bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation in novice and expert parachutists while jumping
Authors: Roth Walton T. , Breivik Gunnar , Jørgensen Per Erik , Hofmann Stefan
Published: February 2007

Heart and respiration rates were measured ambulatorily in 16 novice and 25 expert (>380 delayed free‐fall jumps) sports parachutists while making a static‐line jump. Self‐reported anxiety and heart rate peaked near the point of jumping in both groups rather than earlier in experts, as reported by Fenz, and Epstein (1967, Psychosomatic Medicine, 29, 33–51). While sitting in the airplane 1 min before exit, mean heart rate was 124 bpm in novices and 102 in experts and increased during jumping to 170 and 145, respectively. The almost identical rise in the two groups could be accounted for largely by physical exertion, replicated with jumps from a training model on the ground. Exercise testing at a different location showed that experts were more fit. Respiration rate was higher in the airplane than at baselines, especially for novices. In conclusion, out results are more compatible theoretically with extinction of anticipatory anxiety than with learned anxiety inhibition.
Autonomic response patterns during voluntary facial action
Authors: Boiten Frans
Published: February 2007

The effects of six voluntarily adopted emotional facial expressions on heart rate, respiration, emotional report, and effort ratings were examined. The results indicate that the facial expressions that were most difficult to produce (anger, fear, and sadness) showed larger cardiac accelerations than those that were easy to produce (disgust and surprise); the happiness expression fell somewhere in between. Emotional self‐report revealed that in the majority of the facial configuration trials subjects experienced ones moderate or no emotion at all. In addition to the emotional configurations, a nonemotional expression was examined. Post hoc comparisons showed that the heart rate data of the nonemotional face were not significantly different from any of the other emotional expulsions. With respect to respiration, the production of facial expressions induced an increase in functional residual capacity, a decrease in tidal volume, shortened inspirators and expiratory phase duration, and an increase in inspiratory pause duration. These effects were most pronounced during the facial expressions that were difficult to produce. We conclude that changes in heart rate are not the consequence of the capacity of facial activity to recruit emotion‐specific autonomic activity but instead are modulated by effort‐related changes in respiration.
An ERP developmental study of repetition priming by auditory novel stimuli
Authors: CYCOWICZ YAEL M. , FRIEDMAN DAVID , ROTHSTEIN MAIRAV
Published: February 2007

Event‐related potentials were recorded from participants 5–7, 9–11, 14–16, and 22–28 years old during an auditory novelty oddball task. In this task, stimuli about which the participant is not instructed (i.e., novel or uncategorized) typically elicit a more frontally oriented P3 scalp topography (novelty P3). In contrast, stimuli to which the participant must respond (i.e., target or precategorized) elicit a P3 with a more posterior scalp topography. Repetition of identical novel stimuli led to a similar reduction in novelty P3 amplitude for all age groups. Moreover, with repetition the shift in scalp topography of the novelty P3 to a more parietally oriented distribution was similar in children and adults. A second component, the P32(assumed to be an analog of the P3b), exhibited a repetition priming effect in both the adults and the youngest children. The fact that age‐related differences induced by novel repetition were small and not systematic indicates that the processing of novel information is similar across a wide age range.
Autonomic interactions and chronotropic control of the heart: Heart period versus heart rate
Authors: QUIGLEY KAREN S. , BERNTSON GARY G.
Published: February 2007

Autonomic control of the heart varies more linearly with heart period than with rate. Relative linearity confers a greater independence of basal autonomic activation and heart period changes. Thus, heart period appears to be more appropriate for characterizing cardiac phenomena such as autonomic interactions that involve significant baseline shifts. Simulated and published empirical data were used to demonstrate the importance of the chronotropic metric for characterizing autonomic interactions. Simulations revealed a significant autonomic interaction when heart rate, but not heart period, was the chronotropic metric. Published heart rate data also show a substantial autonomic interaction, whereas heart period data do not. These findings suggest that the choice of chronotropic metric can overstate the extent of autonomic interactions on cardiac chronotropic function.
Magnetic fields elicited by tones and vowel formants reveal tonotopy and nonlinear summation of cortical activation
Authors: DIESCH EUGEN , LUCE THOMAS
Published: February 2007

A long‐latency response component (N1m) and the sustained field (SF) of the auditory evoked magnetic field elicited by two composite stimuli (a two‐tone combination and a two‐formant vowel) and their individually presented components (a 600‐Hz and a 2100‐Hz pure tone and two single‐vowel formants with formant frequencies matched to the tone frequencies) were recorded using a 37‐channel magnetometer. The response to the composite stimuli differed from the linear sum of the responses to the respective components in latency, equivalent dipole moment, and equivalent dipole location, suggesting an interaction among the processes elicited by the constituents of composite stimuli. Nlm and SF source locations were more medial for the response to the high tone than to the low tone and more medial for the response to the high vowel formant than to the low vowel formant. The Nlm formant sources were more lateral than the Nlm tone sources. These findings suggest that, at the level of the auditory cortex, vowels are represented in terms of both the spectral pitches determined by their most prominent harmonics and, within the latency range of the Nlm, the virtual pitch determined by the spacing of the harmonics.
Effects of foreperiod duration on reflexive and voluntary responses to intense noise bursts
Authors: SOLLERS JOHN J. , HACKLEY STEVEN A.
Published: February 2007

The question of whether a common mechanism underlies the facilitation of voluntary and reflexive reactions by a warning stimulus was investigated in two experiments. In both studies, the foreperiod preceding an intense noise burst was manipulated within and between blocks of trials. Previous reaction time experiments have shown that individuals respond fastest at the shortest foreperiod for between‐block manipulations and fastest at the longest foreperiod when foreperiod duration is varied unpredictably from trial to trial. In the present research, this pattern was found for voluntary hand‐grip responses, but acoustic startle blinks were facilitated at long foreperiods for both within‐ and between‐block manipulations. Invariance of the trisynaptic postauricular reflex across foreperiod conditions was evidence against any general activation of low‐level motor pathways by warning stimuli. Analyses of nonreflexive lid movements subsequent to startle blink suggested that inhibition of spontaneous blinking during the foreperiod may have contributed to the unexpected divergence between voluntary reactions and eyeblink reflexes.
An ERP study of visual spatial attention and letter target detection for isoluminant and nonisoluminant stimuli
Authors: WIJERS ALBERTUS A. , LANGE JAN J. , MULDER GIJSBERTUS , MULDER LAMBERTUS J. M.
Published: February 2007

The event‐related potential (ERP) effects of visual spatial attention and letter target detection for stimuli presented against a (nonisoluminant) dark background or against an isoluminant grey background were investigated. The goal was to study how the perceptual variable of luminance would influence early ERP reflections of selective attention. Such effects could further substantiate the claim that selective attention operates at the level of early perceptual processing and could provide evidence regarding the role of different visual routes in selective attention. Isoluminance increased the peak latency of the early ERP deflections (NP80, PI, and NI) by 40–50 ms. The ERP effects of spatial attention. consisting of PI and NI amplitude enhancements, were similarly delayed by isoluminance. supporting the idea that early selective processing is strongly dependent on bottom‐up perceptual processing. P300 latency and reaction time were delayed by 70–75 ms, the additional delay probably reflecting that isoluminance affected decision processes in addition to perceptual processes. Isoluminance left the scalp topographies of the early ERP deflections largely unaffected, although a slight shift of the NI topography in the isoluminant condition toward more inferior lateral posterior regions of the scalp could have reflected an increased contribution from ventral (occipitotemporal) brain areas. Relative to nontarget letters, targels presented at both attended and unattended spatial positions elicited an early contralaterally dominant lateral occipitotemporal negativity (N2pc). This ERP component is proposed to reflect an early, partly automatic process of template matching, consistent with indications from spatiotemporal dipole modelling that the N2pc was generated in inferior occipitotemporal brain regions.
Defensive hostility and anger expression: Relationship to additional heart rate reactivity during active coping
Authors: LARSON MARK R. , LANGER ALAN W.
Published: February 2007

The main purpose of the present study was twofold: (a) to assess the relationship between defensive hostility (high hostility/high defensiveness) and additional heart rate reactivity during active coping and (b) to determine if the construct of anger‐out might lend additional, sensitivity to the predictive power of the defensive hostility model. Forty individuals were randomly assigned to complete a mental arithmetic task with or without the threat of shock. Participants also completed the Cook‐Medley Hostility Inventory (Ho), the Marlowe‐Crowne Social Desirability Scale (MC), and the Spielberger Anger Expression Scale. Defensive hostile subjects (high Ho/high MC) were significantly more reactive than any other subgroup. In addition, the combination of low Ho/high anger‐out scores yielded a subgroup significantly less reactive than any other subgroup. These findings clarify the complex relationship of hostility and cardiovascular reactivity.
The psychopathic individual: A lack of responsiveness to distress cues?
Authors: JAMES RICHARD BLAIR ROBERT , JONES LAWRENCE , CLARK FIONA , SMITH MARGARET
Published: February 2007

In this study, we investigated the psychophysiological responsiveness of psychopathic individuals to distress cues and to threatening and neutral stimuli. Eighteen psychopathic individuals and 18 incarcerated control individuals, identified using the Revised Psychopathy Checklist (Hare, 1991, The Hare Pscyhopathy Checklist‐Revised, Toronto: Multi‐Health Systems), were shown slides of these three types of stimuli, and their electrodermal responses were recorded. The psychopathic individuals showed (relative to the controls) reduced electrodermal responses to the distress cues. In contrast, the two groups did not differ in their electrodermal responses to the threatening stimuli and to the neutral stimuli. The results are interpreted within the Violence Inhibition Mechanism model (Blair, 1995, Cognition, 57, 1–29) of the psychopathic individual.
45‐Hour continuous quintuple‐site actimetry: Relations between trunk and limb movements and effects of circadian sleep‐wake rhythmicity
Authors: MIDDELKOOP HUUB A. M. , VAN DAM ELLEN M. , SMILDE‐VAN DEN DOEL DINI A. , VAN DIJK GERT
Published: February 2007

Diurnal and nocturnal trunk and limb motor activity of 20 healthy individuals was evaluated by actimetry for 45 consecutive hours. Sleep was assessed by sleep logs. Overall, motor activity significantly (p < .05) decreased in the order wrist, ankle, and trunk. There was significantly more motor activity in the dominant wrist during the diurnal period. Motor activity was significantly affected by the 24‐hr sleep‐wake cycle, with lower levels and prolonged immobility during the night. Time series analyses revealed different but significant correlations between motor activity at all sites. These data imply that (a) motor activity should be recorded at the dominant wrist when the highest level of motor activity is of importance, (b) recordings at the nondominant wrist are better indicators of trunk movement than are dominant wrist recordings, and (c) sites other than the conventional nondominant wrist recording site should be evaluated to improve the validity of motor activity‐based sleep‐wake scoring.
A comparison of methods for the analysis of event‐related potentials in deception detection
Authors: ALLEN JOHN J. B. , IACONO WILLIAM G.
Published: February 2007

We previously reported that a Bayesian‐based event‐related potential memory assessment procedure (Allen, lacono, & Danielson. 1992, Psychophysiology. 29, 504‐522) was highly accurate at identifying previously learned material, regardless of an individual's motivational incentive to conceal information. When a bootstrapping procedure (Harwell & Donchin, 1991. Psychophysiology, 2ft, 531‐547) is applied to these same data, greater motivational incentives appear to increase the accuracy of the procedure. Receiver operating characteristic (ROC) curves were used to examine these two procedures and a new procedure. ROC curves indicated that all three methods produce extremely high rates of classification accuracy and that the sensitivity of the bootstrapping procedure to motivational incentive is due to the particular cut points selected. One or the other method may be preferred depending upon incentive to deceive, the cost of incorrect decisions, and the availability of extra psychophysiological data.
When syntax meets semantics
Authors: GUNTER THOMAS C. , STOWE LAURIE A. , MULDER GUSBERTUS
Published: February 2007

Three experiments concerning the processing of syntactic and semantic violations were conducted. Event related potentials (ERPs) showed that semantic violations elicited an N400 response, whereas syntactic violations elicited two early negativities (150 and 350 ms) and a P600 response. No interaction between the semantic and early syntactic ERP effects was found sentence complexity and violation probability (25% vs 75%) affected only the P600 and not the early negativities. The probability effect was taken as evidence that the P600 resembles the P3B, The temporal order of word processing in a sentence as suggested by the data was such that a more automatic syntactic analysis was performed (earlier syntactic‐related negativities) in parallel with a semantic analysis 9N400), after which a syntactic reanalysis was performed (P600). A reanalysis interpretation of the P600 could explain why the extent of the reanalysis differed with syntactic complexity and probability of ungrammaticality.
Effects of attentional and stressor manipulations on the P50 gating response
Authors: WHITE PATRICIA M. , YEE CINDY M.
Published: February 2007

The decline in amplitude of the P50 component of the event‐related potential to the second of paired clicks has been suggested as a measure of preattentional gating. Two experiments were conducted to assess the effects of attention and .a psychological stressor on P50. Experiment 1 included two choice reaction time tasks designed to direct attention selectively to the first or second click in each pair. Results suggest that the NIOO component was responsive to attentional manipulations, whereas P50 was not affected. Experiment 2 examined the impact of a brief psychological stressor on the P50 response Parallel mental arithmetic tasks were administered silently and orally. Self‐report and measures of autonomic activity were used to assess the level of stress occurring during the performance of the mental arithmetic tasks Results indicate that P50 suppression was sensitive to the acute stressor, the oral mental arithmetic task Implications of these findings for studies ofP50 suppression in schizophrenia are discussed.
Attentional modulation of the cardiac defense response in humans
Authors: VILA JAIME , PÉREZ MARÍA NIEVES , DEL CARMEN FERNÁNDEZ MARÍA , PEGALAJAR JOAQUÍN , SÁNCHEZ MARÍA
Published: February 2007

How cardiac components of the defense reaction are modulated by attentional factors related to sensory intake versus sensory rejection was examined. Forty‐eight men participated in a test of the heart rate response to three presentations of an intense auditory stimulus while performing one of three attentional tasks during the 80 s following stimulus onset: (a) internal (rejection) task, (b) external (intake) task, and (c) no task. Results showed a potentiation of the defense response only under the external attention condition. We concluded that defensive reactions, far from provoking the rejection of the aversive stimulus, require allocation of attention to processing that stimulus in detail.
Relationships between startle and cardiovascular reactivity
Authors: GAUTIER CLARA H. , COOK EDWIN W.
Published: February 2007

Although startle and cardiovascular reactivity have been studied extensively, little is known about their relationship. In the present study, we examined cardiovascular responses and affective startle modulation in 112 normotensive individuals varying in self‐reported fearfulness and parental cardiovascular health history. An initial intense noise burst elicited a phasic cardiac acceleration that was larger for fearful individuals. Startle blink responses were larger during aversive than during pleasant relaxing imagery but did not differ with fear group. Cognitive challenge tasks elicited heart rate and blood pressure increases that were unrelated to fearfulness or parental health history. However, greater startle potentiation by aversive imagery predicted larger pressor responses to cognitive challenge, especially among men. The observed relationship between startle and cardiovascular reactivity suggests a common mechanism for their affective modulation.
The role of comparison questions in physiological detection of deception
Authors: HOROWITZ STEVEN W. , KIRCHER JOHN C. , HONTS CHARLES R. , RASKIN DAVID C.
Published: February 2007

Comparison questions in physiological detection of deception were studied with 60 “guilty’ and 60 “innocent’ participants in a mock crime experiment. Different types of comparison questions were used in four conditions: relevant–irrelevant (R‐I) participants answered only relevant and neutral questions; trivial directed lie participants were instructed to lie to three of the six neutral questions; personal directed lie participants were instructed to lie to personally relevant questions; and probable lie participants received traditional probable lie comparison questions. Respiration, cardiovascular, vasomotor, and electrodermal activity were recorded. Manipulation of the comparison questions produced different patterns of physiological responses for innocent but not for guilty participants. The R‐I test produced an unacceptable rate of false positive decisions.
Development of 14 multiplexed microsatellite loci for raccoons Procyon lotor
Authors: FIKE JENNIFER A. , DRAUCH ANDREA M. , BEASLEY JAMES C. , DHARMARAJAN GUHA , RHODES OLIN E.
Published: February 2007

In order to complement ecological information with genetic data we isolated and characterized 14 polymorphic microsatellite markers from raccoons (Procyon lotor). Three multiplexed panels comprising the loci were developed and 29 individuals from a contiguous habitat patch in northern Indiana, USA were genotyped. The number of alleles per locus ranged from four to 18, and overall heterozygosities ranged from 0.31 to 1.00. One locus was identified as possibly being X‐linked, since males appeared to be hemizygous. Data generated using these markers will be used to further our understanding of small‐scale raccoon population dynamics in a highly fragmented landscape.
Recent trends in lime use and soil pH in England and Wales
Authors: Church B. M.
Published: February 2007

Abstract. Survey information on the use of lime in England and Wales between 1974 and 1983 shows year‐to‐year fluctutions but no marked trend. Areas limed per year are compared for different types of region and cropping, and estimates given of the percentages of agricultural soils by pH according to rotation type. There was no general change in soil acidity between 1969–73 and 1974–78 but recent data show some reductions in grassland pH.
Acidification of soils by trees and forests
Authors: Hornung M.
Published: February 2007

Abstract. The impact of isolated trees and natural forest vegetation on soil acidity is discussed. There is a considerable variation in impact between species on similar soils and between sites for any given species. The effect of coniferous plantations on soil acidity is reviewed and the causes of any increased acidity discussed. Crop species, initial soil conditions, silvicultural practices and the proportion of the tree removed at felling are all important factors influencing the long‐term impact of plantations on soil acidity.
Causes of soil acidification: a summary
Authors: Rowell D. L. , Wild A.
Published: February 2007

Abstract. A review of recent data shows that (i) dissolved CO2 has its greatest acidifying effect in soils with pH values above about 6.5, (ii) fertilizers containing NH−1+ ions or urea will acidify soil whether the ions are taken up directly by plants or are first nitrified, (iii) oxidation of nitrogen and sulphur in soil organic matter causes acidification especially after deforestation, and (iv) the acidifying effect of rainfall and dry deposition is due to sulphuric and nitric acids, SO2 and NH−1+ ions. A table is given showing the order of magnitude of each source of acidification.
Long‐term rates of acidification of UK upland acidic soils
Authors: Edwards A.C. , Creasey J. , Skiba U. , Peirson‐Smith T. , Cresser M.S.
Published: February 2007

Abstract. The approximate time‐scales for serious lowering of the base status of acidic upland soils in northeast Scotland have been based on assessments of geochemical weathering rates in two upland catchments. Periods of 1100 and 12000 years are obtained for soils evolved primarily from granite and quartz‐biotite‐norite respectively. Factors regulating the rate of removal of base cations in drainage water are discussed, to elucidate those which significantly influence long‐term rates of soil acidification. The relationship between base cation leaching and river water acidity is briefly considered.
Computer simulation of winter leaching losses of nitrate from soils cropped with winter wheat
Authors: Whitmore A.P. , Addiscott T.M.
Published: February 2007

Abstract. A computer simulation model was used to estimate the effects of season, site, sowing date, residual‐N after harvest, autumn‐N and field drains on winter losses of nitrate from soils growing winter wheat. The simulations were based on weather data between 1970–71 and 1983–84 and soil data from Rothamsted and Woburn. The residual‐N after harvest was predicted to have most effect on nitrate losses, followed by season and site. For the values of residual‐N and autumn‐applied fertilizer‐N tested, the predicted average nitrate‐N losses differed between seasons by up to 100 kg N ha‐1, and the nitrate‐N concentrations varied between 30 and 80 mg N l‐1.
Cultivation and drainage performance on former opencast coal mining land
Authors: Scullion J. , Mohammed A.R.A.
Published: February 2007

Abstract. The effect of various cultivation sequences on the performance of field drainage systems was investigated in a number of case studies carried out on former opencast coal mining land. Comparisons of drain flow patterns before and after cultivation indicated marked deteriorations in performance following preparation of the final seedbed. Neither mouldboard ploughing nor discing alone affected drain flow.

Soil moisture, hydraulic conductivity and drain flow data suggested that drainage performance may have deteriorated as a result, initially, of secondary drainage channels being blocked with fine materials translocated from the seedbed. A subsequent collapse of tilth to form a surface pan reinforced this adverse effect. It was not clear to what extent the failure of secondary drainage channels contributed to this collapse.

Implications for the management of former opencast land and the advantages of various cultivation techniques are discussed.
Computerized quality control, statistics and regional mapping of the concentrations of trace and major elements in the soil of England and Wales
Authors: McGrath S.P.
Published: February 2007

Abstract. An automated system for the chemical analysis of large numbers of soil samples from a national survey has been developed. Computers are used for the quality control and the management of the resulting data. The software for this includes checks for possible errors thereby minimizing them. Human intervention is necessary only to correct them. Additionally, the data are analysed statistically and the geographical distribution automatically displayed in map form. Much of the software runs interactively, enabling rapid reporting of results and mapping of specific areas cheaply and swiftly with little effort from the operator.
Variation of rainfall ‐ the background to soil and water management in dryland regions
Authors: Dennett M.D.
Published: February 2007

Abstract. Dryland regions are found in both tropical and middle latitudes. In the former, rainfall occurs mainly as a result of convection giving greater spatial variation than in the latter, where much rainfall is associated with frontal systems. The year‐to‐year variation in rainfall regimes is illustrated with examples from dryland regions in Kenya, Botswana and Syria. The importance of the fact that most rain occurs on few rain days is discussed. Although forecasting of rainfall is not possible, crop management can be improved by taking into account the current state of the rainy season. The need for an effective description of the rainfall regime is emphasized.
Soil salinization as an effect of grazing in a native grassland soil in the Flooding Pampa of Argentina
Authors: Lavado Raul S. , Taboada Miguel A.
Published: February 2007

Abstract. The salt regimes in soil under grazed and ungrazed natural grassland were compared on a Natraquoll in the Flooding Pampa of Argentina. The salt concentration in the topsoil of the grazed land increased sharply and episodically after flooding, whereas in the ungrazed land it did not.

When the area was flooded groundwater rose and increased the salt content of the deep horizons. Thereafter the topsoil became salinized during drought when the atmospheric water demand was large. The evaporation from the soil surface in the grazed area was faster than in the enclosed field, being probably the cause of the accumulation of salts in the topsoil.
Long‐term leakage of nitrate from bare unmanured soil
Authors: Addiscott T.M.
Published: February 2007

Abstract. The Rothamsted Drain Gauges built in 1870 comprise blocks of soil, 0.5, 1.0 and 1.5 m deep, isolated laterally by brickwork and undermined for the collection of drainage water but otherwise undisturbed. The soil has not been cropped, manured or cultivated subsequently. The annual nitrate leakages from these blocks were recorded for the 38 years from 1877/8 to 1914/5. The soil in the 0.5 and 1.5‐m gauges lost on average about 45 kg ha−1 of nitrate‐N per year during the first seven years of this period; that in the 1.0‐m gauge lost slightly less. The overall decline in leakage was masked by large annual fluctuations attributable mainly to variation in rainfall. Fitting a simple function that assumed an exponential decline and took account of rainfall fluctuations gave a rate constant for each gauge from which the half‐life could be estimated for the organic nitrogen feeding the leakage. The half‐life for the 1.5‐m gauge was 41 yr. The average nitrate leakage during the first seven years of the record differs little from estimates of the current leakage from soil carrying fully fertilized crops of winter wheat. This and the long half‐life of the leakage show that pollution of drainage water by nitrate will not be controlled by limiting the use of fertilizer in the short term.
Predicting the lime requirement of soils under permanent grassland and arable crops
Authors: Goulding K.W.T. , McGrath S.P. , Johnston A.E.
Published: February 2007

Abstract. Graphs of soil pH against time were plotted for the Park Grass Experiment at Rothamsted Experimental Station, begun in 1856, and the Long‐term Liming Experiments at Rothamsted and Woburn farms, begun in 1962. These showed that the magnitude and duration of the effect of lime applications varied with soil type, initial pH, fertilizer nitrogen application, and the crop grown. Simple equations for each situation were linked to form an empirical model which, with appropriate input data for soil type, crop, and initial and target pH, predicted the lime needed to reach that pH. Model predictions compared well with estimates from a Woodruff‐type buffer method. The model forms a sound basis for a more comprehensive lime requirement model covering the whole of the United Kingdom.
Factors affecting the cropping potential of reinstated soils
Authors: Younger A.
Published: February 2007

Abstract. Comparisons of crop production on recently reinstated soil in Northumberland have shown that the reduced yield potential of such soil may not be inevitable. Storage of soil in bunds did not greatly reduce subsequent crop yields, but failure to drain the land did. Provided an effective drainage scheme was installed, arable and grass crops could be grown successfully, responding very well to additions of nitrogen fertilizer and other normal good husbandry practices. To date it seems that neither deep cultivation nor the use of grass leys were as effective in the restoration process as had been expected.
Changes in the microbial community and physico‐chemical characteristics of topsoils stockpiled during opencast mining
Authors: Harris J.A. , Birch P. , Short K.C.
Published: February 2007

Abstract. Experiments on the effects of stockpiling soil on an opencast coal mine in Derbyshire showed that there were significant changes in the microbial community. Numbers of aerobic bacteria in stored soils ranged from 0.5 to 12.8 ± 107 colony‐forming‐units (CFU)g‐1 with the smallest values being in the deepest parts of the oldest stores, whereas an adjacent undisturbed soil contained 6.6 ± 107 CFU g‐1. There was a greater effect on the numbers of fungal spores, which ranged from 0.1 to 6.7 ± 105 CFU g‐1 soil, all less than the 10 ± 105 CFU g‐1 recorded for the undisturbed control soil. The number of fungal spores in the deepest part of the older soil stores was only 1/100 of the number in the undisturbed soil. This was mirrored by the biomass values, as determined by adenosine triphosphate (ATP) assay. Values of ATP ranged from 0.38 to 13.13 nmol g‐1 as compared to 5.8 nmol g‐1 in the undisturbed soil. All three of these microbiological properties decreased in value with both age and depth of storage. Neither anaerobic nor spore‐forming bacterial numbers were greatly affected by storage.

The pH values tended toward neutrality in the deeper parts of the soil stores, and there was less organic matter in the older stores.
A comparison of nutrient losses following grassland improvement using two different techniques in an upland area of mid‐Wales
Authors: Roberts A.M. , Hudson J.A. , Roberts G.
Published: February 2007

Abstract. Water samples from ditches draining small upland areas in mid‐Wales were collected before, during and after the improvement of the pasture using two different cultivation techniques. The samples were analysed for nitrogen, phosphorus, potassium and pH. The greatest release was associated with disc harrowing where nitrogen, in its nitrate form, exceeded European Economic Community maximum recommended concentrations for potable water supply for two weeks. Smaller losses of nitrogen, in the ammonium form, and of ortho‐phosphate were observed following a minimum cultivation technique. It is concluded that, on a scale normally associated with upland Britain, pasture improvement is not likely to deteriorate significantly the quality of runoff within water supply catchments. This is confirmed by the results obtained from monitoring streamflow from catchments in which some degree of pasture improvement had been undertaken in the past.
Problems in the use of urea as a nitrogen fertilizer
Authors: Bremner J.M.
Published: February 2007

Abstract. N‐(n‐butyl) thiophosphoric triamide (NBPT) is the most effective compound currently available for retarding hydrolysis of urea fertilizer in soil and for decreasing ammonia volatilization and nitrite e accumulation in soils treated with urea. It is a poor inhibitor of plant or microbial urease, but decomposes quite rapidly in soil with formation of N‐(n‐butyl) phosphoric triamide, which is a potent inhibitor of urease activity.

The adverse effects of urea fertilizers on seed germination and seedling growth in soil are due to ammonia produced through hydrolysis of urea by soil urease. They can be eliminated by addition of a urease inhibitor to these fertilizers.

The leaf‐burn commonly observed after foliar fertilization of soybeans with urea results from accumulation of toxic amounts of urea in the soybean leaves rather than formation of toxic amounts of ammonia through urea hydrolysis by leaf urease. Leaf‐burn is accordingly increased rather than decreased by addition of a urease inhibitor to the urea fertilizer applied.
Allium white rot and its control
Authors: Entwistle A.R.
Published: February 2007

Abstract. White rot (Sclerotium cepivorum) causes serious losses in Allium crops throughout the world. The pathogen produces sclerotia which survive for long periods and are the main source of inoculum. Sclerotial germination is stimulated by the host and new sclerotia are produced on the host near the soil surface. Allium crops are cultivated in various systems and environments and no one method of control is effective. There is increasing interest in control strategies based on combinations of treatments which decrease the populations of sclerotia in the soil, thereby improving the effectiveness of present methods of control. Materials and methods being tested for inclusion in programmes of integrated control include germination stimulants, soil fumigants, solar heating, roguing, aerobic composting, microbial control and combined chemical/microbial control with fungicide‐resistant micro‐organisms.
Relationships among rainfall, runoff and soil loss for the design of soil and water conservation works in submontane Punjab
Authors: Hadda M.S. , Kukal S.S.
Published: February 2007

Abstract. Linear, exponential and power function regressions were compared for rainfall, runoff and soil loss data. The power function performed better (R2= 0.77) than exponential or linear functions for estimating runoff from daily rainfall. However, this relationship was improved (R2= 0.96) by inclusion of a random component to the deterministic part of the function. A linear relationship between runoff and soil loss data performed better (R2= 0.77) than exponential or power functions. These relationships help in designing soil and water conservation works for supplemental irrigation in the area.
Dealing with contaminated soils
Authors: Bridges E.M.
Published: February 2007

Abstract. Although there is a need to protect soils against future pollution, many sites are already badly contaminated by past activity. The paper describes some of the contaminants which affect soils, and the policies for acceptable levels adopted by national governments. Various appropriate clean‐up policies are discussed.
Soil Ca, Al, acidity and penetration resistance with subsoiling, lime and gypsum treatments
Authors: McCray J. M. , Sumner M. E. , Radcliffe D. E. , Clark R. L.
Published: February 2007

Abstract. Crop growth on strongly weathered soils is often limited by soil compaction in addition to aluminium toxicity and/or calcium deficiency. This study examines the effects of subsoiling, lime and gypsum on penetrometer resistance, acidity, aluminium and calcium levels and cotton (Gossypium hirsutum L.) root growth on soils transitional between Cecil and Appling series (clayey, kaolinitic, thermic Typic Hapludults) in the Piedmont region of Georgia, USA. The main plots were subsoiled to depths of 0.35 or 0.80 m or untreated. Dolomitic limestone (0 or 4.03 t per hectare on subplots) and phosphogypsum (0 or 10 t per hectare on sub‐subplots) were incorporated into the surface soil (0.15 m). Deep subsoiling (0.80 m depth) decreased penetrometer resistance at 0.3–0.5 m depth and increased yield in two of three years, but there was no response to shallow subsoiling (0.35 m depth). Lime increased yield when surface soil water pH prior to amendment was less than a Cate‐Nelson critical value of 4.6. Gypsum moved downward much more rapidly than lime, increasing soil solution calcium ion activity to a depth of 0.8 m within 5 months of application. There were differences in clay content between replicate plots and calcium movement was faster where the clay content was less. Yield responses to gypsum in 1986 were attributed to increased root growth below 0.2 m resulting from the increased calcium ion activity. Yield response to gypsum in limed sub‐subplots was significant only in 1986.
Prototype agricultural land evaluation systems for Canada: II. Selected applications and prospects
Authors: Brklacich M. , MacDonald K. B.
Published: February 2007

Abstract. This paper describes the application of prototype Canadian land evaluation systems to selected issues. Two categories of applications are recognized. Routine evaluations employ standardized data sets and provide a backdrop for framing broader land‐related concerns (e.g. assessments of land supply and suitability). Iterative analyses investigate implications of modified conditions (e.g. soil erosion, global climatic warming, altered food demands) on land use and production options, and require additional data and expertise. The paper demonstrates the capacity of land evaluation systems to address a wide range of issues, and illustrates the range of skills required to maintain and apply these systems.
Adsorption and leaching behaviour of the herbicide alachlor (2‐chloro‐2′, 6′diethyl‐N‐(methoxymethyl) acetanilide) in a soil specific management
Authors: Vink J. P. M. , Robert P. C.
Published: February 2007

Abstract. Uniform application rates of fertilizers and herbicides may result in over‐treating some soils and under‐treating others; costs may be unnecessarily large and soil, ground water and surface waters may be contaminated. An alternative is site specific treatment, tailored to individual soil types present in agricultural fields of any size. To study the pollution hazards of the herbicide alachlor, leaching and adsorption experiments used disturbed samples and undisturbed soil columns. Adjoining Ves, Normania and Webster soil series (Udic Haplustoll; Aquic Haplustoll; Typic Haplaquoll) were sampled and analysed for various properties. Ring uniformly 14C‐labelled alachlor was used to study adsorption and leaching characteristics in these soils. Results show different alachlor behaviour in topsoil and subsoil layers.
An approach to the identification of potentially toxic concentrations of manganese in soils
Authors: Goss M. J. , Carvalho M. J. G. P. R. , Cosimini V. , Fearnhead M. L.
Published: February 2007

Abstract. The tolerance of wheat plants to manganese is shown to depend on the magnesium concentration in shoot tissue, such that growth is a function of the ratio of the two ions Mg: Mn. This ratio in the plant (Rp) and in the soil solution (Rs) was related by the equation:

ln Rp= 1.45+0.31 ln Rs.

Values of Rp not limiting to growth need to be determined for different crops, but we conclude that corresponding values of Rs can be predicted using solution culture trials. They can then be used to identify remedial treatments in soils where manganese toxicity occurs. In the Eutric Cambisol examined, small amounts of calcium carbonate decreased manganese concentrations in the soil solution such that amounts of magnesium which could easily be applied to a field gave appropriate values of Rs for wheat.
Water availability in a restored soil
Authors: Davies R. , Younger A. , Chapman R.
Published: February 2007

Abstract. The water contents of a restored and an undisturbed soil were monitored over two ‘dry’ growing seasons in order to examine the differences in crop water availability from different horizons. Bulk density was approximately 10% greater in the topsoil of restored land than in undisturbed land, and the water holding capacity was less, probably because there was less organic matter. In the subsoil a major problem was the inability of the soil to allow winter rainfall to recharge the water reserves. Bulk density and penetration resistance were greater in the restored subsoil than in the undisturbed subsoil. Increases in penetration resistance on drying may have restricted rooting activity, especially in the restored subsoil.

Ripping of the subsoil to a depth greater than the usual 0.5 m, possibly early in the year in a grass crop to allow new root growth to exploit the cracks, may increase water availability for future dry seasons.
Irrigation and dryland cultivation effects on the surface properties and erodibility of a Zimbabwe vertisol
Authors: Hussein Janet , Adey M. A. , Elwell H. A.
Published: February 2007

Abstract.Changes in chemical and physical properties and erodibility of a vertisol were studied in relation to land use. The vertisol, which occurs extensively in the semi‐arid south‐east of Zimbabwe, is derived from basalt and has a self mulching surface layer. Irrigated crops show static yields despite introduction of improved varieties. Four uncultivated sites were selected as controls and compared with five irrigated and four dryland sites. Surface soils were analysed for a range of chemical and physical properties, and laboratory rainfall simulation was used to measure soil erodibility under high intensity rain. The irrigated soils had greater exchangeable sodium and available phosphorus than the uncultivated soils. In contrast, dryland soils showed no such changes apart from a decrease in the amount of small water‐stable aggregates. The soils are very erodible under high intensity rain but no significant differences were found between sites. We conclude that, although soil chemical changes have taken place in the irrigated soils, significant soil degradation has not occurred at the sites examined. The static yields probably result from management problems. However, immediate measures should be taken to improve drainage and irrigation management in the irrigated soils to avoid further sodium increases.
The effect of ditches, slope and peat thickness on the water regime of a forested gley soil
Authors: Ray D. , White I. M. S. , Pyatt D. G.
Published: February 2007

Abstract. The soil water regime was monitored at a forested experimental site in Cumbria, UK. Over an 83‐week period following the clearfelling of 35‐year‐old Sitka spruce, soil water level measurements were related to total weekly rainfall in drainage treatment plots (10, 20 and 40 m ditch spacing) in three replicate blocks. Analysis showed a block × treatment interaction which might be related to soil differences between blocks. Significantly deeper soil water levels were measured in the most intensively drained plots of the two gently sloping blocks on a peaty gley soil. Drainage intensity had no effect on soil water level in the third block situated on a surface‐water gley soil on a steep slope.
Nitrogen leaching from soils in the Kopais area of Greece
Authors: Theocharopoulos S. P. , Karayianni M. , Gatzogiani P. , Afentaki A. , Aggelides S.
Published: February 2007

Abstract.The contribution of agriculture to the nitrogen pollution of surface and ground waters of calcareous lake soils in the Kopais area (190 km2) of Greece was studied over three cropping seasons. Sample fields were chosen from seven representative soil units under different crop rotations. The distribution of mineral N (NO3‐N + NH4‐N) throughout the soil profile and the concentration of NO3‐N in the ground water and drainage water were measured and allocated to 6‐month winter or spring periods. For all fields N was leached to the deeper soil layers and to the saturated zones by both excess winter rainfall and spring irrigation of different crops The amount of nitrogen leached depended on the amount of nitrogen fertilizer applied; the depth of leaching varied with the physical properties of the soils. Losses in individual fields accounted for the equivalent of 17.6–80.8% of the nitrogen applied to maize and 70.5–94.1% of that applied to wheat. For the whole region estimated minimum N losses ranged from 175, 912 to 783, 564 kg for the 6‐month period. Nitrate concentrations in the ground and surface waters were often more than the EC target level of 25 mg/1.
The components of variation associated with sampling soil for the measurement of major and trace nutrients in grazed fields in S.E. Scotland
Authors: Cameron D. , Paterson J.E. , Hunter E.A.
Published: February 2007

Abstract. The laboratory, spatial and temporal components of variation associated with sampling soil for the measurement of pH, organic matter and extractable P, K, Mg, S, Cu, and Co were studied over two years using soil samples from 15 farms in S.E. Scotland. On each farm a selected field was divided into 4–8 sectors, and sampled three times each year, in June, August and October, by bulking 25 cores taken in a ‘W’ pattern. Analysis of variance showed that inter‐field variation was greater than that between sampling dates for most of the properties measured. Restricted Maximum Likelihood Estimation showed that for all elements except K and S the variation between fields was greater than that within a field. Temporal variation was usually smaller than spatial, but K and Co showed similarly small temporal and spatial variations. Variation associated with laboratory procedures was much less than either spatial or temporal variation except for S, most of the total observed variation of which resulted from laboratory error. It is suggested that the most cost effective field sampling technique is to split a field into sectors, sample each individually and analyse a bulked sample made up from the sectors.
Agro‐climatic zoning and physical land evaluation in Jamaica
Authors: Batjes N.H.
Published: February 2007

Abstract. Analysis of agro‐climatic conditions forms the first stage of physical land evaluation. Monthly rainfall, potential evapotranspiration and air temperature data are analysed by the agro‐climatic module of the Jamaica Physical Land Evaluation System (JAMPLES). Dependable rainfall (R75), the minimum amount exceeded in a given time period in 75% of the years, ranges from 537 to 5332 mm/yr at the 141 recording stations under review, and mean potential evapotranspiration (PET) ranges from 1120 to 1580 mm/yr. Annual R75/PET ratios range from 0.3–5.0 island‐wide and regional differences permit delineation of four ‘moisture availability’ zones. These are subdivided with respect to the length of the ‘dependable’ growing periods (DGP) and dry periods. The DGP is less than 2 months in the southern coastal plains and 12 months long in the north‐eastern part of the island. Mean daily air temperature decreases from 26 to 13°C with elevation, permitting the delineation of five temperature classes. Suitable regions for growing particular crops can be determined with the Jamaica Geographical Information System (JAMGIS), which includes a digitized version of the 1:250000 map of agro‐climatic zones. More specific land suitability assessments, taking soil conditions and feasible land management practices into account, are prepared with the physical land evaluation module of JAMPLES.