and low soil carbon/phosphorus (C/P) ratio. In broad-leaved forests on acidic soil, base saturation played a major role, but the vegetation was also influenced by the C/N and C/P ratios. In coniferous forests on acidic soil, soil pH and organic layer depth were important, as were the C/N, C/P and N/P ratios. Conclusion: Our results show that eutrophication in understorey forest vegetation is not monocausal. Rather, oligotrophic species of forest communities are reduced at sites with higher N or P availability and/or higher base saturation and soil pH. These conditions favor fast-growing ubiquitous species in the competition for light and other limiting factors. Since these factors were of varying importance between the forest types examined, differences shaping the forest communities need to be regarded when evaluating the impact of environmental changes, for example through atmospheric nitrogen deposition. [ABSTRACT FROM AUTHOR]

Chemical fertilizers (CF) are the major input on arable farms in Nigeria. Current increasing rate of nutrient depletion in CF treated soils calls for the need to study their reactions in soils. To achieve this, three CF based treatments, namely NPK 15:15:15 applied at 40 kg P2O5 ha-1, Urea applied at 20 kg N ha-1 mixed with Single superphosphate at 40 kg P2O5 ha-1, and single superphosphate at 40 kg P2O5 ha-1 mixed with Gliricidia sepium leaves at 20 kg N ha-1 were studied. Sole lime (CaCO3) at 1 Mg ha-1 and a plot that received no amendment were compared. Cowpea was grown for two consecutive cropping seasons in 2012 and 2013 on the treated fields. The results indicated that CF reduced soil pH from initial 4.8 to 4.0. The NPK 15:15:15 fertilizer was the most severe of the CF tested, removing up to 133% alkalinity from the soil relative to lime. The NPK 15:15:15 reduced calcium saturation (from 25% to 21%) and magnesium saturation (from 12% to 8.3%) and increased acidity saturation (from 53% to 66%) with significant reductions in organic carbon content (from 13.2 g kg-1 to 11.0 g kg-1). Precaution including co-application of CF with organic materials such as Gliricidia sepium leaves can benefit for the soils.

Successful adaptation of introduced trees requires providing appropriate conditions for their growth and life. In this context, our study aim was a soil survey in the Arboretum Mlyňany, on the basis of which the soils could be classified. Detailed soil investigations were done at seventeen sites under dense monocultures of trees and the grassland. For each site, there was dug one soil pit, near which there were made three soil bores. Over most area of the locality, the prevailing soil-forming substrates were decalcified loess and silt, with gravelly patches, with prevailing medium soil texture, and acid to slightly acid pH. Based on the morphological features and the results concerning the physical and chemical soil properties, seven quality-degrees of soil cover were classified. The lowest-quality was recognised in Fragic Stagnic Retisol, in the highest-situated, east part of Arboretum, and also in the central part of the Ambrozy’s park under Thuja plicata, where there was discerned also low quality Albic Stagnic Luvisol. The most area east of the manor house is covered with Stagnic Cutanic Luvisol (the North American and East Asian area with Stagnic Cutanic Luvisol (Anthric)). North of the manor, on a slight slope of the North American area was found a Cutanic Luvisol (Anthric). West of the manor, the terrain evenly declines, and there has been developed Luvic Chernozem, whose cultivated form, Luvic Chernozem (Anthric), was determined in the East Asian area.

Taking into account the fact that (a) measurement of the cation exchange capacity and base saturation is practically unavailable in the field, that formally makes impossible the reliable field classification of many soils, (b) base saturation is measured or calculated by various methods those results significantly differ, (c) base saturation and soil pH are highly positively correlated, it is suggested to replace the base saturation with pHw (measured in distilled/deionized water suspension) in the classification criteria for diagnostic horizons and soil units/subunits, both in the Polish Soil Classification and FAO-WRB. Based on statistical analysis of 4500 soil samples, the following pHw values are recommended instead of 50% base saturation: pHw

Since tillage technologies considerably influence soil properties and have a major impact on soil sustainability, the objective of this study was to evaluate the effects of conventional (CT) and reduced (RT) tillage on basic soil chemical properties at selected Slovak agricultural farms. Subsequently, the relationships between the chemical properties and soil organic matter (SOM) in both tillage technologies were ascertained. Differences in soil properties between long-term RT and CT were investigated at the adjacent plots on thirteen sites, where six soil pits were excavated on each RT and CT plots. Soil samples were collected from all pits, for each 0.1 m layers from the depth of 0.0-0.4 m. The results revealed that the regular overturn of topsoil, and thus the transfer of leached base cations to the surface layer, as well as deeper incorporation of crop residues and fertilizers in the soil cultivated conventionally has been manifested by higher values of pH, lower hydrolytic acidity (H) and the almost uniform content of base cations (mainly in the layer 0.0-0.3 m) compared to the soil cultivated by RT. Apart from H,, none of the examined sorption properties and pH differed significantly between the compared tillage technologies. Therefore, H can be considered as an important indicator of the change of basic chemical soil characteristics. While in RT, there was a significant correlation only between labile SOM fractions and basic soil chemical properties, in CT the sorption parameters and pH were influenced by labile and also stable SOM. [ABSTRACT FROM AUTHOR]

The substrate is essential to ensure suitable conditions for the growth of Passiflora setacea seedlings. Thus, a study was conducted to investigate the effect of alternative substrates formulated with bee nest and termite mound materials on the growth of P. setacea cv. BRS Pérola do Cerrado seedlings. Six substrate combinations formulated from different proportions (v:v) of bee nest material (BNM) and termite mound material (TMM) or commercial substrate were tested considering the randomized block design with four replicates. The following substrates were used: S1 = BNM100%; S2 = BNM75% + TMM25%; S3 = BNM50% + TMM50%; S4 = BNM25% + TMM75%; S5 = TMM100%; and S6 = commercial substrate (Click Mudas®). The plant height, stem diameter, root length, root dry matter (RDM), shoot dry matter (SDM), total dry matter (TDM), and morphological indices were measured. Passiflora setacea seedlings have better development with the use of substrates S1, S2, and S3, with greater emphasis on the substrate S1. The substrate S1 (100% BNM) should be recommended for the production of P. setacea cv. BRS Pérola do Cerrado seedlings, for improving plant development and providing higher quality seedlings. [ABSTRACT FROM AUTHOR]

The WRB (World Reference Base for Soil Resources) 2014 adopted 'effective base saturation (EBS),' which is the ratio of exchangeable bases (Ca + Mg + K + Na) to effective CEC (Ca + Mg + K + Na + Al), instead of base saturation (BS), the ratio of exchangeable bases to the cation exchange capacity, as the criterion for the addition of qualifiers concerning the condition of exchangeable bases. An EBS of less than 50% was defined as Dystric conditions, and that of 50% or more was defined as Eutric conditions. These newly defined qualifiers were applied to 49 soil samples from grasslands of Andosols in central Kyushu and 132 horizons from a database of Japanese Andosols. It was found that 80% of the samples met the criterion for Eutric conditions according to WRB2014, despite their small amount of exchangeable bases and low BS, whereas only 2% were Eutric when the criterion of WRB2006 (BS ≥ 50%) was used. In the case of uncultivated soils, the definitions of Dystric and Eutric according to WRB2014 corresponded mainly to non-allophanic and allophanic soils, respectively. All pedons of allophanic Andosols were classified as Eutric, but those of non-allophanic Andosols were classified as Dystric, according to WRB2014, because of the high EBS recorded in them. Conversely, all pedons were classified as Dystric based on the WRB2006 criteria. These characteristics of the Dystric and Eutric qualifiers in the classification of Andosols according to WRB2014, which is related to the variable charge of the samples, should be noted for the proper understanding and management of base conditions of Andosols. [ABSTRACT FROM AUTHOR]

ABSTRACT Leucochloron incuriale can be used in projects to restore degraded areas and for logging purpose. Soil has been used in nurseries to produce seedlings; however, most soil types in Brazil have low nutrient availability and high acidity level. The aim of the current study is to assess the effect of liming and phosphate fertilization on the growth and quality of Leucochloron incuriale seedlings. Treatments were arranged in factorial design with five base saturation levels – 3.5 (original), 25, 40, 55 and 70% – and six P levels – 0, 120, 240, 360, 480 and 600 mg dm–3 – in completely randomized blocks with four repetitions. The morphological features and their relations were assessed 82 days after planting. Phosphorus levels had significant effect on most of the assessed traits. The recommended P dose was 475 mg dm–3.

The conversion of Pampa Biome soils into no-till system for grain production requires acidity correction, at least to fully neutralize exchangeable aluminum (Al). The aim of the study is to evaluate changes in solid phase acidity and Al speciation in soil solution that was conducted to prepare the soil for the implementation of a no-tillage system in a natural pasture area in Southern Brazil. We collected soil samples from the 0–5, 5–10, 10–15 and 15–20 cm layers in soils subjected, or not, to acidity correction to pH 6.0, as well as in soils with, and without, limestone incorporation through plowing and harrowing. Changes in the solid and solution phase attributes, such as soil acidity, were limited to 5 and 10 cm, respectively, 44 months after surface and incorporated liming. Regardless of liming addition to, or lack of thereof in the soil, Al found in the soil solution was mainly associated with organic carbon. This was the main way to decrease plant toxicity under these conditions, which can be supported by plant behavior, especially that of soybean. Liming induced the soil solution Al to exchange its ligand from organic carbon to hydroxyl. [ABSTRACT FROM AUTHOR]

In this paper we investigate the effects of biochar alone and its reapplication and combination with N-fertilizer (1) on the soil pH, and (2) sorption parameters. The soil samples were taken during growing period in 2018 from plots with different biochar (first application in 2014 – A, reapplication in 2018 – B) at application rates: 0 t.ha−1 (B0 control), 10 t.ha−1 (B10) and 20 t.ha−1 (B20) and different nitrogen fertilization: N0 (no nitrogen) and N40 (40 kg.ha−1). Our results showed that the first application of biochar at the rate of 20 t.ha−1 (B20A) without N-fertilizer significantly increased the values of soil pH in H2O, soil pH in KCl, the sum of base cations (SBC) and cation exchange capacity (CEC) compared to control (B0). Similar effects were observed also after reapplication of biochar (B10B). All investigated parameters in fertilized control treatment (B0N40) were worst and the first application, as well as the reapplication of biochar with N, caused significant increase of soil pH in H2O, soil pH in KCl, SBC, CEC, BS and decrease of hydrolytic acidity. [ABSTRACT FROM AUTHOR]

• Fine root biomass totals are much larger in deep soils compared to shallow soils. • We did not observe a clear relation between fine root biomass and soil base richness. • Root morphology was only slightly effected by soil chemistry. • On-site root morphological differences are bigger than among-site variation. We studied the fine root system of Fagus sylvatica in six mature stands on different bedrock down to the rock surface (or to 2 m) to investigate whether (1) the stand total of fine root biomass (FRB) increases, while the fine root live:dead ratio decreases, with decreasing soil base richness, (2) specific root area (SRA) and root tip frequency increase with a decrease in base richness, and (3) FRB is related to profile depth. The three beech stands on deep soil (>2 m profile depth) had on average by 38% larger FRB totals than the stands on shallow soil (60–80 cm), suggesting that limited root space is an important determinant of fine root system size in F. sylvatica. Despite large variation among sites, soil chemistry influenced root morphology only little: fine root diameter depended on soil C/N ratio and root tip frequency on base saturation in a few soil horizons. Much larger morphological differences were found between topsoil and subsoil roots within a profile. We conclude that the fine root system of F. sylvatica varies under similar climatic conditions remarkably little between base-poor and base-rich sites, in contrast to the pronounced topsoil-subsoil differences in root morphology and fine root density. [ABSTRACT FROM AUTHOR]

Forest ecosystems worldwide are subjected to human-induced stressors, including eutrophication and acidification, and to natural disturbances (for example, insect infestation, windstorms, fires). The occurrence of the later is expected to increase due to the ongoing climate change. These multi-stressor forcings modify ecosystem biogeochemistry, including the retention of limiting nutrients, with implications for terrestrial and aquatic biodiversity. Here we present whole ecosystem nutrient (N, Ca, Mg, K) mass balances in the forested catchment of Plešné Lake, CZ, which has undergone transient changes linked to the recovery from anthropogenic acidification and to the forest disturbances caused by severe infestations by the bark beetle (Ips typographus). Measured fluxes and storage of nutrients in the lake-catchment ecosystem were used to constrain the process-oriented biogeochemical model MAGIC (Model of Acidification of Groundwater In Catchments). Simulated lake water chemistry and changes in soil nutrient pools fitted observed data and revealed that (1) the ecosystem N retention declined, thus nitrate leaching increased for 10 years following the bark beetle disturbance, with transient adverse effects on the acid–base status of lake water, (2) the kinetics of nutrient mineralisation from decaying biomass coupled with nutrient immobilisation in regrowing vegetation constrained the magnitude and duration of ecosystem losses of N, Ca and Mg, (3) the excess of mineralised base cations from decomposing biomass replenished the soil cation exchange matrix, which led to increased soil base saturation, and (4) the improvement of the catchment soil acid–base status led to an increase of lake water pH and acid neutralising capacity. Forested ecosystems underlain by nutrient-poor soils and bedrock are prone to human-induced damages caused by acidification and eutrophication, and any natural disturbance may further lead to nutrient imbalances. We demonstrated that in this natural forest ecosystem protected from human intervention, disturbances together with natural post-disturbance vegetation recovery have temporally positive effects on the nutrient stores in the soil. [ABSTRACT FROM AUTHOR]

Natural forests and managed plantations constitute the largest land-use systems in the humid tropics of southwestern parts of Peninsular India comprising the Western Ghats and coastal plain. Soils therein are naturally acidic and the acidity is enhanced in managed land-use systems through inputs of chemical fertilizers. Plant nutrient deficiencies and mineral toxicities constrain crop production in acid soils. Surface soil and subsoil acidity in forest, coffee, rubber and coconut land-use systems was evaluated. The spatial pattern of surface soil and subsoil acidity pointed to low intensity of acidification in Malnad region of Karnataka, moderate acidity in northern Kerala and strong acidity in southern Kerala. Among the land-use systems studied, soils under natural forests and coffee plantations were only slightly acidic in surface soil and subsoil, whereas rubber- and coconut-growing soils were strongly acidic. Both natural and managed land-use systems, however, had strongly acid reaction in surface soil and subsoil in southern Kerala. Biomass production and crop yield are constrained in strongly acid soil by toxic levels of aluminium (Al) on soil exchange complex (>0.5 cmol (+) kg-1 soil) and depletion of basic cations of calcium, magnesium and potassium (base saturation less than 50% or Al saturation more than 50%). Surface soil acidity can be ameliorated by incorporating liming materials into surface soils. In case of subsoil acidity gypsum too should be incorporated. Under humid climate partial solubility of gypsum permits movement of calcium into the subsoil layers, wherein calcium replaces the aluminium on exchange complex and sulphate radical precipitates the aluminium by formation of aluminium sulphate. [ABSTRACT FROM AUTHOR]

The paper deals with physico-chemical properties of Regosols in Bulgaria. Ten soil profiles are studied in North and South part of the country. These soils are spread mainly on unconsolidated rocks (regolith), slopes and eroded terrains in semi-arid areas. Sediments in these areas are manly alkaline with good sorption capacity. Regosols are moderately acidic to slightly alkaline soils. Exchangeable Ca2+ is almost equal to the soil cation exchange capacity. The amount of exchangeable Ca2+ is between 8 to 26 mequ/100g. Regosols have high base saturation from 75 to 100 %.

Since the late 1960s, the occurrence of Schoenus nigricans in Irish blanket bogs has been attributed to inputs of salt spray to the blanket bogs, due to their proximity to the coast and the predominant westerly winds from the Atlantic Ocean. To test this hypothesis we carried out an ecohydrological field study at a large blanket bog in the western part of Connemara, Ireland. We described peat profiles in two transects and sampled pore water from peat at different depths. The water samples were analysed and their macro-ionic composition was used to locate possible inputs of calcareous groundwater to the system. We found clear evidence for inflow of calcareous groundwater at various sites and depths. Inflow of rather base-rich groundwater was indicated by high values of electrical conductivity (EC), high contents of calcium and bicarbonate, and high pH of the pore water. The peat profiles contained macro-remains of reed (Phragmites australis), in most cases only in deeper layers of peat, but at one location throughout the profile. This is another indication that the blanket bog was a groundwater-fed fen for quite some time. We conclude that the occurrence of S. nigricans in the blanket bog studied could be well explained by the hypothesis that S. nigricans is a relic from former more base-rich conditions. Relatively high base saturation could have persisted due to the prevailing groundwater flow in the upper layers preventing decalcification or other loss of cations from the whole soil profile including the topsoil.