Manganese status op Rajasthan soils

Because of its significant role in the enzymatic and physiological activities of the plant body, manganese has received the attention of several workers. Though manganese may be present in appreciably large quantities, its availability to plants is controlled by various soil properties, the dominant ones among them being pH, calcium carbonate, clay and organic matter present in the soil (BISWAS, (1), (2), LEEPER, (6)).     

Forms of phosphorus in soils of Rajasthan

Phosphorus in soils is found to be present in organic combinations, inorganic form or in adsorted form on clay complex. Different forms of soil phosphorus have different solubilities and consequent availability in soils. A knowledge about the content and types of soil phosphorus enables one to understand the organic behaviour and predict the response of added phosphatic material to crops (Parker 1953). The form in which phosphorus is present in soil is directly related to pH and CaCO₃ in the soil as well as the intensity of the development of the soil. Williams (1950) has found that in calcareous soils of South Australja most of the phosphorus was in combination with calcium, whereas in acid soils it forms compounds with alumina and iron. Hibbard (1931) concluded that in alkaline and calcareous soils, phosphorus exists mostly in the form of hydroxyapatite, chloroapatite, and the like. Kanwar and Grewal (1959) studied fractionation of phosphorus in Punjab soils and reported that differences in the nature and amounts of the phosphorus present in acid and alkaline soils of the State explain the causes of different phosphatic fertilizer responses to the crops. A similar report has been given by Goel and Agarwal (1959) who studied the fractionation of phosphorus in Kanpur soils and concluded that the mature soils are rich in iron and aluminium bound phosphorus and respond better to phosphatic fertilizer than the immature soils rich in Ca²⁺ and Mg²⁺ bound phosphorus. Chai Moo Cnoo and Caldwell (1959) reported that Fe³⁺ and Al³⁺ bound phosphorus was abundant in acid soils while Ca²⁺ and Mg²⁺ bound phosphorus content in alkaline soils, and organic phosphorus agreed, in general, with the content of organic matter, with some deviations.     

Some relationships between quality of irrigation waters and chemical characteristics of irrigated soils of the Nagaur district,Rajasthan

Studies were conducted on the effects of waters of different quality on the chemical characteristics of 74 surface and subsurface soils of the Nagaur district, Rajasthan. The electrical conductivity (EC) of the saturation extract of these sandy and loamy sand soils were found to be less than that of the irrigation water. Correlations were observed between EC and the constituent ions (Na⁺, Ca²⁺ and Mg²⁺ of the irrigation water and of the saturation extract of the soil samples. The pH values of the irrigation water and soil suspensions also showed a positive correlation. The carbonate and bicarbonate ion concentrations in both the irrigation water and the saturation extract of the soils correlated with their respective pH values. EC of both the irrigation water and the saturation extract from surface and subsurface soil layers correlated with total cations. Correlations between the chemical characteristics of the irrigation water and the saturation extract of the soils are of limited value for prediction purposes, due to other factors operating under field conditions.     

Ecology,classification and soil pattern of colluvial soils of the bornhoeved lake district (North-Germany)

Water erosion causes the accumulation of soil material, especially at the bottom slope and in landscape depressions. According to FAO-UNESCO (1990) colluvial soils can be classified as Cumuli-Aric Anthrosols if the minimum thickness of the altered topsoil is 5 dm or more. These soils are characterized by addition of small amounts of soil material that has been incorporated into the underlying material by tillage and/or turbation. As a result of geological factors and land-use intensities, Cumuli-Aric Anthrosols differ markedly in their ecological properties. In the study area ‘Bornhoeved Lake District (Schleswig-Holstein, North-Germany)’ soil patterns have been investigated showing the interdependence of soil landscapes and their soil units by water erosion and accumulation. Examples of various colluvial soils in catenary sequences in the study area are presented. Colluvial soils in the study area are characterized by a layer thickness between 5 and 14 dm and show significantly higher quantities of organic matter, nitrogen and plant-available water in comparison with eroded soils.     

Genesis and micromorphology of loess-derived soils from central Kansas

The genesis and micromorphology of three Harney soils from different precipitation regions (from 540 mm to 715 mm) (fine, smectitic, mesic Typic Argiustolls) in the Smoky Hills of central Kansas were investigated. The objectives were to (1) examine the morphological, chemical, physical and mineralogical characteristics of Harney soils formed in loess; (2) determine the clay mineral distribution with depth and the origin of the clay minerals present; and (3) investigate the relationship between the clay mineralogy and other soil properties such as soil plasmic fabric, COLE values and fine clay/total clay ratios. Mineralogical and micromorphological techniques were used to evaluate the characteristics of the loess-derived soils. The first pedon was formed in 88 cm of Bignell loess over Peoria loess and the other two pedons were formed from Peoria loess. The chemical properties were similar for the pedons studied. Differences were observed in physical properties, especially in particle size distribution, oven-dry bulk density and coefficient of linear extensibility values. Although the soils were mapped in the same soil series, the geomorphic positions of the pedons and the nature of the parent material affected the characteristics of the soils. Smectite was the predominant clay mineral, especially in the fine clay fraction, regardless of the location in the precipitation gradient. The dominance of smectite increased in the C-horizons. This implies a detrital source of smectite in the B-horizons formed in both Bignell and Peoria loess units. The presence of randomly interstratified mica-smectite and the micromorphological observations of weathering biotite indicate that weathering also plays an important role in the mineralogy of Harney soils. The high content of clay mica in the surface horizons was caused by dust fall in the study area. Thick and continuous argillans were observed when FC/TC and COLE values were low and crystalline smectite was present. In the lower part of the soil profiles, the plasmic fabric was mostly ma-skelsepic (granostriated b-fabric) and smectite was more crystalline as indicated by sharper X-ray diffraction peaks.     

Long-term dynamics of the anthropogenic salinization of soils in Moscow (by the example of the Eastern district)

The long-term (1989–2010) and seasonal dynamics of the anthropogenic salinization of soils related to the use of deicing mixtures in the Eastern Administrative District of Moscow were examined. Data on the chemical composition of deicing mixtures and on the contents of soluble salts in the snowmelt and in the soil profiles of different functional zones were analyzed. The maps of soil salinization were compiled for 1989, 2005, and 2010; on their basis, the resulting map of the degree of soil degradation was developed. The areas with abnormal concentration of salts in the soils expanded during the study period (21 yrs), and the average content of salts in such areas increased by 3.2 times. The maximum total content of salts was found in the spring season in the soils along major highways.     

Genesis of gypsum enriched soils in north-west Isfahan,Iran

Most of gypsum-enriched soils in Isfahan and neighboring provinces occur on alluvial fans, dissected flood plains (old dissected alluvium)and piedmont plains. Herein we investigate the processes of formation and alteration of gypsic horizons and their pedofeatures. We described and sampled representative pedons on a transect from the mountain to the piedmont plain. In the study area, different gypsic pedofeatures have various kinds of internal lenticular cryslalitic fabrics. Micromorphologic observations confirmed that gypsic horizons have an evolutionary sequence across the different geomorphic surfaces from the upper fan to the piedmont plain. In primary stages (upper fan), gypsum crystals occur individually in the soil groundmass or as clusters in voids with idiotopic or xenotopic fabrics. Eventually, they form internal coatings or infillings and pendants (in middle and lower fans). In the more developed horizons (dissected flood plains or plateaus), the fibrous gypsum crystals are banded and perpendicularly distributed with reference to the gravels and soil surface. These loosely compacted fibers constitute the bulk of the soil materials, leaving non-gypsic particles as islands between crystals. In these pedofeatures, perpendicularly oriented fibrous crystals, with their lateral inter-connections give rise to a continuous three-dimensional firm structure.The fabric of these lenticular gypsum crystals is xenotopic or hyp-idiotopic. In the piedmont plain, the idiotopic crystals have no preferred orientation and have random distribution. Internal fabric of these pedofeatures is porphyrotopic. This study indicates that, physical environment plays a great role in formation of different gypsic pedofeatures.     

Genesis and evolution of soils in the Selenga River delta

Five types of soils representing an evolutionary sequence have been distinguished within the Selenga River delta. At the first stage. alluvial meadow-swampy, swampy, and stratified soddy alluvial soils are formed. At the second stage, meadow calcareous alluvial soils are developed. At the third stage of evolution, leached meadow soils are widespread. This soil sequence is related to changes in the hydrological regime of delta areas upon gradual aggradation of the surface with corresponding changes in the character of vegetation.     

Genesis and characterization of manganiferous soils in the Eastern Piedmont, USA

Manganese is normally a trace element in soils, but it is important due to its effects on soil chemistry and morphology. There are rare, Mn-rich soils in the Eastern Piedmont of the USA that have not been previously studied. The morphology, mineralogy, and chemical and physical properties of these manganiferous soils were documented in order to better understand their pedogenesis. The soils were found to contain as much as 169 g kg⁻¹ Fe and 140 g kg⁻¹ Mn as oxides (dithionite-citrate-bicarbonate extractable). These high levels of Mn oxides impart an extremely dark color to the soil material (moist Munsell value and chroma commonly < 2/1). Manganiferous soil materials have unusual physical properties such as high particle density (up to 3.25 × 10⁻⁶ Mg m⁻³ on bulk soil), low bulk density (as low as 0.39 × 10⁻⁶ Mg m⁻³), and extremely high porosity (maximum calculated 88%). X-Ray Diffraction and Fourier Transform Infrared spectra show that the dominant Fe oxide and Mn oxide minerals in the soils are hematite and lithiophorite, respectively. Samples of the parent marble were dissolved in acid for Fe and Mn analysis and collection of non-carbonate residues (NCR). Based on the quantities of Fe and Mn in the bedrock, the mineralogy of the NCR, and micromorphological observations, it appears that the black, porous, Mn-rich material is derived directly from the dissolution of marble bedrock and accumulation of silicate residues plus Mn and Fe from within the rock. These soils, which appear to have a similar origin to Mn wad deposits, offer a unique opportunity for future studies of soil Mn due to the naturally high concentration of this metal.     

Genesis and transformation of minerals in the formation of red (Alfisols) and black (Inceptisols and Vertisols) soils on Deccan basalt in the Western Ghats, India

Six noncalcareous pedons from the basaltic terrain of the Western Ghats in Maharashtra, India, were identified for the present study. Of these, two red-soil pedons (Typic Haplustalfs) and one black-soil pedon (Vertic Ustropept) are from the Bhimashankar plateau at an elevation of 1000 m above mean sea level, experiencing a humid (>5000 mm rainfall) tropical climate. The other three pedons of black soils (Typic Chromusterts and Typic Ustropept) are from the semi-arid zone (500–1000 mm rainfall), at an elevation of 825–893 m. Clay mineralogical investigation indicated that interstratified smectite-kaolin (Sm/K) is dominant in red soils whereas smectite is dominant in black soils. The Sm/K is formed by the transformation of montmorillonite, the first weathering product of Deccan basalts in a humid tropical climate. We suggest that the interstratification of kaolin with chloritized smectite may also be an important ephemeral stage during the transformation of smectite to kaolinite. The presence of zeolites provided sufficient bases to prevent the complete transformation of Sm/K to kaolinite. The presence of smectites and zeolites made the formation of black soils possible in microdepressions even in a tropical humid climate. The genesis of Sm/K and smectite in red and black soils, respectively, suggests that these soils formed through a progressive landscape reduction process. The presence of both Sm/K and smectite in black soil clays of semi-arid climate suggests that the smectite of these soils was formed in an earlier humid climate.     

Study of ultramicrobacteria (Nanoforms) in soils and subsoil deposits by electron microscopy

The use of multiple centrifuging and filtration of water suspensions from different soils and subsoil deposits allowed revealing the ultrafine forms (nanosized, nanoforms) of bacteria. In the soils studied, the number of bacteria obtained by filtration using 0.2-??m filters was 20?C300 mln cells in 1 g soil; the share of these bacteria of their total population in the natural soils reached 5% and was higher (up to 15%) in the polluted urban soils. The study of bacterial nanoforms in situ by the methods of scanning and transmission microscopy has shown the presence of dividing cells, which testifies to their viability. The cells without signs of division were similar in their ultrastructural characteristics to dormant forms of nonspore-forming bacteria. They were observed in permafrost deposits. The data obtained attest that the bacterial nanoforms are widespread in soils and subsoil deposits. According to their morphological and cytological characteristics, they are represented by both active and dormant forms to survive unfavorable conditions.     

Decomposition of nitrilotriacetate (NTA) in soils

The trisodium salt of nitrilotriacetic acid (NTA) has been proposed as a substitute for phosphate in detergents. The decomposition of this chelating agent in soils was studied by performing analyses for NTA and inorganic nitrogen after incubation of NTA-treated soils for various times. The results showed that NTA is readily decomposed by soil micro-organisms under aerobic or anaerobic conditions and that NTA-nitrogen is converted to nitrate under aerobic conditions. The latter finding indicates that use of detergents containing NTA may lead to nitrate enrichment of water resources.     

Estimation of charcoal (char) in soils

Abstract

A method for the semiquantitative estimation of charcoal (char) in soils is reported. The technique, performed on the <53 μm fraction of soils, utilizes the highly aromatic nature of char and its relative stability to two hours of high energy ultraviolet photo‐oxidation compared to other soil carbon fractions. The proportion of char in the <53 μm fraction is estimated as the aromatic carbon (C) content measured by solid‐state nuclear magnetic resonance spectroscopy using cross polarization and magic angle spinning. Corrections are made for the underestimate of aryl C by the cross polarization method in highly condensed aromatic char structures and for the small lignin content that occurs in some samples. Evidence is also provided for the occurrence of >90% of soil char in the <53 μm fraction. Because of the assumptions used, estimates of char by this approach must be considered to be semiquantitative, but are conservative and provide estimates of the minimum char content of a soil.     

Radioactivity of the granitic soils in the middle district of tottori prefecture

The greater part of the middle district of Tottori Prefecture is formed of biotite granite, hornblende andesite, augite andesite and hornblende andesitic volcanic detritus. The granite occurs in the region streching to the north-east from the border between both Tottori and Okayama Prefecture. In this granite area, there can be seen many dikes of aplite and micropegmatite. These granitic rocks, and the soils derived from them have higher radioactivity than other rocks and soils. In this district, there are radioactive hot springs-Sekigane, Misasa, Shikano and Hamamura, and, recently uranium ore was found at Ogamo and Ningyotoge. A study was made on the radioactivity of the soils derived from the granitic rocks, andesite and tertiary shale, of the ashes from plants grown on these soils, and on the extraction of thorium X in the soils.     

Genesis and characteristics of brown forest soils derived from Serpentine in Kyushu,Japan

One of the main objects of the present study is to determine what genetic soil types have been formed from ultra-basic rocks such as serpentine under humid, subtropical conditions. Red-Yellow soils, which are important zonal soils in Kyushu, have not been formed from serpentine, but Brown Forest soils have been formed, as will be described in the part 2 of this paper. This fact for the most part has been governed by the mineralogical and chemical peculiarities of serpentine. Therefore the part 1 of this paper deals with the mineralogical and chemical characteristics of serpentine as a parent rock from which Brown Forest soils have developed.     

Volatile organic compounds (VOCs) in soils

Soils may act as sources or sinks of volatile organic compounds (VOCs). Many of the formed VOCs are produced by microorganisms, and it would be a challenge to investigate soil microbial communities by studying their VOC profile. Such “volatilomics” would have the advantage of avoiding extraction steps that are often a limit in genomic or proteomic approaches. Abundant literature on microbially produced VOCs is available, and in particular novel detection methods allow additional insight. The aim of this paper was to give an overview on the current knowledge of microbial VOC emissions from soils.     

Genesis and characteristics of brown forest soils derived from serpentine in Kyushu,Japan

Recently, micropedological investigations have become an important means to explain some pedogenetical processes. The micromorphological features of Brown Forest soils and Mountain Brown Forest soils have been reported by several investigators(12, 14–15), Braunerde can be distinguished from Braunlehm by the presence of a spongy structure, immobility of peptizable iron hydroxides, or by the absence of any fluidal structure in its (B) horizon. In his review on micropedology, osmond(16) has stated that Brown Earths do not show any evidence of illuviation of ferruginous compounds or clay formed by oxidative weathering. As a result of micromorphological investigations on soils derived from serpentine in Greece, Krause(12) has described that the dominant soil of the hillsides is rubefied Braunlehm (Rotlehm), whereas the soil developed on valley terraces is Braunerde which appears as a transformation product of Rotlehm and has a spongy fabric in the A horizon.     

Nitrogen-fixing microorganisms in paddy soils (XVIII)

In previous papers (1–5), it was concluded that among the many organic acids produced in the mixed culture of R. capsulatus with ether heterotrophic bacteria, especially pyruvic acid is a hydrogen donor for the nitrogen fixation by R. capsulatus. All previous experiments were dove under a light condition. In this paper, the nitrogen fixation under a dank conditien is presented, and the difference between light and dark condition is discussed.     

Zinc forms in soils (Review of publications)

Zinc has no particular bearing phases in soils, and it forms very diverse compounds; this complicates zinc’s identification by chemical fractionation. However, Zn-containing particles may be identified using synchrotron X-ray analysis. Franklinite, willemite, hemimorphite, and Zn-containing magnetite are found to be the main technogenic Zn-containing pollutants in the heavy fraction of the contaminated surface soil horizon. Among the secondary zinc compounds, Zn-containing trioctahedral structures and clay minerals (unidentifiable by chemical extraction), as well as zinc fixed by manganese oxides and iron hydroxides, predominate in the soil clay fraction. Being a chalcophile element, zinc precipitates in the form of sulfides and forms complexes with organic substances in organic soils and peats. The degree of affinity to chalcophile metals increases in the following sequence: O-, P-, N-, and S-containing functional groups of organic substances.     

Ecological-geochemical state of soils in Ulaanbaatar (Mongolia)

Based on the results of the soil-geochemical survey, the assessment of the soil cover pollution in different Ulaanbaatar functional zones is given. The soils of the industrial and traffic zones concentrating a wide spectrum of pollutants (Zn, Mo, Cr, Cr, Cd, Pb, and Cu) are characterized by the strongest technogenic transformation. The soils of the residential areas accumulate Pb and Zn, while those of the recreation zone, Mo, Ni, and Cr. The geochemical mapping allowed distinguishing four groups of elements with similar distribution patterns determined by the common pollution sources, the specific features of the parent rocks, and the intensity of the migration. Among the natural and technogenic factors responsible for the accumulation of microelements in soils, the basic ones are the soil physical and chemical properties: the contents of organic matter (for As, Cd, Cu, Mo, Zn), physical clay (Ni, Co), sulfates (Pb, Sr), and the pH (Cr). The character of the land use noticeably affects the concentration of many elements. The soils of the city are assessed as weakly polluted (Zc = 11). The contents of As, Zn, Mo, and Pb exceeded their MPC in 100, 34, 20, and 16% of the city’s territory, respectively. As compared to the state of the soil cover in 1990, no significant changes were revealed.