ALBERT

Description: SUMMARYThe herbicide chlorsulfuron is commonly applied to cereals and may persist in alkaline soil long enough to damage subsequent sensitive crops. Sewage water, a potential source of the heavy metal cadmium (Cd), is used to irrigate agricultural soils in many developing countries. The current work evaluated the effects of the residual herbicide chlorsulfuron and Cd on maize seedlings, with particular attention to the mechanism of their action on plant growth. Maize seeds were planted in soil that had been sprayed with chlorsulfuron and Cd, after which residues in both seedlings and the soil were measured. The chlorsulfuron dose was correlated with the amount of residue found in seedlings but not in the soil. In all, 39 metabolites were identified in seedlings using the Automated Mass spectral Deconvolution and Identification System software program and the retention index method. The combination of chlorsulfuron and Cd significantly reduced multiple metabolites in the shikimate pathway, malic acid and citric acid production in the tricarboxylic acid cycle, and lactic acid, glucose, aspartic acid, asparagine and 3-glycerophosphoric acid production. In addition, chlorsulfuron caused an increase in multiple amino acids, including tyrosine, methionine and asparagine, and a marked decrease in caffeic and cinnamic acids (the secondary metabolites derived from the shikimate pathway and galactose). Finally, chlorsulfuron and Cd stress markedly increased shikimate acid, decreased 3-glycerophosphoric acid and caused negative correlations between the amounts of phenylalanine and tyrosine and those of quinic- and cinnamic-acid. In conclusion, chlorsulfuron and Cd did not have a synergistic effect on maize seedlings; rather, the combination of these pollutants had an antagonistic effect on some amino acids.

Description: The Vila Pouca de Aguiar granite pluton, emplaced during the latest event of the Variscan orogeny of northern Portugal, is here subjected to a detailed study that combines magnetic fabric measurements and gravity modelling of its shape at depth. This laccolith, less than 1 km in thickness over ≈60% of its outcrop area, appears to be fed from its northern area, through narrow conduits, up to 5 km deep, belonging to a set of Y-shaped valleys that almost perfectly correspond to the local Régua–Verin fault-system identified in the geological maps. A normal petrographical zonation, already identified geologically, appears to be rather progressive, although a gradient in magnetic suceptibility magnitude in-between the two main magma types is evidenced. It is suggested that the first to be emplaced and the least evolved granite type (Vila Pouca de Aguiar Granite) upwelled from the local, NE-trending fault-zone, acting as a dyke, and formed a thin sill where NE-directed magma flow was dominant, at least close to the floor. The more evolved granite type (Pedras Salgadas Granite), located just above the main feeder zone, and deeply rooted at the intersection beween underlying faults, is at the centre of a remarkably regular concentric distribution of the foliation trajectories. They may reflect the late doming of the laccolith's northern part, coeval with a slight E-W extension of the inflating magma reservoir, as marked by the E-W-trending lineations. Along with ubiquitous magmatic to near-magmatic microstructures and particularly low anisotropy magnitudes, such patterns can be entirely explained by magma movement within its inflating reservoir. This composite laccolith, during emplacement of which no interference with the regional strain pattern can be recorded, is therefore considered as typical of post-tectonic emplacement.

Description: 1. Data on the crude-protein content and crudeprotein production of five grass species (each sown with white clover) over the period 1954–56, at six levels of compound fertilizer application, are reported. Perennial rye-grass (S. 101), meadow fescue (S. 215), timothy (S. 48), cocksfoot (S. 26) and bent (N.Z. Browntop) were sown in 1953 at appropriate seed rates, each with 2 lb./acre S. 100 white clover. The fertilizer treatments were 0, 1, 3, 5, 7 and 9 cwt./ acre of a compound of composition 10% N, 4%P2O5, 9·5% K2O applied in the early spring of each of the years 1954–56. The swards were cut three times a year in 1954 and 1956, but only two cuts were possible in 1955.2. Bent mixtures had a higher crude-protein content than any other mixture in all years and (with one exception) at every cut within years. Differences between other mixtures were smaller and often erratic, though timothy invariably had the lowest crude-protein content at the second cut and cocksfoot at the third. Application of the fertilizer raised the crude-protein level of the herbage at the first cut, but depressed it in subsequent cuts.3. The bent mixture gave the highest yield of crude-protein per acre followed by the timothy mixture, while the lowest yield was produced by the perennial rye-grass mixture. The bent mixture differed from all others in its distribution of crudeprotein production over the season, producing less at the first cuts and more at the second and third cuts. This reflects its pattern of production of dry-matter. Response to spring application of fertilizer in terms of crude-protein yield declined rapidly from cut to cut. Over the whole period of the experiment 1 cwt./acre/ annum of fertilizer containing 10% N gave a response of about 0·5 cwt. crude-protein/annum.

Description: 1. Data on the dry-matter production of five grass species (each sown with white clover), over the period 1954–56, at six levels of compound fertilizer application, are reported. Perennial ryegrass (S. 101), meadow fescue (S. 215), timothy (S. 48), cocksfoot (S. 26) and bent (N.Z. browntop) were sown in 1953 at appropriate seed rates, each with 2 lb. per acre S. 100 white clover. The fertilizer treatments were 0, 1, 3, 5, 7 and 9 cwt. per acre of a compound of composition 10% N, 4% P2O5 and 9·5% K2O, applied in the early spring of each of the years 1954–56. The swards were cut three times a year in 1954 and 1956, but only two cuts were possible in 1955.2. The timothy mixture gave the highest total production of dry-matter over the 3 years, the bent and perennial rye-grass mixtures giving the lowest total productions. Differences between mixtures in annual yield varied in sign and in magnitude from year to year. For example, bent gave the lowest yield in 1954, but outyielded the meadow fescue and the cocksfoot mixtures in 1955, and the perennial rye-grass mixture in 1956. As regards the distribution of dry-matter production over the season, it was found that bent differed from the other mixtures in that a higher proportion of its annual yield was produced at the second and third cuts.3. There were significant linear relationships of dry-matter yield to fertilizer application rate in most of the data. On average over the 3 years, 1·6 cwt. of dry-matter were produced for each cwt. of spring applied fertilizer in the first cut, 0·7 cwt. per cwt. of fertilizer in the second cut, while very small and non-significant responses were found in the third cut. There was no evidence of systematic differences between grass mixtures in response to fertilizer level.4. The yield of clover dry-matter in 1956 (the third harvest year) was least from the cocksfoot and timothy swards, and was significantly and linearly depressed by fertilizer application in all three cuts.

Description: A bibliometric analysis of research articles published on water-use efficiency was performed using the Web of Science database and evaluated. Journal titles, publication years, subject categories, keywords and countries publishing were obtained. A number of 2077 papers were retrieved, two-thirds of them published in the last decade. The articles were published in 439 journals, with Agricultural Water Management, Agronomy Journal, Crop Science, Field Crops Research and Indian Journal of Agricultural Sciences the most productive. Most of the leading productive journals have Impact Factors in the top quartiles of the Journal Citation Reports. Agronomy, Plant Sciences, Water Resources and Agriculture Multidisciplinary were the most common journal subject categories, indicating a wide diversity of research fields ascribed to this topic. The predominant key words and phrases used were growth, ‘carbon isotope discrimination’, yield, photosynthesis, ‘gas exchange’, evapotranspiration and ‘stomatal conductance’. The productivity ranking for countries was headed by China (456 papers), followed by the USA (410), Australia (176) and India (165). A content analysis of the papers made identification of the key issues of greatest scientific concern possible, as well as their evolution over time. The most cited papers relate to physiological aspects, but also important studies on experimental biology, drought resistance, effects of climate, crop production and ecology, among others.

Description: Journal of Climate, Ahead of Print. 〈br/〉

Description: 〈div data-abstract-type="normal"〉〈p〉Following pioneering work in Norway, cirque glaciers have widely been viewed as rigidly rotating bodies. This model is incorrect for basin-filling cirque glaciers, as we have demonstrated at West Washmawapta Glacier, a small glacier in the Canadian Rocky Mountains. Here we report observations at the same glacier that assess whether complex temporal variations of flow also occur. For parts of three summers, we measured daily displacements of the glacier surface. In one year, four short-duration speed-up events were recorded. Three of the events occurred during the intervals of warmest weather, when melt was most rapid; the fourth event occurred immediately following heavy rain. We interpret the speed-up events as manifestations of enhanced water inputs to the glacier bed and associated slip lubrication by increased water volumes and pressures. No further speed-ups occurred in the final month of the melt season, despite warm temperatures and several rainstorms; the dominant subglacial water system likely transformed from one of poorly connected cavities to one with an efficient channel network. The seasonal evolution of hydrology and flow resembles behaviors documented at other, larger temperate glaciers and indicates that analyses of cirque erosion cannot rely on simple assumptions about ice dynamics.〈/p〉〈/div〉

Description: During Early, as proposed by the International commission on stratigraphy Pleistocene times, interacting fluvial and aeolian processes constructed wide alluvial plains over an evaporite-dominated Miocene substratum in the central Ebro Basin. An exceptional site where these deposits show faults, folds, diapirs, karst structures and unconformities has been studied in detail. Analysis of particular structures demonstrates the interaction by that time of tectonic faulting, diapirism, karstification and sedimentation in an area where deformation was traditionally linked to the presence of underlying evaporites, without proposing any precise mechanism. Multiple approaches (sedimentology, structural geology and geophysics) have been used in order to discriminate the origin of each type of structure as well as to understand the interaction between different processes. Numerous normal faults and fractures of variable size are consistent with the regional stress field. Pleistocene deposits are pierced by diapirs of Miocene evaporites and disrupted by karst structures with different geometries (tubular, funnel and vault), both partially controlled by tectonics. The example described is proposed as an analogue model that could successfully illustrate evolution patterns of basins of potential interest for petroleum geology where similar processes have actuated, resulting in complex stratigraphical architectures.