ALBERT

Notes: The paper presents a straightforward method of calculating approximate orientation parameters (six degrees of freedom) of a known targeted object relative to a single calibrated camera. These can then initialise an optimised non-linear calculation of the same parameter values. The method uses the mathematics of a scaled parallel projection and is particularly suited to narrow angle images obtained using a telescope, telephoto or zoom lens. However, the method can also be used with cameras having wider fields of view provided the target group occupies a moderately small part of the image.

Notes: This paper describes three mathematical modelling methods for high-resolution declassified CORONA KH-4B images. Since CORONA images are collected with a panoramic camera, several types of geometric distortions are involved. Two methods use the modified collinearity equations, and the third involves the terrain-dependent rational function model (RFM) which is considered to be a generic sensor model. Comparative analysis of the three mathematical modelling methods is undertaken. The results show that a ± 1·5 pixels level of horizontal and vertical accuracy can be obtained. A digital elevation model (DEM) of a test site is also created.

Notes: Digital photogrammetry and softcopy workstations have added a new dimension to aerial triangulation, and some of the previously manual procedures are now available in automated form. Also, commercial software packages for automatic aerial triangulation came on to the market in the last decade. In this study, the results of automatic aerial triangulation using four triangulation software packages, Z/I Imaging's MATCH-AT (ISMAT) and ISAT, LH Systems’ MST and VirtuoZo AAT, are presented. For the comparison of the results of the tie point extraction and the bundle block adjustment for triangulation, a sub-block from the Uster block in Switzerland was selected and used. Differences between these software packages are discussed with respect to their functionality and performance in detail. The achieved standard deviation of image coordinates varies between 0·2 and 0·5 pixel for the systems tested. The more signalised control points and check points to be used, the better the σ0 estimate which could be expected. The average number of extracted tie points varied from system to system with respect to the matching method and the resolution of the images used in the programs. The digital aerial triangulation of the Uster sub-block was faster than analytical triangulation and the elapsed time for triangulation of one image using different systems varies between about 0·5 and 6 min. Nevertheless, results also show that automated aerial triangulation is still prone to error in all systems. Image matching produces many blunders, which can only be handled efficiently by using a sophisticated blunder detection procedure, as is available with robust estimation. This is not the case for all the systems tested, however. There still remains a lot to be done in terms of development (improvement of matching, for example, by integrating robust estimation for error detection at an early stage, implementation of on-line triangulation, better internal quality control procedures, more transparent and simple user interfaces and more useful information for the user with better software manuals). However, it was shown that automatic aerial triangulation provides higher redundancy and reliability of results and much more economical photogrammetric practice than ever before.

Notes: The Photogrammetric Society was formed in 1952. The Council of the Society considered that the twentieth anniversary was a good point at which to record the events which led to its formation and the significant occasions and decisions which have taken place since 1952. Consequently, Paul Lamboit was invited to compile this History. He has placed the birth and development of the Society within the national and international photogrammetric context and his record of the deliberations which took place between 1947 and 1952 will be of particular interest to historians of our subject.This account was first published in a limited edition in 1971. Sufficient interest has since been expressed to prompt a wider circulation through publication in the Photogrammetric Record.The author served the Society continuously in several official capacities from 1953 to 1969 and he was elected to Honorary Membership in 1969.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLa Photogrammetric Society a été fondée en 1952. Excellente occasion pour faire le point qu'un vingtiéme anniversaire, a estimé le Conseil de la Société; pour rappeler les circonstances de sa naissance, les étapes de sa croissance et les décisions importantes prises depuis 1952. Ce qu'on invita Paul Lamboit à faire. Son exposé resitue la naissance et le développement de la Société dans le contexte national et international de la photogrammétrie; la relation qu'il fait des décisions prises entre 1947 et 1952 intéressera particulièrement ceux qui s'occupent d'histoire de la photogrammétrie.Ce rapport d'abord publié en édition limitée en 1971, a suscité un intérêt suffisant pour que l'on se presse en le publiant dans le Photogrammetric Record de le porter à la connaissance d'un plus large public.L'auteur a exercé différentes fonctions de 1953 à 1969 dans l'appareil de la Société. Il a étéélu membre honoraire en 1969.〈section xml:id="abs1-3"〉〈title type="main"〉Zusummenfussung1952 wurde die Britische Gesellschaft für Photogrammetrie gegründet. Der Rat der Gesellschaft erwog, dass der zwanzigste Jahrestag eine günstige Gelegenheit sei, um die Ereignisse, die zur Gründung der Gesellschaft führten sowie die bedeutenden Veranstaltungen, die stattfanden und die Entscheidungen, die getroffen wurden, darzustellen. Aus diesem Grunde wurde Paul Lamboit eingeladen, diesen historischen Rückblick zu schreiben. Er hat dabei die Gründung und die Entwicklung der Gesellschaft in den nationalen und internationalen photogrammetrischen Zusammenhang gestellt nd sein Bericht über die zwischen 1947 und 1972 erfolgten Beratungen wird für an unserer Sache interessierte Historiker sehr aufschlussreich sein.Diese Zusammenstellung wurde erstmals in einer begrenzten Auflage im Jahre 1971 veröffentlicht. Genügend Interesse wurde inzwischen bekundet, um eine weitergehende Verteilung mit Hilfe des Photogrammetric Record zu veranlassen.Der Autor diente der Gesellschaft kontinuierlich in verschiedenen Ämtern von 1953 bis 1969, wo er aum Ehrenmitglied gewählt wurde.

Notes: The effect of haze in vertical daylight air photography for various solar altitudes is considered. If appreciable haze is present the density of negatives exposed when the solar rays are inclined to the vertical at angles less than the lens field semi-angle may vary over the field to such an extent that the photographs will be unsuitable for survey purposes. A theoretical investigation is made and practical results analysed. Methods by which the phenomena may be avoided are suggested. The effect on negative density of the variation in shadow length across the picture is also discussed.

Notes: Architecture at the Maya archaeological site of Uxmal in Yucatan, Mexico has been documented since the 17th century by historians, archaeologists, illustrators, photographers, and most recently photogrammetrists. This paper reviews the work of the major contributors to recording of architecture at Uxmal with a particular focus on the 19th century stereophotography of Alice and Augustus Le Plongeon who worked to record all the standing architecture at Uxmal, and the close range stereophotogrammetric projects that recorded the Adivino Pyramid during the late 20th century.

Notes: This article presents a complete mathematical model, which translates discrepancies between two orthophotographs created from different photographs, into precise corrections of the Digital Elevation Model (DEM). These corrections are the differences from the real surface and, if applied over the existing DEM, can produce a more accurate one. The mathematical model is straightforward, and is not approximate, and therefore there is no need for iterations.Possible applications include checking of automatically created DEMs, refinement of existing DEMs using aerial photographs and update of orthophotographs based on the previous DEM and new imagery.

Notes: A scholarly account of the formative discussions, the founding and the first 20 years of the Photogrammetric Society was published in 1971 and republished in 1974. This present review concentrates on the latter years of the life of the Photogrammetric Society prior to its merger with the Remote Sensing Society in 2001.The authors joined the Photogrammetric Society in 1960 and were conspicuous in its affairs for many years. Although both occupied the Society's presidential chair, they also fulfilled several other roles in its efficient management. Atkinson's first contribution to the Photogrammetric Record was published in 1968 and Newton's in 1971.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméOn a publié en 1971 un compte-rendu détaillé des 20 premières années de la “Photogrammetric Society”, à commencer par les discussions qui présidèrent è sa fondation. Ce récit fut republié en 1974. On se focalise dans cet article sur les dernières années d'activité de la “Photogrammetric Society” qui aboutirent à sa fusion avec la “Remote Sensing Society” en 2001.Les deux auteurs adhérèrent à la “Photogrammetric Society” en 1960 et y furent d‘éminents animateurs pendant de nombreuses années. Tous deux occupèrent le poste de président de cette Association mais remplirent égulement plusieurs autres fonctions qui contribuèrent à une gestion efficace. La première intervention d'Atkinson dans le Photogrummetric Record remonte à 1968, et celle de Newton à 1971.〈section xml:id="abs1-3"〉〈title type="main"〉ZusummenfussungEine wissenschaftliche Abhandlung über die Diskussionen zur Gründung, die Gründung selbst und die ersten 20 Jahre der Photogrammetrischen Gesellschaft wurde in 1971 publiziert und in 1974 wiederholt. Dieser aktulle Rückblick konzentriert sich auf die darauffolgenden Jahre der Photogrammetrischen Gesellschaft bis hin zur Vereinigung mit der Gesellschaft für Fernerkundung in Jahre 2001.Die Autoren wurden 1960 Mitglieder in der Photogrammetrischen Gesellschaft und trugen viele Jahre massgeblich zu deren Aktivitäsidenten der Gesellschaft auch verschiedene andere Aufgaben im Management wahrgenommen. Der erste Beitrag von Atkinson im Photogrammetric Record erschien 1968, der erste von Newton in 1971.

Notes: The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term “exterior orientation” of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects.This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first. a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point-bused methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line-based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméLa détermination de l'attitude, de la position et des caractéristiques intrinsèques de la chambre photographique constitue un problème fondamental en photogrammétrie. Il se résume à la détermination des paramètres de l'orientation de la chambre de prise de vue (paramètres des orientations externe et interne), ainsi qu'à la détermination des coordonnées 30 des points de l'objet. L'orientation externe se rapporte à la détermination de la position et de l'orientation d'une chambre par rapport à un système externe de coordonnées. Différentes méthodes peuvent être utilisées pour calculer les éléments dorientation externe d'une photo, d'un couple ou de plusieurs photos. Le calcul de l'orientation peut être réalisé par étapes (par exemple les orientations relative et absolue) mais les méthodes simultanées (la compensation par faisceaux par exemple) sont actuellement proposées dans la plupart des logiciels. Plusieurs méthodes ont aussi été développées pour l'orientation d'images isolées. Ells sont basées en général sur les caactéristiques géométriques et topologiques des objets photographiés.Dans cet article on présente un ensemble de méthodes classiques et modernes pour la détermination des paramètres de l'orientation externe, certaines d'entre elles étant téléchargeables sous la forme d'applications sur Internet. Les méthodes présentées sont classées en trois groupes principaux. Le premier groupe contient une sélection de méthodes approximatives utilisées d'habitude quand une grande précision n'est pas exigée, ou encore pour calculer des vuleurs approchées des paramètres extrinsèques requises pour les méthodes itératives rigoureuses. Dans le deuxième groupe, on rappelle brièvement les jondements des méthodes basées sur les conditions photogrammétriques fondamentales (la colinéarité, la coplanéité et la coangularité). Dans ce groupe, les méthodes basées sur l'extraction des points ou des lignes sont également abordées. Le troisième groupe traite des méthodes d'orientation basées sur les contraintes et les concepts de la géométrie projective, de plus en plus utilisées par les photogrammètres. Le dernier paragraphe se rapporte aux méthodes destinées à automatiser le calcul de l'orientation externe en photogrammétrie aérienne.〈section xml:id="abs1-3"〉〈title type="main"〉ZusummenfussungDie Bestimmung der Neigung, der Position und den geometrischen parametern der Kamera wird als das fundamentale Problem der Photogrammetrie angesehen. Es kann zusammenfassend sowohl als die Bestimmung der Parameter der inneren und äusseren Orientierung der Kamera angesehen werden, als auch als die Bestimmung von 3D Koordinaten von Objektpunkten. Der Ausdruck “äussere Orientierung” eines Bildes bezieht sich auf die Lage und Orientierung bezogen auf ein äusseres (Objektraum-) Koordinatensystem. Es können verschiedene Methoden angewandt werden, um die Parameter von einem, zwei oder mehreren Bildern zu bestimmen. Die orientierung kann in Schritten erfolgen, was als Relative und Absolute Orientierung bezeichnet wird, aber auch simultane Methoden, wie die Bündelausgleichung, sind in vielen Softwarepaketen implementiert. Es wurden auch Methoden für die Orientierung von Einzelbildern entwickelt, die geometrische und topologische Eigenschaften der abgebildeten Objekte nutzen. In diesem Beitrag wird Beitrag wird eine Studie klassischer und moderner Methoden der Photogrammetrie zur Bestimmung der Parameter der äßeren Orientierung vorgestellt, wovon einige in Softwarepaketen zur Verfügung stehen, die von praktischen Beispielen im Internet ergänzt werden. Die untersuchten Methoden werden in drei Hauptgruppen eingeteilt. In einer ersten Gruppe werden Näherungslösungen vorgestellt, die für Anwendungen mit geringen Genauigkeitsanforderungen geeignet sind. Diese Methoden werden ansonsten für die Näherngswertberechunggen für iterative Prozesse verwendet. IN der zweiten Gruppe werden zuerst die punktbasierten Standardmethoden vorgestellt, die von Bedingungen zur Kollinearität. Koplanarität und Kowinkligkeit abgeletet sind. Danach folgen linienbasierte Ansätze. Die dritte Gruppe umfasst Orientierungsmethoden, die auf Zwangsbedingungen und auf Konzepte der projektiven Geometrie aufbauen, die für Photogrammeter von zunehmendem Interesse sind, Im letzten Abschnitt wird eine Zusammenfassung existierender Strategien für eine automatische äussere orientierung in der Luftbildphotogrammetrie gegeben.

Notes: In Part I the visual processes involved in depth perception are briefly described and discussed, while in Part II their application in stereo plotting and allied observations is considered. Reference is made to the visual axis, the need for and nature of eye movements, the conception of the horopter space within which fusion of the binocular images occurs and objects are seen in three-dimensions, and the tolerances for fusion implied by the existence of Panum's areas. Monocular clues make an important contribution to the perception of depth, and the apparent location of an object in space is determined by the factors of retinal disparity, convergence, angular size, perspective, motion parallax, elevation, aerial haze, etc. The following problems are then discussed: The significance of the horopter in relation to the general contour in a stereo photograph; the fusion of the images in a stereo plotting machine; the arguments for and against some convergence of the eyepiece axes; the special problems of spectacle wearers; the functions of field stop. An analysis of the visual task in contour plotting is attempted, but a more complete analysis would be possible if records were available of the observer's eye movements while plotting. Finally, chromatic aberration in relation to the Multiplex system is considered, and also in connection with the stereoscopic effect observed with differently coloured objects lying in a plane.

Notes: The object of this paper is to provoke discussion and not to present a finished study. It deals briefly with quantitative analysis of drainage patterns in geomorphological studies and refers to methods that have recently received some attention in the United States. It points to the value of aerial photographs in such studies and asks for discussion of two important points: firstly, whether the mathematical approach is soundly based; and, secondly, whether the analytical method is likely to give useful practical results.

Notes: Book reviewed in this article: Trees, crops and soil fertility: concepts and research methods. By G. Schroth and F.I. Sinclair (Editors).

Notes: Abstract. Current tillage erosion models account for the influence of tillage direction in the magnitude of the soil transport coefficient. It is argued that a re-modelling of tillage erosion is preferable in which the influence of tillage direction is separated from the soil transport coefficient, which is a measure of tillage intensity. This has been achieved here by developing a two-dimensional tillage erosion model that incorporates tillage direction in the measure of slope and uses soil transport coefficients that are independent of tillage direction and based on relationships between transport and the slope in the direction that bisects tillage direction and the overturning direction. Mean tillage erosion, associated with a single pair of opposing tillage directions and pair of overturning directions, can be described by a two-dimensional diffusion-type equation if the dimensions are defined as the tillage direction and the direction perpendicular to tillage. Application of the model to a real-world case allows quantification of the potential soil conservation benefits associated with optimization of tillage direction. The scope for amelioration is related to the ratio between the coefficients for transport in the direction of tillage and perpendicular to tillage. As this ratio approaches unity, the potential for amelioration reduces towards zero. For the study site investigated, use of the experimentally derived ratio of 0.66 indicated that a 12% reduction in tillage erosion could be obtained by ploughing across the dominant field slope as compared to ploughing up and down the dominant slope. For an implement with a coefficient ratio of 0.2 the reduction in tillage erosion intensity, associated with optimizing the tillage direction, reaches 28%. Nevertheless, such benefits must be considered in the context of other management considerations. The tillage direction that minimizes erosion is associated with lateral slopes of 10°, or more, over 20% of the field. To the land-user this disadvantage may outweigh the soil conservation benefits.

Notes: Abstract. Efforts to understand the fate of organochlorine compounds in arable soil have concentrated on anthropogenic compounds, in spite of the fact that organochlorine compounds are both produced and mineralized in soil through natural processes. In order to understand the fate of chlorinated pesticides, it is necessary to take account of the natural chlorine cycle. The present study is a first attempt to illuminate the relationship between the natural chlorine cycle and agricultural practices. The concentration and storage of organic chlorine (Clorg) and chloride (Clinorg) were determined in topsoil of a paddy field compared to an adjacent afforested hill at a sampling site in the Meicun area, Anhui Province, China. The concentration of Clorg, as well as the chlorine-to-carbon ratio, was significantly lower in the paddy field samples than in the forest soil samples. A weak relationship between the concentration of Clorg and the organic carbon content was observed in the paddy field, in contrast to the observations made in the adjacent forest soil as well as those made in previous studies, which have suggested a positive correlation between organic carbon content and Clorg. The similarity between our results at the forest site and the previous studies, which have been carried out in temperate regions, suggests that it is the land use rather than the climate that makes the current paddy soil results different. Our results suggest that the contribution of Clorg to the paddy soil from above-ground litter and from production within the soil are small or negligible compared with the contribution from pesticide application and wet and dry deposition.

Notes: Book reviewed in this article: The Identification of Soils for Forest Management. By Fiona Kennedy.

Notes: Abstract. A no-tillage (NT) system was developed in semiarid Morocco to improve the soil fertility and stabilize yield through conservation of water. Results in two long-term trials (4 and 11 years) were able to show the effects of a no-tillage system in increasing total soil organic matter and total nitrogen. Over time, the quality of the NT soil surface was improved compared with that under conventional tillage (CT) with disc harrows. This effect was the result of an increase in soil organic carbon (SOC) and a slight decline in pH. However, over time, nitrogen decreased in both tillage practices, especially in the 0–25 mm layer (from 0.59 to 0.57 t ha−1 and from 0.44 to 0.42 t ha−1 under NT and CT, respectively). After 4 years of NT an extra 5.62 t ha−1 of SOC was sequestered in the 0–25 mm layer, and after 11 years the SOC increased further to 7.21 t ha−1.

Notes: Book reviewed in this article: Agriculture, Hydrology and Water Quality. By P.M. Haygarth and S.C. Jarvis (Editors).

Notes: Abstract. For an efficient abatement of diffuse N pollution from arable land, it is important to have practical and reliable tools that can quantify the effect of different management practices on leaching, and also analyse the effect of alternative management scenarios aimed at reducing leaching. We present here an application of soilndb, a management-oriented model for quantifying nitrate leaching from arable land. Simulations with soilndb were compared with measurements of pipe-drain discharge of nitrate taken in a 14-year field experiment on a sandy loam soil in south-west Sweden. Following adjustment of parameters connected to litter and faeces decomposition and mineralization, the model gave satisfactory predictions of nitrate leaching for all 10 treatments. The temporal pattern was generally well captured by the model, as was confirmed by high model efficiency values (average = 0.59). This application also supports the model's ability to simulate the long-term influence of different crops and catch crops as well as different manure strategies on leaching. However, further studies should be done to evaluate the model under additional agro-environmental conditions (e.g. soils, climates, and crops).

Notes: Abstract. The Phosphorus Indicators Tool provides a catchment-scale estimation of diffuse phosphorus (P) loss from agricultural land to surface waters using the most appropriate indicators of P loss. The Tool provides a framework that may be applied across the UK to estimate P loss, which is sensitive not only to land use and management but also to environmental factors such as climate, soil type and topography. The model complexity incorporated in the P Indicators Tool has been adapted to the level of detail in the available data and the need to reflect the impact of changes in agriculture. Currently, the Tool runs on an annual timestep and at a 1 km2 grid scale.We demonstrate that the P Indicators Tool works in principle and that its modular structure provides a means of accounting for P loss from one layer to the next, and ultimately to receiving waters. Trial runs of the Tool suggest that modelled P delivery to water approximates measured water quality records. The transparency of the structure of the P Indicators Tool means that identification of poorly performing coefficients is possible, and further refinements of the Tool can be made to ensure it is better calibrated and subsequently validated against empirical data, as it becomes available.

Notes: Abstract. We present a semi-quantitative visual and tactile method for assessing soil physical fertility in terms of soil structure, root growth and soil surface condition. A block of topsoil is dug out with a spade. Horizontal layers (usually 2–4) are then identified as they appear. A brief one-page description of the soil is produced. Using a key, structural and rooting scores are assigned to each soil layer from the appearance of the soil and from its response to tactile assessment. These scores are then combined across depths, with weighting appropriate for the depth of each layer. A separate score was made of soil surface condition. Thus, overall soil physical fertility is assessed as three scores for topsoil structure, rooting and surface condition. The usefulness and sensitivity of the procedure were tested in two ley-arable organic rotation experiments on sandy loams in northeast Scotland.

Notes: Abstract. Eleven precipitated phosphates were evaluated as sources of phosphorus (P) for plant growth by comparing their effectiveness with that of monocalcium phosphate, a source of water soluble P that is generally considered to be fully plant available. The precipitated phosphates comprised struvites recovered from waste water discharges (mainly magnesium ammonium phosphate), laboratory synthesised struvites, a synthetic iron phosphate and a recovered calcium phosphate. Precipitating phosphates in these forms could be a way for removing P from waste water before it is discharged to rivers, so reducing the risk of eutrophication. Application to agricultural land would be one potential use for such phosphates. Evaluation was by pot experiments with a sandy loam soil and with a sandy clay loam soil using perennial ryegrass (Lolium perenne) as the test crop. The soils differed in pH (6.6 and 7.1) and in Olsen P (28 and 11 mg L−1). Measured variables were grass dry matter (DM) yield and grass P concentration which were used to calculate offtake of P in the harvested grass. DM yields of ryegrass and P offtakes given by the synthetic and recovered struvites were not significantly different statistically either between themselves or to MCP applied at the same rate. On this basis these struvites could be used to recycle P to similar soils and the effect of the P on crop yield should be similar to that of MCP

Notes: Abstract. The main inputs, outputs and transfers of potassium (K) in soils and swards under typical south west England conditions were determined during 1999/00 and 2000/01 to establish soil and field gate K budgets under different fertilizer nitrogen (N) (0 and 280 kg ha−1 yr−1) and drainage (undrained and drained) treatments. Plots receiving fertilizer N also received farmyard manure (FYM). Potassium soil budgets ranged, on average for the two years, from −5 (+N, drained) to +9 (no N and undrained) kg K ha−1 yr−1 and field gate budgets from +23 (+N, drained) to +89 (+N, undrained). The main inputs and outputs to the soil K budgets were fertilizer application (65%) and plant uptake (93%). Animals had a minor effect on K export but a major impact on K recycling. Nitrogen fertilizer application and drainage increased K uptake by the grass and, with it, the efficiency of K used. It also depleted easily available soil K, which could be associated with smaller K losses by leaching.

Notes: Abstract. Crops on sandy soils (〈5% clay) are exposed to K deficiency due to the small release and high leaching losses of K. Reliable tools are needed to improve the K management in cropping systems with limited K input, such as organic farming where import of nutrients are restricted according to the EC regulations. We investigated K balances and exchangeable K (Kexch) changes in an organic crop rotation experiment. Potassium leaching decreased from 42 kg ha−1 in 1998/99 to 21 kg ha−1 in 2000/01 as an average of a crop rotation (spring barley, grass-clover, winter wheat and pea/barley) with manure application and without catch crops. In the same period, spring Kexch decreased from 5.0 to 3.0 mg K 100 g soil−1 (0–20 cm). The retention of the straw K left in the field after harvest increased with decreasing levels of Kexch. The cereal crops did not respond to K application but in the pea/barley mixture the pea yield increased by 46%. The concordance between measured K balances and changes in Kexch was weak. Exchangeable K is suitable as a tool for K management on a rotational basis, and a Kexch above 3 mg 100 g soil−1 in the autumn should be avoided to minimize K leaching.

Notes: Abstract. Diagnosis of soil salinity and its spatial variability is required to establish control measures in irrigated agriculture. This article shows the usefulness of electromagnetic (EM) and soil sampling techniques to map salinity. We analysed the salinity of a 1-ha plot of surface-irrigated olive plantation in Aragon, NE Spain, by measuring the electrical conductivity of the saturation extract (ECe) of soil samples taken at 22 points, and by reading the Geonics EM38 sensor at 141 points in the horizontal (EMH) and vertical (EMV) dipole positions. EMH and EMV values had asymmetrical bimodal distributions, with most readings in the non-saline range and a sharp transition to relatively high readings. Most salinity profiles were uniform (i.e. EMH=EMV), except in areas with high salinity and concurrent shallow water tables, where the profiles were inverted as shown by EMH 〉 EMV, and by ECe being greater in shallow than in deeper layers. The regressions of ECe on EM readings predicted ECe with R2 〉 84% for the 0–100 to 0–150 cm soil depths. We then produced salinity contour maps from the 141 ECe values estimated from the electromagnetic readings and the 22 measured values of ECe. Owing to the high soil sampling density, the maps were similar (i.e. mean surface-weighted ECe values between 3.9 dS m−1 and 4.2 dS m−1), although the electromagnetically estimated ECe improved the mapping of details. Whereas soil sampling is preferred for analysing the vertical distribution of soil salinity, the electromagnetic sensor is ideal for mapping the lateral variability of soil salinity.

Notes: Abstract. The effects of soil management on soil losses from olive plantations in southern Spain were evaluated using the Revised Universal Soil Loss Equation (RUSLE), a review of published experiments, and preliminary results of an on-going field trial. Experimental data were used to parameterize the RUSLE for olive orchards under various soil management regimes. The predictions agreed qualitatively with the data available, and the model provided a simple way to assess the effects of soil management on erosion. Our results showed that no-tillage caused the greatest soil loss, while cover crops showed the least. Tillage and planting following contours proved only partially effective and did not reduce soil erosion as much as protective crops. One scenario studied suggests that, on slight to moderate slopes, land transformed from row crops to olive orchards may remain below the maximum tolerable soil erosion limit, if a cover crop is included between the trees. A scenario for marginal olive orchards located on steep slopes suggests that effective erosion control could only be achieved with a cover crop system that would have the side-effect of reducing the yield of rain-fed olives. Quantifying the effects of soil management on soil erosion in olive orchards is uncertain because very few experimental results are available. Further research that monitors soil loss in carefully selected long-term experiments at different scales and follows the changes in key soil parameters is urgently required to develop effective erosion control policies.

Notes: Abstract. Rainfall simulation experiments on a laboratory soil flume were conducted to test the hypothesis that the incorporation of slurry into the soil would reduce bacterial transport in overland flow. Presumptive faecal coliform (PFCs) concentrations were higher in the runoff from the surface applied treatment than from the incorporated treatments. The transport of PFCs and organic sediment were strongly correlated, with values of r ranging from 0.72 to 0.91.

Notes: Abstract. Land evaluation is the prediction of land performance over time under specific uses, to guide strategic land use decisions. Modern land evaluation has a 30 year history, yet the results have often been disappointing. Land users and planners have been reported to ignore land evaluations, perhaps reflecting poor quality, low relevance, or poor communication. To test the success of a large land evaluation exercise undertaken as part of micro-catchment project in Santa Catarina State, southern Brazil, we queried agricultural extensionists, considered as the primary land evaluation clients. We used a questionnaire with both structured and open questions, to determine their experiences with, and attitudes to, the current land evaluation method. The soil resource inventory and associated land evaluation had some usefulness, but were not in general used for their intended purpose, namely farm planning. This was mainly because they did not contain crucial information necessary to such planning in the actual context of the farmer taking decisions. The primary deficiencies were identified as:〈list xml:id="l1" style="custom"〉1no estimate of environmental degradation risk;2no financial analysis;3no social analysis of decision-makers' attitudes and preferences;4no risk assessment for weather, yields, profits and market; and5insufficiently-specific alternative land uses.These deficiencies could have been avoided with a demand-driven approach, evaluating and reporting according to the true needs and opportunities of the decision-makers.

Notes: Abstract. The residual value of mineral N fertilizer applied in the spring was investigated in a field experiment where four cereals (winter wheat, winter barley, spring barley and spring oats) had been grown at reduced (0.7N), normal (1N) or high (1.3N) N fertilizer rates for 20 to 28 years. The effect of previous N fertilizer dressing was tested in two succeeding years by replacing the original N rate with five test N rates ranging from 0 to 240 kg N ha−1 for winter cereals and 0 to 200 kg N ha−1 for spring cereals. In the first test year, winter wheat grown on plots previously supplied with the high rate of mineral fertilizer (202 kg N ha−1 yr−1) yielded more grain and straw and had a higher total N uptake than wheat on plots previously supplied with the normal (174 kg N ha−1 yr−1) or reduced (124 kg N ha−1 yr−1) rate. The grain yield response and N uptake was not significantly affected by the N supply in the test year. The winter wheat grown in the second test year was unaffected by the previous N supply. Grain and straw yield response and total N uptake for spring barley, winter barley and oats, were almost identical irrespective of the previous N rate.After 20 to 28 years there were no significant differences in soil C and N (0 to 20 cm) between soil receiving three rates of N fertilizer. Soil from differently fertilized oat plots showed no significant differences in N mineralizing capacity. Nitrate leaching losses from the soils at the three N rates were estimated and the N balances for the 20 to 28 years experimental period calculated. The data indicated a reduction in overall loss of 189 to 466 kg N ha−1 at the normal and high N rates compared with the reduced N rate. We conclude that the N supplying capacity and soil organic matter content of this fertile sandy loam soil under continuous cereal cropping with straw removal was not significantly affected by differences in N fertilizer residues.

Notes: Abstract. This paper compares nitrate leaching losses from organic farms, which depended on legumes for their nitrogen inputs (66 site years) with those from conventional farms using fertilizers under similar cropping and climatic conditions (188 site years). The conventional farms were within Nitrate Sensitive Areas in England, but sites following special practices associated with that scheme were excluded. Nitrate losses during the organic ley phase (including the winter of ploughing out) were similar (45 kg N ha–1) to those from conventional long-term grass receiving fertilizer N inputs of less than 200 kg N ha–1 (44 kg N ha–1) and from the grass phase of conventional ley-arable rotations (50 kg N ha–1). Losses from conventional grass receiving higher N inputs were greater than from organic or less intensive grass. Nitrate losses following arable crops averaged 47 and 58 kg N ha–1 for the organic and conventional systems respectively, with part of the difference being due to the greater proportion of non-cereal break crops in the latter. Thus under similar cropping, losses from organic systems are similar to or slightly smaller than those from conventional farms following best practice.

Notes: 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.

Notes: Abstract. Nutrient balance calculations have been advocated as indicators of the risk of nitrate loss from agricultural land. To explore this concept, a spatially distributed UK agricultural nitrogen balance was derived using annually updated statistics. The mean UK N surplus for 1995 was 115 kg N ha–1, made up of 51 kg ha–1for arable land, 140 kg ha–1 for agricultural grassland (excluding rough grazing) and an additional 14 kg N ha–1for agricultural land from pig and poultry units. Nitrogen surpluses were greater in lowland grassland (mainly in western, wetter areas) than in arable areas. However nitrate concentrations in rivers were generally greater in arable areas. The relationship between N balance and nitrate leaching was very different for grassland and arable systems, and was also sensitive to climate, level of inputs and management practices. Nitrogen surplus was therefore weakly or even negatively correlated with river nitrate concentrations or loads. A positive correlation was found only where the comparison was restricted to grassland-dominated catchments. Nitrogen surplus calculations identified areas of very high livestock densities, which would be associated with increased risk of pollution. However their use in isolation as indicators of N leaching, or of progress towards mitigation, could be misleading especially if comparing areas differing in land use, climate or soil type.

Notes: Abstract. Dynamic simulation models are increasingly used in environmental and agricultural science. Here we present a method that allows models to be used to determine optimum timing of sampling for field trials. The model is used to decide when to concentrate sampling effort before the field trial begins. The model chosen to design sampling strategy should include an appropriately sensitive description of all processes that influence measurements significantly. The simulation is run, using predicted weather data, to generate the full time series before the trial begins. Every point in the simulation is considered initially to be a potential sampling point. The potential error due to not including a measurement at each point is calculated using the ‘dot-to-dot’ method of b10Smith et al. (2002) by omitting simulated values consecutively. The calculated potential error provides a measure of the priority that should be given to sampling at each point. Where the error introduced by omitting the simulated value exceeds an acceptable error, the value at the last discernible time step should be measured so that all statistically significant changes in the system can be observed. The output from the calculation is a plan of sampling times needed to capture all statistically significant events that are likely to occur over the course of the trial.

Notes: Abstract. In grazed dairy pasture systems, a major source of NO3– leached and N2O emitted is the N returned in the urine from the grazing animal. The objective of this study was to use lysimeters to measure directly the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in decreasing NO3– leaching and N2O emissions from urine patches in a grazed dairy pasture under irrigation. The soil was a free-draining Lismore stony silt loam (Udic Haplustept loamy skeletal) and the pasture was a mixture of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). The use of DCD decreased NO3–-N leaching by 76% for the urine N applied in the autumn, and by 42% for urine N applied in the spring, giving an annual average reduction of 59%. This would reduce the NO3–-N leaching loss in a grazed paddock from 118 to 46 kg N ha–1 yr–1. The NO3–-N concentration in the drainage water would be reduced accordingly from 19.7 to 7.7 mg N L–1, with the latter being below the drinking water guideline of 11.3 mg N L–1. Total N2O emissions following two urine applications were reduced from 46 kg N2O-N ha–1 without DCD to 8.5 kg N2O-N with DCD, representing an 82% reduction. In addition to the environmental benefits, the use of DCD also increased herbage production by more than 30%, from 11 to 15 t ha–1 yr–1. The use of DCD therefore has the potential to make dairy farming more environmentally sustainable by reducing NO3– leaching and N2O emissions.

Notes: 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.

Notes: Abstract. Regions in the Po Valley, Northern Italy, are characterized by intensive crop-livestock farming systems. A simulation model has been chosen for an inter-regional project, which should help in defining groundwater vulnerability and pollution risk on a regional scale, in relation to agricultural land use, by allowing the prediction of nitrate leaching under different climate, soil, crop and management scenarios. The model derives from the coupling of a hydrological model, MACRO, simulating water flow and solute transport in structured soils, with a model simulating soil N dynamics, SOILN. The aim of this work was to test the model's ability to simulate nitrate leaching through soil after land spreading of pig slurries. A dataset obtained from lysimeter experiments which had been carried out in the period 1976–1981 was used for this purpose. Four soil types were compared (silty clay, sandy loam, loam and sand) in factorial combination with four rates of pig slurry (0, 142, 284, 426 g of N m–2, accumulated values from 1976 to 1979) for a seven crop sequence. The efficiency of the MACRO model ranged from 0.96, in the sandy-loam soil, to 0.81, in the sand. Percolation was usually under-estimated, the relative error ranging from 0.7 to 14.6, depending on the soil. The low efficiency of the SOILN model in simulating nitrate leaching is attributed to the lack of knowledge of the mechanisms regulating N transformation processes and especially the mineralization of pig slurry N. This lack of knowledge hampers the correct setting of the N transformation parameter values. A remarkable improvement of the model's performance was obtained by changing a few coefficients which control the mineralization-immobilization turnover of the faeces-organic N. The model efficiency, following this recalibration, ranged from –0.62 to 0.84, and the relative error ranged from –56 to 35, depending on soil and treatment. N leaching was under-estimated at the low pig slurry N application rates and over-estimated at the high ones.

Notes: Abstract. The effectiveness of contour grass strips in erosion control was investigated in a field experiment involving two grass treatments (Festuca ovina and Poa pratensis) and a bare soil control on an erodible sandy loam soil on a 5° slope using simulated rainstorms of 40 mm h–1 for 45 minutes duration. The grass strips resulted in significantly (P 〈 0.05) lower runoff and soil loss than the bare soil but there was no significant difference in the performance of the two grasses, despite their differences in density, height and leaf size. The effect of the lower density of the Poa pratensis was offset by its larger stem diameter so that the surface area facing the flow was similar for both grasses. Instead of acting as a filter with sedimentation occurring within the barrier, the grass strips operated by ponding water upslope of the barriers. Deposition then occurred in the ponded area above the barrier.

Notes: Abstract. Since the 1980s, land use in rural areas of China has changed greatly as the result of political initiatives. These changes have caused soil nutrient changes which are examined in this paper for Zunhua County, northern China from 1980 to 1999. The areas of farmland, grassland, and paddy decreased greatly and were replaced by increases in forest and residential land. The soils under forest in 1999 transformed from farmland in 1980 increased in organic matter by 21%, total nitrogen by 18%, available nitrogen by 65%, available phosphorus by 17% and available potassium by 17%. Similarly, in the area which was converted from farmland in 1980 to grassland in 1999, soil organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium increased by 38%, 37%, 71%, 2% and 28%, respectively. Changes from farmland to forest and grassland not only changed land cover but also improved soil fertility and probably reduced soil nutrient losses.

Notes: Abstract. Much of the low-lying farmland around the coastline of south-east England was once inter-tidal salt marsh, which was subsequently reclaimed from the sea and converted to farmland. It is becoming increasingly uneconomic to maintain the embankments which protect this land from the sea. ‘Managed retreat’ involves relocating the embankments further inland and recreating inter-tidal habitat in front of them. Salt marsh not only provides a protective buffer for these sea walls by dissipating wave energy, but is also important as a habitat for birds and as a source of organic matter for fish and inter-tidal fauna. When ‘managed retreat’ takes place, the creation of inter-tidal habitat occurs on soils that have undergone physical and chemical changes, some of which are irreversible. However, the indications are that rapid sedimentation creates conditions in which salt marsh plants germinate and become established; soil salinity rises quickly to a level which restricts competition from terrestrial plants, and deposited sediment is relatively rich in available phosphorus. The physical properties of the old agricultural soil influence the subsequent development of creeks.

Notes: Abstract. When the farmers of the Highlands of Tigray (northern Ethiopia) consider rock fragment cover in their fields to be excessive, they remove some of them. In addition, large amounts of rock fragments of all sizes are removed from fields for building stone bunds. Semi-structured interviews indicate that the farmers are often reluctant to take away the smaller rock fragments (i.e. 〈 5 cm across) from their fields, since they believe these benefit soil moisture conservation and protect topsoil from erosion. A field experiment was carried out on a Vertic Cambisol (average slope: 0.125 m m–1), 2 km east of Hagere Selam (subhumid climate). Rock fragments were totally, partially or not removed from the 12 runoff plots (5 m × 6 m) before the beginning of the 1999 cropping season, during which a local mixture of wheat varieties (Triticum spp.) was sown. After harvest, erosion rates were assessed by measuring deposited sediment volume in trenches at the lower side of each subplot, and grain and straw yields were assessed. We found a significant negative relationship between rock fragment cover and soil loss by water erosion. However, the resulting positive relationship between rock fragment cover and grain and straw yield was weak. This might be explained by the fact that the plot did not suffer from drought due to soil and climatic conditions. Detailed analysis showed that cover by medium and large rock fragments (〉 2 cm diameter) showed an optimum percentage cover above which crop yields decrease. A recommendation resulting from this study is to rely on the farmers’ experience: smaller rock fragments should never be removed from the surface of fields during soil and water conservation works; instead rock fragment rich soil can be used to top the stone bunds.

Notes: Abstract. The fertilizer nitrogen requirement of winter wheat was assessed in sixteen experiments on marine silt soils in Eastern England. Eight experimental sites followed potatoes (Solanum tuberosum), six vining peas (Pisum sativum) and two wheat (Triticum aestivum). The yield response to nitrogen fertilizer was much less following peas than potatoes or wheat, five sites following peas showed little response to more than 30 kg N ha–1. Previous crop explained some 79.7% of the variation in nitrogen optima. When autumn soil mineral nitrogen was also taken into account 81.9% of the variation in optimum nitrogen rate was explained (P〈0.001). The study revealed noticeably higher levels of autumn soil mineral nitrogen following vining peas on some sites than those found elsewhere in the UK and as assumed in the standard national fertilizer recommendation system.

Notes: Abstract. The aim of this study was to investigate the effects of water submergence depth on radial oxygen loss (ROL), soil solution chemistry and rice growth performance in acid sulphate soils in southern Vietnam. ROL was measured in a solution culture. In a separate pot experiment the impact of water submergence depth on rice growth and soil solution chemistry was studied. Three submergence depths were used in the two experiments (5, 10 and 15 cm). ROL declined with submergence depth and was significantly greater in young roots (with no root hairs) than in older roots. In the pot experiment rice growth and soil solution chemistry were clearly affected by the submergence depth. During the first crop at 5 cm submergence, there was a significantly higher yield and a higher oxidation state (pe+pH) compared to 10 or 15 cm submergence. The Fe concentration was significantly greater at the 5 cm depth compared to the 10 or 15 cm depth. SO42– reduction was delayed at the 5 cm depth. Rice yield was c. 25% less at the 15 cm than at the 5 cm depth. During a second crop, there was a substantial SO42- reduction and H2S formation and almost no significant effects of submergence depth on either soil solution chemistry or crop yield. In a field experiment with a dry-season rice crop, yield and Fe, Al and SO42– concentrations were higher at a shallow submergence depth than at greater depths in the same field, showing similar depth trends to those found during the first crop in the pot experiment. Farmers should be advised to use a shallow submergence depth and, if possible, avoid deep-rooted rice varieties. A conceptual model is suggested, which summarizes the relationships between ROL and soil solution chemistry.

Notes: Abstract. Tillage displaces large amounts of soil from upper slopes and deposits soil in lower landscape positions, greatly affecting productivity in these areas. The long-term effect of tillage on soil erosion was studied in four field sites growing mainly rainfed wheat. The soil loss from landscape positions with slopes, ranging from 3 to 28%, was estimated by: (a) comparing data of horizon thickness described at the same position at different times; and (b) using soil movement tracers added to the soil. Existing empirical relationships were used for estimating soil loss by tillage and runoff water, and loss in wheat biomass production. The experimental data showed soil losses of 0.4 to 1.4 cm yr–1 depending on slope gradient, plough depth, and tillage direction. In two of the sites, soil depth has been reduced by 24–30 cm in a period of 63 years. The mean soil displacement of the plough layer (30 cm thick), measured by soil movement tracers, ranged from 31 to 95 cm yr–1 depending mainly on slope gradient, corresponding to a rate of soil loss of 0.3 cm to 1.4 cm yr–1. Soil eroded from the upper slopes was deposited on the lower slopes increasing soil thickness by 0.4 cm to 1.4 cm yr–1. The application of empirical relationships, estimating soil loss by tillage and water runoff, showed that soil erosion at the field sites can be mainly attributed to tillage. The loss in wheat biomass production due to erosion was estimated at 26% on upper slopes for a period of 63 years, while a 14.5% increase in wheat production was estimated due to deposition of soil material in the lower landscape.

Notes: Abstract. The most common way of assessing soil organic matter content is by loss on ignition, which is both simple and inexpensive. This method tends to overestimate organic matter content because additional weight losses occur during ignition. An alternative, more expensive and time-consuming method for determining soil organic matter content is by an acid dichromate oxidation. This paper compares the results of applying these methods to soil on different parent materials in two arable fields. Summary statistics and correlation coefficients showed that there were consistent relationships between the two sets of values: the stronger was for the sandy soil and the weaker was for the clay loam. This relationship can be used to improve the accuracy with which soil organic matter content is known while using fewer of the expensive measurements and more of the inexpensive ones. Two approaches to prediction were compared: the geostatistical method of cokriging, and simple linear regression. These were used to predict organic matter determined by an acid dichromate oxidation from the loss on ignition. The estimates from cokriging were more accurate but the method requires the spatial correlation to be modelled reliably. The regression results showed it to be a valuable and practical approach. Using the information from nine carefully selected sampling sites a regression line could be fitted that was representative of the full data.

Notes: 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.

Notes: Abstract. A two year field experiment was carried out in a semiarid Mediterranean area in order to evaluate, the effect on soil erosion of adding different urban organic wastes: a stabilized municipal waste (compost), an unstabilized municipal waste, and an aerobic sewage sludge. All the treatments significantly reduced soil erosion, compared to the control soil. The soil amended with compost was the most effective treatment, reducing soil loss by 94% and runoff by 54%.

Notes: Abstract. Cashew soils of South Eastern Tanzania become acidified due to sulphur used for controlling powdery mildew disease (Oidium anacardii Noack). The buffering capacity of surface and subsurface horizons of 35 soil profiles of major cashew growing areas –- the Makonde plateau, its piedmont and inland plains –- was studied. The buffering capacity of surface and subsurface horizons was strongly correlated with clay content and weakly with organic carbon content. In addition, it was only weakly correlated with total exchangeable bases and available P of the surface horizon, but strongly with soil pH, base saturation and cation exchange capacity of the clay fraction of the subsurface horizon. Highly weathered sandy soils, dominant on the Makonde plateau and common on the Piedmont, had the lowest buffering capacity. Soils from the inland plains had better buffering capacities as they are generally more clayey or are less weathered. The risk of severe acidification and of a decline in productivity of cashew and of food crops is highest on the Makonde plateau. Further development and dissemination of methods which can reduce the use of sulphur are required.

Notes: Abstract. Biomass productivity and soil microbial responses to long-term CO2 enrichment 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 ilex L., Phillyrea angustifolia L., Pistacia lentiscus L. and Myrtus communis L. The CO2 concentration 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 situ soil respiration and above- and below-ground productivity were also measured. Microbial responses to CO2 enrichment were observed only at the beginning of the study and a general progressive reduction of the CO2 effect was recorded as monitoring continued. These results are in agreement with data from literature regarding similar studies on natural complex communities.

Notes: Abstract. The Century model was used for estimating soil carbon levels under grassland at the regional scale in the Pampean Region of Argentina. Predicted values were compared with observed soil carbon contents obtained from soil surveys and the differences considered to be the results of cropping on soil organic matter. The Pampean Region was divided into five major sub-regions and carbon in the top 20 cm of each estimated by Century using aggregated soil and climatic data. In four of the sub-regions small differences between predicted and observed carbon contents were obtained which suggested little land use effect on soils. In the Rolling Pampa, a northern portion of the Pampean Region, observed carbon content was about half of Century prediction. In this sub-region, the main agricultural area of the country, cropping intensity, rainfall and temperature are higher than in the rest of the Pampas. A degradation index constructed by a multiplicative approach, taking into account percentage of surface cropped, rainfall and temperature was 2–5 times higher in the Rolling Pampa than in the other pampean sub-region. The difference between predicted C and observed C in the Rolling Pampa was attributed to carbon losses by cropping in a warm and wet climate.

Notes: Abstract. Recent developments in in situγ ray spectrometry offer a new approach to measuring the activity of radionuclides such as 137Cs and 40K in soils, and thus estimating erosion or deposition rates and field moist bulk density (ρm). Such estimates would be rapid and involve minimal site disturbance, especially important where archaeological remains are present. This paper presents the results of a pilot investigation of an eroded field in Scotland in which a portable hyper pure germanium (HPGe) detector was used to measure γ ray spectra in situ. The gamma (γ) photon flux observed at the soil surface is a function of the 137Cs inventory, its depth distribution characteristics and ρm. A coefficient, QCs, derived from the forward scattering of 137Cs γ ray photons within the soil profile relative to the 137Cs full energy peak (662 keV), was used to correct the in situ calibration for changes in the 137Cs vertical distribution in the ploughed field, a function of tillage, soil accumulation and ρm. Based on only 8 measurements, the agreement between in situγ ray spectrometry and soil sample measurements of 137Cs inventories improved from a non significant r2=0.05 to a significant r2=0.62 (P〈0.05). Erosion and deposition rates calculated from the corrected in situ137Cs measurements had a similarly good agreement with those calculated from soil cores. Mean soil bulk density was also calculated using a separate coefficient, QK, derived from the forward scattering γ photons from 40K within the soil relative to the 40K full energy peak (1460 keV). Again there was good agreement with soil core measurements (r2=0.64; P〈0.05). The precision of the in situ137Cs measurement was limited by the precision with which QCs can be estimated, a function of the low 137Cs deposition levels associated with the weapons testing fallout and relatively low detector efficiency (35%). In contrast, the precision of the in situ ρm determination was only limited by the spatial variability associated with soil sampling.

Notes: Books Reviewed in this Article: Fertiliser recommendations for agricultural and horticultural crops (RB209) Published with the permission of MAFF by HMSO, 7th edition 2000.

Notes: Abstract. In organic farming, potassium (K) deficiency may become a significant problem due to nutrient import restrictions. Knowledge about potential K leaching in systems with different K budgets is therefore important for effective agricultural management. We investigated the effect of four organic farming systems (two livestock densities in combination with two types of organic manure) on crop yields, K leaching and K balances in a six course crop rotation from 1993/94 to 1997/98. Average K concentrations in soil water extracted by means of ceramic suction cups at 1 m depth were 0.6 mg K l−1 corresponding to a K leaching loss of 1.5 kg ha−1 yr−1 which was less than expected from values reported in the literature. Variation in K budgets from −12 to +30 kg ha−1 yr−1 did not affect K leaching. In an additional experiment with application of 988 kg K ha−1 as KCl, K leaching accounted for only 0.2% of the applied K although 40% of the accompanying Cl was leached. The main part of the applied K was retained in the topsoil. It was concluded that K leaching was a result of the fertilizer history rather than of the current K budget.

Notes: Abstract. Nitrate nitrogen (NO3-N) leaching from animal production systems in the northeast USA is a major non-point source of pollution in the Chesapeake Bay. We conducted a study to measure NO3-N leaching from dairy slurry applied to orchardgrass (Dactylis glomerata L., cv. Pennlate) using large drainage lysimeters to measure the direct impact of four rates of slurry (urine and faeces) N application (0, 168, 336, 672 kg N ha−1 yr−1) on NO3-N leaching on three soil types. We then used experimentally-based relationships developed earlier between stocking density and NO3-N leaching loss and leachate NO3-N concentration to estimate the added impact of animal grazing. Nitrate N leaching losses from only dairy slurry applied at the 0, 158, 336, and 672 kg N ha−1 yr−1 rates were 5.85, 8.26, 8.83, and 12.1 kg N ha−1 yr−1, respectively with corresponding NO3-N concentrations of 1.60, 2.30, 2.46, and 3.48 mg l−1. These NO3-N concentrations met the 10 mg l−1 US EPA drinking water standard. However, when a scenario was constructed to include the effect of NO3-N leaching caused by animal grazing, the NO3-N drinking water standard was calculated to be exceeded.

Notes: Abstract. The African oil palm (Elaeis guineensis) is relatively well adapted to the pedoclimatic conditions of central Amazonia. The clayey upland soils of the region are well supplied with nitrogen, although they are deficient in most other nutrients. Under these conditions, oil palm does not respond to N fertilization with yield increases. In this research, the N status of a central Amazonian upland soil was evaluated after having supported a productive oil palm plantation for 15 years without N fertilization. Mineral N in the upper 2 m of soil showed pronounced spatial patterns, with very low concentrations close to the palms, indicative of efficient N uptake by the palms, and evidence for nitrate leaching into the subsoil in the inter-tree spaces despite the near-absence of a leguminous cover crop during the previous ten years. The pronounced increases of mineral N with increasing tree distance were explained by increases in N mineralization and a strong decrease in fine root length density of the palms, especially in the subsoil. Failure of the palms to fully occupy the available soil volume with their roots was apparently related to fertilizer placement close to the stem base, which over the years had led to steep fertility gradients between the soil under the trees and the inter-tree spaces. Broadcast fertilization would have presumably favoured a more extensive lateral root development of the palms, and consequently improved nutrient and water uptake from the inter-tree spaces. The incomplete soil occupation by the palm roots also suggests that young oil palms can be associated with shade tolerant crops without much risk of root competition. These conclusions may be valid also for other tree crops and may help to reduce nitrate leaching and consequently the need for N fertilization in Amazonian tree crop agriculture.

Notes: Abstract. Four experiments studying ground preparation for the restoration of disturbed land to a woodland cover are described. They provide consistent evidence to suggest that methods of soil replacement which minimize compaction are preferable to conventional methods followed by deep ripping to relieve compaction induced in the placement operation. In addition, soil loosening using an excavator is more effective than that achieved by ripping. The research supports modern guidance which advocates ‘loose tipping’ as the best method of ground preparation for a woodland or forestry after-use on sites reclaimed after dereliction or mineral extraction.

Notes: Abstract. Denitrifying enzyme activity (DEA) declined to a greater extent and was more variable in soils stored air-dried for 6 months than after storage at 4 °C. DEA was greatest in fertilized soils. The relative differences in DEA between soils were maintained after storage at 4 °C. We suggest that storage at 4 °C is more appropriate than air-drying.

Notes: Book reviewed in this articles: Agriculture, Fertilizers and the Environment. Edited by M. Lægreid, O. C. Bøckman and O. Kaarstad. Ramiran 98. Proceedings of the 8th International Conference of the FAO European System of Co-operative Research Networks in Agriculture (ESCORNENA) on Management Strategies for Organic Waste Use in Agriculture. Edited by J. Martinéz & M.-N. Maudet.

Notes: Abstract. The incidence of soil water erosion was monitored in 12 erosion-susceptible arable catchments (c. 80 fields) in England and Wales between 1990 and 1994. Factors associated with the initiation of erosion were recorded, and the extent of rills and gullies measured. Approximately 80% of the erosion events were on land cropped to winter cereals. In 30% of cases, the initiation of erosion was linked to valley floor features, which concentrated runoff. Poor crop cover, wheelings and tramlines were also assessed as contributory factors in 22%, 19% and 14% of cases, respectively. In c. 95% of cases rainfall events causing erosion were ≥10 mm day−1 and c. 80% were 〉15 mm day−1. Erosion was also associated with maximum rainfall intensities of 〉4 mm h−1 for c. 90% of cases and 〉10 mm h−1 for c. 20%. Mean net soil erosion rates were approximately 4 t ha−1 per annum (median value 0.41 t ha−1 per annum) and associated mean P losses 3.4 kg ha−1.

Notes: 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.

Notes: Abstract. Under the Kyoto Protocol, the European Union is committed to an 8% reduction in CO2 emissions, compared to baseline (1990) levels, during the first commitment period (2008–2012). However, within the overall EU agreement, the UK is committed to a 12.5% reduction. In this paper, we estimate the carbon mitigation potential of various agricultural land-management strategies (Kyoto Article 3.4) and examine the consequences of UK and European policy options on the potential for carbon mitigation.We show that integrated agricultural land management strategies have considerable potential for carbon mitigation. Our figures suggest the following potentials (Tg yr−1) for each scenario: animal manure, 3.7; sewage sludge, 0.3; cereal straw incorporation, 1.9; no-till farming, 3.5; agricultural extensification, 3.3; natural woodland regeneration, 3.2 and bioenergy crop production, 4.1. A realistic land-use scenario combining a number of these individual management options has a mitigation potential of 10.4 Tg C yr−1 (equivalent to about 6.6% of 1990 UK CO2-carbon emissions). An important resource for carbon mitigation in agriculture is the surplus arable land, but in order to fully exploit it, policies governing the use of surplus arable land would need to be changed. Of all options examined, bioenergy crops show the greatest potential. Bioenergy crop production also shows an indefinite mitigation potential compared to other options where the potential is infinite.The UK will not attempt to meet its climate change commitments solely through changes in agricultural land-use, but since all sources of carbon mitigation will be important in meeting these commitments, agricultural options should be taken very seriously.