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A two-year field experiment was carried out with maize (Zea mays L.) at two biochar (BC) doses of (5 and 10 t. ha-1) and two nitrogen fertilizer rates (130 and 260 kg. ha-1) in Tsalapitsa village (Plovdiv) on Alluvial-meadow soil (Fluvisol). The aim of the study was to find out the influence of biochar as an aftereffect, as well as nitrogen fertilization on soil physicochemical and agrochemical properties. In order to observe the effect of biochar in the second year, the variants from the first year (B(1)5N130, B(1)10N130, B(1)5N260 and B(1)10N260, without the controls K1N130 and K2N260 were left without the addition of biochar, and for the second year, new variants were set up according to the same scheme. During the vegetation of maize, the influence of biochar as the aftereffect was observed with increase in pH values (0.2 - 0.3 units) in comparison with the control variants (without biochar, nitrogen fertilization only), which was confirmed by its application in the second year. There were positive changes in the mineral N content of the studied treatments as the aftereffect, compared to the controls and the second-year treatments, which may be related to the ability of the biochar to fix nitrogen and protect it from leaching, especially on vulnerable soils such as the Fluvisol studied. A slight increase in organic carbon (0.09-0.32%) was also found at the lower N rate (130 kg. ha-1) in the aftereffect variants. In these variants, a slight increase in cation exchange capacity, exchangeable Ca and the degree of base saturation was also observed. Biochar utilization had little effect on the investigated properties of the Fluvisol. Applying the lower doses of biochar in longer term would have a more significant impact. [ABSTRACT FROM AUTHOR]

The present study was conducted in the Department of Agricultural Chemistry and Soil Science, SASRD, Nagaland University during 2018 to evaluate the seasonal variation of soil physico-chemical properties under forest (natural), pineapple and paddy (low land) land use systems (LUS) of Medziphema block, Dimapur, Nagaland. 432 geo-referenced composite soil samples were collected during pre-monsoon, monsoon and post-monsoon seasons from surface and sub-surface soil. pH of soils under paddy LUS was found highest (4.95) followed by forest (4.84) and pineapple (4.65) LUS. Significantly minimum values of BD was recorded in forest LUS (1.17 and 1.20 Mg m-3) followed by higher BD (1.21 and 1.25 Mg m-3) in pineapple and maximum in paddy LUS (1.34 and 1.37 Mg m-3) during post-monsoon season at surface and sub-surface soil respectively. Forest LUS recorded maximum average content of organic carbon (16.72 g kg-1). Available nitrogen, available phosphorus, exchangeable calcium and magnesium content was also found maximum in soils of forest LUS. Significant positive correlation among soil fertility parameters were obtained in different seasons. Results of the investigation revealed that the pineapple LUS in the study area can be considered as a sustainable LUS owing to its comparable soil physico-chemical properties with the forest LUS. However, there is need for large scale adoption of location specific soil management practices for sustainable production and management of soil health in order to counteract deterioration of soil fertility under traditionally practiced low land paddy LUS. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at University of Agricultural Sciences, Bangalore, during kharif, 2016 to study the effect of organic sources of nutrients on soil chemical properties, microbial population and nutrient uptake by plants. The experiment was laid out in a RCBD with seven treatments replicated thrice. A significant increase in the available NPK status of soil after harvest as compared to initial status was observed. The available nitrogen, phosphorous and potassium were significantly higher with FYM at 50 kg N eq. ha-1 + vermicompost at 50 kg N eq. ha-1 + EBDLM at 50 kg N eq. ha-1 + panchagavya spray (3 %) at 15 and 45 DAS + vermiwash spray at 30 DAS (381.93, 37.67 and 275.73 kg ha-1, respectively) as compared to other treatments. The same treatment also recorded significantly higher population of bacteria, fungi and actinomycetes (85.37, 13.57 and 14.07 × 10³ CFU g-1 soil, respectively). The nutrient uptake was also higher in the same treatment. [ABSTRACT FROM AUTHOR]

A survey was conducted to know the sulphur status in rice domains of Mandya district. Out of 119 soil samples collected from entire taluks of the district (4-5 samples for each hobli of all taluks), 92 samples (77.32 %) were sufficient and 27 samples (22.68 %) were deficient in sulphur content. Among the taluks, Mandya, Maddur, S.R. Patna and Pandavapura have a sufficient range of sulphur, whereas other taluks namely Malvalli, K.R. Pet and Nagamangala taluks have deficient sulphur status. Nagamangala taluk has the least sulphur status among taluks of Mandya district with all five hoblis showing deficiency range. To know the response of rice to different sources and levels of sulphur application, a field experiment was conducted during kharif, 2015 on sandy loam soil at the College of Agriculture, V.C. Farm, Mandya, University of Agriculture Sciences, Bangalore. The results revealed that application of RDF+FYM+26 kg sulphur ha-1 through ammonium sulphate recorded significantly higher grain and straw yield of 2716.45 kg ha-1 and 4240.49 kg ha-1, respectively. Higher grain and straw yields were mainly attributed to growth parameters like higher plant height (85.87 cm), number of tillers (20.47) and number of leaves per hill (83.20) at harvest, and yield parameters i.e., number of panicles per hill (15.93), length of panicle (20.03c m), number of grains per panicle (117.0), 1000 grain test weight (23.65g) and lower per cent chaffyness (6.33). [ABSTRACT FROM AUTHOR]

This article analyzes the results of four-year research which examined the effectiveness of pre-sowing treatment (soaking, spraying) of white cabbage seeds with trace element solutions of various concentrations. The research was conducted under laboratory conditions at the Agricultural Chemistry and Soil Science Department of Omsk State Agrarian University with a mid-season-ripening, medium-yielding and high-yielding variety of white cabbage (Sibiryachka 60) found in the Omsk region. 0.02%, 0.04% and 0.05% solutions of ZnSO4 · 7H2O and 0.01%, 0.02%, 0.03% and 0.05% solutions of H3BO3 were used in the experiment. The cabbage seeds were soaked in water (control) and in trace element solutions for 6-12-24 hours. The germination energy and germination capacity of the seeds, the zinc distribution, and the biometric indicators of the seedlings and of the cabbage transplant seedlings were determined. The optimal concentrations of the trace element solutions and the optimal duration of pre-sowing treatment were established, which stimulated the development of seedlings and increased seed germination by 5-9%. It was noted that, compared with the control, 2 times more plants reached the 6-leaf phase by the time of planting when transplant seedlings were treated with a boric acid solution in the optimal concentration, and 3.6 times more plants did when fertilized with zinc. Based on the results the following is recommended for implementation in production: soaking seeds in a 0.03% solution of H3BO3; soaking seeds in a 0.04% solution of ZnSO4; soaking time - 6 hours; a 1:2 ratio of seeds to the solution; and concentration of solutions per element for boron -- 0.005% and zinc -- 0.01%. [ABSTRACT FROM AUTHOR]

In seventeenth-century England agriculturalists, projectors and natural philosophers devoted special attention to the chemical investigation of plants, of soil composition and of fertilizers. Hugh Plat's and Francis Bacon's works became particularly influential in the mid-seventeenth century, and inspired much of the Hartlib Circle's schemes and research for improving agriculture. The Hartlibians turned to chemistry in order to provide techniques for improving soil and to investigate plant generation and growth. They drew upon the Paracelsian chemistry of salts, as well as upon the works of van Helmont and Glauber. Benjamin Worsley, Boyle's scientific companion in the 1640s and 1650s, played a leading role in the Hartlib Circle's research on saltpetre and on fertilizers. The Hartlib Circle's research in agricultural chemistry shaped much of the research carried out by the Royal Society in the 1660s and in the 1670s. Daniel Coxe, who adopted Boyle's chemical theories and pursued original experimental research on the composition of plants, played a central part in the early Royal Society's agricultural projects and notably in the investigations of plants. [ABSTRACT FROM AUTHOR]

Question: European temperate forests have been managed for millennia, and this management has left a long-lasting legacy in soil chemistry and plant species composition and diversity. One of the most common practices was the raking of leaf litter, which was used as bedding for farm animals. We asked, what is the legacy of historical litter raking for contemporary forest plant communities? Location: Czech Republic. Methods: We explored the effect of historical litter raking on species richness and diversity of the forest herbaceous layer. We also tested whether long-term soil acidification and nutrient depletion caused by litter raking were reflected in Ellenberg indicator values for nutrients and soil reaction and in the higher abundance of specialists of acidophilous forest types. We used written historical evidence to identify areas where litter raking was practised in the 19th century. We analysed the differences between vegetation plots located in areas affected and unaffected by the past litter raking. Our analysis included almost 2,500 vegetation plots recorded between 1980 and 2015. Results: Litter raking was historically practised in a striking 85% of forested townships. Although litter raking had no significant effect on overall species richness, we found significant differences of diversity patterns among forest types. Historically raked plots were taxonomically more similar. We found no difference in the mean Ellenberg indicator values for soil reaction and nutrients between the affected and unaffected plots, and only a weak positive response of selected herb species of acidophilous forests. Conclusions: We provide the first empirical evidence of the historical litter-raking legacy in forest communities on a large scale. Despite its historical frequency, we found only a weak legacy of historical litter raking in present-day plant communities. Future studies could potentially use other, finer-scale methods in smaller territories to complement our results. [ABSTRACT FROM AUTHOR]

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Western Indian Himalaya is very rich in biodiversity. Being a cold climatic region, it possesses various psychrotolerant and psychrophilic microorganisms. Psychrotolerant bacterium Dyadobacter sp. was isolated from this region and studied for its plant growth promoting potential against four legumes and finger millet. This bacterium was able to grow at nitrogen (N) deficient medium at both 10°C and 28°C and gave positive nifH amplification that confirms the psychrotolerant and diazotrophic nature of this bacterium. Pot trial-based study showed that this bacterium was able to promote plant growth by fixing atmospheric nitrogen (N2) and making it available to plants. Agronomical parameters, leaf nitrate reductase activity, and total chlorophyll content were recorded at 30, 45, 60, and 90 days after sowing and found to be increased over their respective controls. The 16S rDNA and nifH genes were quantified by q-PCR to study the dynamics of total bacterial and diazotrophic abundance due to inoculation of Dyadobacter sp. in soil. Soil chemical properties related to soil fertility were also studied at different time intervals after sowing. We found positive correlation among soil pH, soil nifH gene abundance, soil nitrate concentration, and plant leaf nitrate reductase activity. PCR-DGGE was performed to study persistence of Dyadobacter sp. in soil after inoculation, which showed good persistence of plant growth promoting rhizobacteria (PGPR). Hence, it is concluded that Dyadobacter sp. has potential to promote plant growth by fixing atmospheric N2 and making it available to plant. Further, psychrotolerant nature of this bacterium can be exploited to enhance plant growth in cold climate agriculture due to its ability to fix atmospheric N2 at low temperature. [ABSTRACT FROM AUTHOR]

The use of biochar in agricultural soils has received increasing attention over the last decade and enhancing biochar through chemical modification offers a strategy to reduce the amount of biochar required for improving soil productivity. However there is limited knowledge on how mineral enhanced biochars alone, or in combination with conventional fertilisers impact on microbial processes and edaphic parameters of soil or the root, and how this influences agricultural yield in the long-term. To investigate this we assessed crop yield, edaphic parameters and microbial communities within the bulk soil and on roots at the end of the third crop-cycle from a long-term agricultural trial where pre-existing enhanced biochar applications (from previous crop-cycles) totalled between 0 and 5.5 t ha −1 and were then supplemented with fresh enhanced biochar (0.1 t ha −1 ) and traditional N fertiliser (50 kg ha −1 ) in a crossed design. We found an array of effects associated with existing and new enhanced biochar applications in conjunction with N fertiliser on plant yield, soil nutrients and microbial communities. Yield decreased up to 27% with any soil amendment and was greatest in the unamended control. Soil nitrate increased from 30.4 to 59.6 mg kg −1 due to N fertiliser with little effect of the enhanced biochar. Soil pH increased from 4.59 to 4.86 due to previously applied enhanced biochar and was associated with applications of at least 1 t ha −1 . There were differing responses in the microbial communities between bulk soil (294 taxa changes) and roots (383 taxa changes) to the fertilisation regimes, which were unrelated to the nitrate content in the soil and appeared to be driven by pH changes, especially for communities associated with plant roots. This has important implications on which soil compartments should be investigated in future studies of microbial communities. The short- and long-term effects of enhanced biochar observed here question the relevance of studies examining once-off applications of biochar and their extrapolation to real world scenarios i.e. where sequential application of biochar might occur. It is likely that responses of agricultural systems may depend on the historical use of biochar. [ABSTRACT FROM AUTHOR]

The foliar status and the factors affecting the foliar chemistry in a natural Aleppo pine forest grown on calcareous soils in Greece were examined. It was found that the Aleppo pine needles had significantly higher calcium (Ca) concentrations, but significantly lower concentrations of magnesium (Mg), potassium (K), phosphorus (P), iron (Fe) and manganese (Mn) than the respective average concentrations of natural Aleppo pine forests in Spain. It was also found that only foliar Ca and Mn had a significant correlation with the exchangeable Ca and available Mn in soils, respectively. Principal component analysis showed that the nature of the calcareous parent material, (colluvial rocks and hard limestones) were the main factors affecting both foliar and soil chemistry. This finding is important as colluvial soils always coexist with other soil types in hilly and mountainous regions containing calcareous material. [ABSTRACT FROM PUBLISHER]

Fungi play critical roles in ecosystem processes and interact with plant communities in mutualistic, pathogenic, and commensal ways. Fungal communities are thought to depend on both associated tree communities and soil properties. However, the relative importance of the biotic and abiotic drivers of soil fungal community structure and diversity in lowland tropical forests remains poorly understood., We examined the community structure of trees and fungi at different levels of phosphorus (0·17-16·3 mg kg−1) in moist tropical forests in Panama. We predicted that arbuscular mycorrhizal ( AM) fungal composition would be more strongly associated with soil properties than with local tree communities while the composition of other fungal clades would be more strongly correlated with local tree communities than soil properties. We also predicted that fungal operational taxonomic unit (OTU) richness would be negatively correlated with soil fertility and positively correlated with tree species diversity within and among forests., We characterized soil chemistry, fine root biomass, and sequenced the ITS1 barcode region to describe fungal community composition from 70 soil cores across three 1-ha tropical rainforest sites in Panama. The sites vary in soil chemistry, including P, and in tree species community composition, but experience similar annual rainfall., AM fungal community composition was partially correlated with soil chemistry ( r = 0·32, P ≤ 0·001), but not with local tree communities, while non- AM fungal communities were nearly equally correlated with soil chemistry (Partial Mantel test, r = 0·38, P ≤ 0·001) as with tree communities ( r = 0·36, P ≤ 0·001). Linear models showed that AM OTU richness was not explained by any independent variable. For non- AM fungi, phosphorus, pH, and soil moisture better predicted OTU richness across all cores than other biotic and abiotic factors., Synthesis. Our results show that AM fungal structure is driven primarily by soil chemistry. For non- AM fungi, soil properties and the local tree community can play a joint role in structuring communities. Furthermore, we found that more diverse local tree communities did not harbour more fungal species. Our results suggest that soil properties act as an environmental filter for both trees and fungi, setting the stage for interactions between the two. [ABSTRACT FROM AUTHOR]

Development of environmentally-friendly pesticides for sustainable agriculture is a key focus in the agrochemical industry. Identifying novel active ingredients and improving the delivery system of a pesticide are the main challenges in developing new pesticides. Strategies for the control of delivery systems for slow and sustained release of agrochemicals are of great interest to environmental scientists. In this context, the selection of materials to be used as carrier agents in pesticide formulations is crucial. In recent years, the efficacy of several materials for agrochemical formulations has been evaluated by researchers. These materials have unique properties, such as being biodegradable and biocompatible, and having low toxicity and involving a simple preparation process. This review summarises recent applications of various materials in pesticide formulations. The application of the materials can effectively encapsulate or bind the pesticide's active ingredients in the material's matrix with a sustained release profile and slow mobility in soil. This review also discusses some issues and concerns that are faced in formulating pesticide products. [ABSTRACT FROM AUTHOR]

Introduced, invasive plants can alter local soil chemistry and microbial communities, but the underlying mechanisms and extent of these changes are largely unknown. Based on characteristics associated with invasiveness in plants, it was hypothesized that introduced species that produce large amounts of litter with distinctive secondary compounds can a) alter the chemistry of both extractable and bulk carbon in the soil, b) shift microbial communities towards microbes better able to metabolize the compounds in the litter and c) cause soil carbon chemistry and microbial communities to shift to relatively uniform, novel states at multiple sites., Composition of phenolics in senescent tissues (leaves and roots) of Polygonum cuspidatum was compared to the composition of extractable phenolics and non-extractable bulk organic carbon in soils under and adjacent to large, long-established stands of P. cuspidatum at four sites in the eastern U.S. Rates of degradation of phenolics, activities of enzymes associated with the breakdown of phenolics and shifts in microbial community composition were also measured at the sites., Soils under P. cuspidatum stands contained twice as much phenolics as adjacent soils, but the composition of phenolics differed greatly between soils under stands and senescent tissues of P. cuspidatum. Flavonoids and proanthocyanidins constituted >90% of the identified phenolics in P. cuspidatum tissues, whereas monophenolic compounds accounted for >90% of the phenolics in soils under stands. Soils under and adjacent to stands also exhibited distinctive compositions of relatively persistent bulk organic carbon; composition differed less between soils under stands at different sites than between soils under and adjacent to stands at the same site., Soils under P. cuspidatum had 2·8 times greater abundance of fungi than soils adjacent to stands, and fungal markers showed clear separation of soils under and adjacent to P. cuspidatum. However, the potential activity of enzymes that degrade polyphenols was lower in soils under stands. Exogenously applied, chemically complex polyphenols persisted in both P. cuspidatum-invaded and adjacent non-invaded soils, whereas less complex compounds rapidly disappeared from both soils., Synthesis. Results suggest that interactions between plant inputs, abiotic reactions and biotic transformations may create and maintain new states in invaded soils that are chemically and biologically less diverse. In the case of polyphenol-rich, fast-growing invasive species, these interactions may alter the composition of bulk soil organic matter that has relatively slower turnover rates, resulting in legacy effects. Restoration could thus require, not just removal of the species, but also post-removal interventions such as soil amendments. [ABSTRACT FROM AUTHOR]

Recently, in the Sudan, traditional gold mining has been growing rapidly and has become a very attractive and popular economic activity. Mining activity is recognized as one of the sources of radioactivity contamination. Hence, the radioactivity concentration and radiological hazard due to exposure of radionuclides Ra, Th, and K were evaluated. The measurements were performed using gamma-ray spectrometry with an NaI (Tl) detector. The results show that Ra, Th, and K activity concentration ranged from 2.66 to 18.47, 9.20 to 51.87, and 0.17 to 419.77 Bq/kg with average values of 7.54 ± 4.91, 20.74 ± 11.29, and 111.87 ± 136.84 Bq/kg, respectively. In contrast, Rn in soil, Rn in air, and Ra in vegetables along with radiation dose were computed and compared with the international recommended levels. Potential radiological effects to miners and the public due to Ra, Th, K, and Rn are insignificant. Ra transferred to vegetables appears to be negligible compared with the allowable limit 1.0 mSv/year set by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The average value of the annual gonadal dose equivalent (AGDE) is lower than the global average of 300 µSv/year (UNSCEAR ). However, some locations exhibit values >300 µSv/year. To the best of our knowledge, so far there seems to be no data regarding radioactivity monitoring in traditional mining areas in the Sudan. [ABSTRACT FROM AUTHOR]

Much has been learned about the microbial decomposition of plant litter, but relatively little is known about microbial contributions to litter and soil chemistry. We conducted a 3-year litterbag experiment and measured hydrolyzable amino acids (AA) and amino sugars (AS) to gain insights about microbial contributions to the chemical characteristics of decomposing litter and soil. Microscopic observations of hyphae were used to estimate fungal contributions to litter. The carbon (C)-normalized yields of AA and AS increased during decomposition along with nitrogen (N), indicating a shift in chemical characteristics from C-rich plant-derived biopolymers to N-rich, microbially-derived biochemicals. The contributions of fungal biomass to C and N were minor, but necromass of fungi as melanized and clamp-bearing hyphae increased during litter decomposition. Yields of glucosamine and galactosamine in litter approached those in microorganisms, particularly bacteria, suggesting major contributions of bacterial residues to litter during decomposition. The microbial contributions to decomposing litter were consistent with those observed in organic and mineral soils. Microorganisms play important roles in the organization and stabilization of soil organic matter as well as N immobilization and organic C preservation. [ABSTRACT FROM AUTHOR]

The area is 4,993 km2 Mehedinti, representing 2.1% of the country. Mehedinti County due to its potential, diversity of terrain and geographical location, has a well-defined economic landscape, being one of the few counties with the smooth articulation of agricultural use, featuring a whole range agrochemical and pedological, which requires a scientific approach permanently and agricultural phenomenon. Structural changes in agriculture, the existence of conflicting properties with optimal criteria, economic and biological, agricultural farms, impose a number of restrictions that require us to promote research priorities and objectives able to rehabilitate agricultural infrastructure around. Knowing in detail yielding and technological features, favouring and restricting factors of agricultural production on each land portion both from the point of view of present response and of real possibilities of turning them into better ones can be, for the decision-maker a precious tool in achieving the most suited practical measures of producing plant biomass in a dynamics well correlated with environmental ecological requirements. [ABSTRACT FROM AUTHOR]

Background & Aims: The consequences of fertiliser addition to semi-natural grasslands are well understood, but much less is known about the consequences of cessation of nitrogen fertiliser regimes, including rates of recovery. This study aimed to investigate whether the effects of nitrogen (N) additions to a mesotrophic grassland were still apparent 15 years after the cessation of N inputs. Methods: A long-term experiment at Tadham Moor, UK, received N additions at rates of 0, 25, 50, 100 and 200 kg N ha yr between 1986 and 1994. Fifteen years after the cessation of N additions soil chemistry, plant tissue chemistry, plant biomass and Ellenberg N values were assessed. Results: KCl-extractable ammonium-N, total soil N, total organic carbon and microbial biomass N differed between the controls and the higher historic levels of N addition. Plant tissue chemistry showed no significant effects of previous N addition. Above-ground biomass was higher where N had been added, although this response was only weakly significant. The species composition of the vegetation showed effects of the N addition with mean Ellenberg N values significantly higher than the control in most treatments. Conclusion: The effects of long-term N addition can be seen for many years. [ABSTRACT FROM AUTHOR]

Two-phase olive oil mills generate a semi-solid waste made of olive pulp, olive stone, and vegetation water commonly called ‘alperujo’. Lack of disposal alternatives drives many Argentinean olive oil producers to apply it directly as soil amendment to the olive orchards. Even though this practice has been widely evaluated in Mediterranean countries, there is little agreement on the environmental impact that it may produce. In this work a surface layer of alperujo was applied to a high-density, drip-irrigated olive orchard, and different parameters were monitored. This report summarises the dynamics of soil chemical properties during the first 200 days after application. The results obtained showed that soil amended with alperujo increased total organic matter (OM), nitrogen (N) and available potassium (K), without affecting soil electrical conductivity (EC), pH and C/N ratio. The results suggest that surface application of alperujo may represent an attractive alternative to disposal under conservationist management. Further research evaluating long term effects on chemical and biological indicators must be performed to ensure the sustainability of alperujo as soil amendment. [ABSTRACT FROM PUBLISHER]

Massbalance studies and direct measurement of changes in soil chemistry have provided evidence of depletion of base cations in soils across decadal time scales. Losses of base cations have been attributed to leaching as a consequence of elevated levels of S and N deposition. Chemical properties of mineral soil horizons were determined at seven plots in a tolerant hardwood forest at the Turkey Lakes Watershed in 1986 and in 2003 and 2005. Archived soils from the original sampling were used to assess the impact of storage and changing methodology on results. Exchangeable cation concentrations were compared between the two sampling times, as were concentrations normalized for organic C. The effects of air-dry storage were significant for some cations, but in absolute terms the changes were small when contrasted with the spatial variation in exchangeable cation concentrations for the samples collected in 2003 and 2005. There were no statistically significant declines in pH, exchangeable Ca, Mg, or K concentrations, or Ca, Mg or K concentrations normalized for organic C concentration during the 17- to l9-yr samplin period across the watershed. Exchangeable Na and normalized Na concentrations decreased in deeper horizons of the soil profile. There were various patterns of cation change at the plot level, but these changes were unable to be attributed to the range of soil profile base status at the site. Mineral weathering inputs appeared to provide stability to the exchangeable base cation pool in spite of large leaching losses at the Turkey Lakes site. [ABSTRACT FROM AUTHOR]

St. Catherines Island, located off the coast of Georgia (United States), has been inhabited by humans for close to 5000 years. The island's long-term habitation and varied history of land use has left a legacy of anthropogenic impacts that has strongly influenced the composition and function of the current vegetation communities and underlying soils. In this study, we examined the chemistry of surface soils collected from 32 sites representing five historical land uses (old cotton plantations, longleaf pine savanna, hickory forest, maritime forests, and shell middens) to determine how human activities have affected the island's surface soils. We found that shell deposition left a strong chemical signal, significantly increasing soil pH, cation exchange capacity, and concentrations of Ca, total nitrogen, and several micronutrients. Soils under the hickory-dominated forest had chemical characteristics that were intermediate between the middens and the other three cover types. Despite a wide range in pH, all sites had very high concentrations of extractable P, possibly because of retention by Ca and Fe. Shell deposition has altered soil chemistry in numerous areas across the island, and this has important implications for soils and the resultant vegetation patterns currently seen along St. Catherine's coastlines as well as other coastlines throughout the world. [ABSTRACT FROM AUTHOR]

The bioavailability of cobalt and its transfer from soil to vegetables and rice were investigated. Among 312 soils collected from vegetable and paddy fields in the suburban areas of some major cities of Fujian Province, southeast China, total soil Co ranged from 3.5 to 21.7mgkg−1, indicating a slight accumulation compared with the background value of the province. DTPA extracted 0.1–8.5% of soil total Co. Total and DTPA-extractable Co correlated with soil pH, CEC, free Fe, total Mn, clay and silt content more significantly in paddy soils than in the soils from vegetable fields. The average Co concentrations in the edible parts of vegetables and rice were 15.4μgkg−1 and 15.5μgkg−1, respectively. The transfer factor (the ratio of plant Co to soil DTPA-extractable Co, TFDTPA) ranged from 0.003 to 0.126 with a median of 0.049. The TFDTPA decreased in the order of leafy vegetables>fruit vegetables>root vegetables>rice. The TFDTPA of all crops decreased with increasing DTPA-extractable Co. Increase in pH, CEC, organic matter, clay, silt, free iron and total Mn limited the soil-to-plant transfer of Co to varying degrees. The transfer of Co from the soils to the edible parts of the crops was lower than that of Zn, Cu and Cd, but higher than that of Pb in the same areas. The concentrations of Co in rice and vegetables in the study areas were considered to be safe for the local residents because of the slight anthropogenic input and the low transfer potential to the edible parts of Co from the soils. [Copyright &y& Elsevier]

Copper (Cu) and zinc (Zn) amounts extracted with 0.1molar L-1 HCl (HCl) for the most representative soil types of Rio Grande do Sul State (Brazil) were compared with those extracted with Mehlich-1 (M3) and Mehlich-3 (M3) solutions. The nutrients' amounts extracted by different methods indicated high correlation degree. The M3 solution extracted similar copper amounts than HCl; however, lower amounts of Zn. The M1 and M3 solutions are efficient for simultaneous multielement extraction and can be used in soil testing laboratories for RS and SC states. [ABSTRACT FROM AUTHOR]

A study was conducted in Soil Chemistry Section, Ayub Agricultural Research Institute, Faisalabad, Pakistan. The objective was to assess the micronutrients status (Zn, Cu, Fe, Mn and B) of soils under mango orchards of Multan and Lodhran districts. For this purpose 540 soil samples were collected from all tehsils of two districts. After completing the analysis, soils were classified into low, marginal and adequate levels of these nutrients. The results indicated that in case of Zn at upper surface (0-15 cm) 74, 90, 86, 100 percent soil samples were low (< 1.0 mg/kg) in Multan, Shujabad, Lodhran and Kehror Pakka tehsils and 95 and 62 percent samples in Jalalpur Pirwala and Dunyapur tehsils, respectively. At lower depth (15-30 cm) 95-100 percent samples were found low. In case of B at upper surface, 8, 17, 61, 25, 25 and 39 percent soil samples were low (<0.45 mg/kg) in Multan, Shujabad, Jalalpur Pirwala, Lodhran, Kehror Pakka and Dunyapur tehsils, respectively whereas 92, 83, 63, 69, 69 and 43 percent soil samples were at marginal level (0.45-1.0 mg/kg) in these tebsils. At lower depth more than 50 percent soil samples were found at marginal level (Multan80, Shujabad59, Jalalpur Pirwala54, Lodhran50, Kehror Pakka57 and Dunyapur49 %) while 20, 10, 27, 48, 30 and 23 percent were found adequate in above mentioned tehsils, respectively. Remaining soil samples had low level. B of Cu and Mn concentration was adequate in soil whereas Fe concentratin was at marginal level (2.0-4.0 mg/kg) in 3, 6, 3 and 3 percent samples in tehsils Jalalpur Pirwala, Lodhran, Kehror Pakka and Dunyapur. Other soil samples had adequate level of Fe (>4.0 mg/kg). [ABSTRACT FROM AUTHOR]

Soil compaction affects crop yield in many ways. Knowing its spatial variability provides possibilities for site-specific soil treatments that can increase the profitability and sustainability of crop production. The purposes of this study were (1) to investigate the spatial variability of particle size distribution, gravimetric water content, bulk density, and penetration resistance using classical and geostatistical methods in a field in which conventional soil tillage methods and a particular crop rotation were applied, and (2) to evaluate the spatial relations among soil properties in the field studied. Topsoil (0 to 20 cm) and subsoil (20 to 40 cm) were separately sampled at each of 94 predetermined sampling points based on an irregular grid design in a 45 ha areaypic Ustifluvents). Bulk density showed the lowest variability (CV = 9.09% for topsoil and 6.00% for subsoil), and the penetration resistance showed the highest variability among the soil properties investigated (CV = 64.08% and 42.69%, for topsoil and subsoil, respectively). Gravimetric water content and bulk density showed high correlation particularly with clay and sand content, whereas no significant correlation occurred between penetration resistance and any of the textural components. Spatial correlation ranges varied from 72 to 510 m. Clay content had strong spatial dependence in topsoil, whereas, only moderate spatial dependence occurred in subsoil. Spatial dependence classes of other soil properties evaluated did not change with depth. Strong spatial dependence occurred for penetration resistance and sand content, and a moderate spatial dependence occurred for bulk density, gravimetric water content, and silt content. Comparisons of kriged maps of bulk density, penetration resistance, and textural components revealed that greater penetration resistance and bulk density were associated with greater sand content. However, most of the soils of study area had a clayey texture. Therefore, farmers need to be careful in application of soil tillage and other management practices that could cause compaction. [ABSTRACT FROM AUTHOR]

Abstract: Little information is available regarding the responses of biological soil crusts to sand burial in desert ecosystems. Therefore, in this study, we evaluated the effects of sand burial (sand depth of 0, 1, 2, 3 and 4mm) followed by simulated precipitation (1, 3 and 5mm distilled water, sprayed at 2-day intervals) on CO2 exchange and growth by four types of crust collected from a revegetated area of the Tengger Desert (Northern China) in 2007. The results revealed that the respiration rate was significantly decreased and that moss shoot elongation was significantly increased (P <0.001) following burial. Both of these responses may have acted as compensatory mechanisms that favoured the recovery of crust after burial. The burial responses among the four crusts were also compared by measuring the cryptogam cover variations after burial and then computing the speed of emergence and a tolerance index (by standardizing the speed of emergence with a burial ratio of sand burial depth to the initial maximum height of the crust). Among the four crusts evaluated, Bryum argenteum crust showed the fastest speed of emergence (average 11.5% cover week−1) and highest tolerance index (average 0.182), followed by Didymodon vinealis crust (emergence, 11.3% week−1; tolerance, 0.129), Syntrichia caninervis crust (emergence, 7.7% week−1; tolerance, 0.097) and Collema tenax crust (emergence, 4.2% week−1; tolerance, 0.022). This sequence was in agreement with the successional order of these crusts that has been observed in the revegetated area evaluated in this study, which suggests that sand burial is one of the most important factors driving the succession of crusts in desert ecosystems. Furthermore, water played a role in the recovery process, as evidenced by pronounced decreases in dark respiration and increases in photosynthesis, speed of emergence and tolerance index for each crust type, as well as by shoot elongations by three mosses in response to the accretion of water. The restriction of tolerance against sand burial under limited precipitation conditions emphasizes the necessity for sand-binding measures to alleviate the negative effects of sand burial on crusts, which are crucial to preventing revegetated areas from undergoing desertification. [Copyright &y& Elsevier]

The two native Antarctic vascular plant species, Colobanthus quitensis and Deschampsia antarctica, were sampled from 15 points along a 1480 km latitudinal transect from South Georgia (54°S, 36°W) through to the Léonie Islands on the western Antarctic Peninsula (67°S, 68°W). Roots of plants were cleared and stained and fungal structures recorded. The commonest type of fungal association was that formed by dark septate endophytes (DSE): 32% and 27% of the root lengths of C. quitensis and D. antarctica were colonized by hyphae of these fungi, respectively. Hyaline and stained septate hyphae were also common in roots. Coarse and line arbuscular mycorrhiza (AM) occurred in the roots of both plant species from South Georgia, and fine AM colonization with occasional arbuscules was also sporadically recorded in roots from the South Shetland Islands, suggesting functional associations between higher plants and AM symbionts. Fungal abundances were not associated with soil chemistry, but AM abundance was associated with seasonal surface air temperature, with lower colonization in more southerly, colder habitats. We conclude that DSE are widespread, and that AM fungi are sparse but present and decline in abundance at higher latitudes, in the roots of C. quitensis and D. antarctica. [ABSTRACT FROM AUTHOR]

The benefits of Mn and Zn fluid fertilizers over conventional granular products in calcareous sandy loam soils have been agronomically demonstrated. We hypothesized that the differences in the effectiveness between granular and fluid Mn and Zn fertilizers is due to different Mn and Zn reaction processes in and around fertilizer granules and fluid fertilizer bands. We used a combination of several synchrotron-based x-ray techniques, namely, spatially resolved micro-x-ray fluorescence (μ-XRF), micro-x-ray absorption near edge structure spectroscopy (μ-XANES), and bulk-XANES and -extended x-ray absorption fine structure (EXAFS) spectroscopy, along with several laboratory-based x-ray techniques to speciate different fertilizerderived Mn and Zn species in highly calcareous soils to understand the chemistry underlying the observed differential behavior of fluid and granular micronutrient forms. Micro-XRF mapping of soil-fertilizer reactions zones indicated that the mobility of Mn and Zn from liquid fertilizer was greater than that observed for equivalent granular sources of these micronutrients in soil. After application of these micronutrient fertilizers to soil, Mn and Zn from liquid fertilizers were found to remain in comparatively more soluble solid forms, such as hydrated Mn phosphate-like, Mn calcite-like, adsorbed Zn-like, and Zn silicate-like phases, whereas Mn and Zn from equivalent granular sources tended to transform into comparatively less soluble solid forms such as Mn oxide-like, Mn carbonate-like, and Zn phosphate-like phases. [ABSTRACT FROM AUTHOR]

A technique is developed in this paper to unify the methods of analyzing scour by turbulent water jets in cohesionless and cohesive soils. Data from previous studies using circular turbulent impinging jets and circular turbulent wall jets are used to compare the scour in low void ratio cohesive soils to that in uniform sands and gravels. Scour by these jets is related to the dimensionless excess stress on the soil bed. It is seen that this parameter will likely work well for developing a method to predict scour for circular wall jets that is applicable to both materials. However, a circular impinging jet appears to vary appreciably in its interaction with the bed between the two types of soil, which makes developing a unified method to predict scour by impinging jets more difficult. [ABSTRACT FROM AUTHOR]

Abstract: Cadmium sorption, basic soil properties and water retention were jointly analyzed in an acidic sandy podzol under pine forest in the North of Germany. Samples were taken along a 10 m transect at a depth of 0.15 m with a sample-support of 0.15 m. The small-scale Cd sorption variability was upscaled in two steps. Firstly, it was simplified and, secondly, aggregated from the sample to the pedon scale. We evaluated different models to simplify Cd sorption variability at different levels of spatial aggregation. Our evaluation method was the numerical simulation of Cd transport in the topsoil where the variability of Cd sorption is the key input. We described Cd sorption with the Freundlich parameterization and tested three models to simplify its spatial variability. The reference model (model 1) had two and the simplified models only one spatially variable sorption parameter. Model 2 varied the parameter K f of the Freundlich parameterization and set the exponent constant. Model 3 expressed only the linear variability of sorption. Each sample had a scaling factor that related to a constant sorption reference function. The Freundlich parameter K f of the third simplification model (model 4), was derived by a local pedotransfer function. Its variability was, therefore, filtered by the available variation of a limited number of basic soil properties. The average sorption was at all aggregation levels not significantly different between the models. However, the corresponding uncertainty was smallest for model 3, intermediate for model 4 and largest for model 2. We evaluated the different sorption variability models with the simulation of Cd transport. The mean Cd concentrations in the topsoil predicted by the different models were statistically not different. However, at all support scales, the uncertainties of the predicted mean Cd concentrations and the RMSE''s were smallest when model 3 was used, where the error was about 20% at the sample scale and decreased to below 10% at the pedon scale. Therefore, if measurements of sorption isotherms are available, we recommend to use model 3 to derive the mean sorption behavior with minimal uncertainty. [Copyright &y& Elsevier]

Nutrient retention and dynamics with time in turfgrass sand-based rootzone mixtures (RZMs) are not well documented. This study was conducted to determine chemical properties of putting greens as impacted by (i) RZM, (ii) establishment (EST), and (iii) putting green age. United States Golf Association (USGA) specification greens were constructed and established with creeping bentgrass (Agrostis stolonifera L.) sequentially from 1997 to 2000. Treatments included two RZMs [i.e., 80:20 (v-v) sand and sphagnum peat mixture and an 80:15:5 (v-v-v) sand, sphagnum peat, and soil] and two EST procedures (i.e., accelerated vs. controlled). The accelerated treatment received 2.6-, 3.0-, and 2.6-fold N, P, and K, respectively, when compared with the controlled treatment during the EST year. Soil samples were taken and analyzed annually. The RZNI generally had no effect on soil chemical properties during the EST year or beyond. All but five of the chemical properties investigated were significantly greater for the accelerated treatment compared with the controlled during the EST year. Soil pH in the accelerated treatment was lower than the controlled treatment, pH 6.7 vs. 7.4. Establishment treatments did not have an effect on chemical properties beyond the EST year, except for Bray1-P. All soil chemical properties investigated, excluding pH and available K, decreased after the EST year, but began to increase several years later. [ABSTRACT FROM AUTHOR]

Abstract: A greenhouse experiment was set up with maize, ryegrass, Indian mustard, wheat and pea to evaluate to what extent differences in uranium (U) transfer factors can be explained by root-mediated changes in selected soil properties. The experiment involved an acid and an alkaline soil contaminated with 238U. U soil-to-shoot transfer factors (TFs) ranged between 0.0005 and 0.021 on the acid soil and between 0.007 and 0.179 on the alkaline soil. Indian mustard showed the highest U uptake in shoots and maize the lowest. The root TFs, only available for the acid soil, ranged from 0.58 for maize and Indian mustard to 1.38 for ryegrass. The difference in U uptake between the two soils and the five plants was only partially explained by the different initial U concentrations in soil solution or differences in soil properties in the two soils. However, we obtained a significant relation for differences in shoot TFs observed between the two soils when relating shoot TFs with concentration of UO2 2+ and uranyl carbonate complexes in soil solution (R 2 =0.88). The physiological mechanisms by which root-to-shoot U transfer is inhibited or promoted seemed at least as important as the plant-induced changes in soil characteristics in determining soil-to-shoot TFs. [Copyright &y& Elsevier]

The coupling products (CPs), which were formed via the peroxosulfate catalyzed oxidation of pentachlorophenol (PCP) with iron(III)-tetrakis(sulfonatophenyl)porphyrin (Fe(III)-TPPS) in the presence of hydroxypropyl-β -cyclodextrin (HP-β -CD) or HP-γ -CD, were separated by ultrafiltration from the reaction mixture. When the percentages of chlorine species in the reaction mixture were calculated from the concentrations of organic chlorine in the reaction mixture and CPs, 10–25% of chlorine species in the reaction mixture was organic chlorine that was incorporated into CDs. Analyses of the CPs by pyrolysis-GC/MS (Py-GC/MS) and 13 C NMR showed that the PCP-derived products were covalently incorporated into the CDs. To evaluate the acute toxicity of the CPs, a Microtox® test was examined. Toxicities of the CPs were reduced slightly, compared to the controls (PCP alone and PCP + reaction blanks). In the reaction blanks, mesaconic acid (MA) moieties were detected as a result of the oxidation of CDs in the absence of PCP. Thus, factors in the toxicities, detected in the CPs, can be attributed to the oxidation products derived from CDs, such as MA, as well as the PCP-derived products incorporated into the CDs. [ABSTRACT FROM AUTHOR]

Abstract: Rock-derived nutrients in soils originate from both local bedrock and atmospheric dust, including dust from far-distant sources. Distinction between fine particles derived from local bedrock and from dust provides better understanding of the landscape-scale distribution and abundance of soil nutrients. Sandy surficial deposits over dominantly sandstone substrates, covering vast upland areas of the central Colorado Plateau, typically contain 5–40% silt plus clay, depending on geomorphic setting and slope (excluding drainages and depressions). Aeolian dust in these deposits is indicated by the presence of titanium-bearing magnetite grains that are absent in the sedimentary rocks of the region. Thus, contents of far-traveled aeolian dust can be estimated from magnetic properties that primarily reflect magnetite content, such as isothermal remanent magnetization (IRM). Isothermal remanent magnetization was measured on bulk sediment samples taken along two transects in surficial sediment down gentle slopes away from sandstone headwalls. One transect was in undisturbed surficial sediment, the other in a setting that was grazed by domestic livestock until 1974. Calculation of far-traveled dust contents of the surficial deposits is based on measurements of the magnetic properties of rock, surficial deposits, and modern dust using a binary mixing model. At the undisturbed site, IRM-based calculations show a systematic down-slope increase in aeolian dust (ranging from 2% to 18% of the surface soil mass), similar to the down-slope increase in total fines (18–39% of surface soil mass). A combination of winnowing by wind during the past and down-slope movement of sediment likely accounts for the modern distribution of aeolian dust and associated nutrients. At the previously grazed site, dust also increases down slope (5–11%) in sediment with corresponding abundances of 13–25% fines. Estimates of the contributions of aeolian dust to the total soil nutrients range widely, depending on assumptions about grain-size partitioning of potential nutrients in weathered bedrock. Nevertheless, aeolian dust is important for this setting, contributing roughly 40–80% of the rock-derived nutrient stocks (P, K, Na, Mn, Zn, and Fe) in uppermost soil over most of the sampled slope at the undisturbed site, which shows no evidence of recent wind erosion. [Copyright &y& Elsevier]

The removal of phosphorus in point and non-point-source pollution has become one of the leading problems in water quality since the beginning of the 21st century. Several natural, domestic, and industrial treatment systems already exist, but with very limited efficiencies and serious procedural defects. Lignocellulose-based Anion Removal Media (LAM) was developed in association with iron nanocoating technology as means of phosphorus adsorption from various concentrations of contaminated water. Results revealed that trivalent iron coated lignocellulose pellets can be used to effectively remove phosphorus contaminants from point and non-point-source polluted water. Removal capacities of pelletized cotton media surpass existing materials for phosphorus removal by at least 22 times, while remaining both efficient and cost effective. The materials were also investigated for regeneration, yielding high removal capacities even after the fifth regeneration. Treatment methodology and outlines are proposed, and procedural mechanisms are explored in this study. An economic evaluation of this technology is also assessed for a practical application of LAM to point/non-point-source polluted water. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) fluxes from soil under mown grassland were monitored using static chambers over three growing seasons in intensively and extensively managed systems in Central Switzerland. Emissions were largest following the application of mineral (NH4NO3) fertilizer, but there were also substantial emissions following cattle slurry application, after grass cuts and during the thawing of frozen soil. Continuous flux sampling, using automatic chambers, showed marked diurnal patterns in N2O fluxes during emission peaks, with highest values in the afternoon. Net uptake fluxes of N2O and subambient N2O concentrations in soil open pore space were frequently measured on both fields. Flux integration over 2.5 years yields a cumulated emission of +4.7 kgN2O-N ha−1 for the intensively managed field, equivalent to an average emission factor of 1.1%, and a small net sink activity of −0.4 kg N2O-N ha−1 for the unfertilized system. The data suggest the existence of a consumption mechanism for N2O in dry, areated soil conditions, which cannot be explained by conventional anaerobic denitrification. The effect of fertilization on greenhouse gas budgets of grassland at the ecosystem level is discussed. [ABSTRACT FROM AUTHOR]

The present study quantifies changes in soil organic carbon (SOC) stocks in Belgium between 1960, 1990 and 2000 for 289 spatially explicit land units with unique soil association and land-use type, termed landscape units (LSU). The SOC stocks are derived from multiple nonstandardized sets of field measurements up to a depth of 30 cm. Approximately half of the LSU show an increase in SOC between 1960 and 2000. The significant increases occur mainly in soils of grassland LSU in northern Belgium. Significant decreases are observed on loamy cropland soils. Although the largest SOC gains are observed for LSU under forest (22 t C ha−1 for coniferous and 29 t C ha−1 for broadleaf and mixed forest in the upper 30 cm of soil), significant changes are rare because of large variability. Because the number of available measurements is very high for agricultural land, most significant changes occur under cropland and grassland, but the corresponding average SOC change is smaller than for forests (9 t C ha−1 increase for grassland and 1 t C ha−1 decrease for cropland). The 1990 data for agricultural LSU show that the SOC changes between 1960 and 2000 are not linear. Most agricultural LSU show a higher SOC stock in 1990 than in 2000, especially in northern Belgium. The observed temporal and spatial patterns can be explained by a change in manure application intensity. SOC stock changes caused by land-use change are estimated. The SOC change over time is derived from observed differences between SOC stocks in space. Because SOC stocks are continuously influenced by a number of external factors, mainly land-use history and current land management and climate, this approach gives only an approximate estimate whose validity is limited to these conditions. [ABSTRACT FROM AUTHOR]

We present the most comprehensive pan-European assessment of future changes in cropland and grassland soil organic carbon (SOC) stocks to date, using a dedicated process-based SOC model and state-of-the-art databases of soil, climate change, land-use change and technology change. Soil carbon change was calculated using the Rothamsted carbon model on a European 10 × 10′ grid using climate data from four global climate models implementing four Intergovernmental Panel on Climate Change (IPCC) emissions scenarios (SRES). Changes in net primary production (NPP) were calculated by the Lund–Potsdam–Jena model. Land-use change scenarios, interpreted from the narratives of the IPCC SRES story lines, were used to project changes in cropland and grassland areas. Projections for 1990–2080 are presented for mineral soil only. Climate effects (soil temperature and moisture) will tend to speed decomposition and cause soil carbon stocks to decrease, whereas increases in carbon input because of increasing NPP will slow the loss. Technological improvement may further increase carbon inputs to the soil. Changes in cropland and grassland areas will further affect the total soil carbon stock of European croplands and grasslands. While climate change will be a key driver of change in soil carbon over the 21st Century, changes in technology and land-use change are estimated to have very significant effects. When incorporating all factors, cropland and grassland soils show a small increase in soil carbon on a per area basis under future climate (1–7 t C ha−1 for cropland and 3–6 t C ha−1 for grassland), but when the greatly decreasing area of cropland and grassland are accounted for, total European cropland stocks decline in all scenarios, and grassland stocks decline in all but one scenario. Different trends are seen in different regions. For Europe (the EU25 plus Norway and Switzerland), the cropland SOC stock decreases from 11 Pg in 1990 by 4–6 Pg (39–54%) by 2080, and the grassland SOC stock increases from 6 Pg in 1990 to 1.5 Pg (25%) under the B1 scenario, but decreases to 1–3 Pg (20–44%) under the other scenarios. Uncertainty associated with the land-use and technology scenarios remains unquantified, but worst-case quantified uncertainties are 22.5% for croplands and 16% for grasslands, equivalent to potential errors of 2.5 and 1 Pg SOC, respectively. This is equivalent to 42–63% of the predicted SOC stock change for croplands and 33–100% of the predicted SOC stock change for grasslands. Implications for accounting for SOC changes under the Kyoto Protocol are discussed. [ABSTRACT FROM AUTHOR]

The general lack of significant changes in mineral soil C stocks during CO2-enrichment experiments has cast doubt on predictions that increased soil C can partially offset rising atmospheric CO2 concentrations. Here, we show, through meta-analysis techniques, that these experiments collectively exhibited a 5.6% increase in soil C over 2–9 years, at a median rate of 19 g C m−2 yr−1. We also measured C accrual in deciduous forest and grassland soils, at rates exceeding 40 g C m−2 yr−1 for 5–8 years, because both systems responded to CO2 enrichment with large increases in root production. Even though native C stocks were relatively large, over half of the accrued C at both sites was incorporated into microaggregates, which protect C and increase its longevity. Our data, in combination with the meta-analysis, demonstrate the potential for mineral soils in diverse temperate ecosystems to store additional C in response to CO2 enrichment. [ABSTRACT FROM AUTHOR]

Abstract: The multi-layer dynamic model SAFE was applied to the forested catchment Istebna (Southern Poland), to study recovery from acidification. Environmental pollution in the area has been historically high. The model uses data from an intensive monitoring plot established in 1999 in a spruce stand, which was planted in 1880. Observations showed that the soil was depleted of base cations. The measured base saturation in 1999 was between 5 and 8% in the different soil layers. Model predictions assuming full implementation of the UNECE 1999 Gothenburg Protocol and present day base cation deposition show that the base saturation will slowly increase to 20% by 2100. Despite large emission reductions, Istebna still suffers from the very high loads of acidifying input during the past decades. Soil recovery depends on future emissions especially on base cation deposition. The recovery will be even slower if the base cation deposition decreases further. [Copyright &y& Elsevier]

We analyzed the temporal trends of elemental changes in the soil of the Hermine, a 5.1-ha watershed of the Lower Laurentians, Quebec, Canada, from 1993 to 2002. The forest canopy of the Hermine is dominated by sugar maple (Acer saccharum Marshall) growing on Podzols formed in a shallow (<2 m) anorthositic till. The results show a significant long-term decrease of SO4 concentration in the solution of both the LFH (-1.33 μmol L-1 yr-1; α = 0.05) and B (-0.78 μmol L-1 yr-1; α 0.01) horizons. This SO4 decline is associated with a reduction in dissolved Ca and Mg in the B (-1.83 and -0.38 μmol L-1 yr-1 for Ca and Mg, respectively; α = 0.001) and, to a lesser extent, in the LFH horizons (-2.09 and -0.69 μmol L-1 yr-1 for Ca and Mg, respectively; α = 0.01). Thus, the combined change in dissolved Ca and Mg in the B horizon not only follows that of SO4 but it proceeds, on an equivalent basis, at a rate almost three times faster than that of SO4. For SO4, the concentration changes in solution are accompanied from 1994 to 2002 by a moderate depletion of the H2O-soluble SO4 pool in the podzolic B horizon of Zones A and C (mean rate for Zones A and C of -3.5 μmol kg-1 yr-1; α = 0.05). Indeed, SO4 desorption from the B horizon occurs even under constant S deposition levels and seems to respond to changes in atmospheric deposition that occurred decades ago. In the case of exchangeable calcium and magnesium (Caex and Mgex), decreasing trends are present in the FH horizons but they are statistically significant only for Mgex, in the B horizons of Zones A and C. A decrease of up to 50% of the Mnex pool is observed in the FH and B horizons, a decline that is partly balanced by an increase in Mn uptake by sugar maple since 1994. A tendency toward acidification is also noted in the solution (mean rate of +3.48 μmol H+ L-1 yr-1, α = 0.01) and in the solid phase (mean rate of +36.4 μmol H+ kg-1 yr-1, α = 0.001) of the organic horizons. The increase in exchangeable aluminum (Alex) in the FH horizons of zones B and C (mean rate for zones B and C of +0.16 cmol(+) kg-1 yr-1; α = 0.01) could reflect these decreasing pit trends. Finally, a recurrent seasonal pattern in exchangeable cations is observed where Alex increases at the expense of Cex, Mgex, and exchangeable manganese and potassium (Mnex and Kex) during the growing season. This study shows that long-term, seasonal, and episodic trends in soil properties create a complex temporal pattern that needs to be recognized and partitioned when assessing the response of soil materials to changes in environmental conditions. [ABSTRACT FROM AUTHOR]

This article presents a study, which examined the impact of accelerated soil dissipation of tebuconazole following multiple applications to peanut. Results indicated accelerated dissipation in field-treated samples with the time to fifty percent dissipation. Corresponding increases in rates of accumulation and decay of degradates were also indicated. Best-fit equations to dissipation kinetic data combined with estimates of canopy interception rates were used to predict tebuconazole and degradates concentration in soil after each successive application. Predicted concentrations compared with values measured in surface soil samples were from two-fold less to two-fold greater. Use of kinetic data will likely enhance assessments of treatment efficacy and human and ecological risks from normal agronomic use of tebuconazole on peanut. However, the study indicated that varying soil conditions may have an equal or greater impact on field dissipation rate than development of accelerated dissipation.

Vermicomposting of fly ash has been attempted, using red earthworm, Eisenia foetida. Fly ash, which was obtained from thermal power station, was mixed with cowdung in different proportions (20, 40, 60 and 80%). These mixtures were used as feed for earthworms, and after 30 days, vermicast recovery, worm zoomass and numbers of juveniles produced were recorded. A total of six runs each of 30 days were conducted during the whole study. Concentrations of heavy metals in different mixtures of fly ash–cowdung, before and after vermicomposting and in the earthworms used in the study were also estimated. Results show maximum output of vermicasts and maximum number of juveniles produced was in reactors with 40% fly ash while maximum weight gain by earthworm was in 20% fly ash vermireactors. Performance of vermireactors up to 60% fly ash was more or less similar but at 80% fly ash, there is a marked reduction in overall performance of the reactors. Chemical analysis of different samples of fly ash–cowdung mixtures prior to vermicomposting revealed high concentrations of zinc, chromium, lead, nickel and copper. Chemical analysis of vermicomposted samples showed 30–50% reduction in heavy metals up to 60% fly ash and 10–30% reduction in 80% fly ash. Metal analysis of earthworms revealed considerable bioaccumulation of heavy metals in their body. The Present study indicates the feasibility of E. foetida for mitigating the toxicity of metals and up to 60% fly ash–cowdung mixtures can be used for sustainable and efficient vermicomposting. [ABSTRACT FROM AUTHOR]

Conversion of methanol to CH4 has a large isotope effect so that a small contribution of methanol-dependent CH4 production may decrease the d13CH4 of total CH4 production. Therefore, we investigated the role of methanol for CH4 production. Methanol was not detectable above 10 µM in anoxic methanogenic rice field soil. Nevertheless, addition of13C-labeled methanol (99% enriched) resulted in immediate accumulation of13CH4. Addition of 0.1 µM13C-methanol resulted in increase of the d13CH4 from -47 to -6‰ within 2 h, followed by a slow decrease. Addition of 1 µM13C-methanol increased d13CH4 to +500 ‰ within 4 h, whereas 10 µM increased d13CH4 to +2500‰ and continued to increase. These results indicate that the methanol concentrationsin situ, which diluted the13C-methanol added, were =0.1 µM and that the turnover of methanol contributed only about 2% to total CH4 production at 0.1 µM. However, contribution increased up to 5 and 17% when 1 and 10 µM methanol were added, respectively. Anoxic rice soil that was incubated at different temperatures between 10 and 37 °C exhibited maximally 2-6% methanol-dependent methanogenesis about 1-2 h after addition of 1 µM13C-methanol. Only at 50 °C, contribution of methanol to CH4 production reached a maximum of 10%. After longer (7-10 h) incubation, however, contribution generally was only 2-4%. Methanol accumulated in the soil when CH4 production was inhibited by chloroform. However, the accumulated methanol accounted for only up to 0.7 and 1.2% of total CH4 production at 37 and 50 °C, respectively. Collectively, our results show that methanol-dependent methanogenesis was operating in anoxic rice field soil but contributed only marginally to total CH4 production and the isotope effect observed at both low and high temperature. [ABSTRACT FROM AUTHOR]

Past research strongly indicates the importance of amino acids in the N economy of the Arctic tundra, but little is known about the seasonal dynamics of amino acids in tundra soils. We repeatedly sampled soils from tussock, shrub, and wet sedge tundra communities in the summers of 2000 and 2001 and extracted them with water (H2O) and potassium sulfate (K2SO4) to determine the seasonal dynamics of soil amino acids, ammonium (NH4+), nitrate (NO3-), dissolved organic nitrogen (DON), dissolved organic carbon (DOC), and phosphate (PO42-). In the H2O extractions mean concentrations of total free amino acids (TFAA) were higher than NH4+ in all soils but shrub. TFAA and NH4+ were highest in wet sedge and tussock soils and lowest in shrub soil. The most predominant amino acids were alanine, arginine, glycine, serine, and threonine. None of the highest amino acids were significantly different than NH4+ in any soil but shrub, in which NH4+ was significantly higher than all of the highest individual amino acids. Mean NO3- concentrations were not significantly different from mean TFAA and NH4+ concentrations in any soil but tussock, where NO3- was significantly higher than NH4+. In all soils amino acid and NH4+ concentrations dropped to barely detectable levels in the middle of July, suggesting intense competition for N at the height of the growing season. In all soils but tussock, amino acid and NH4+ concentrations rebounded in August as the end of the Arctic growing season approached and plant N demand decreased. This pattern suggests that low N concentrations in tundra soils at the height of the growing season are likely the result of an increase in soil N uptake associated with the peak in plant growth, either directly by roots or indirectly by microbes fueled by increased root C inputs in mid-July. As N availability decreased in July, PO42- concentrations in the K2SO4 extractions increased dramatically in all soils but shrub, where there was a comparable increase in PO42- later in the growing season. Previous research suggests that these increases in PO42- concentrations are due to the mineralization of organic phosphorus by phosphatase enzymes associated with soil microbes and plant roots, and that they may have been caused by an increase in organic P availability. [ABSTRACT FROM AUTHOR]

Assessing the timescales of recovery, by the use of dynamic models, will be used as input to the policy process to abate acidification. In this study the multilayer dynamic soil chemistry model SAFE was applied to 16 forest sites in Sweden, covering a sulfur deposition gradient of 1.2-11 kg S/ha/yr. Soil samples were collected at all sites and the pH and sulfate concentration dependent isotherm, used for modeling sulfate adsorption in SAFE, was parameterized for every site. A new way of implementing the nutrient uptake distribution in SAFE was developed, which allows the uptake distribution between layers in the rooting zone to vary with time, depending on the availability of base cations in the individual layers. Model output was compared to measurements of base cation concentration, total inorganic Al, pH and Bc/Al both site-by-site and cumulatively for all sites, and the usefulness of these comparisons is discussed from a policy viewpoint. Future projections of recovery show that the overall recovery, expressed as minimum Bc/Al ratio>1 in the rooting zone, is slow. Assuming full implementation of the UNECE LRTAP Gothenburg Protocol and no further emission reductions thereafter, 44% of the modeled sites still have a Bc/Al ratio below 1 in 2100 in some soil layer within the rooting zone. [ABSTRACT FROM AUTHOR]

Critical N loads for ombrotrophic bogs, which often contain rare and N-sensitive plants (especially those in lower plant groups: lichens, mosses and liverworts), are based on very few experimental data from measured, low background N deposition areas. Additionally the relative effects of reduced versus oxidised N are largely unknown. This paper describes an automated field exposure system (30 km S. of Edinburgh, Scotland) for treating ombrotrophic bog vegetation with fine droplets of oxidised N (NaNO3) and reduced N (NH4Cl). Whim Moss exists in an area of low ambient N deposition (ca.8 kg N ha-1 y-1), the sources and quantification of which are described. The wet N treatment system is run continuously, and is controlled/activated by wind speed and rainfall to provide a unique simulation of “real world” treatment patterns (no rain=no treatment). Simulated precipitation is supplied at ionic concentrations below4mMin rainwater collected on site. Treatments provide a replicated dose response to 16, 32 and 64 kg N ha-1 y-1 adjusted for ambient deposition (8 kg N ha-1 y-1). The 16 and 64 kg N ha-1 y-1 are duplicated with a P+K supplement. Baseline soil chemistry and foliar nutrient status was established for all 44 plots forCalluna vulgaris, Sphagnum capillifolium, Hypnum jutlandicumandCladonia portentosa. [ABSTRACT FROM AUTHOR]

Fifty samples of natural surface soils with high but variable organic matter content were analyzed for 13 elements (Na, Al, K, Sc, V, Cr, Mn, Fe, Co, Zn, Sr, Ba, La) by INAA. The same samples were analyzed for the “total-recoverable' fraction of these elements by ICP-OES after decomposition with 7M HNO3, and the results are compared. The data are discussed separately for two groups of samples with organic matter contents of respectively >80% and <70%. In the group with < 70 % organic matter the "total-recoverable" fractions show the following sequence (% of total): Co (83)>Mn (77)>La (60)>Fe=Zn (53)>V (33)>Cr (29)>Sc (25)>Al=Ba (17)>Sr (13)>K (5)>Na (2). The results are in good agreement with corresponding literature data for mineral soils in the case of Al, K, Sc, V, Cr, Fe, and La. In the case of Na, Mn, Co, Zn, Sr, and Ba the present surface soils showed significantly higher “total-recoverable' fractions than the previously studied subsoils. Possible reasons for these differences are discussed. INAA remains a convenient reference technique for determination of total concentrations with the rapidly increasing use of strong mineral acids in environmental studies of elements. [ABSTRACT FROM AUTHOR]

Harvesting stem biomass from the forest inevitably involves exporting nutrients from the ecosystem. The amount exported is increased when the logging residues are also removed for use as fuel. Recycling of the resulting wood ash has been advocated as a measure to compensate for the nutrient losses and to sustain future forest production. The physical formulation of the wood ash may have an important influence on its effects on soil properties. In this paper, we report effects of two different types of wood ash (one self-hardened and crushed, the other pelleted), with differences in solubility, on soil chemistry in the humus layer and upper 15 cm of the mineral soil, at two coniferous sites in south-central Sweden, 5 yr after their application. The crushed ash was applied at three doses (3, 6 and 9 ton ha-1), while the pelleted ash was applied at only one dose (3 ton ha-1). At both sites the soil was podzolized. The two sites differed with respect to soil conditions, despite being situated only a few kilometers apart. The application of wood ash increased both soil pH and base-cation content in the humus layer at both sites. In the mineral soil, the effects were less pronounced. Treatment effects on soil chemistry did not differ between the two ash formulations. The retention (i.e. the extractable amount of nutrients found in the soil that could be attributed to the ash application) of nutrients varied strongly between the two sites, and K retention (ca. 10%) was generally lower than that of Ca and Mg. [ABSTRACT FROM AUTHOR]