Soil Type Research Papers - Academia.edu (original) (raw)

Pest control technology, developed for temperate countries was introduced into the Caribbean without any consideration for the fragility of the islands ecosystem. A signi®cant increase in the utilization of pesticides by banana farmers in St. Lucia occurred during recent years. The mobility of two commonly used pesticides,`ametryn' [N 2-ethyl-N 4-isopropyl-6-methylthio-1,3,5-triazine-2,4-diamine] and`pirimiphos-ethyl' [O-2-diethylamino-6-methylpyrimidin-4-yl O,O-diethyl phosphothiorate] on two different soils on banana cultivated hillsides in St. Lucia was studied. Ametryn and pirimiphos-ethyl were applied to both sites, and soil samples were collected at different time intervals and were analyzed using gas chromatography. At both sites and on both soil types, quite early in the season, both pesticides leached down to 0.4 m depth. However, there appeared to be equal or greater leaching and downslope transport of pesticides on hillside 2. Pesticide concentration showed a reducing trend with respect to time and depth in both soil types at both sites. However, because of runoff interference, the half-life of pirimiphos-ethyl could not be properly de®ned, but half-life for ametryn was estimated to be 3 to 8 days. The short half-life for ametryn indicates the fast degradation of this pesticide under tropical conditions which could reduce the risk of environmental pollution. The environmental mobility of both pesticides suggests that leaching of ametryn and pirimiphos-ethyl may, in some circumstances create surface and groundwater pollution problems.

- by
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- Groundwater Pollution, Environmental Pollution, Technology development, Seasonality

The threshold between geochemical background and anomalies can be influenced by the methodology selected for its estimation. Environmental evaluations, particularly those conducted in mineralized areas, must consider this when trying to determinate the natural geochemical status of a study area, quantifying human impacts, or establishing soil restoration values for contaminated sites. Some methods in environmental geochemistry incorporate the premise that anomalies (natural or anthropogenic) and background data are characterized by their own probabilistic distributions. One of these methods uses exploratory data analysis (EDA) on regional geochemical data sets coupled with a geographic information system (GIS) to spatially understand the processes that influence the geochemical landscape in a technique that can be called a spatial data analysis (SDA). This EDA-SDA methodology was used to establish the regional background range from the area of Catorce-Matehuala in north-central Mexico. Probability plots of the data, particularly for those areas affected by human activities, show that the regional geochemical background population is composed of smaller subpopulations associated with factors such as soil type and parent material. This paper demonstrates that the EDA-SDA method offers more certainty in defining thresholds between geochemical background and anomaly than a numeric technique, making it a useful tool for regional geochemical landscape analysis and environmental geochemistry studies.

- by Marcos Monroy and +1
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- Geochemistry, Spatial Data Analysis, Applied Geochemistry, Human impact

Structural information on soil organic matter (SOM) at the molecular level can be obtained on diverse structural units that are amenable to degradation techniques. Chemolytic techniques in combination with colorimetric analyses or GC MS are used to determine amino acids (proteins), sugars (polysaccharides), lipids, or aromatic oxidation products from lignin or charred organic matter. Microbial markers (amino sugars, muramic acid) are analyzed after hydrolysis and gas chromatographic separation. Macromolecular structures can also be subjected to thermochemolytic degradation or pyrolysis and subsequent analysis of the fragments by GC MS. Alternative techniques for the examination of organic matter in heterogeneous macromolecular mixtures are non-destructive spectroscopic methods, such as nuclear magnetic resonance (NMR) spectroscopy. Although this technique can give good results concerning the gross chemical composition, speci®c compounds are hardly identi®ed. The combination of spectroscopic techniques with thermolytic and chemolytic methods will add substantially to the understanding of the nature of refractory soil organic matter. Physical fractionation prior to analysis provides a means to dierentiate between distinct SOM pools that can be further characterized by the methods described above. Studies on SOM structural characteristics have focused mainly on the A horizons of soils under agriculture and litter biodegradation in forest soils and need to be extended to a wider variety of soil types and the subsoil. #

Laboratory batch experiments were carried out to study the competitive sorption behavior of metals in three types of Indian soils, differing in their physicochemical properties: acid laterite (SL1), red alfisol (SL2) and black vertisol... more

- by Michael Powell and +2
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- Civil Engineering, Chemistry, Environmental Geology, Earth and Environmental Sciences

This paper describes an attempt to model soil moisture over the Australian continent with an integrated system of dynamic models and a Geographic Information System (GIS) data base. A land surface scheme with improved treatment of soil hydrological processes is described. The non-linear relationships between soil hydraulic conductivity, matric potential and soil moisture are derived from the Broadbridge and White soil model. For a single location, the prediction of the scheme is in good agreement with the measurements of the Hydrological and Atmospheric Pilot Experiment (HAPEX). High resolution atmospheric and geographic data are used in soil moisture prediction over the Australian continent. The importance of reliable land surface parameters is emphasized and details are given for deriving the parameters from a GIS. Predicted soil moisture patterns over the Australian continent in summer, with a 50 km spatial resolution, are found to be closely related to the distribution of soil types, apart from isolated areas and times under the influence of precipitation. This is consistent with the notion that the Australian continent in summer is generally under water stress. In contrast, predicted soil temperatures are more closely related to radiation patterns and changes in atmospheric circulation. The simulation can provide details of soil moisture evolution both in space and time, that are very useful for studies of land use sustainability, such as plant growth modelling and soil erosion prediction.

- by Lance M Leslie
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- Atmospheric sciences, Soil Erosion, Soil moisture, Land Use

The spectacular performance of Indian agriculture witnessed during the second half of the 20th century against the onslaught of rising demographic pressure is a vivid demonstration of the growing effectiveness of our agricultural research and development system. However, the issue of sustainability in agriculture still remains a question. Management of natural resources, especially soil and its fertility status and vegetation following suitable agronomic management practices for sustainable agricultural production, represents a most daunting task and is certainly going to receive much attention in the years to come. Many workers established functional relationships between nutrients and other agronomic factors at different locations in India but systematic compilation of those relationships is a rare effort. The present paper reviews the latest information on inter-relationships between nutrients and other agronomic factors (seed rate, planting density, age of the seedling, planting method, irrigation, weed control, tillage, bacterial inoculation and cultivar etc.) on field crops. Major findings of first and second order interactions are highlighted. None of the second order interaction was found signifi-P. K. Ghosh is Senior Scientist

- by jagroop liddar
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- Sustainable agriculture, Phosphorus, Soil moisture, Nitrogen

The primary objective of this study was to develop a simple method that can be used to extract the more readily mobilizable and bioavailable arsenic species from soil and sediment while at the same time minimizing the transformation between (As III) and (As V), the two most commonly found arsenic species in the environment. Several extraction strategies were evaluated using phosphate as extractant in combination with either ethylenediaminetetraacetic acid (EDTA), hydroxylamine hydrochloride (NH 2 OH•HCl), or sodium diethyldithiocarbamate trihydrate (NaDDC).The addition of EDTA in the phosphate solution did not prevent As III from oxidation. While promising results were shown when 1% NH 2 OH•HCl was added, conversion of As III began to occur with extended extraction time (>12 h). Good results were achieved using 10 mM phosphate and 0.5% NaDDC where As III oxidation was clearly minimized. The combined phosphate and NaDDC solution was applied to several soil and sediment samples. As III spiked was quantitatively recovered in all soil types tested.

- by Helena Solo-gabriele
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- Soil, Arsenic, Environmental Pollution, Multidisciplinary

Recent developments in hydrological modelling of river basins are focused on prediction in ungauged basins, which implies the need to improve relationships between model parameters and easilyobtainable information, such as satellite images, and to test the transferability of model parameters. A large-scale distributed hydrological model is described, which has been used in several large river basins in Brazil. The model parameters are related to classes of physical characteristics, such as soil type, land use, geology and vegetation. The model uses two basin space units: square grids for flow direction along the basin and GRU-group response units-which are hydrological classes of the basin physical characteristics for water balance. Expected ranges of parameter values are associated with each of these classes during the model calibration. Results are presented of the model fitting in the Taquari-Antas River basin in Brazil (26 000 km 2 and 11 flow gauges). Based on this fitting, the model was then applied to the Upper Uruguay River basin (52 000 km 2 ), having similar physical conditions, without any further calibration, in order to test the transferability of the model. The results in the Uruguay basin were compared with recorded flow data and showed relatively small errors, although a tendency to underestimate mean flows was found.

- by Daniel Allasia
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- Environmental Engineering, Civil Engineering, Prediction, Discharge

This paper investigates the productivity and optimal rotation for economic timber management of Eucalyptus urophylla S.T Blake clones being planted in Northeast Vietnam in Fluvic Gleysol and Ferric Acrisol soils. In the first section of the paper, timber yield functions for all eucalyptus monoculture clones and seedlings are identified. Next, the biological optimum rotation period for maximizing sustained yield is calculated based on the yield functions for each soil type. In the last section, the economically optimal rotation (EOR) lengths for all clones and seedlings planted in the two types of soil are calculated using a modified Faustmann model. The results indicate that eucalypts in Fluvic Gleysol will produce larger timber yields than in Ferric Acrisol. Among the clones commonly planted in Northeast Vietnam, eucalyptus clones U16 and PN14 can yield the largest timber volumes in Fluvic Gleysol and Ferric Acrisol, respectively. Our EOR model reveals that EOR lengths of eucalyptus plantations in Northeast Vietnam are longer than the biological rotation time by 1-3 years under the governmentally subsidized credit scheme for rural households. If growers borrow from commercial and private entities, such rotation period will be substantially shortened and negative site values will appear in a number of cases. Nevertheless, wherever eucalyptus clones are economically qualified, their EOR length is longer than what is currently practiced. To capture the highest profits from eucalypt plantations, growers should extend their current farming business cycle of 7 years to 14-18 years under the subsidized credit scheme and to 10-12 years under the commercial borrowing interest rate. As increasing land use profitability is of great concern across the region, these findings are of practical importance for Vietnamese farmers in choosing clones, land lots, and economic optimal rotation for their farming businesses.

- by Huu Dung Nguyen
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- Vietnam, Applied Economics, Land Use, Profitability

The application of soil solarization (SS), one of the most promising techniques for the control of soilborne pathogens, is seriously limited by the drawback regarding the disposal of the used plastic materials. A possible solution to this problem is the use of biodegradable plastics. The aim of this study was to make comparisons between the impact of SS performed with biodegradable materials and that of SS with plastic films and other pest management techniques (i.e. organic matter amendment, calcium cyanamide and Dazomet fungicide application) on crop productivity, soilborne disease incidence, weed suppression, and soil chemical (total N, NH 4 -N, nitrate, available phosphorus, organic matter, hydrolysis of fluorescein diacetate) and microbial (cultivable Pseudomonas, DGGE fingerprinting of bacterial 16S-and fungal 28S rRNA gene fragments from total soil community DNA) parameters. We carried out field experiments in two types of soil with different textures (clay and sand) artificially inoculated with Fusarium oxysporum f.sp. lycopersici (vs. tomato) and Sclerotinia minor (vs. lettuce). The temperature of soils covered with solarizing materials was always higher than that of bare soils, but plastic cover was more effective and consistent in rising soil temperature compared to biodegradable materials. Plant growth promotion by SS was limited, especially compared to Dazomet and organic matter applications, and a positive effect was observed only for lettuce in the clay soil. Differently, both plastic and biodegradable solarizing materials were effective in reducing lettuce drop caused by S. minor. Weed development was significantly suppressed by Dazomet application and SS with plastic film, while control with biodegradable materials was limited. SS had a variable and limited effect on chemical and microbial parameters, with a general tendency to reduce richness of bacteria and fungi. Dazomet caused the most pronounced reduction of the microbial community diversity in both soil types and a significant stimulation of the fluorescent Pseudomonas group. Organic amendment significantly enhanced the organic matter content, the hydrolysis of fluorescein diacetate and the Pseudomonas population. Among all measured soil parameters, the size of the fluorescent Pseudomonas population emerged as the most important factor affecting crop productivity. The results of this experimentation show the potential of using biodegradable solarizing materials in place of plastic films, but also indicate the need for improving their properties to obtain performances comparable to those of other pest management techniques.

- by Giancarlo Moschetti
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- Pest Management, Biological Sciences, Environmental Sciences, Crop Production

Soil carbon (C) losses and soil translocation from tillage operations have been identified as causes of soil degradation and soil erosion. The objective of this work was to quantify the variability in tillage-induced carbon dioxide (CO 2 ) loss by moldboard (MP) and chisel (CP) plowing across an eroded landscape and relate the C loss to soil properties. The study site was a 4 ha wheat (Triticum aestivum L. cv. Marshall) field with rolling topography and five soil types in the Svea-Barnes complex in west central Minnesota (N. Latitude = 45841 0 W, Longitude = 95843 0 ). Soil properties were measured at several depths at a 10 m spacing along north-south (N-S) and west-east (W-E) transects through severely eroded, moderately eroded and non-eroded sites. Conventional MP (25 cm deep) and CP (15 cm deep) equipment were used along the pre-marked transects. Gas exchange measurements were obtained with a large, portable chamber within 2 m of each sample site following tillage. The measured CO 2 fluxes were largest with the MP > CP > not tilled (before tillage). The variation in 24 h cumulative CO 2 flux from MP was nearly 3-fold on the N-S transect and 4-fold on the W-E transect. The surface soil organic C on the transects was lowest on the eroded knolls at 5.1 g C kg À1 and increased to 19.6 g C kg À1 in the depositional areas. The lowest CO 2 fluxes were measured from severely eroded sites which indicated that the variation in CO 2 loss was partially reflected by the degradation of soil properties caused by historic tillage-induced soil translocation with some wind and water erosion.

- by D. Malo and +2
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- Air Quality, Carbon Dioxide, Biological Sciences, Environmental Sciences

Processes governing the mobilization of A1 and Cd in podzols and cambisols of S. Sweden having different tree layer vegetation (Picea abies, Fagus sylvatica, or Betula pendula) were investigated. Speciation of A1 and Cd in soil solutions were performed by a column cation exchange procedure (cf. Driscoll, 1984) in combination with thermodynamic calculations. Podzols in spruce and beech stands were characterized by a high release of organic compounds from the O/Ah horizons, resulting in a high organic complexation of A1 (c. 93%) in the soil solution from the E horizon (15 cm lysimeters). Organic complexes were mainly adsorbed/precipitated in the upper Bh horizon and the overall transport of A1 at 50 cm depth was governed by a pH dependent dissolution of a solid-phase A1 pool. In the cambisols, inorganic A1 forms were predominant at both 15 and 50 cm depth, and A1 solubility was closely related to solution pH. Secondary minerals like synthetic gibbsite, jurbanite, kaolinite or imogolite could generally not explain measured solution AP + activities. Results instead indicated that the relatively large organically bound solid-phase A1 pools present in both soil types could do so. The column fractionation procedure could be used only qualitatively for Cd, but results strongly indicated that Cd-organo complexes contributed significantly to the overall mobilization of Cd in the podzol E horizons. In all other soil solutions, Cd 2+ was the predominant species. Both solid-phase and solution chemistry suggests that ion exchange processes controlled the Cd 2+ activities in these solutions. All reactive solidphase Cd was extractable by NH4C1 and Cd 2+ activities could in most cases effectively be modeled by the use of ion exchange equations. Solubilized AP + efficiently competed for exchange sites and played an important role for the Cd mobilization in these soils.

- by Dan Kleja
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- Thermodynamics, Speciation, Multidisciplinary, Ph

Nutrient and organic carbon (OC) losses are important components of the soil degradation processes produced by continuous agriculture. It was hypothesized that coarse textured soils will be more affected by cultivation than fine textured ones. The purpose of this study was to evaluate the status of OC, total nitrogen (Nt), and three phosphorous fractions (total inorganic, Pi; organic, Po; and available, Pa) in different textured virgin (under Prosopis caldenia forest) and cultivated soils of the semi-arid pampa of Argentina. Three virgin and non-fertilized cultivated soil pairs, representative from soils of the region, were selected for this study: two fine sandy loam Entic Haplustolls and a sandy Typic Ustipsamment. The element content of each soil was analysed from the (0)1-mm to 0)1}2-mm sized aggregates. Results indicated that cultivation decreased the OC, Po and Pi contents in fine aggregates of the fine textured soils, and in coarse aggregates of the coarse textured soil. Plant absorption and wind erosion were probably the main processes which decreased element contents in both textural soil types. It was speculated that in the sandy soil the elements lost from fine sized aggregates were restored by the break down of the weak coarse aggregates produced by tillage. The C/N ratios showed mostly small changes due to cultivation, indicating that no changes of organic matter quality occurred. Only the sandy soil showed C/N increases in the fine sized aggregates and decreases in the coarse sized aggregates. The C/Po quotients were not changed by cultivation, indicating that the qualitative composition of P organic compounds remained unchanged. Large OC decreases and Pa increases after cultivation detected in one of the fine textured soil were apparently linked to the occurrence of natural fires.

- by Francisco Babinec
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- Earth Sciences, Arid environments, Biological Sciences, Environmental Sciences

The Humus Index, based on the visual assessment of topsoil horizons and a classification of humus forms, is a numerical score which can be used as a correlate of stand and soil properties. In oak stands from the Montargis forest (Loiret, France) we observed a good linear relationship of the Humus Index with most parameters describing stand development (age, basal area (BA), height and diameter at breast height of dominants) and soil type (depth of clay horizon). The relationship with parameters describing nutrient availability (exchangeable bases, base saturation) was similarly good but nonlinear. In the studied forest the Humus Index was affected first by stand age and second by soil type. When corrected for age and soil type, data (96 pooled estimates) indicated a slight decrease in the Humus Index (shift towards more active humus forms) in stands converted from old coppices-with-standards when compared with even-aged high forest.

- by Jean-François Ponge
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- Temperate Forests, Tree growth, Oak forests, Humus Index

by high water drainage and nitrates leaching. The first soil group caused a mean of 517 mm of runoff in annual basis, 200 mm higher than this arising from coarse soils. Moreover, 3 tonnes of sediments per hectare, 24.6 kgN/ha and 0.54 kgP/ha were lost annually to surface water from fine soils while the average respective losses originating from coarse soils were only 1.3 tn of sediments/ha, 13.6kgN/ha and 0.17kgP/ha. The sensitivity ranking of the soil types to TN and TP losses was silty-clay-loam>silty-loam>clay>loamy>sandy-loam>sandy. An average of 277 mm of water was percolated annually under the bottom of the soil profile in coarse soils causing the additional leaching of 5.6 kgN-NO 3 /ha whereas the losses originating from fine-textured soils were 153 mm and 2.5 kg/ha respectively. According to their sensitivity in nitrates leaching, the six soil types were ranked in the following order: sandy>loamy>sandy-loam>silty-loam>silty-clay-loam>clay. Conclusions and Perspectives. The results showed that even though under cold climate conditions, with monthly periods of average air-temperatures below zero, the overall amounts of annual TN and TP losses to surface waters as well as nitrates leaching to groundwater were considerable. This demonstrates that the cold climate conditions did not affect the long-term behavior of the six widespread Norwegian soils, which on an annual basis responded similarly to the respective European soils. According to the model's estimations, infiltration with N and P transport still occur in wintertime, and comparing to other studies that reported similar results, different possible explanations were considered. The results demonstrate the need of considering the soil differentiation in Scandinavian countries similarly to the rest of Europe in order to apply mitigation measures against nitrogen and phosphorus losses to surface and groundwater. Please cite this paper as: Panagopoulos I, Mimikou M, Kapetanaki M (2007): Estimation of Nitrogen and Phosphorus Losses to Surface Water and Groundwater Through the Implementation of the SWAT Model for Norwegian Soils. J Soils Sediments 7 (4) 223-231

- by Maria Mimikou
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- Earth Sciences, Phosphorus, Environmental Sciences, Surface Water

Este trabalho objetivou verificar a resposta na produtividade de erva-mate em função da adubação nitrogenada. Foi conduzido no município de Fernandes Pinheiro, PR, de 1993 a 1995, numa altitude de 893 m e a 50°35' de longitude oeste e 25°27' de latitude sul. O clima da região, segundo Köppen, é do tipo Cfb, subtropical úmido sem estação seca, precipitação média anual de 1.442 mm. Geologicamente, a área é composta por siltitos, arenitos e folhelhos do Grupo Guatá do Permiano. Foram selecionadas três áreas para o desenvolvimento dos ensaios; Latossolo Vermelho Escuro álico A moderado textura média; Latossolo Vermelho Escuro álico epidistrófico A proeminente textura muito argilosa e Latossolo Vermelho Escuro álico A proeminente textura muito argilosa. Os tratamentos foram os seguintes: T1 (Testemunha) = 0 g de uréia/planta; T2 = 75 g de uréia/planta; T3 = 150 g de uréia/planta; T4 = 225 g de uréia/planta; T5 = 322,8 g de sulfato de amônio/planta; T6 = 150 g de uréia/planta + cobertura morta, "palitos" resultante do beneficiamento da erva-mate. Considerando a produtividade das erveiras em três safras de ano e meio, concluiu-se que: a utilização da cobertura morta é altamente recomendável; a adubação nitrogenada é recomendável somente nos solos de textura média; é indiferente a utilização de uréia ou de sulfato de amônio. PALAVRAS-CHAVE: Cobertura morta; uréia; sulfato de amônio.

- by Moacir Medrado
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- Ilex paraguariensis, Soil Type

Background: Ziziphus lotus, wild jujube, is a xerophytic shrub of the Rhamnaceae family widely distributed in arid and semiarid regions of Tunisia, where it occupies most soil types. Phenological patterns of desert plants are strongly affected by the seasonality of water availability and phreatophytes represent a particularly interesting case for studying such relationships. Aim: This study aims to investigate the relationship between phenological traits and water potential patterns of the wild jujube as a tool for understanding how plants cope with extreme drought. Methods: Phenophases and predawn (Y pd ) and midday (Y md ) xylem water potentials of wild jujube were studied monthly (Nov 2007-Oct 2008 at Samaâliate and Oued El Hallouf in southern Tunisia. These sites receive164 mm and 191 mm of annual rainfall, respectively, and differ in slope and soil type.

- by Mustapha Gorai
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- Plant Biology, Water Availability, Ecology, Phenology
- by Jannick Schmidt
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- Environmental Engineering, Agriculture, Life Cycle Assessment, Global Warming

apsule'': Soil pH greatly in¯uenced adsorption and movement of heavy metals.

- by Liovando Da Costa
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- Soil, Brazil, Hazardous Waste, Environmental Pollution

Soil contamination with heavy metals - Cd, Cu, Mn, Ni, Pb and Zn was studied in the main soil types of Imerti region. An attention was paid to diffusion pollution and metal distribution along the river valleys represent- ing the major flow paths for transporting different pollutants including heavy metals. The results of the laboratory analyses were compared to maximum permissible concentrations and guide values defined by Georgian legislation. An attempt was made to establish background concentration for heavy metals in studied soils and to use them as reference values in assessment of soil pollution. The comparison shows that the concentrations of Cd, Cu, Mn, Ni, Pb and Zn exceed their background contents in some soil samples. © 2007 Bull. Georg. Natl. Acad. Sci.

- by Giorgi Ghambashidze
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- Geography, Soil Pollution, Soil contamination, Legislation
- by Richard Pouyat
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- Soil Science, Ecology, Invasive Species, Nitrogen Cycle

Climate change may have profound eff ects on phosphorus (P) transport in streams and on lake eutrophication. Phosphorus loading from land to streams is expected to increase in northern temperate coastal regions due to higher winter rainfall and to a decline in warm temperate and arid climates. Model results suggest a 3.3 to 16.5% increase within the next 100 yr in the P loading of Danish streams depending on soil type and region. In lakes, higher eutrophication can be expected, reinforced by temperature-mediated higher P release from the sediment. Furthermore, a shift in fi sh community structure toward small and abundant plankti-benthivorous fi sh enhances predator control of zooplankton, resulting in higher phytoplankton biomass. Data from Danish lakes indicate increased chlorophyll a and phytoplankton biomass, higher dominance of dinophytes and cyanobacteria (most notably of nitrogen fi xing forms), but lower abundance of diatoms and chrysophytes, reduced size of copepods and cladocerans, and a tendency to reduced zooplankton biomass and zooplankton:phytoplankton biomass ratio when lakes warm. Higher P concentrations are also seen in warm arid lakes despite reduced external loading due to increased evapotranspiration and reduced infl ow. Th erefore, the critical loading for good ecological state in lakes has to be lowered in a future warmer climate. Th is calls for adaptation measures, which in the northern temperate zone should include improved P cycling in agriculture, reduced loading from point sources, and (re)-establishment of wetlands and riparian buff er zones. In the arid Southern Europe, restrictions on human use of water are also needed, not least on irrigation.

- by Martin Søndergaard and +2
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- Earth Sciences, Climate Change, Wetlands, Structure
- by Amir Shemshaki
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- Engineering, Geology, Time Series, Time series analysis

We compared regeneration, tree diversity and floristic diversity of natural and planted tropical deciduous forests (dominated by Shorea robusta and Tectona grandis; Acacia catechu and Syzygium cumini, respectively) in western Uttar Pradesh, India. Species diversity (70 species in natural and 59 species in planted forests) as well as species evenness was higher in natural forests than in planted forests. Natural forest sites also had higher mature tree, pole, sapling and seedling densities compared with planted forests. In spite of differences in diversity, natural and planted forests did not differ strongly in species composition, fifty-six species occurred in both sites. This may reflect similar soil types but differences in soil moisture, organic carbon, available nitrogen, phosphorus, potassium and soil pH in natural and planted forests. Dominant families in both forest types are Fabaceae, Euphorbiaceae, Verbenaceae, Rubiaceae and Caesalpiniaceae (5 species each), followed by Moraceae, Mimosaceae and Combretaceae. Of the 126 species found in both sites, 32.5% showed good regeneration, 19.8% fair, 24.6% poor and 11.1% lacked regeneration. The remaining 11.9% of species were present as seedlings but not as adult individuals. Good quality timber species are not regenerating, with the exception of Shorea robusta, although mortality at seedling stage of this species is high. In all, our results suggest that species richness and diversity differed between natural forest and planted forest and regeneration of some important tree species also varied in natural and planted forests because of variation in their microclimate and edaphic characteristics. Moreover, these conditions indicate succession pattern and a potential for forestry plantations in dry forests. This study will help in the formulation of effective forest management and conservation strategies.

- by N. Todaria
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- Tropical Ecology, Phosphorus, Soil moisture, Forest Management
- by Mari Ivask
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- Microbiology, Soil Science, Data Analysis, Biological Sciences

We compared below-canopy and open-site climatic conditions for 14 different forest sites in Switzerland and analysed the forest influence on local summer and winter climate according to the forest type (coniferous, mixed, deciduous), soil type, slope orientation, basal area and tree height. We compared below-canopy and open-field data for minimum, maximum and daily mean temperature, relative humidity, maximum and daily mean photosynthetically active radiation (PAR) and wind speed from 1998 to 2007. We found clear differences between below-canopy and open-field temperatures, humidity, wind speed and PAR and could relate them to the specific site conditions and forest type. The forest influence on PAR and maximum temperature is clearly determined by the forest type, whereas the influence on minimum temperature is affected by both forest type and slope orientation and impact on humidity depends on the soil type. The wind speed is most impacted by topography and slope orientation.

- by John Innes and +1
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- Earth Sciences, Climate, Biometeorology, Biological Sciences

This paper examines the status of land resources in the Sudan after over half a century of unsustainable use. Several studies indicate that about 120 million ha of land, including 64 million ha of soils, are degraded to varying degrees. A remarkably high correlation seems to exist between human population densities and degraded soil in different aridity zones. The most degraded zones were the arid and semi-arid zones where 76% of the human population of the Sudan live. Wind erosion was the most widespread soil degradation type in the arid zone, while water erosion was dominant in the semi-arid zone. Chemical deterioration through nutrient loss was affecting all climatic zones. The central clay plains and the ironstone soils of south-west were the least degraded soil types. Overgrazing is the most widespread cause of soil degradation, particularly around permanent settlements and watering centres, affecting about 30M ha (47%) of the total degraded areas. Clearance of forests and woodlands cover for firewood and charcoal making and overexploitation of vegetation is the second cause of soil degradation affecting 22M ha. Cropping without appropriate nutrient inputs have degraded about 12M ha, particularly in small-scale farming on sandy and loamy soils. When these processes of resource mismanagement coincided with the recent recurrent droughts, collapse of the economic base of fragile areas took place.

- by Gashaw Telay
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- Earth Sciences, Assessment, Arid environments, Desertification

Simultaneous soil acidification and deposition of heavy metals is a major concern for forest and agricultural soils of the Black Triangle region of East Central Europe including southern former East Germany, northern Bohemia of the Czech Republic, and southern Poland. The objective of this project was to develop historical and future projections of acid and heavy metal deposition to soils (As, Cd, Pb, Zn) and to produce a preliminary map of soil sensitivity to cadmium pollution and uptake by crops. Ultimately, we wish to assess the relative hazard and recovery times of soils to metals deposition in the region. Emission and deposition data bases obtained from several models developed at IIASA were linked using the Geographical Information System ARC/INFO to produce soil maps of sensitivity to cadmium mobility based on metals deposition, soil type, soil texture, organic matter content, and acid deposition. RAINS 6.1 ) was utilized to produce maps of acid deposition for EMEP grids (150 km x 150 km). The largest amount of acid load is deposited in southern East Germany. Sulfur deposition in that area was 10-12 gS/m2/yr in 1990, and S+N deposition exceeded 8000 eq/ha/yr. But the "hot spot" for metals deposition is further to the east, in the Silesia area of southern Poland. The TRACE2 trajectory model of Alcamo, was used to estimate cumulative metals deposition since 1955 with scenarios to 2010. Pb has improved over Europe since 1970 when depositions in the Ruhr River Valley of West Germany exceeded 60 mg/m2/yr. But cadmium deposition in southern Poland (Katowice and Krakow) has now accumulated to 60-70 mg/m 2 by atmospheric deposition alone. During base case simulations from 1955-87, approximately 1.8 mg/kg Pb and 0.12 mg/kg Cd have been added to the mixed plow-layer of ~30 cm. If these emissions continue indefinitely, the accumulation of metals will become problematic for agriculture and the food chain.

- by K. Olendrzynski
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- Multidisciplinary, Czech Republic, Atmospheric deposition, Soil contamination

The detection of buried land mines in soil is a well-studied problem; many existing technologies are designed and optimized for performance in different soil types. Research on mine detection in shallow water environments such as beaches, however, is much less developed. Electrical impedance tomography (EIT) shows promise for this application. EIT uses current-stimulating and voltage-recording electrode pairs to measure trans-impedances in the volume directly beneath the electrode array, which sits flat over the ground surface. The trans-impedances are used to construct a conductivity profile of the volume. Non-metallic and metallic explosives appear as perturbations in the conductivity profile, and their location and size can be estimated. Lab testing has yielded promising results using a submerged array positioned over a sand bed. The instrument has also successfully detected surrogate mines in a traditional soil environment during field trials. Resolution of the detector is roughly half the pitch of electrodes in the array. In underwater lab testing, non-conducting targets buried in the sand are detected at a depth of 1.5 times the electrode pitch with the array positioned up to one electrode pitch above the sand bed. Results will be presented for metallic and non-metallic targets of various shapes and sizes.

- by John McFee
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- Water, Soil Mechanics, Tomography, Sensors

and a soil water potential sensor (Watermark 200SS, Irrometer Company, Inc., Riverside, CA) in laboratory and field conditions. Soil water content/potential values measured by the sensors were compared with corresponding volumetric water content (Â v , m 3 m −3) values derived from gravimetric samples, ranging approximately from the permanent wilting point (PWP) to field capacity (FC) volumetric water contents. Under laboratory and field conditions, the factory-based calibrations of Â v did not consistently achieve the required accuracy for any sensor in the sandy clay loam, loamy sand, and clay loam soils of eastern Colorado. Salt (calcium chloride dihydrate) added to the soils in the laboratory caused the CS616, TDT, and 5TE sensors to experience errors in their volumetric water content readings with increased bulk soil electrical conductivity (EC; dS m −1). Results from field tests in sandy clay loam and loamy sand soils indicated that a linear calibration (equations provided) for the TDT, CS616 and 5TE sensors (and a logarithmic calibration for the Watermark sensors) could reduce the errors of the factory calibration of Â v to less than 0.02 ± 0.035 m 3 m −3. Furthermore, the performance evaluation tests confirmed that each individual sensor needed a unique calibration equation for every soil type and location in the field. In addition, the calibrated van Genuchten (1980) equation was as accurate as the calibrated logarithmic equation and can be used to convert soil water potential (kPa) to volumetric soil water content (m 3 m −3). Finally, analysis of the Â v field data indicated that the CS616, 5TE and Watermark sensor readings were influenced by diurnal fluctuations in soil temperature, while the TDT was not influenced. Therefore, it is recommended that the soil temperature be considered in the calibration process of the CS616, 5TE, and Watermark sensors. Further research will be aimed towards determining the need of sensor calibration for every agricultural season.

Commercially available cone penetrometer (CPT) fluorescence based sensor platforms have been used to detect non-aqueous phase liquids (NAPLs), such as petroleum oils and lubricants, in situ for more than a decade. These approaches have also been used to detect dense non-aqueous phase liquid (DNAPL) source zones by detecting commingled oils, fuels, and naturally occurring organic materials entrained by DNAPLs and carried to depths below the water table. Several neat NAPLs and mixtures were added to various soil types and analyzed for specific fluorescence characteristics to determine the optimal excitation source for site characterization efforts. Using excitation/emission matrices (EEMs), we demonstrate that an optimized excitation wavelength can be determined for specific fluorophores within the NAPL mixtures, and that available systems can be ranked based on the specific contaminant and site soil types. An optimal excitation wavelength yields the maximum fluorescence within an EEM spectrum. We ranked commercially available cone penetrometer fluorescence detection systems according to the potential for ease of detection based on maximum fluorescence response. When soils were added to complex NAPL mixtures, analyte fluorescence emission was attenuated in preferential portions of the EEM, leading to differences in the optimal excitation source wavelength. Furthermore, impure silica-containing minerals impact the emission signal, potentially leading to incorrect conclusions for several commercially available systems. Our findings suggest that a frequency-agile (e.g., tunable excitation source) probe system would be superior to any other system commercially available, provided the system would be relatively easy to operate and would have rapid in-situ EEM generating capabilities for optimization in the field.

- by Arturo A Keller
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- Materials Science, Fluorescence, Environmental Sciences, Soil contamination

Tension infiltrometry has become quite popular to determine near saturated hydraulic properties of soils and to examine the effects of macropores on infiltration. The unsaturated hydraulic conductivity has traditionally been determined from steady-state tension infiltrometer data using Wooding's analytical solution. Recently, hydraulic parameters are increasingly being estimated from transient data using a numerical solution of the flow problem and nonlinear parameter optimisation. This inverse approach is convenient but its accuracy will vary with soil type. In this study, tension-disc infiltration data obtained on a tilled clay soil, located in the Basilicata region in Southern Italy, were analysed using both the traditional analytical and the numerical inversion approach. Three different parametric models were used for the unsaturated hydraulic conductivity for Wooding's solution; the two-line exponential and the bimodal piecewise-continuous models yielded similar results while the Mualem-van Genuchten (MvG) model provided a somewhat poorer description of the cumulative infiltration. The estimates for K s were one to two orders larger than those reported for core samples in soil databases. The optimised hydraulic functions revealed the presence of a bimodal pore system with a break-point in pressure head at À30 mm. Excellent agreement between measured and fitted infiltration curves was obtained for the numerical inversion procedure. The hydraulic conductivities obtained with Wooding's solution were systematically higher than those obtained from the inverse solution. The difference is presumably due to a lack of steady-state conditions and was greater than found in previous studies on coarser soils; the greatest difference (about 50%) occurred at lower pressure heads. The inverse solution may produce better results if another parametric model is used for the hydraulic properties instead of the Mualem-van Genuchten function. D

Loss of nitrogen from the agricultural production system is of concern in Ontario. The challenge for researchers and farmers is to fulfill crop water requirements while limiting chemical movement with surface and subsurface runoff. The... more

- by Bahram Gharabaghi and +1
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- Water quality, Water Pollution, Nutrient Management, Computer Model
- by Sali Ndindeng
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- Microbiology, Plant Biology, Risk assessment, Disease Severity

Experiments were carried out to study which soil physical factors, if any, would restrict germination and emergence of sorghum (Sorghum bicolor (L.) Moench.) and cowpea (Vigna unguiculata (L.) Walp.), under field conditions in Tanzania. The study also aimed to consider the usefulness of mulching as a strategy to overcome such problems, and to contribute to the development of a strategy for modelling seedling emergence in seedbeds in the field.

- by Peter Mtakwa
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- Biological Sciences, Environmental Sciences, Sorghum, Water Stress

BACKGROUND: Cadmium (Cd) is a trace element that has been associated with various human health problems. Cd enters plants, either by direct absorption through leaves or by uptake from soils, allowing Cd into the food chain. Nitrogen (N) fertilizer management is important in optimizing crop yield and protein content of durum wheat, but may influence Cd availability and hence Cd concentration in crops, with the effects being strongly influenced by environmental conditions and crop cultivar.

- by Michele Pisante
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- Engineering, Soil, Agriculture, Manitoba

This study examines the effect of the variety of reed canary-grass (RCG), location, soil type, and yearly variation on the ash content of the stem, the RCG's pulp yield, and the RCG's fibre properties. Thirteen RCG varieties were grown in 11 locations in northern Europe. The RCGs were harvested using the delayed harvesting method. Two years (1997 and 1998) were included to obtain information of the yearly variation. The yearly variation had the greatest influence on the pulp properties. The ash content of the stem fraction of RCG mainly depends on location and soil type. The overall variation in the measured properties, however, was within reasonable limits, and a substantial reduction of the variation could be achieved by selecting varieties suitable to the climatic and soil conditions of the location.

- by Calle Nilsson
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- Multivariate Data Analysis, Variation, Reed canary grass, Soil Type

Stable isotope analysis is a powerful tool in the study of soil organic matter formation. It is often observed that more decomposed soil organic matter is 13 C, and especially 15 N-enriched relative to fresh litter and recent organic matter. We investigated whether this shift in isotope composition relates to the isotope composition of the microbial biomass, an important source for soil organic matter. We developed a new approach to determine the natural abundance C and N isotope composition of the microbial biomass across a broad range of soil types, vegetation, and climates. We found consistently that the soil microbial biomass was 15 N-enriched relative to the total (3.2 %) and extractable N pools (3.7 %), and 13 C-enriched relative to the extractable C pool (2.5 %). The microbial biomass was also 13 C-enriched relative to total C for soils that exhibited a C3-plant signature (1.6 %), but 13 C-depleted for soils with a C4 signature (À1.1 %). The latter was probably associated with an increase of annual C3 forbs in C4 grasslands after an extreme drought. These findings are in agreement with the proposed contribution of microbial products to the stabilized soil organic matter and may help explain the shift in isotope composition during soil organic matter formation. r

- by Bruce A Hungate and +1
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- Soil Science, Stable Isotope Analysis, Carbon, Stable Isotopes

MicroLEIS, a support system for agro-ecological land evaluations, can be used to assess soil quality and land use planning. Although this system was developed to assist in solving agro-ecological problems in the Mediterranean region, MicroLEIS is also useful in semi-arid regions, such as Iran, where modern land evaluation technologies are rarely used. Land attributes considered in MicroLEIS include site/soil, climate and crop/management factors. Additionally, MicroLEIS contains software packages for data storage, including SDBm plus, CDBm and MDBm. Two procedures that promote sustainable agriculture include land use planning and farm level management based on soil assessments. Implementing recommendations from agro-ecological land evaluations that protect soil and prevent land degradation may enhance sustainable development of rural land. To enhance sustainable development, MicroLEIS successfully classified the study area as optimal or marginal agricultural land and related land use suitability to soil type, erosion risk and vulnerability. In summary, results revealed that decision support systems (e.g. MicroLEIS) are exceptional tools for obtaining successful and reliable information related to agriculture, food and the environment. Consequently, sustainable development can be achieved with the use of MicroLEIS and subsequent implementation of recommendations.

- by Farzin Shahbazi
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- Agroecology, Sustainable agriculture, Environmental Management, Ecology

A statistical prediction of terrestrial gamma radiation dose rate has been performed, covering the Kota Tinggi district of Peninsular Malaysia. The prediction has been based on geological features and soil types. The purpose of this study is to provide a methodology to statistically predict the gamma radiation dose rate with minimum surveying in an area. Results of statistical predictions using the hypothesis test were compared with the actual dose rate obtained by measurements. r

- by Ahmad Rahman
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- Geology, Soil, Malaysia, Forecasting
- by Ahmed Trigui and +1
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- Biological Sciences, Environmental Sciences, Olea europaea, Water Stress

The Khulna City Corporation (KCC) in southwestern Bangladesh lies on the Late Holocene-Recent alluvium of the Ganges deltaic plain in the north and Ganges estuarine plain in the south. Lithologically the area is composed of coarse to very fine sand, silt, silty clay and clay in various porportion upto a depth of 300m. Stratigraphically shows seven cycles of sedimentation having age connotation from Upper Miocene to Recent age. The SPT (Standard Penetration Test) value of the investigated area range between 1 and 9 from surface to 5m deep and 1 to 27 from 5m to 15m below which was used to prepare a SPT zonation map that clearly delineates the KCC area into 4 zones. Here, the liquid limit, plasticity index and the natural moisture content (NMC) range from 38 to 59%, 9 to 30% and 16.5% to 42% respectively. The shear strength of the upper subsoil horizons in the investigated area is low. Low shearing strength in the upper soil horizon with compressive index from 0.123 to 0.335 is indicative of soil vulnerability to excessive settlement under high load. The cohesive nature of soil in the KCC area with high colloidal content, high liquid and plastic limit indicate medium to high sensitivity of the soil to moisture that could not support heavily loaded buildings and structures. The problems can be avoided by considering special type of foundation, increasing the width of basements of structures and granular backfilling. Based on geomorphology, stratigraphic litho-succession, soil types, percentage of sand, silt and clay in the soil, liquid limit, plasticity index, NMC, liquefaction, settlement and SPT zonation, the study area have been classified into four geotechnical units, where unit-I is best and unit-IV is rank lowest for urbanization. Considering the factors of geotechnical parameters and environmental degradation by natural and anthropogenic hazards a future land suitability map has been prepared for future urban planning of the Khulna City area.

- by Abdul Malik
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- Urban Planning, Case Study, Late Holocene, Environmental degradation

Root lodging is an important adversity affecting sunflower (Helianthus annuus L.) production in Argentina under current husbandry practices, and may limit progress towards the achievement of higher yields via increased plant population density. Although there are perceptions that lodging susceptibility varies across developmental stages, crop population densities, genotypes and soil types, these perceptions have not been tested for sunflower using a standardized experimental protocol. This study aimed at: (1) identifying the sources of the variation in root lodging susceptibility in response to variations in crop population density in two genotypes of reputedly different susceptibility; (2) detecting the crop developmental stages most susceptible to root lodging; and (3) examining the relationships between root failure moment, root plate diameter and soil shear strength. We mechanically induced lodging at three developmental stages in plants rooted in pre-wetted plots. The crops were grown at 5.6 plants m À2 over 3 years on either Typic Argiudoll or Typic Hapludoll soils and at 3, 5.6, 10 and 16 plants m À2 on a Typic Argiudoll. The force needed to induce root lodging (root failure moment) and root plate diameter varied across genotypes, plant densities and developmental stages. Root failure moment and root plate diameters were greater ( p < 0.05 for both variables) in the resistant hybrid across the three development stages and almost all crop population densities. For both hybrids, the most susceptible development stage was R2, and root failure moment and root plate diameter diminished ( p < 0.05) as crop population density increased. Although root failure moment did not differ between soil types, root plate diameter was greater ( p < 0.0001) in the coarser soil. The relationship between root failure moment and the product of root plate diameter cubed by soil shear strength (a measure of plant anchorage strength) for both hybrids, both soil types, and all crop population densities could be described by a single linear relationship (y = 0.2382x; R 2 = 0.812; p < 0.025).

- by Mariano Sposaro
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- Field Crops, Population Density, Soil sciences, Plant population ecology

A Viking Lander 1 image was modeled as mixtures of reflectance spectra of palagonite dust, gray andesitelike rock, and a coarse rocklike soil. The rocks are covered to varying degrees by dust but otherwise appear unweathered. Rocklike soil occurs as lag deposits in deflation zones around stones and on top of a drift and as a layer in a trench dug by the lander. This soil probably is derived from the rocks by wind abrasion and/or spallation. Dust is the major component of the soil and covers most of the surface. The dust is unrelated spectrally to the rock but is equivalent to the global-scale dust observed telescopically. A new method was developed to model a multispectral image as mixtures of end-member spectra and to compare image spectra directly with laboratory reference spectra. The method for the first time uses shade and secondary illumination effects as spectral end-members; thus the effects of topography and illumination on all scales can be isolated or removed. The image was calibrated absolutely from the laboratory spectra, in close agreement with direct calibrations. The method has broad applications to interpreting multispectral images, including satellite images.

- by John Adams
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- Petrology, Image Analysis, Multidisciplinary, Planetology

Marton (Argillic Perched-gley Pallic, Typic Endoaqualf), Ohakune (Typic Orthic Allophanic, Typic Hapludand), and Westmere (Mottled Mafic Melanic, Mollic Hapludalf) soils with differing structural vulnerability were compared at matched... more

- by louis Schipper
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- Plant Biology, Land Use, New Zealand, Forests

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- by DIEGO AGUSTIN VARGAS BRICEÑO
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- Leaching, Agriculture, Multidisciplinary, Adsorption

GIS (Geographical Information System) is a special information system that was introduced to analyse geographic data. In the last two decades GIS became an important tool in the understanding and forming of the environment. Our goal was the integration of GIS and environmental modelling in the areas of risk analysis and resources assessment, with help three-dimensional surface models. Three-dimensional geographical

- by Tamás János
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- Risk Analysis, Complexity Analysis, Three Dimensional, Soil Type

The capacity of 36 Western Australian soils to adsorb phosphorus (P) was measured by three different methods: P retention index (PRI), P buffering capacity (PBC), and P adsorption (PA). The P adsorption values measured by all three methods varied markedly with soil type. When the P adsorption values were correlated with several soil properties, using simple and multiple linear regressions, PRI, PBC, or PA values were found to be significantly correlated with the aluminium oxide content of the soils. In addition, PBC and PRI was correlated with organic carbon content. The role of aluminium oxide (Al 2 O 3 ) in the soil was apparently more important in determining the P adsorption capacity of the soils than that of iron (Fe), even though the iron oxide (Fe 2 O 3 )content of all the soils studied was consistently higher than the aluminium oxide content. The relationship between P adsorption and the selected soil properties, as determined by multiple linear regression, explained 45-59% of the variation:

- by Ross Brennan
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- Plant Biology, Phosphorus, Iron Oxide, Iron

The maintenance of soil organic carbon (SOC) in terrestrial ecosystems is critical for long-term productivity. Simulation models of SOC dynamics are valuable tools in predicting the impacts of climate on carbon storage and developing management strategies for the mitigation of greenhouse gas emissions, however, their utility is generally reduced due to need for specific data. The SOCRATES model is a

- by Stuart Gage
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- Land Use Change, Biological Sciences, Environmental Sciences, Carbon Storage