E. A. Fitzpatrick

Some population sizes and effects of the Enchytraeidae (Oligochaeta) on soil structure in a selection of Scottish soils

Abstract This paper is a summary of the results obtained from an investigation of the occurrence of Enchytraeidae in several Scottish soils. Population counts from two sites, one consisting of a rotation of eight crops each grown on plots at four different pH levels and the other consisting of a mixed pine and larch forest, show the highest numbers of enchytraeids at low soil pH levels. Soil thin sections from five sites show that at low pH the main effects of enchytraeids on soil structure are (1) the production of a large number of small granules (faecal pellets) which later fuse to form a soil matrix, and (2) their deposition in channels, other pores and old roots. At higher pH levels enchytraeids consume earthworm aggregates and replace them with their small faecal pellets and they form new pores due to their burrowing activities.

Biological influences on the morphology and micromorphology of selected Podzols (Spodosols) and Cambisols (Inceptisols) from the eastern United States and north-east Scotland

Abstract Biological activities greatly influence the formation of many soils, especially forest soils under cool humid climates. The objective of this study was to investigate the effects of vegetation and soil biota on the formation of selected soils. Field morphology, micromorphology, and carbon and organic matter analysis were determined on six Podzols (Spodosols) and two Cambisols (Inceptisols) from the eastern United States and north-east Scotland. Humification of plant material by soil fauna and fungi occurs in all organic horizons. Thick organic coatings are observed on soil peds and rock fragments from the E1 to the Bs horizon in a Haplic Podzol from Clingmans Dome Mt., TN. Thin sections reveal large accumulations of root material in different stages of decomposition in the spodic horizons of a Haplic Podzol from Whiteface Mt., NY. Organic carbon ranges from 5.4 to 8.5% in the spodic B horizons of the Whiteface Mt. Podzol. Earthworms and enchytraeids have a great effect on the structure of the surface and subsurface horizons in the Dystric Cambisols from Huntly and Clashindarroch Forests, Scotland and a Cambic Podzol from the Corrie Burn Basin, Scotland. Podzols from Speymouth Forest, Scotland (Gleyic Podzol), Clingmans Dome Mt., and Whiteface Mt. have thick organic horizons. The Podzols from the Flatwoods in Georgia, the Pine Barrens in New Jersey, the Corrie Burn Basin, and the Cambisol from Huntly Forest have only A horizons at the surface. The Clashindarroch Forest soil has a very thin organic horizon. Warm and humid climates and sandy parent material are responsible for thick E horizons and lack of thick organic horizons in the Flatwoods (Carbic Podzol) and Pine Barrens (Ferric Podzol) soils. Earthworms and enchytraeids thrive in the Corrie Burn Basin and Huntly Forest soils due to the vegetation and the highly weathered basic parent material. The site at Clashindarroch once carried oak, and then birch forest, both of which produce a mild litter and also encourage earthworm and enchytraeids. This fauna is responsible for much mixing of the topsoil. The present conifer vegetation will eventually produce a deep litter and cause podzolization.

Micromorphology of the Beiyuan loess-paleosol sequence in Gansu Province, China: geomorphological and paleoenvironmental significance

Abstract The 35.5 m thick loess section at Beiyuan in Gansu Province, China provides the most detailed record on the Loess Plateau of the periodicities in earth orbital changes during and since the last interglacial. It contains ten paleosols, one of which is in the Holocene loess, four in the Malan loess and five in the upper Lishi loess and associated alluvium. Micromorphological study of the S1 paleosol series indicates that all of the component soils were subjected to moderate carbonate leaching and biological activity. Paleosols S1-c, S1-d and S1-e developed in alluvium over a time interval equivalent to stage 5e of the deep-sea core V28–238. Alluvial deposition was episodic as evidenced by the separation of the paleosols. Since the development of S1-c, the terrace has not been affected by floods and has received only wind-blow dust additions. The SBC index, a ratio of the content of channels and excrements to the content of primary calcite grains, appears to be a sensitive indicator of environmental change between the arid and sub-humid environments represented by the loess and paleosols, respectively. The trends, periodicities and amplitudes of environmental change revealed by the SBC ratio are in good agreement with those derived from other indices through the Beiyuan section and with records from other parts of the world.

The application of multilayer digital image processing techniques to the description of soil thin sections

Abstract A multilayer approach to the image analysis of soil thin sections is presented. Sixteen images from the same microscope field were digitized from photomicrographs obtained with different light polarizations combined with different colour filters. The light sources were plain transmitted light (PTL), between crossed polars(BXP), circularly polarized light (CPL) and CPL with gypsum plate. ERDAS : a digital imaging processing (DIP) system normally applied to remote sensing was used. This, together with the hardware, allowed the creation of multilayer images on which supervised and unsupervised classification procedures were applied to distinguish and quantify features such as quartz, clay coatings, matrix and pores. A combination of PTL and CPL images gave the best multilayer image. Inaccuracies in the classification procedures were corrected manually to produce a reference image which was compared with the images created by the classifications. The unsupervised classification had many limitations, however the supervised classification was very successful in differentiating the features.

The micromorphology of soils

In this chapter emphasis is given to the micromorphological description of diagnostic horizons as defined by the USDA (1975). The description of each horizon commences with a brief general definition merely to act as a reminder of the most distinctive features. In addition other types of soil horizon and soil material are given. Some of the diagnostic horizons have such a wide range of properties both morphological and otherwise that it is difficult to describe them accurately micromorphologically. It was decided therefore to run in parallel the diagnostic horizons of the USDA (1975) and the horizons defined by FitzPatrick (1980). This allows a more complete cover of the various soil horizons and soil materials and in a number of cases allows for more precise definitions and descriptions to be given. In a number of cases the horizons of FitzPatrick (1980) are synonymous with those of the USDA, therefore the definition is given under the USDA term. On the other hand certain horizons such as the cambic horizon have a wide range of variability and include no less than about twelve different horizons as described by FitzPatrick (1980). In such cases it seems more appropriate to define these horizons using FitzPatrick’s terms under the general heading of cambic horizons. Differentiating between the terms of US taxonomy and FitzPatrick should be very simple since all the terms of the latter have an -on ending whereas most of the terms of the former have an -ic ending. Because micromorphology is in its infancy most of the definitions should be regarded as tentative. In addition there are numerous intergrades and compound horizons that are not defined below.

Soil nomenclature and classification

It appears that nearly all the discussions in pedology that seem to be about classification are really about nomenclature. A new system of soil classification and soil nomenclature is proposed in which it is suggested that all soil horizons be recognised, defined, named and be given symbols which are made up of the first letter of the name plus one other. Each soil is given a formula compiled by placing in order the symbol for each horizon, followed by a subscript number which indicates the depth of each horizon and so the depth of the whole soil. Each set of symbols represents a different soil group. A synaptic classification, which would have classes and subclasses, is produced by ad hoc methods. These classes would have names such as podzol and chernozem, but would have somewhat diffuse definitions. The subclasses are established on the basis of two or three prominent horizons in the same soil and are designated by placing the symbols for the horizons in square brackets.

Use of stained bacterial inocula to assess spatial distribution after introduction into soil

Abstract Cells of Pseudomonas fluorescens, stained with a fluorescent brightner, calcofluor white M2R, were introduced into soil aggregates at specific matric potentials. The soil was impregnated with resin and the hardened blocks cut and polished. The inocula, dispersed through the pore network as single cells, were observed to be located in soil pores of a particular size class, determined by the antecedent matric potential and the inoculum volume in relation to the moisture release characteristic. It is proposed that the methodology developed will enable the importance of location to be assessed in terms of both the fate of inocula and many other spatial considerations of the soil ecology of introduced organisms.

Heavy Metal Pollution in Some Soil and Water Resources of Bursa Province, Turkey

Abstract Bursa, the fourth most densely populated province in Turkey, is important to the national economy for agricultural and industrial production. During the past two decades, substantial migration into the region has increased drastically the risk of soil degradation. Urbanization and industrial development in the province have mainly occurred on soil types with land capability Class 1 and 2 and produce large amounts of nonbiodegradable urban and industrial waste, much of which is disposed of in the Nilufer River, the Ayvali Canal, and on agricultural land. Regulation of effluent quality disposed of to surface waters has been limited, so it was decided to conduct a preliminary survey of selected potentially toxic element (PTE) concentrations in agricultural soils and the PTEs in irrigation waters in the area to determine what potential pollution and health risk may exist. The pH and concentrations of calcium (Ca), magnesium (Mg), and heavy metals were determined in water samples from along the Nilufer River, above and below the industrialized area, and one of its tributaries, the Ayvali Canal. The results indicated considerable pollution from industry and city sewage in the surface waters, which are used directly by local farmers for irrigation of adjacent fields. Total heavy metal contents of the Fluvisols and Vertisols showed that these agricultural soils were polluted with iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni), and lead (Pb). The DTPA‐extractable Cd, Cu, Fe, Mn, and Zn concentrations in irrigated Fluvisols and Vertisols indicated that the practice caused the accumulation of the Cd and Cu in the upper parts of the soil profiles. In the longer term, irrigation of the soils with the polluted waters may damage soil, crop, and human health.

Long-term changes in the Cu, Pb, and Zn content of forest soil organic horizons from north-east Scotland

Forest soil organic horizons from old and young plantations in the Alltcailleach Forest, N.E. Scotland were first sampled in 1949/50 and resampled in 1987. Copper, Pb and Zn in the soils were determined simultaneously on the original (stored) and the resampled soils. Overall mean Cu and Pb concentrations increased from 12.7 to 15.3 and 49.5 to 60.8 mg kg−1 between 1949/50 and 1987. Zinc concentrations decreased from 76.4 to 60.7 mg kg−1. Amounts of all 3 heavy metals increased because of increases in the thickness of organic horizons. Mean accumulation rates for Cu, Pb and Zn were 39.1, 186 and 114 g ha−1 yr−1, respectively. The rate of accumulation of Pb was significantly related to the rate of accumulation of organic matter. Copper and Zn concentrations were directly correlated with pH and inversely correlated with C/N ratio, whereas Pb was inversely correlated with pH and directly correlated with % C and C/N ratio. The more acidic soil organic horizons therefore contained higher concentrations of Pb and lower concentrations of Cu and Zn.

Three-dimensional representation of tubular horizons in sandy soils

Soil horizons are three-dimensional bodies and this is widely recognised. However, many soil descriptions are still based on the soil profile and the move to three-dimensional diagrams to represent horizons or other soil phenomena is just starting. In the present study computer reconstruction and visualization techniques were used to illustrate the geometry of the illuvial Bh horizon in a buried podzol. The 3D computer representation revealed a complex of tubular forms with diameters varying from 10 to 25 cm and length around 100 cm. Similar tubular shapes are found in Australian podzols.