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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]

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]

• 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]

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 fromthe whole soil profile including the topsoil. [ABSTRACT FROM AUTHOR]

The influence of different tillage and fertilization practices on changes in soil pH and sorptive parameters of loamy haplic Luvisol was evaluated in a long-term field experiment (established in 1994, in the locality of Dolná Malanta, at the experimental station of the Slovak University of Agriculture in Nitra). The field experiment included two types of soil tillage (conventional tillage -- CT and reduced tillage -- RT) and also three treatments of fertilization (1. Co -- control, 2. PR+NPK -- crop residues together with added NPK fertilizers, and 3. NPK - with added NPK fertilizers). The soil was sampled from all treatment sites throughout 1994-2011. The results showed a statistically significant influence of tillage and fertilization on pH and sorptive complex of haplic Luvisol. The values of pH were higher (by 4%) in RT than in CT. The sum of basic cations (SBC), cation exchangeable capacity (CEC) and base saturation (BS) were all higher in RT, by 11%, 8% and 3% respectively, than in CT. In NPK (by 16%) and in PR+NPK (by 20%) the values of hydrolytic acidity (Ha) were decreased in comparison to the control. On the other hand, SBC was elevated. This led to the increase of CEC and BS. Conventional tillage and application of crop residues together with NPK fertilizers increased pH by 0.06 and 0.03 units per year, respectively, which means that the pH in the soil increased by 14% and 8%, correspondingly, between 1994 and 2011. In CT and in PR+NPK, an increase of SBC occurred at an average rate of 3.17 and 1.93 mmol kg-1 year-1, respectively. A positive correlation between the content of soil organic carbon (TOC) and Ha (r = 0.334, P ≤ 0.01, n = 54), as well as a negative correlation between TOC and BS (r = -0.307, P ≤ 0.05, n = 54) were determined only in CT. [ABSTRACT FROM AUTHOR]

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This study, aiming to unravel whether topsoil conditions under tree species with nutrient-poor leaf litter can be altered by admixing a shrub layer, was performed in 12 pine (mainly Pinus sylvestris ) and 12 oak ( Quercus robur ) stands on sandy podzolic soils in north-east Belgium. We examined the effects of presence of a shrub layer on forest floor mass and topsoil chemical properties related to soil acidification. The shrub species included were European rowan ( Sorbus aucuparia ), alder buckthorn ( Rhamnus frangula ) and black cherry ( Prunus serotina ). For each tree species, 60–90 years old stands were selected containing shrubs present in varying cover classes: sparse (<20%), intermediate (20–70%) and dense (>70%). The oak stands were characterized by less but ‘nutrient-richer’ litterfall, compared to the pine stands. This was reflected in less humus build-up (FH-horizon) and higher pH, CEC, BS and lower C/N in the topsoil in the oak stands compared to the pine stands. However, despite the fact that the shrubs produced litter with significantly higher base cation and N concentrations than that of the studied tree species, we did not find any significant changes in topsoil conditions in the pine and oak stands under study, even under dense shrub layers (87–91% cover). [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The role of soil and bedrock in acid neutralizing processes has been difficult to quantify because of hydrological and biogeochemical uncertainties. To quantify those roles, hydrochemical observations were conducted at two hydrologically well-defined, steep granitic hillslopes in the Tanakami Mountains of Japan. These paired hillslopes are similar except for their soils; Fudoji is leached of base cations (base saturation <6%), while Rachidani is covered with fresh soil (base saturation >30%), because the erosion rate is 100–1000 times greater. The results showed that (1) soil solution pH at the soil–bedrock interface at Fudoji (4.3) was significantly lower than that of Rachidani (5.5), (2) the hillslope discharge pH in both hillslopes was similar (6.7–6.8), and (3) at Fudoji, 60% of the base cations leaching from the hillslope were derived from bedrock, whereas only 20% were derived from bedrock in Rachidani. Further, previously published results showed that the stream pH could not be predicted from the acid deposition rate and soil base saturation status. These results demonstrate that bedrock plays an especially important role when the overlying soil has been leached of base cations. These results indicate that while the status of soil acidification is a first-order control on vulnerability to surface water acidification, in some cases such as at Fudoji, subsurface interaction with the bedrock determines the sensitivity of surface water to acidic deposition. [Copyright &y& Elsevier]