bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehending how visual context influences incremental sentence processing: Insights from ERPs and picture‐sentence verification
Authors: Knoeferle Pia , Urbach Thomas P. , Kutas Marta
Published: August 2010

To re‐establish picture‐sentence verification—discredited possibly for its over‐reliance on post‐sentence response time (RT) measures—as a task for situated comprehension, we collected event‐related brain potentials (ERPs) as participants read a subject‐verb‐object sentence, and RTs indicating whether or not the verb matched a previously depicted action. For mismatches (vs. matches), speeded RTs were longer, verb N400s over centro‐parietal scalp larger, and ERPs to the object noun more negative. RTs (congruence effect) correlated inversely with the centro‐parietal verb N400s, and positively with the object ERP congruence effects. Verb N400s, object ERPs, and verbal working memory scores predicted more variance in RT effects (50%) than N400s alone. Thus, (1) verification processing is not all post‐sentence; (2) simple priming cannot account for these results; and (3) verification tasks can inform studies of situated comprehension.
Human Y‐79 Retinoblastoma Cells Exhibit Specific Insulin Receptors
Authors: Saviolakis George A. , Kyritsis Athanassios P. , Chader Gerald J.
Published: August 2010

The presence of insulin receptors was investigated in human Y‐79 retinobastoma cells grown in suspension culture. The binding of [125I] insulin to these cells was time, temperature, and pH dependent, was competed for by insulin and proinsulin but not other peptides, and was inhibited by antibodies against the insulin receptor. The Scatchard plot of insulin competition data was curvilinear and was resolved into a high‐affinity (KD∼0.5 × 10‐‐9 M)/low‐capacity (∼3,000 sites/cell) and a low‐affinity (KD∼ 1 × 10‐‐7M)/high‐capacity (∼155,000 sites/cell) component. Negative cooperativity was not found, in agreement with other studies in rodent neural cells. However, in contrast to studies with rodent cells, insulin specifically down‐regulated its receptor on human Y‐79 cells after prolonged exposure. In conclusion, these data show for the first time the presence of specific insulin receptors in human Y‐79 retinoblastoma cells. Because these cells were previously shown to have several characteristics typical of neural cells, we propose their use as a model to study the effects of insulin on neural and retinal tissues of human origin.
Differential Release of Endogenous 5‐Hydroxytryptamine, Substance P., and Neurokinin A from Rat Ventral Spinal Cord in Response to Electrical Stimulation
Authors: Franck Johan , Brodin Ernst , Fried Gabriel
Published: August 2010

Abstract: The release of endogenous 5‐hydroxytryptamine (5‐HT), substance P (SP), and neurokinin A (NKA) from superfused tissue slices of rat ventral lumbar spinal cord, where SP and NKA coexist with 5‐HT in terminals of descending bulbospinal neurons, was investigated. Electrical field stimulation was performed using square‐wave pulses of 2‐ms duration and 30 mA stimulus intensity. The following four different patterns of stimulation were used: 2 Hz continuous, 20 Hz continuous, 20 Hz intermittent, and 50 Hz intermittent. 5‐HT was measured in the slice superfusates by HPLC with electrochemical detection. SP and NKA were measured by radioimmunoassay. The release of 5‐HT was significantly enhanced using all stimulation paradigms and the evoked release of 5‐HT per pulse was independent of the stimulation frequency. The release was found to be calcium dependent and there was no increase in the efflux of 5‐hydroxyindoleacetic acid in response to stimulation. At 2 Hz (continuous), no significant increase in the release of SP was observed. Stimulation at higher frequencies yielded a significant increase in the release of SP per pulse. At 20 Hz, the release was increased by 73% (continuous) and 74% (intermittent), and at 50 Hz (intermittent) by 175% of basal efflux. The evoked release of NKA was also frequency dependent. At 2 Hz (continuous), no significant increase in the release of NKA was observed. At 20 Hz (intermittent), the evoked release per pulse was increased by 33% and at 50 Hz (intermittent) by 53% compared with the basal efflux of NKA. The results suggest that coexisting neurotransmitters/neuromodulators in the spinal cord may be released in different proportions depending on the stimulation frequency and that only 5‐HT is released when the nerve terminal is activated by low‐frequency stimulation.
The biphasic NAD(P)H fluorescence response of astrocytes to dopamine reflects the metabolic actions of oxidative phosphorylation and glycolysis
Authors: Requardt Robert P. , Wilhelm Franziska , Rillich Jan , Winkler Ulrike , Hirrlinger Johannes
Published: August 2010

J. Neurochem. (2010) 115, 483–492.

The NAD+/NADH redox pair constitutes an important metabolic node connecting catabolic pathways to energy production. We took advantage of the fluorescence of NADH to monitor changes in NADH levels by 2‐photon laser scanning microscopy in cultured cortical astrocytes and acutely isolated brain slices in response to dopamine (DA), a major neurotransmitter involved in modulation of attention, motivation, and learning. DA induced a dose‐dependent biphasic response of the NAD(P)H fluorescence signal, consisting of an initial decrease followed by a subsequent increase. This response was mediated by D1‐receptors, protein kinase A, and 5′‐AMP‐activated protein kinase signaling. While the initial decrease could be inhibited by blocking mitochondrial respiratory chain, the increase was inhibited by blocking glycolysis. Finally, activation of DA receptors on astrocytes in acutely isolated mouse cortical brain slices also induced an increase in the NAD(P)H fluorescence signal. We conclude that DA activates two opposing components of astrocytic metabolism with different kinetics. This response of the astroglial metabolism might contribute to fine‐tuned participation of astrocytes to neuronal activity and functional states of the brain.
Differential regulation of NMDA receptor function by DJ‐1 and PINK1
Authors: Chang Ning , Li Lijun , Hu Rong , Shan Yuexin , Liu Baosong , Li Lei , Wang Hanbin , Feng Hua , Wang Dianshi , Cheung Carol , Liao Mingxia , Wan Qi
Published: August 2010

Dysfunction of PTEN‐induced kinase 1 (PINK1) or DJ‐1 promotes neuronal death and is implicated in the pathogenesis of Parkinson’s disease, but the underlying mechanisms remain unclear. Given the roles ofN‐methyl‐d‐aspartate receptor (NMDAr)‐mediated neurotoxicity in various brain disorders including cerebral ischemia and neurodegenerative diseases, we investigated the effects of PINK1 and DJ‐1 on NMDAr function. Using protein overexpression and knockdown approaches, we showed that PINK1 increased NMDAr‐mediated whole‐cell currents by enhancing the function of NR2A‐containing NMDAr subtype (NR2ACNR). However, DJ‐1 decreased NMDAr‐mediated currents, which was mediated through the inhibition of both NR2ACNR and NR2B‐containing NMDAr subtype (NR2BCNR). We revealed that the knockdown of DJ‐1 enhanced PTEN expression, which not only potentiated NR2BCNR function but also increased PINK1 expression that led to NR2ACNR potentiation. These results indicate that NMDAr function is differentially regulated by DJ‐1‐dependent signal pathways DJ‐1/PTEN/NR2BCNR and DJ‐1/PTEN/PINK1/NR2ACNR. Our results further showed that the suppression of DJ‐1, while promoted NMDA‐induced neuronal death through the overactivation of PTEN/NR2BCNR‐dependent cell death pathway, induced a neuroprotective effect to counteract DJ‐1 dysfunction‐mediated neuronal death signaling through activating PTEN/PINK1/NR2ACNR cell survival–promoting pathway. Thus, PINK1 acts with DJ‐1 in a common pathway to regulate NMDAr‐mediated neuronal death. This study suggests that the DJ‐1/PTEN/NR2BCNR and DJ‐1/PTEN/PINK1/NR2ACNR pathways may represent potential therapeutic targets for the development of neuroprotection strategy in the treatment of brain injuries and neurodegenerative diseases such as Parkinson’s disease.
Twenty‐five years of monitoring pH and nutrient status of soils in England and Wales
Authors: Skinner R.J. , Todd A.D.
Published: August 2010

Abstract.The Representative Soil Sampling Scheme of England and Wales was started in 1969. During the 25 year period 1969–1993 mean soil pH values under arable and ley‐arable cropping changed little, but under grassland they fell by 0.3 units. Under arable cropping, mean available phosphorus declined whilst available potassium increased fairly steeply for the first eight years then declined again to near the start value by 1993. No significant changes in soil phosphorus and potassium levels were found under ley‐arable cropping, but the percentage of fields under ley‐arable rotations declined from 33% to 14%. Under grassland, phosphorus and potassium levels both declined, although potassium levels rose initially before falling.

For this report England and Wales were also divided into five regions. Wales and the West Country had the lowest pH values; these regions together with the Northern region were also found to have declining pH values. Phosphorus and potassium concentrations have been falling in the Northern region which stands out as having the lowest current potassium status with 20% of all fields deficient at index 0.

Changes in pH and nutrients are discussed for soils sampled following the main arable crops. The largest changes found were the reductions in phosphorus and potassium in soils after potatoes. In 1993 almost one in ten sugarbeet crop soils had an excessive phosphorus level (index 5+) giving an increased risk of water pollution by this element.

Under arable cropping the proportion of soils with low (< 1.8%) organic matter declined. Average soil organic matter levels for all crops and grass have remained static during the period. It is concluded that agricultural soils in England and Wales have not contributed to an increase in the greenhouse gas carbon dioxide.
Effect of hydroquinone, dicyandiamide and encapsulated calcium carbide on urea N uptake by spring wheat, soil mineral N content and N2O emission
Authors: Chen L. , Boeckx P. , Zhou L. , Van Cleemput O. , Li R.
Published: August 2010

Abstract. At present about half of the N fertilizer used in China is as urea. However, recovery of urea N in crops is often limited to 30–40%. Application of urea in combination with hydroquinone plus dicyandiamide (U‐HQ‐DCD) gave an improved urea‐N recovery and grain yield by spring wheat in a pot experiment. The apparent total urea‐N recovery was 69% and 73% of this recovered N was found in the grain. The grain yield was 32% higher than in the treatment where urea was applied without inhibitors. The application of hydroquinone and dicyandiamide also resulted in a smaller soil nitrate content, which might restrict post‐harvest leaching of N. Another beneficial effect of these inhibitors was that the N2O emission from the soil—plant system was reduced by 35% compared to the treatment where only urea was applied. The use of urea in combination with hydroquinone plus encapsulated calcium carbide gave smaller beneficial effects.
Contour grass strips for soil erosion control on steep lands: a laboratory evaluation
Authors: Boubakari M. , Morgan R. P. C.
Published: August 2010

Abstract. The effectiveness of Festuca ovina and Poa pratensis as contour grass strips for erosion control was examined in a laboratory experiment for an crodible sandy loam soil on 21, 25 and 29% slopes. No significant differences P<0.05 were observed in runoff between the plots with grass strips and bare soil but significant differences in soil loss were recorded. Both grasses reduced crosion in the early part of the simulated storms by ponding water behind the barrier, filtering sediment and causing deposition within the ponded area. The P. pratensis barrier was less rigid and became flattened under submergence in the later part of the storms. Runoff flowed over the grass strip forming rills on the slope below, which then cut back and undermined the barrier. These barriers resulted in as much soil loss as bare soil towards the end of the storms on all three slopes. The F. ovina was effective in controlling erosion on the 21% and 25% slopes but not on the 29% slope.
Effects of overwinter cover on nitrate loss and drainage from a sandy soil: consequences for water management?
Authors: Shepherd M.A. , Webb J.
Published: August 2010

Abstract. A lysimeter study from April 1993 to June 1997 assessed the effects of winter cover crops and unfertilized grass on both the volume of water draining over winter and the amounts of nitrate leached. There were three to five replicates of each treatment in a fully randomized design. The lysimeters were undisturbed monoliths of loamy medium sand, 1.2 m deep and 0.8 m diameter.

There were six treatments: sown cover before spring‐sown crops (SC), natural regeneration (‘tumbledown’) before spring‐sown crops (T), unfertilized grass (UG), bare soil permanent fallow, (PF), winter barley (WB) and conventional overwinter fallow before spring‐sown crops (WF). Sugarbeet replaced cereals in 1996 as a disease break, and in consequence no cover was established in SC and T in autumn 1996. Of the four years of the study, two were above‐average rainfall, while two were of less than average rainfall. Results are only quoted if statistically significantly different from WB (P=0.10).

Over the first winter, NO3―N losses were similar under UG (26 kg ha−1) and PF (29 kg ha−1), due to the slow establishment and growth of the grass. In the following three winters NO3―N losses under UG were small (c. 6 kg ha−1), giving an overall mean of c. 11 kg ha−1. Sown cover crops and T gave means of c. 16 and 22 kg ha−1 respectively, compared with c. 27–31 kg ha−1 under PF, WB and WF.

Mean NO3―N concentrations were smallest under UG (4.4 mg l−1) and SC (10.6 mg l−1), although both T (13.7 mg l−1) and PF (12.4 mg l−1) were less than under WB and WF (15.8–18.7 mg l−1). Overwinter drainage was greatest from UG and PF, at 239 and 247 mm respectively. In the three winters that cover crops were grown, drainage was decreased by, on average, 30 mm year−1 compared with WF. However, there were large differences in effects between years, with significant decreases in only one year.

We conclude that the widespread adoption of cover crops before spring‐sown crops will reduce overwinter drainage in UK Nitrate Vulnerable Zones by no more than c. 2%, compared with no cover before spring‐sown crops.
Predicting nitrogen availability and losses following application of organic manures to arable land: MANNER
Authors: Chambers B.J. , Lord E.I. , Nicholson F.A. , Smith K.A.
Published: August 2010

Abstract. A decision support system to predict the plant availability of nitrogen (N) following organic manure applications to land has been developed, drawing together the latest UK research information on factors affecting manure N availability and losses. The ADAS MANure Nitrogen Evaluation Routine (MANNER) accounts for manure N analysis, ammonia volatilization, nitrate leaching and mineralization of manure organic N. Only a few easily available inputs are required to predict the amount of N volatilized or leached, and the fertilizer N value for the next crop grown. Predictions from MANNER have been evaluated by comparison with independently collected data from a range of experimental studies where pig, cattle and poultry manures were applied to arable crops. Good agreement was found (r2 60–79%, P<0.001), confirming that MANNER can provide a reliable estimate of the fertilizer N value of farm manures spread to arable land under a range of conditions.
The effects of starter fertilizers on the growth and nitrogen use efficiency of onion and lettuce
Authors: Stone D. A.
Published: August 2010

Abstract. Broadcast granular fertilizers are inefficient at supplying nitrogen (N) to wide‐spaced row crops. Substantial nitrate residues can remain in the soil post‐harvest, even when recommended fertilizer practices are followed. This paper explores the benefits of an alternative strategy based on targeting small amounts of liquid nitrogen starter fertilizer close to the seed at drilling to increase N use efficiency and reduce potential pollution. Bulb onion (Allium cepa) and crisp lettuce (Lactuca sativa) were grown with various rates and combinations of ammonium phosphate (AP) and urea ammonium nitrate (UAN) as ‘starters’, in comparison with seedbed incorporated ammonium nitrate. AP consistently improved early growth and final yield of both crops compared to broadcast ammonium nitrate, but UAN showed no additional benefits. AP in combination with broadcast N, or injected UAN, generally increased N recovery, and produced yields of marketable quality produce matched only by much higher rates of broadcast N. A reduced N input system based on starter fertilizers is likely to be acceptable to the industry, but would rely on a method to predict how much N is required to supplement that provided by the starter.
Land requirements for Pinus halepensis Mill. growth in a plantation in Huesca, Spain
Authors: Olarieta J.R. , Usón A. , Rodríguez R. , Rosa M. , Blanco R. , Antúnez M.
Published: August 2010

Abstract. Land requirements for Pinus halepensis Mill. growth were studied in thirty plots of a 40 year‐old plantation in the semiarid Lower Ebro valley, northeast Spain, by comparing site index values to land characteristics. Site index at 40 years ranges from 4.1 m to 12.3 m. Moisture availability is the basic requirement for growth while nutrient availability has only a minor influence. Changes in moisture availability in the area are controlled by changes in soil rootable depth, with a minor effect of aspect. Soils developed on Tertiary gypsum rock are not suitable for afforestation with this species. Geomorphic and soil information may be combined, at various degrees of detail, to provide reliable estimates of Aleppo pine growth.
Comparison of type and depth of lysimeter for measuring the leaching losses of nitrogen under urine patches
Authors: Pakrou N. , Dillon P.J.
Published: August 2010

Abstract. A study of the leaching losses of nitrate under urine patches in irrigated and non‐irrigated dairy pastures in the South East of South Australia was undertaken with repacked and monolith lysimeters 1 m deep, and with monolith lysimeters 150, 300 and 450 mm deep. The aim was to quantify differences in measurements of drainage and nitrogen fluxes for these different lysimeters. Drainage of water and N flux were found to vary significantly between types and depths of lysimeters. Drainage volumes in repacked lysimeters were 78% and 33% more than in monolith lysimeters in irrigated and non‐irrigated paddocks, and N fluxes were 5 and 3 times higher in repacked lysimeters respectively. The results indicate that lysimeter estimates of recharge rates and N fluxes to water tables are best determined by leaching studies which are longer term, and use deep monolith lysimeters. Shorter term studies and the use of shallow or repacked lysimeters have potential to distort conclusions.
Residual tillage and bush‐fallow effects on soil properties and maize intercropped with legumes on a tropical Alfisol
Authors: Kirchhof G. , Salako F.K.
Published: August 2010

Abstract. After six years of bush‐fallow, residual effects on soil productivity of tillage practices prior to the fallow were investigated on an Alfisol in south western Nigeria. In 1996 fallow was followed by maize intercropped with cover crops of Pueraria phaseoloides, Mucuna pruriens or cowpea (Vigna unguiculata) and no intercrop. Parameters measured included soil properties, ground cover, crop growth and yield, rainfall erosivity, runoff and soil loss.

In spite of six‐years of bush‐fallow and establishment of cover crops, soil erosion was significantly greater on plots that had been conventionally cultivated previously using disc ploughs, harrows and mechanical rotovators (1.78 t ha−1season−1) compared to previously no‐till plots (1.34 t ha−1season−1). Crop growth and yields were least and soil loss greatest (2.83 t ha−1season−1) on the previous bare plot.

Maize grain yield was highest using Pueraria phaseoloides as an intercrop (2.15 t ha−1) followed by a cowpea intercrop (1.92 t ha−1), maize without intercrop (1.87 t ha−1) and Mucuna pruriens intercrop (1.71 t ha−1). The maize grain yields reflected levels of competition from the cover crops. Cowpea–maize intercrop may be most suitable for farmers because maize yields were satisfactory and cowpea grain serves as additional subsistence. Cowpea yields were 390 kg ha−1. Soil erosion was also moderate using cowpea as an intercrop (1.71 t ha−1season−1). However, Pueraria phaseoloides gave the best erosion control with a soil loss of 1.34 t ha−1season−1.
Pilot‐scale test of a soil filter for treatment of malodorous gas
Authors: Kikuchi R.
Published: August 2010

Abstract. A pilot‐scale test confirmed that malodorous air containing 600 mg l−1 ammonia can be passed through a soil filter with 98.5% removal efficiency. Furthermore, the concentrations of methyl mercaptan, dimethyl sulfide, dimethyl disulfide, actaldehyde, and trimethyl amine were also significantly reduced using soil as a filter. The tests provide technical information for planning of industrial‐scale soil filters: linear velocity, bed depth, properties of soil, reliability, and effects of soil deodorization on various types of odorous substances. It is concluded that the soil can be an effective filter to remove noxious and malodorous gases derived from industrial processes.
Development of improved advice for farmers and advisers
Authors: Dampney P.M.R. , Lord E.I. , Chambers B.J.
Published: August 2010

Abstract. The MAFF Nitrate Programme has provided policy makers and the agricultural industry with a much improved understanding of soil nitrogen cycling, and the cost‐effectiveness of a range of nitrate reduction strategies. This understanding has been disseminated as improved economically‐based advice on fertilizer N inputs to arable and grass crops, and information on the N value of livestock manures as affected by timing and method of application. In addition, strategies for reducing nitrate losses have been developed, including the use of over‐winter cover crops, the management of cultivations and crop residues, and the conversion of arable land to low‐input grassland.

A wide variety of information dissemination methods have been used, including face‐to‐face discussions, demonstrations, articles in the farming press, booklets aimed at farmers, technical information for advisers and consultants, recommendation reference books and computer‐based fertilizer recommendation systems.
The role of soil science in the land use negotiation process*
Authors: Bouma J.
Published: August 2010

Abstract. The hierarchial concept of land use planning becomes less relevant in a society with continuous interactions between stakeholders, researchers, planners and politicians. In this context, land use negotiation rather than land use planning appears to be the most appropriate concept. In the negotiation process, good quality data about the land is important as land properties are, obviously, key elements to be considered. Case studies at farm and regional level have been analysed to explore answers to a number of questions. How can soil data be presented most effectively? What are the research needs? How can the large existing body of data be mobilized most effectively? Studies on regional land use in Costa Rica used methods in a logical sequence including projections, explorations and predictions of land use patterns. The work involved upscaling of data, obtained at farm level, to the regional level. Work at farm level focussed on prototyping procedures in which farming systems were ‘designed’ by close interaction between farmers and scientists, including applications of precision agriculture. Soil data demands were analysed, emphasizing the effects of using data with different degrees of detail together with the application of pedotransfer functions which effectively transform existing data into parameters that are difficult or expensive to measure directly. This not only facilitated interactions with stakeholders but also with colleague scientists in interdisciplinary teams. In addition, use of Geographical Information Systems allowed visual presentations of alternative geographical land use patterns that were associated with various scenarios, thereby facilitating the interaction processes. A plea is made to increase interaction of stakeholders and researchers by considering research programmes as vehicles for joint learning.
The carbon content of topsoil and its geographical distribution in France
Authors: Arrouays D. , Deslais W. , Badeau V.
Published: August 2010

Abstract. An estimate of organic carbon stored in French soils to a depth of 30 cm was made using data from geo‐referenced databases. We produced statistics on carbon stocks in soils according to land use, different land uses and soil type. Then, using a combination of maps of soil and land use we were able to estimate regional and national carbon stocks. This soil carbon map of France allowed us to identify the main controlling factors of the carbon distribution: land use, soil type in some cases, clay content, and elevation. Carbon stocks in French soils were found to be about 3.1 Pg (1015g).
Field and modelling studies to assess the risk to UK groundwater from earth‐based stores for livestock manure
Authors: Gooddy D. C. , Hughes A. G. , Williams A. T. , Armstrong A. C. , Nicholson R. J. , Williams J. R.
Published: August 2010

Abstract. Boreholes have been constructed at eight sites on the Permo‐Triassic Sandstone and Chalk aquifers to assess the extent of chemical and microbiological contamination emanating from unlined farm manure stores. Slurry along fracture faces in the Chalk was found on cores taken from beneath two stores. Porewaters from the Chalk sites and one of the Sandstone sites were discoloured and showed high concentrations of nitrate, ammonium and organic carbon to depths in excess of 10 m. Although Cryptosporidia and Escherichia coli O157 were found in many of the cattle slurry lagoons, neither were found in the aquifer material beneath. The self‐sealing of unlined slurry stores is seen as a crucial step in minimizing leakage. A simple mass balance shows farm boreholes near to contaminant sources are at greater risk than public supply wells. Contaminant modelling shows discontinuing use of an unlined farm manure store will lead to little difference in solute concentrations over the short to medium term. Groundwater is most at risk where the water table is shallow since direct hydraulic connection between the lagoon base and the water table considerably increases the rate of vertical migration. This is of greatest significance for pathogens that are thought to be relatively short lived in the subsurface. Under the majority of situations minimal threat is posed to potable groundwater drinking supplies.
Phosphorus cycling in UK agriculture and implications for phosphorus loss from soil
Authors: Withers P.J.A. , Edwards A.C. , Foy R.H.
Published: August 2010

Abstract. Phosphorus (P) use in UK agriculture is reviewed and a P balance sheet presented. The productive grassland and arable area has accumulated an average P surplus of c. 1000 kg ha–1 over the last 65 years. Over the period 1935–1970, the annual P surplus more than doubled due to an increase in animal numbers and associated requirements for inorganic fertilizers and livestock feeds. Since 1970, surplus P has declined by c. 40% as crop yields and P offtake have continued to increase while fertilizer and manure P inputs have remained relatively constant. In 1993, P use efficiency (P imports/P exports) in UK agriculture was estimated at 25% leading to an average annual surplus of 15 kg P ha–1 yr–1, although the latter has since decreased slightly due to reduced fertilizer use. Intensification and specialization of agriculture has also increased the range in P surpluses that are likely between livestock and arable dominated systems. The largest P surpluses occur in the relatively limited areas of arable soils which receive manure from intensive pig and poultry units, whilst farms without manure inputs generate only small surpluses, or are in balance. The cumulative P surplus has led to a build‐up of soil total and easily‐exchangeable P, especially in areas receiving both fertilizers and manures. Fundamental differences in P use efficiency, surplus P accumulation and the potential for P loss to water, exist between arable and grassland farms and it is important to separate these, due to the marked regionalization of UK agriculture. More judicial use of feeds and fertilizers is required to further reduce the P surplus and minimize the long‐term risk of water eutrophication.
Mediterranean natural forest living at elevated carbon dioxide: soil biological properties and plant biomass growth
Authors: Moscatelli M.C. , Fonck M. , De Angelis P. , Larbi H. , Macuz A. , Rambelli A. , Grego S.
Published: August 2010

Abstract.Biomass productivity and soil microbial responses to long‐term CO2enrichment have been investigated in a Mediterranean natural forest ecosystem. Several biochemical parameters have been measured on soil samples taken from six open top chambers (OTCs), enclosing clumps of natural Mediterranean woody vegetation including:Quercus ilexL.,Phillyrea angustifoliaL.,Pistacia lentiscusL. andMyrtus communisL. The CO2concentration of the air inside the OTCs was either ambient or ambient plus 350 μmol mol–1(c. 710 ppm as mean daily value). Microbial C biomass, microbial respiration, dehydrogenase, β‐glucosidase, acid phosphatase and protease activities, inorganic N and soluble P, were tested in order to evaluate soil microbial size and activity. Statistically correlated seasonal patterns have been identified in some biochemical parameters in response to climatic conditions, soil nutritional status and the physiology of the vegetative cover.In situsoil respiration and above‐ and below‐ground productivity were also measured. Microbial responses to CO2enrichment were observed only at the beginning of the study and a general progressive reduction of the CO2effect was recorded as monitoring continued. These results are in agreement with data from literature regarding similar studies on natural complex communities.
Leaching and plant offtake of N in field pea/cereal cropping sequences with incorporation of 15N‐labelled pea harvest residues
Authors: Thomsen I.K. , Kjellerup V. , Christensen B.T.
Published: August 2010

Abstract. Field peas (Pisum sativum L.) were grown in sequence with winter wheat (Triticum aestivum L.) or spring barley (Hordeum vulgare L.) in large outdoor lysimeters. The pea crop was harvested either in a green immature state or at physiological maturity and residues returned to the lysimeters after pea harvest. After harvest of the pea crop in 1993, pea crop residues (pods and straw) were replaced with corresponding amounts of 15N‐labelled pea residues grown in an adjacent field plot. Reference lysimeters grew sequences of cereals (spring barley/spring barley and spring barley/winter wheat) with the straw removed. Leaching and crop offtake of 15N and total N were measured for the following two years. These treatments were tested on two soils: a coarse sand and a sandy loam. Nitrate concentrations were greatest in percolate from lysimeters with immature peas. Peas harvested at maturity also raised the nitrate concentrations above those recorded for continuous cereal growing. The cumulative nitrate loss was 9–12 g NO3‐N m–2 after immature peas and 5–7 g NO3‐N m–2 after mature peas. Autumn sown winter wheat did not significantly reduce leaching losses after field peas compared with spring sown barley. 15N derived from above‐ground pea residues accounted for 18–25% of the total nitrate leaching losses after immature peas and 12–17% after mature peas. When compared with leaching losses from the cereals, the extra leaching loss of N from roots and rhizodeposits of mature peas were estimated to be similar to losses of 15N from the above‐ground pea residues. Only winter wheat yield on the coarse sand was increased by a previous crop of peas compared to wheat following barley. Differences between barley grown after peas and after barley were not statistically significant. 15N lost by leaching in the first winter after incorporation accounted for 11–19% of 15N applied in immature pea residues and 10–15% of 15N in mature residues. Another 2–5% were lost in the second winter. The 15N recovery in the two crops succeeding the peas was 3–6% in the first crop and 1–3% in the second crop. The winter wheat did not significantly improve the utilization of 15N from the pea residues compared with spring barley.
Nitrate leaching and adsorption in a Kenyan Nitisol
Authors: Warren G.P. , Kihanda F.M.
Published: August 2010

Abstract. 15N labelled NH4NO3 (fertilizer N) was applied at a rate of 50 kg N ha–1 to an Ando‐Humic Nitisol and two maize crops grown on it. About 20 months later, soil cores were taken to a depth of 2.5 m. Leached fertilizer N was found between 1.4 m and 1.8 m deep and was delayed relative to net drainage by between 4.2 and 4.9 pore volumes. Anion exchange capacity (AEC) increased ten‐fold down the profile, up to 2.9 cmolckg–1. The delay to fertilizer N leaching was predicted to be between 4.1 and 5.3 pore volumes when calculated from the AEC and from an equation relating delay due to AEC in laboratory columns of repacked soil obtained by Wong et al. (1990b). It was concluded that the nitrate leaching delay equation was also valid in undisturbed field profiles. Two concentration maxima for mineral N were found, which did not usually coincide with the fertilizer N and were thought to result from mineralization of soil organic matter and plant residues at the end of each season. The delay equation overestimated their leaching delay but the results were considered close enough to support the hypothesis for their formation.
A review of fertilizer, lime and organic manure use on farm crops in Great Britain from 1983 to 1987
Authors: Chalmers A.G.
Published: August 2010

Abstract. In 1983, an annual Survey of Fertiliser Practice in England and Wales was extended to Scotland, to provide comprehensive information on inorganic fertilizer, lime and also organic manure use in mainland Britain. It was based on an annual sample of about 1500 farms, selected from the Agricultural Census and stratified by farm type and size. Results from the first fifteen years (1983–97) show that fertilizer nitrogen (N) rates on both tillage crops and grassland peaked at 157 and 132 kg ha–1, respectively, in the mid 1980s and subsequently decreased by c.10%. The majority of N was applied in straight form (without P or K) to tillage crops and in compound form (containing two or more nutrients e.g. NPK; NK) to grassland. Total N use on cereals showed little change but autumn‐applied N decreased on both winter cereals and winter oilseed rape. Total N rates decreased on oilseed rape and, to a smaller extent, on maincrop potatoes and sugarbeet. Between 1983–87 and 1993–97, mean phosphate (P2O5) rates declined by almost 10% on both tillage crops (from 58 to 53 kg ha–1) and on grassland (from 25 to 23kg ha–1). The corresponding mean potash (K2O) rates decreased slightly on both tillage crops (from 64 to 62 kg ha–1), and on grassland (from 32 to 31 kg ha–1), although annual usage was more variable on grassland. Sulphur use increased appreciably on cereal and oilseed rape crops between 1993, when S data were first recorded in the survey, and 1997 when 13% and 30%, respectively, of these crop areas received S‐fertilizer. However, on grassland, S use remained very low. Average lime use increased on both tillage crops and grassland between the mid 1980s and mid 1990s, from 10 to 12% and 4 to 7% of the total area, respectively. The proportion of land receiving organic manures remained at c. 16% for tillage cropping but increased slightly for grassland, from a mean of 40% in 1983–87 to 44% in 1993–97. Manures were applied throughout the year but about half the applications to tillage land, and a quarter of those to grassland, were made in autumn when the risk of subsequent nitrate leaching loss is greatest.
Soil mechanical behaviour of sandy loams in a temperate climate: case studies on long‐term effects of fertilization and crop rotation
Authors: Munkholm L.J. , Schjønning P. , Petersen C.T.
Published: August 2010

Abstract. Two case studies on Danish sandy loams investigated the long‐term effects of fertilization and crop rotation. Case Study 1 compared a diversely cropped organically farmed soil (DFG(1)) with a conventionally farmed soil predominantly growing annual crops (DFA), both receiving animal manure. In Case Study 2, a diversely cropped organically managed soil (DFG(2)) receiving animal manure was compared with an almost exclusively cereal cropped conventionally farmed soil receiving no animal manure (CCC). A multi‐level experimental strategy was followed to compare integrating field methods with specialized laboratory methods. Ease of tillage was described in the field and characterized using a drop shatter field test and by measuring aggregate tensile strength. Fitness as a seedbed was characterised visually in the field and from the drop shatter test. Impedance to seedling emergence and root penetration was evaluated by measuring bulk soil shear strength. For Case Study 1, soil tilth was better for the DFA soil than for the DFG(1) soil (i.e. lower soil strength and higher ease of fragmentation and friability index for DFA). However, a crumbly structure and a moderate bulk density suggested that the DFG(1) soil was also a favourable medium for plant growth. For Case Study 2, the CCC soil had a lower organic matter content, higher bulk density, higher soil strength, and lower ease of fragmentation in comparison with the DFG(2) soil.
Environmental problems of Red Soil along the coast of South China
Authors: Zhu Zhaoyu , Zhu Zhaoyu , Zhou Houyun , Xu Yifang , Ouyang Tingping , Deng Qinglu
Published: August 2010

Abstract. This study employed both natural and social sciences to examine the relationship between resources and economic development in the Red Soil Zone along the coast of South China. Based on the data collected by field investigation and laboratory analysis as well as from literature sources, the authors discuss the environmental problems and the main factors influencing them by using the case of Guangdong province. The results indicate that there are three important problems of Red Soil utilization: soil degradation and pollution, soil erosion and geological hazards. The main reasons for these problems involve the physical and chemical characteristics and mineral composition of the soil, climate and meteorological changes and human activities. The latter is currently the dominant factor influencing the change and deterioration of the Red Soils.
Parameterization of the MACRO model to represent leaching of colloidally attached inorganic phosphorus following slurry spreading
Authors: McGechan M.B. , Jarvis N.J. , Hooda P.S. , Vinten A.J.A.
Published: August 2010

Abstract. The dual porosity soil water and contaminant transport model MACRO was tested for its suitability to represent water flows and leaching of phosphorus (P) through field drains following spreading of slurry. These flows are characterized by very high loadings of P, including a high proportion in colloidally attached form, for about one week following winter spreading of slurry, followed by quite a rapid decline to the low background level. Use was made of the option in MACRO for representing colloid facilitated contaminant transport. The model simulates transport through macropores and soil matrix pores (micropores) of contaminant carrying colloids, as well as trapping of colloids by straining and filtration using an adaptation of standard filtration equations. Calibration involved selecting soil hydraulic parameters, colloid filtration coefficients and P sorption characteristics for two soils from measured and literature values. Both P in solution and P attached to colloids were represented in simulated outputs. Reasonable agreement was found between simulated and measured water and leached P flows. Work with the model suggests that macropore flow through the soil to field drains of colloidally transported P is an important component of water pollution associated with slurry spreading
Leaching losses of sulphur from different forms of sulphur fertilizers: a field lysimeter study
Authors: Riley N.G. , Zhao F.J. , McGrath S.P.
Published: August 2010

Abstract. Inputs and outputs of sulphur (S) were quantified over a three year period using field lysimeters containing undisturbed 60 cm deep soil monoliths of a sandy loam. There were four treatments, including a control (no S) and three forms of sulphur fertilizers: ammonium sulphate (AS); micronized elemental sulphur (MS0); and bentonite clay and elemental sulphur mixture (BS0). Sulphur was applied at the beginning of the experiment in autumn at 50 kg ha–1. Atmospheric deposition varied between 6.7 and 7.8 kg S ha–1 yr–1. Leaching losses of S ranged from 35 kg ha–1 in the control to 83 kg ha–1 in the AS treatment over three years, with dissolved organic S accounting for 6–10% of the S leached. In the first year, 7, 26 and 72% of the applied S was lost to drainage water in the BS0, MS0 and AS treatments, respectively, and the percentages increased to 33, 75 and 96% by the end of year 3. No significant differences in sulphur uptake by herbage were found in any of the harvests except a significant increase in the BS0 treatment in the second cut of the second year. Over three years, total S outputs exceeded total S inputs in all treatments, with the control and the AS treatments showing a larger S deficit (34–35 kg ha–1) than the MS0 (23 kg ha–1) and BS0 (7 kg ha–1) treatments. The deficits indicate a depletion of soil S, probably through net mineralization of organic S. The results confirm that sulphate was highly mobile and prone to leaching under the experimental conditions, whereas the slow release characteristics of elemental S, particularly BS0, led to smaller leaching losses and larger residual values.
Mitigation of N2O emissions from grassland by nitrification inhibitor and Actilith F2 applied with fertilizer and cattle slurry
Authors: Merino P. , Estavillo J.M. , Graciolli L.A. , Pinto M. , Lacuesta M. , Muñoz‐Rueda A. , Gonzalez‐Murua C.
Published: August 2010

Abstract. Nitrous oxide (N2O) is involved in both ozone destruction and global warming. In agricultural soils it is produced by nitrification and denitrification mainly after fertilization. Nitrification inhibitors have been proposed as one of the management tools for the reduction of the potential hazards of fertilizer‐derived N2O. Addition of nitrification inhibitors to fertilizers maintains soil N in ammonium form, thereby gaseous N losses by nitrification and denitrification are less likely to occur and there is increased N utilization by the sward. We present a study aimed to evaluate the effectiveness of the nitrification inhibitor dicyandiamide (DCD) and of the slurry additive Actilith F2 on N2O emissions following application of calcium ammonium nitrate or cattle slurry to a mixed clover/ryegrass sward in the Basque Country. The results indicate that large differences in N2O emission occur depending on fertilizer type and the presence or absence of a nitrification inhibitor. There is considerable scope for immediate reduction of emissions by applying DCD with calcium ammonium nitrate or cattle slurry. DCD, applied at 25 kg ha–1, reduced the amount of N lost as N2O by 60% and 42% when applied with cattle slurry and calcium ammonium nitrate, respectively. Actilith F2 did not reduce N2O emissions and it produced a long lasting mineralization of previously immobilized added N.
On‐farm evaluation of ridging and residue management options in a Sahelian millet‐cowpea intercrop. 2. Crop development
Authors: Bielders C.L. , Michels K.
Published: August 2010

Abstract. In the Sahel, promising technologies for agricultural intensification include millet stover mulching and ridging. A four year on‐farm experiment was set‐up in order to assess the effect of various combinations of these two technologies on crop development and yield in a millet (Pennisetum glaucum (L.) R. Br.) ‐ cowpea (Vigna unguiculata (L.) Walp.) intercropping system. Treatments included bare surface, ridging, a surface applied banded millet stover mulch (2 t ha–1) and a banded millet stover mulch (2 t ha–1) buried in ridges. The latter three treatments were implemented exclusively in the cowpea rows, with an annual rotation between the millet and cowpea rows. On bare and ridged plots, millet yields fell below 100 kg grain ha–1 after the first year. This was ascribed mainly to soil acidification and loss of soil organic matter rather than to soil physical constraints or water availability despite extensive surface crusting and high soil penetration resistance and bulk density. Compared to the bare plots, ridging increased cowpea hay production by 330% over the four years which was attributed to lower soil penetration resistance and bulk density but also to a reduction of 0.15 cmol+ kg–1 exchangeable acidity in the ridges. Except during the severe drought year of 1997, millet grain yield in the banded mulch treatment remained fairly stable over time at 526 ± 9 kg ha–1. However, a detailed analysis revealed yield compensation mechanisms between various yield components depending on the timing of occurrence of the abiotic stresses. Cowpea productivity was always higher in buried banded mulch plots than in surface applied banded mulch plots but the former treatment appeared unable to sustain millet yields. This decline was attributed to a greater nutrient uptake by cowpea and more rapid acidification in the buried mulch treatment compared to the banded mulch treatment.
Application of a mobile electromagnetic sensing system (MESS) to assess cause and management of soil salinization in an irrigated cotton‐growing field
Authors: Triantafilis J. , Ahmed M.F. , Odeh I.O.A.
Published: August 2010

Abstract. Generally, traditional soil surveys do not adequately account for the spatial variability of soil properties. Maps that are derived using these cursory soil data are likely to contain errors and thus make interpretation and soil management difficult. On the other hand quantitative methods of soil inventory at the field scale involve the design and adoption of sampling regimes and laboratory analysis that are time consuming and costly. In the latter case new technologies are required to efficiently sample and observe the soil in the field. This is particularly the case where soil salinization is prevalent, and detailed quantitative information for determining its cause is required. In this paper, a Mobile Electromagnetic Sensing System (MESS) is described and its application in an irrigated‐cotton field, located in the lower Namoi valley in New South Wales, Australia. Results from the EM38 instrument were found to be correlated with the effective cation exchange capacity (r2= 0.81). This was related to variability in soil mineralogy across the field. In addition, differences in soil chemical and textural variables, measured along a transect and adjacent to water storage, were used to identify seepage areas near a water reservoir where soil salinization was evident.