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

Trenbolone acetate (TBA) is a synthetic androgenic steroid hormone administered as a subcutaneous implant for growth promotion in beef cattle. The primary metabolite excreted in manure from implanted cattle is 17a-trenbolone with lesser amounts of 17b-trenbolone and trendione also present. At 22°C and favorable moisture conditions in a controlled laboratory environment, trenbolone degrades to trendione in a few hours; however, these conditions are often not what exist in the field. Therefore, aerobic degradation rates of 17a-trenbolone, 17b-trenbolone and trendione were determined in a sandy soil and silty clay loam under a range of temperature and water availability combinations that may be expected in the field. A first-order exponential decay model was used to estimate rates and generally resulted in good model fits to the data. Degradation rates decreased with decreasing water availability (i.e., more negative soil matric potential) and decreasing temperature. However, when water availability was substantially reduced (À1.0 MPa), hotter temperatures (35°C) significantly reduced trenbolone degradation rates. Once temperature was low enough to limit microbial activity, no further changes were observed with decreasing matric potential. Trendione also exhibited similar moisture and temperature dependent degradation, but persisted longer than the parent trenbolone. The latter was discussed in light of extracellular versus intracellular enzymatic degradation and sorption. Half lives at colder temperatures (5°C) even under favorable moisture conditions were 2-3 d for the trenbolone isomers and approached 10 d for trendione.

- by Bushra Khan
- •
- Soil, Water Availability, Multidisciplinary, Temperature

The objective of the study has been to investigate whether cold-adapted microorganisms (CAMs) are metabolising hydrocarbons in situ at sub-zero temperatures. Since the summer 2001, soil temperatures and soil gas concentrations of oxygen (O 2 ) and carbon dioxide (CO 2 ) at various depths at a petroleum hydrocarbon contaminated permafrost site at Longyearbyen, Spitsbergen, have continuously been measured and compared to data from a nearby non-contaminated site. We have previously reported on unchanged microbial O 2 consumption in the active layer for about 12 days after the soil temperatures decreased below 0 8C in late October 2001 and we are now reporting on the microbial activity in the soil profile from January to September 2002. The empirical data have been compared to theoretical simulations of O 2 concentration as a function of soil depth and time from when the CAMs became active in spring until steady-state conditions were achieved in the summer. At the 0.7 m depth in the oil-plume site, microbial O 2 consumption started in the middle of April, about 45 days before the soil thawed. There was no coincidence between the microbial activation time and the thawing time of the soil. The CAMs became active at temperatures of about À6 8C, but the main degradation activity occurred at temperatures between À1 and À3 8C. When the soil thawed, the hydrocarbon degradation was probably limited by the O 2 supply. In the summer months where we expected the greatest degradation activity to occur because of positive temperatures and access to water, the degradation was limited by O 2 depletion. The overall data from this arctic permafrost site indicate that without other limiting conditions such as O 2 and 0165-232X/$ -see front matter D substrate availability, the active biodegradation period can be extended to about 6 months despite periods with sub-zero soil temperatures. D

- by Cam Gunn
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- Civil Engineering, Carbon Dioxide, Permafrost, Steady state

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

There is a need to develop technology to allow the remediation of soil in polar regions that have been contaminated by hydrocarbon fuel spills. Bioremediation is potentially useful for this purpose, but has not been well demonstrated in polar regions. We investigated biopiles for on-site bioremediation of soil contaminated with Arctic diesel fuel in two independent smallscale field experiments at different sites on the Arctic tundra. The results were highly consistent with one another. In biopiles at both sites, extensive hydrocarbon removal occurred after one summer. After 1 year in treatments with optimal conditions, total petroleum hydrocarbons were reduced from 196 to below 10 mg per kg of soil at one site, and from 2,109 to 195 mg per kg of soil at the other site. Addition of ammonium chloride and sodium phosphate greatly stimulated hydrocarbon removal and indicates that biodegradation was the primary mechanism by which this was achieved. Inoculation with cold-adapted, mixed microbial cultures further stimulated hydrocarbon removal during the summer immediately following inoculation. At one site, soil temperature was monitored during the summer season, and a clear plastic cover increased biopile soil temperature, measured as degree-day accumulation, by 30-49%. Our results show that on-site bioremediation of fuel-contaminated soil at Arctic tundra sites is feasible.

- by Marie-Claude Fortin
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- Applied microbiology, Multidisciplinary, Seasonality, Soil contamination

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

The presidedress soil nitrate test (PSNT) and the presidedress tissue nitrogen test (PTNT) have been developed to assess residual soil nitrogen (N) sufficiency for corn (Zea mays L.) in the humid eastern U.S. We conducted field studies at 47 sites during 1990 and 1991 to evaluate the use of the PSNT and PTNT for corn in Coastal Plain, Piedmont, and Appalachian Ridge and Valley regions of Virginia. Seven rates of fertilizer N (0, 45, 90, 135, 180, 225, and 270 kg/ha) were applied at corn height of 0.40 to 0.50 m and replicated four times in a randomized complete block design. Whole corn plants and soil to a depth of 0.30 m were sampled when corn height was 0.15 to 0.30 m to estimate available soil N prior to the application of fertilizer N treatments. Corn grain yield response to fertilizer N was used to assess residual soil N availability. Nitrogen concentration of whole corn plants at 0.15 to 0.30 m height was not an accurate indicator of plant-available soil N. Corn yields were maximized without sidedress N at the 19 sites where soil NO 3 -N was at least 18 mg-kg -1 and at the 17 sites where soil (NO 3 +NH 4 )-N was at least 22 mg-kg -1 . The PSNT predicted corn N sufficiency regardless of soil physiographic region or surface texture; however, the critical values for NO 3 -N and (NO 3 +NH 4 )-N were 3 to 5 mg-kg -1 lower than those established in Pennsylvania and Maryland, where cooler soil temperatures may permit greater residence time of inorganic N.

- by Gregory Evanylo
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- Soil Science, Analytical Chemistry, Inorganic Chemistry, Agronomy

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

Navas-Cortés, J. A., Landa, B. B., Méndez-Rodríguez, M. A., and Jiménez-Díaz, R. M. 2007. Quantitative modeling of the effects of temperature and inoculum density of Fusarium oxysporum f. sp. ciceris races 0 and 5 on development of... more

- by Blanca B Landa
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- Microbiology, Phytopathology, Plant Biology, Modeling
- by Robert Naiman
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- Biological Sciences, Environmental Sciences, Ecological, Relative Humidity

Earthworm casts, formed when organic substrates and soil minerals pass through the digestive tract, may protect soil organic matter from biological degradation if they persist in the soil. Yet, the stability of casts is affected by their location in the soil profile because surface casts are exposed to more disruptive forces (wetting-drying, freezing-thawing) than subsurface casts. It is not known

- by Joann Whalen
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- Biological Sciences, Environmental Sciences, Soil organic matter, Soil Temperature
- by Thomas Kaspar and +1
- •
- Soil Science, Biological Sciences, Environmental Sciences, Soil Temperature

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.

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
- by Frank Forcella
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- Environmental Science, Seed germination, Seed dormancy, Emergence

The grain yields in the no-tillage plots were equivalent to those of conventionally plowed treatments. No-tillage treatments had higher organic matter content and, by controlling soil erosion, the silt and clay content than the plowed plots. The water holding capacity and moisture release characteristics of the surface soil horizon were significantly different for the two tillage treatments. A decrase in the maximum soil temperature and favourable moisture regime in the no-tillage plots stimulated biological activity e.g. earthworms. While the fertilizer had no response on the plowed plots, irrigation had a negative effect due probably to severe leaching losses. No-tillage techniques have a potential in achieving continuous cultivation on otherwise highly erodible and shallow tropical soils.

- by Rattan Lal
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- Biological Sciences, Environmental Sciences, No tillage, Soil Erosion
- by Edwin ethridge
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- Microwave Heating, Thermal Conductivity, Soil Temperature

Root exudates influence significantly physical, chemical and biological characteristics of rhizosphere soil. Their qualitative and quantitative composition is affected by environmental factors such as pH, soil type, oxygen status, light intensity, soil temperature, plant growth, nutrient availability and microorganisms. The aim of the present study was to assess the influence of growth substrate and plant age on the release of carboxylates from Lupinus albus L. and Brassica napus L.

- by Markus Puschenreiter
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- Soil, Plant Biology, Time-of-flight mass spectrometry, Plant Physiology

Soil-climatic zoning of Georgia has been developed on the basis of data on soil temperatures measured at the surface and at a depth of 20 cm at 60 meteorological stations in different physiographic zones from 1947-1990 and the map of... more

- by E. Elizbarashvili and +1
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- Plant Biology, Soil sciences, Soil Temperature

The synergy between highly energy-efficient buildings and low-energy district heating (DH) systems is a promising concept for the optimal integration of energy-saving policies and energy supply systems based on renewable energy (RE). Network transmission and distribution heat loss is one of the key factors in the optimal design of low-energy DH systems. Various pipe configurations are considered in this paper: flexible pre-insulated twin pipes with symmetrical or asymmetrical insulation, double pipes, and triple pipes. These technologies represent potential energy-efficient and cost-effective solutions for DH networks in low-heat density areas. We start with a review of theories and methods for steady-state heat loss calculation. Next, the article shows how detailed calculations with 2D-modeling of pipes can be carried out by means of computer software based on the finite element method (FEM). The model was validated by comparison with experimental measurements, analytical formulas, and data from the literature. We took into account the influence of the temperature-dependent conductivity coefficient of polyurethane insulation foam, which enabled us to achieve a high degree of accuracy. We also showed the influence of the soil temperature throughout the year. Finally, the article describes proposals for the optimal design of pipes for low-energy applications and presents methods for decreasing heat losses.

- by Svend Svendsen
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- Mechanical Engineering, Renewable Energy, Energy, Finite element method

Purpose of the study: The main purpose of this study is to find out the effect of change in soil viscosity, soil temperature and specific gravity on growth of plants sown in the soil prepared from laboratory chemical waste collected from an educational institute and with the plants sown in normal soil.
Methodology: Three-three pots with different soil combinations mixed with solid and liquid chemical waste have been used for growing A. barbadensis Mill, Saussurea obvallata and Lilium plants. Observations were made every fifteen days for three months by checking plant height, the number of leaves, the color of leaves and soil temperature for understanding and comparison of plant growth with respect to variation in temperature. Later on density and viscosity of soils have also been checked with the help of specific gravity bottle and viscometer.
Main Findings: Plants' growth differs with variation in soil viscosity, soil temperature, and soil density. All plants cannot grow potentially at the same temperature, viscosity, and density. A. barbadensis Mill A4 has shown better growth with least viscosity and highest particle density of soil. Saussurea obvallata BK1 has shown better growth with least viscosity and least particle density of soil. Lilium L1 has shown better growth with all the moderate values of soil.
Applications of this study: This study helped to understand that all the plants have their own requirements of nutrients, nutrition and physical factors for their growth. This also helped to understand that although the soil has taken initially is the same, viscosity and density of the soil changes due the plants grown in it.
Novelty/Originality of this study: The use of chemical wastes is taken into consideration instead of fertilizers to reduce pollution.

- by MGES Journals
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- Photosynthesis, Viscosity, Plant growth, Soil Temperature

The work comprises a model to determine the temperature of the soil for predefined depths under the ground surface at any day of the year. The model suggested here is sinusoidal curve of temperature versus day number of the year. For a given depth, temperature could be determined in any given day of the year. The chi-square test was done to compare the observed and calculated data, and the result was found to be highly reliable. Transient heat flow principle was used and certain assumptions were made for example: the heat flow in soil was one-dimensional and thermal diffusivity was taken as constant. The curve was fitted for the depths 5 cm, 10 cm, 30 cm, and 50 cm. The average annual absolute difference between observed and estimated values varied from 1.367 to 1.921 for these depths. This model can be successfully applied to find the temperature of the soil under the ground at any day of the year, given that thermal diffusivity remains constant and average climatic conditions do not vary drastically throughout the year.

- by Bhishan Poudel
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- Soil Science, Climate Change, Climatology, THERMAL DIFFUSIVITY
- by Giacomo Bertoldi and +1
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- Environmental Engineering, Civil Engineering, Energy Balance, SNOW

Hydrothermal alteration is an important soil forming factor in the vicinity of active volcanic centers, yet we are aware of no studies that have addressed the role of active fumaroles on soil development. This paper examines a soil developmental sequence of five pedons established across a thermal gradient (∼100 m) induced by an active fumarole in Lassen Volcanic National Park in

- by Francisco Diaz
- •
- Pedogenesis, Biological Sciences, Environmental Sciences, Soils

A theoretical model of an earth-air heat exchanger (EAHE) is developed for predicting the outlet air temperature and cooling potential of these devices in a hot, arid climate. The model is validated against other published models and shows good agreement. A sub-soil temperature model adapted for the specific conditions in Kuwait is presented and its output compared with measurements in two locations. A building model representative of a typical Kuwaiti dwelling has been implemented and all the models have been encoded within the TRNSYS-IISIBAT environment. A typical meteorological year for Kuwait was prepared and used to predict the cooling loads of the air-conditioned dwelling with and without the assistance of the EAHE. Simulation results showed that the EAHE could provide a reduction of 1700 W in the peak cooling load, with an indoor temperature reduction of 2.8 1C during summer peak hours (middle of July). The EAHE is shown to have the potential for reducing cooling energy demand in a typical house by 30% over the peak summer season. r

- by Khatib Rim
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- Architecture, Heat Exchanger, Seasonality, Energy demand

The experiment was conducted at Regional Agricultural Research Station (RARS), Jamalpur, Bangladesh during the period of 2017-18 and 2018-19 with the objectives to evaluate the effect of different mulch on soil temperature, soil moisture conservation and yield attributes of chilli. There were five treatments comprising T1: no mulch, T2: rice straw mulch @ 5 t ha-1 , T3: water hyacinth mulch @ 5 t ha-1 , T4: black polyethylene mulch and T5: white polyethylene mulch. The results revealed that, all the mulch treatment had higher soil temperature and soil moisture content at 5 cm and 10 cm depth compared to no mulch treatment. Soil temperature was highest in black polyethylene mulch, it increased average soil temperature by about 5.7 o C at 5 cm depth and 5.1 o C at 10 cm depth compared to no mulch treatment at 120 Days. Rice straw mulch treatment recorded highest soil moisture, it increased average soil moisture about 27.87 % at 5 cm depth and 28.57% at 10 cm depth over no mulch treatment. Rice straw mulch treatment produced highest green chilli yield (8.81 t ha-1) which was 26.94 % increased over no mulch treatment (6.94 t ha-1).Considering economic analysis, highest gross return (Tk 352400 ha-1), gross margin (Tk 235400 ha-1) and BCR (3.01) was obtained from same treatment T2 i.e., rice straw mulch treatment.

- by Mohammad Monirul Hasan Tipu
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- Soil Science, Agriculture, Soil moisture, Chilli

Thermal properties dictate the storage and movement of heat in soils and as such influence the temperature and heat flux in soils as a function of time and depth. The ability to monitor soil heat capacity is an important tool in managing the soil temperature regime to affect seed germination and crop growth. The effect of water content and bulk density on the specific heat, volumetric heat capacity, and thermal diffusivity of some sieved and repacked soils was investigated through laboratory studies. These laboratory experiments used the calorimetric method to determine specific heat of soils. The soils used were classified as sand and clay. For the type of soils studied, specific heat increased with increased moisture content. Also, volumetric heat capacity increased with increased moisture content and soil density. Volumetric heat capacity ranged from 1Á48 to 3Á54 MJ m À3 8C À1 for clay and from 1Á09 to 3Á04 MJ m À3 8C À1 for sand at moisture contents from 0 to 0Á25 (kg kg À1 ) and densities from 1200 to 1400 kg m À3 . Specific heat ranged from 1Á17 to 2Á25 kJ kg À1 8C À1 for clay and from 0Á83 to 1Á67 kJ kg À1 8C À1 for sand at moisture contents from 0Á02 to 0Á25 (kg kg À1 ) and soil density of 1300 kg m À3 . The volumetric heat capacity and specific heat of soils observed in this study under varying moisture content and soil density were compared with independent estimates made using derived theoretical relations. The differences between the observed and predicted results were very small. Clay soil generally had higher specific heat and volumetric heat capacity than sandy soil for the same moisture content and soil density. The results also show that thermal diffusivity vary with moisture content and soil texture. Sandy soil exhibited a thermal diffusivity peak at a definite moisture content range. Clay soil, however, did not exhibit a sharp thermal diffusivity peak.

- by Manuel Madeira
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- Environmental Science, Data Mining, Prediction, Agroforestry

Wine is made up of more than one thousand compounds, the majority of which, such as vitamins and minerals, come from the grapes, while others, like ethanol and glycerol, are products of the winemaking process. Although sugars are either partially or completely transformed, sugar import and accumulation into the ripening berry is a major parameter of wine quality. Sugar status is directly related to the final alcoholic content of wine, and regulates several genes responsible for the development of its aromatic and organoleptic properties. Physiological ripeness is reached when the grapes achieve sufficiently high sugar levels without loosing too much acidity; however, aromatic and phenolic compound content must also be taken into account. Softening and water content are other essential characteristics of a ripe berry. From a winemaker point of view, optimal grape maturity is essential for wine quality, but is difficult to assess because it is under multifactorial control, involving grapevine cultivar variety and environmental parameters such as soil, temperature, exposure to sun, and hormonal regulation. Continued study of the key control points in grape ripening is crucial if we ultimately hope to improve grape and wine quality.

- by Serge Delrot and +1
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- Food, Nitrogen, Potassium, Vitis Vinifera

This study evaluated the family of ECH 2 O sensors (EC-5 and ECH 2 O-TE) for measurement of soil moisture content (h), bulk electrical conductivity (EC b ) and temperature for a range of soils, across a range of measurement frequencies between 5 and 150 MHz. Measurement frequency is one of the primary factors affecting the sensitivity of capacitance sensor measurements to soil variables such as soil texture, electrical conductivity, and temperature. Measurements in both soil and solution demonstrated that the ECH 2 O EC and TE measurements were accurate. Using a measurement frequency of 70 MHz, a single calibration curve was determined for a range of mineral soils, independent of soil salinity, suggesting there might be no need for a soil specific calibration. When combining all data for each soil type, the R 2 values remained high (R 2 = 0.98) with little probe to probe variability. After laboratory calibration, the error for h was about 2%, independent of soil EC b , up to a soil solution EC of about 12 dS/m. Our results showed that a single calibration curve could be used for all tested mineral soils, independent of soil salinity. The bulk soil EC b -water content data were excellently described by a polynomial expression. Measurements of temperature sensitivity to soil water content and EC b were sufficiently small. For example, for a temperature change of 10°C, measurements of h and EC b were affected by about 0.02 cm 3 cm À3 and 0.02 dS/m, respectively. Limited sensor calibration requirements are important, when large networks of soil moisture sensors are being deployed. It is concluded that an accurate, cost-effective soil moisture sensor is available that operates at a measurement frequency of 70 MHz, with a low sensitivity to confounding soil environmental factors. ª

- by Gaylon Campbell and +1
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- Hydrology, Soil Salinity, Multidisciplinary, Soil moisture

Mulching is one of the important agronomic practices in conserving the soil moisture and modifying the soil physical environment. Wheat, the second most important cereal crop in India, is sensitive to soil moisture stress. Field experiments were conducted during winter seasons of 2004–2005 and 2005–2006 in a sandy loam soil to evaluate the soil and plant water status in wheat under synthetic (transparent and black polyethylene) and organic (rice husk) mulches with limited irrigation and compared with adequate irrigation with no mulch (conventional practices by the farmers). Though all the mulch treatments improved the soil moisture status, rice husk was found to be superior in maintaining optimum soil moisture condition for crop use. The residual soil moisture was also minimum, indicating effective utilization of moisture by the crop under RH. The plant water status, as evaluated by relative water content and leaf water potential were favourable under RH. Specific leaf weight, root length density and dry biomass were also greater in this treatment. Optimum soil and canopy thermal environment of wheat with limited fluctuations were observed under RH, even during dry periods. This produced comparable yield with less water use, enhancing the water use efficiency. Therefore, it may be concluded that under limited irrigation condition, RH mulching will be beneficial for wheat as it is able to maintain better soil and plant water status, leading to higher grain yield and enhanced water use efficiency.

- by Rabi Narayan Sahoo and +1
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- Civil Engineering, Stress field, Agricultural Water Management, Seasonality

A farm survey was carried out in 155 Ghanaian villages covering parts of the forest and savanna zones of West Africa to assess farmers' views on 'soil organic matter' (SOM) and its management. The results of a closed questionnaire accompanied by open discussions showed that most farmers are well aware of SOM and its importance for crop yields. In southern Ghana, farmers perceive SOM generally by its colour, while in northern Ghana, it is mostly assessed by the density and kind of vegetation. Farmers' perception of the properties of SOM was directed at its main functions as a primary provider of plant nutrients and its ability to conserve water. Other properties mentioned were the improvement of soil aeration and drainage, the loosening of soil structure as well as its impact on soil temperature. The major strategies farmers used in maintaining or augmenting SOM levels were: manure application, mulching with crop residues, slashing weeds without burning, composting, and shifting cultivation (natural fallow). Promoted technologies, such as green manuring, no tillage, or agroforestry were used only by a few of the farmers interviewed. The differences between farmers' views and strategies in the two zones as well as farmers' constraints in SOM management are discussed. It appears that the level of farmers' commitment to excellent soil management can vary with biophysical as well as socio-economic conditions.

- by Charles Quansah and +1
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- Analytical Chemistry, West Africa, IT Management, Indigenous Knowledge

Soil fertility depletion has been described as the single most important constraint to food security in West Africa. Over half of the African population is rural and directly dependent on locally grown crops. Further, 28% of the population is chronically hungry and over half of people are living on less than US$ 1 per day as a result of soil fertility depletion.

- by Joseph Kimetu
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- West Africa, Food Security, Environmental Sciences, Agricultural Systems

Bioremediation is increasingly viewed as an appropriate remediation technology for hydrocarboncontaminated polar soils. As for all soils, the successful application of bioremediation depends on appropriate biodegradative microbes and environmental conditions in situ. Laboratory studies have confirmed that hydrocarbon-degrading bacteria typically assigned to the genera Rhodococcus, Sphingomonas or Pseudomonas are present in contaminated polar soils. However, as indicated by the persistence of spilled hydrocarbons, environmental conditions in situ are suboptimal for biodegradation in polar soils. Therefore, it is likely that ex situ bioremediation will be the method of choice for ameliorating and controlling the factors limiting microbial activity, i.e. low and fluctuating soil temperatures, low levels of nutrients, and possible alkalinity and low moisture. Care must be taken when adding nutrients to the coarse-textured, low-moisture soils prevalent in continental Antarctica and the high Arctic because excess levels can inhibit hydrocarbon biodegradation by decreasing soil water potentials. Bioremediation experiments conducted on site in the Arctic indicate that land farming and biopiles may be useful approaches for bioremediation of polar soils.

- by Jackie Aislabie
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- Microbiology, Soil, Medical Microbiology, Extremophiles
- by Simone Graeff
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- Information, Maize, Plant growth, Soil Temperature
- by Hans Jumbo
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- Potato, Water use efficiency, Field Crops, Drip Irrigation

Soil temperature is a variable that links surface structure to soil processes and yet its spatial prediction across landscapes with variable surface structure is poorly understood. In this study, a hybrid soil temperature model was developed to predict daily spatial patterns of soil temperature in a forested landscape by incorporating the effects of topography, canopy and ground litter. The model is based on both heat transfer physics and empirical relationship between air and soil temperature, and uses input variables that are extracted from a digital elevation model (DEM), satellite imagery, and standard weather records. Model-predicted soil temperatures ®tted well with data measured at 10 cm soil depth at three sites: two hardwood forests and a bare soil area. A sensitivity analysis showed that the model was highly sensitive to leaf area index (LAI) and air temperature. When the spatial pattern of soil temperature in a forested watershed was simulated by the model, different responses of bare and canopy-closed ground to air temperature were identi®ed. Spatial distribution of daily air temperature was geostatistically interpolated from the data of weather stations adjacent to the simulated area. Spatial distribution of LAI was obtained from Landsat Thematic Mapper images. The hybrid model describes spatial variability of soil temperature across landscapes and different sensitivity to rising air temperature depending on site-speci®c surface structures, such as LAI and ground litter stores.

- by Sehee Kim
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- Forest Ecology And Management, Heat Transfer, Sensitivity Analysis, Biological Sciences

In this study, an innovative and intelligent computing regression algorithm, multivariate adaptive regression splines (MARS), was applied to simulate pesticide transport in soils. Using a divide-and-conquer method, the algorithm classifies the training data into several groups, in each of which a regression line or hyperplane is fitted. Compared to other intelligent computing technologies, MARS is fast, flexible, and capable of determining the important sequence of inputs to the output. This study evaluated MARS by applying it to simulate pesticide concentration levels at different soil depths and at various times. The model inputs included the number of days after pesticide application, accumulated rainfall, accumulated potential evapotranspiration, accumulated soil temperatures at depths of 100 mm in the morning as well as in the afternoon, and tillage practices. Several MARS models were developed to simulate the concentration levels of atrazine, deethylatrazine, and metolachlor at depths of 0-75 and 75-150 mm, respectively. The performance of MARS was compared to that of artificial neural networks (ANNs) using standard errors and correlation coefficients of linear regression. The results show the strong potential of MARS to be applied to agriculture as a regression technology.

- by Shiv Prasher and +1
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- Biomedical Engineering, Biosystems engineering, Potential Evapotranspiration, Soil Temperature

Solar chimney (SC) together with earth to air heat exchanger (EAHE) is being employed as a low-energy consuming technique to remove undesirable interior heat from a building in the hot seasons. A numerical program "FLUENT 6.3 code" of an earth to air heat exchanger (EAHE) is studied for predicting the outlet air temperature and cooling potential of these devices in Basrah climate. theoretical analyses have been conducted in order to investigate the ventilation in a solar chimney. The investigation into the viability of Low Energy Earth Pipe Cooling Technology in providing thermal comfort in Basrah. The demand for airconditioning in buildings in Basrah affects the country escalating energy consumption. Therefore, this investigation was intended to seek for a passive cooling alternative to airconditioning. The passive technology, where the ground was used as a heat sink to produce cooler air, has not been investigated systematically in hot and humid countries. A subsoil temperature model adapted for the specific conditions in Basrahis presented and its output compared with CFD modeling. The results have shown the potential of Earth Pipe in providing lower output temperature of air inlet to the room.

- by IAEME Publication
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- Passive Cooling, Soil Temperature, Solar Chimney, earth to air heat exchanger
- by Carla Jimenez
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- Biological Sciences, Environmental Sciences, Soil Temperature

The estimation of the road edge effect is useful to understand changes induced by the road network on ecosystems. Road networks on islands may break ecosystem integrity through microclimate edge effects, which are known to be associated... more

- by Juan D Delgado and +1
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- Engineering, Urban Landscape, Environmental Sciences, Canary Islands

There are very few studies on the effects of temporal changes in soil properties on ecosystem engineers in UK soils. This study addresses this lack by presenting earthworm diversity data from a six-year seasonality study comprising 72 monthly samples from the litter and soil of pasture woodland in the New Forest, southern England. These data were analysed in the context of soil moisture and soil temperature, key factors affecting earthworm abundance, and factors likely to be strongly affected by future climate change. The data for the whole period were analysed using non-parametric regression and an additive model used to separate within-year and between-year effects. Seasonal patterns are present for all the common species, generally with a maximum in March and a minimum in September. A majority of the five commonest species show a strong decline in abundance during the two extremely dry periods (2002-2003 and 2006). In sharp contrast, the same species showed a relative increase during the very wet summer and autumn of 2007. There was, however, no significant overall trend in either the climate data or the earthworm species data. The epigeic species, Dendrobaena octaedra, showed the largest decline in the driest months which caused a crash to the point where there were no adults sampled during the four dry summer months of 2003. A second congeneric species, Dendrobaena attemsi, also epigeic, appears to have invaded the woodland during the six year period and is increasing rapidly in abundance. This may indicate the start of a shift in the distribution of the two species, as D. octaedra generally has a northern European distribution and is frost-tolerant, while D. attemsi has a southern European distribution and is more drought-tolerant. In contrast, the very wet summer of 2007 seems to have damped the usual periodic seasonal oscillations in earthworm numbers. Endogeic worm species do not show the D. octaedra seasonal pattern as obviously, probably because these species are able to move more freely through the soil and because they are able to aestivate. These changes are likely to be due to a combination of human movement of earthworms (e.g. D. attemsi) and variations in local climate.

- by Emma Sherlock and +1
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- Soil Science, Climate Change, Climate, Biological Sciences

Trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings were grown at uniform air temperatures but different soil temperatures (5, 15, and 25°C), and gas-exchange and growth characteristics were examined during active growth and early dormancy. At 5°C, Populus tremuloides had no root growth and limited growth in leaf area and shoot mass compared with the large increases in leaf and shoot mass at 25°C. In contrast, Picea glauca had some root growth at 5°C and moderate growth of roots at 15 and 25°C; however, there were no differences in aboveground mass at the different soil temperatures. Net assimilation and stomatal conductance in Populus tremuloides were reduced with decreasing soil temperatures, while in Picea glauca soil temperatures did not affect these gas-exchange variables. In both species, root mass was higher in the dormant period than during the growing period, while root volume remained constant. Generally, the growth variables of Populus tremuloides were more suppressed by cold soils than in Picea glauca. Root total nonstructural carbohydrates (TNC) decreased between the active growth and dormancy period by nearly 50% in Populus tremuloides, while there was no change in TNC in Picea glauca. Results suggest a more conservative use of TNC reserves in Picea glauca combined with a tolerance to cold soil temperatures compared with Populus tremuloides.

- by Annie Desrochers and +1
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- Earth Sciences, Canadian, Environmental Sciences, Soil Temperature

Earthworm burrows contribute to soil macroporosity and support diverse microbial communities. It is not well known how fluctuations in soil temperature and moisture affect the burrowing activities of earthworms. The objective of this experiment was to evaluate the maximum depth and length of burrows created by the endogeic earthworm Aporrectodea caliginosa (Savigny) and the anecic earthworm Lumbricus terrestris L. for a range of temperatures (5-20 1C) and soil water potentials (À5 and À11 kPa). The laboratory microcosm was a plexiglass chamber (45 cm high, 45 cm wide) containing 0.14 m 2 of pre-moistened soil and litter, designed to house a single earthworm for 7 days. Earthworm mass, surface casting and burrowing activities were affected significantly by soil temperature, moisture and the temperaturemoisture interaction. Burrow length and maximum burrow depth increased with increasing temperature, but there was less burrowing in wetter soil (À5 kPa) than drier soil (À11 kPa). Weight gain and surface casting, however, were greater in soil at À5 kPa than À11 kPa. Our results suggest more intensive feeding and limited burrowing in wetter soil than drier soil. Earthworms inhabiting the non-compacted, drier soil may have pushed aside particles without ingesting them to create burrows. The result was that earthworms explored a larger volume of soil, deeper in the chamber, when the soil was drier. How these burrowing activities may affect the community structure and activity of soil microorganisms and microfauna in the drilosphere remains to be determined.

- by Joann Whalen
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- Plant Biology, Soil sciences, Soil Temperature

This study compares the CH 4 fluxes from two arctic wetland sites of different annual temperatures during 2004 to 2006. The PEATLAND-VU model was used to simulate the emissions. The CH 4 module of PEATLAND-VU is based on the Walter-Heimann model. The first site is located in northeast Siberia, Indigirka lowlands, Kytalyk reserve (70 • N, 147 • E) in a continuous permafrost region with mean annual temperatures of −14.3 • C. The other site is Stordalen mire in the eastern part of Lake Torneträsk (68 • N, 19 • E) ten kilometres east of Abisko, northern Sweden. It is located in a discontinuous permafrost region. Stordalen has a sub arctic climate with a mean annual temperature of −0.7 • C. Model input consisted of observed temperature, precipitation and snow cover data.

- by Trofim Maximov
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- Earth Sciences, Biological Sciences, Environmental Sciences, Biogeosciences