Nitrate leaching and spring wheat bread making quality following cultivation of grasslands of different composition, age and management

The influence of sward botanical composition and ley age on grassland residual effects, quality of spring wheat and subsequent nitrate leaching was investigated. Grazed grasslands of different age (1, 2 and 8 production years) and composition (unfertilised grass-clover and fertilised perennial ryegrass) were ploughed and followed by spring wheat and spring barley. For reference, an adjacent field without grassland history but with the same crop sequence in 2002-2003 was treated with increasing quantities of N fertiliser. Yields and N uptake of spring wheat following grasslands always exceeded those of the reference plots with a history of cereal production. The nitrogen fertiliser replacement values of grass-clover and ryegrass were 59-100 and 72-121 kg ha-1, respectively, with the highest values representing the 8-year-old leys. Grain yield and N uptake increased while those for straw decreased with increasing ley age. There were no effects of previous grassland type (grass-clover/ryegrass) on content of protein, starch and gluten, but grassland age significantly influenced protein (P<0.05) and gluten (P<0.01) contents. It is suggested that N mineralisation following the ploughing of older grass leys occurred later than when following the 1st year ley. The protein and gluten contents of wheat following unfertilised grass-clover corresponded to those following cereals given 125-150 kg N ha-1, but the rheological properties of the gluten were different to what could be achieved using equivalent quantities of mineral fertiliser. Probably, the slow release of N from decomposition of old grassland gave a better synchrony between N release and plant demand. Nitrate leaching in year 1 after ploughing was significantly influenced by type of grassland (P<0.001) with 10 and 29 kg N ha-1 leached from grass-clover and ryegrass, respectively. Nitrate leaching following ploughing of 1-year-old leys averaged 11 kg N ha-1 which was significantly lower than the 24 kg N ha-1 following 2 or 8-year-old leys. The flow-weighted mean nitrate concentration decreased from 8.5 mg N l-1 in year 1 after grassland cultivation to 4.5 mg N l-1 in year 2. More N was released following ploughing of ryegrass swards and from grasslands of increasing age, but differences were moderate compared to the estimated N-surplus. This indicates that when organic matter in grasslands is partially decomposed and readily mineralisable N used, the remaining organic N is released only very slowly

Handels- og forbrugsmønstre i Danmark

Vinterhvede er den største og vårhvede den mindste kornafgrøde i Danmark, både med hensyn til produktion og areal. Den totale produktion af vinter- og vårhvede har med store årsvariationer ligget på henholdsvis 4.700.000 og 40.000 tons gennem de sidste 6 år (Tabel 1). Arealmæssigt afspejler det sig i, at vinterhvede dækker ca. 650.000 ha og vårhvede 7.500 ha (Tabel 2). Årsvariationen i produktionen er betinget af størrelsen af kornarealet og vækstforholdene det enkelte år. Vårbyg er den næststørste kornafgrøde, hvilket til dels kan tilskrives det faktum, at maltbygproduktionen næsten udelukkende er baseret på vårbyg, der kan afregnes til en højere pris. Derudover kan vårbyg have sædskifte- og dyrkningsmæssige fordele. Den samlede danske kornproduktion udgør med sine 4,4 pct. af de 15 EU landes samlede kornproduktion en forholdsvis stor andel af EU’s kornproduktion, idet det danske landbrugsareal kun udgør 2,1 pct. Således har Danmark den 6. største kornproduktion i EU efter Frankrig, Tyskland, Storbritannien, Spanien og Italien

Kvalitet af sidstindlejret protein i kernen ved ekstra kvælstofgødskning

Stort udbytte og god brødmelskvalitet er vigtige parametre ved dyrkning af brødhvede. Begge dele kan forbedres ved kvælstofgødningsstrategier, såsom mængde, tilførselstidspunkt, deling af gødning og kvælstofkilde. Hvedekerner består af tre hovedbestanddele: kimet til den nye plante, frøhviden, der er næringsstofkilden til den nye plante, og skaldele, der beskytter frøet. Frøhviden, der indeholder ca. 80% af kernens protein, består primært af store kantede celler, der er fyldt med stivelse og yderst mod frøskallen et lag aleuronceller med et stort indhold af fedt og protein

Kvalitet af hvede til produktion af brød og andre produkter

På verdensplan anvendes ca. 2/3 af hvedeproduktionen til human ernæring. Af den danske hvedeproduktion er det kun ca. 10% der anvendes til human ernæring. Den danske produktion af hvedemel kan opdeles i to, ca. 2/3 anvendes til brødfremstilling og den sidste 1/3 anvendes til bisquit og kager – samt konfekturevarer, kødvarer, supper m.v. Den almene betydning af vendingen kvalitet er ”anvendelighed til nogle specifikke formål”. Når man taler om kvalitetshvede betyder det ifølge Kent og Evers (1994): · Udbytte af slutproduktet (hvede for landmanden, hvede for grovvareselskabet, mel for mølleren, brød for bageren, etc.) · egnethed for maskinbearbejdning, f.eks. god dejstabilitet, egenskaber ved slutproduktet: ensartethed, smag, udseende, tekstur, volumen, holdbarhed og kemisk sammensætning Kerneudbytte og proteinindhold, opgivet i procent protein, er nøglefaktorer i produktion af og handel med hvede. Udbytte er et mål for aktiviteten og varigheden af processer, der bidrager til indlejring af stivelse i kernen. Proteinindholdet afspejler processerne i kvælstof stofskiftet, selv om dette ikke er uafhængigt af udbyttet (Jenner et al. 1991). Der er en positiv sammenhæng mellem proteinindhold i kernerne og brødvolumen samt tekstur af det bagte brød (Pomeranz, 1988)

Cultivar and Year-to-Year Variation of Phytosterol Content in Rye (Secale cereale L.)

Intake of phytosterols (and -stanols) has been shown to decrease the level of low-density lipoprotein cholesterol and thus protect against development of cardiovascular diseases. Therefore, studies on the cultivar and year-to-year variation in phytosterol content in rye grains have been performed. The phytosterol content and composition of different rye cultivars, grown under identical conditions on the same field in three consecutive years, were analyzed. Both cultivar and year-to-year variation in sterol content were statistically significant (p < 0.0001). The total sterol content varied from 1007 ± 21 mg/kg in the highest yielding cultivar, Tsulpan 3, to 761 ± 10 mg/kg in the lowest yielding cultivar (Amando in the 1999 harvest). Because the meteorological conditions varied substantially between the different years, it was possible to deduce the impact of varying weather conditions on phytosterol content in the different cultivars. The studied cultivars had all the lowest phytosterol contents in the dry and warm harvest season of 1999. Although there were statistically significant cultivar and year-to-year variations in the sterol composition (p < 0.0001), these were only between 2 and 4% of the total sterol content

Grain Characteristics, Chemical Composition, and Functional Properties of Rye (Secale cereale L.) As Influenced by Genotype and Harvest Year

Grain characteristic, chemical composition, and functional properties of rye were measured in 19 different cultivars grown in one location in up to 3 years. The cultivars included 8 adapted hybrids, 7 adapted population cultivars, and 4 nonadapted population cultivars. The results showed a significant influence of both harvest year and genotype on grain characteristics, chemical composition, and functional properties of the grain. Multivariate data analysis confirmed that the variations in the data were explained by yearly and genotype differences. Calculations of variance components showed that the variations in plant height, harvest yield, and protein content were mainly due to genotype differences and to a lesser extent to differences among harvest years. The kernel weight, hardness index, and content of dietary fiber components, however, were more strongly influenced by the harvest year than by the genotype. Differences in starch properties measured by falling number (FN), amylograph peak viscosity, and temperature at peak viscosity were more strongly influenced by harvest year. The water absorption was strongly influenced by genotype effects, compared to yearly differences. FN and amylograph peak temperature were positively correlated (r = 0.94). No correlation was found between the water absorption and the relative proportion of water-extractable arabinoxylan (AX) compared to the total AX content. However, the degree of ferulic acid cross-linking showed a negative correlation (r = -0.70) with the water absorption

Summer and Autumn Movements and Habitat Use by Belugas in the Canadian High Arctic and Adjacent Areas

Twenty-one adult belugas (8M, 13F) were live-captured and instrumented with satellite-linked transmitters in the summer and fall of 1996. Twelve were captured in estuaries along the coast of Somerset Island in July and nine were captured in September in Croker Bay, SE Devon Island. This paper reports on the summer and autumn movements and dive depths of these animals from late July 1996 until the last tags ceased transmitting in November 1996. Of the 12 captured in July, 11 provided data for 30-126 days (mean = 84 days). Most of the animals moved rapidly to southern Peel Sound, where they all spent the month of August, making frequent deep dives, some of which were to depths near or at the seabed of the Franklin Trench. The belugas also used several bays along the coast of Prince of Wales Island and another one on Melville Peninsula. They left southern Peel Sound between late August and early September and moved rapidly to the south coast of Devon Island, many using Maxwell Bay and Croker Bay for several days. All belugas instrumented in Croker Bay in September, as well as the summer-tagged individuals that were still transmitting, moved east and north along the south and east coasts of Devon Island, eventually reaching Jones Sound and north Baffin Bay. They used many bays along the east coast of Devon Island and dove to depths often exceeding 200 m in the surrounding waters. Fifteen of the tags continued to transmit during the period when belugas are normally observed migrating along the West Greenland coast (late September-early October). Only one of the tagged animals moved to Greenland waters in late September. The others remained in the area known in winter as the North Water. The autumn tracking results suggest that the North Water may harbour a larger winter population of belugas than was previously suspected.Durant l'été et l'automne de 1996, on a capturé 21 bélugas adultes (8 mâles, 13 femelles), qu'on a équipés d'émetteurs-satellite. Douze d'entre eux ont été capturés en juillet dans des estuaires de l'île Somerset et neuf autres l'ont été en septembre dans la baie Croker du sud-est de l'île Devon. Cet article fait état des déplacements et profondeurs de plongée de ces animaux en été et en automne, de la fin juillet 1996 jusqu'à ce que les émetteurs cessent de transmettre, en novembre 1996. Sur 12 individus capturés en juillet, 11 ont transmis des données pendant 30 à 126 jours (moy. = 84 jours). La plupart des animaux se sont déplacés rapidement vers le sud du détroit de Peel où ils ont tous passé le mois d'août, plongeant fréquemment à de grandes profondeurs dont certaines atteignaient ou presque le fond marin de la fosse Franklin. Les bélugas ont aussi utilisé plusieurs baies le long de la côte de l'île Prince of Wales et une autre dans la péninsule Melville. Ils ont quitté le sud du détroit de Peel entre fin août et début septembre et se sont déplacés rapidement vers la côte sud de l'île Devon. Plusieurs d'entre eux ont passé quelques jours dans les baies Maxwell et Croker. Tous les bélugas équipés d'instruments dans la baie Croker en septembre, ainsi que ceux relâchés en été et qui continuaient à transmettre, se sont déplacés vers l'est et le nord en suivant les côtes sud et est de l'île Devon, finissant par atteindre le détroit de Jones et le nord de la baie de Baffin. Ils ont occupé de nombreuses baies sur la côte est de l'île Devon et effectué des plongées atteignant souvent plus de 200 m dans les eaux avoisinantes. Quinze des émetteurs ont continué à transmettre durant la période où on observe normalement des bélugas en migration au large de la côte du Groenland occidental (fin septembre - début octobre). Un seul des animaux portant un émetteur a pénétré dans les eaux groenlandaises à la fin septembre. Les autres sont restés dans une zone connue en hiver sous le nom de "North Water" (Eau du Nord). Ces résultats suggèrent qu'en hiver le "North Water" abrite une population de bélugas plus abondante qu'on ne le pensait antérieurement

Fluctuations in the Cosmic Microwave Background I: Form Factors and their Calculation in Synchronous Gauge

It is shown that the fluctuation in the temperature of the cosmic microwave background in any direction may be evaluated as an integral involving scalar and dipole form factors, which incorporate all relevant information about acoustic oscillations before the time of last scattering. A companion paper gives asymptotic expressions for the multipole coefficient $C_\ell$ in terms of these form factors. Explicit expressions are given here for the form factors in a simplified hydrodynamic model for the evolution of perturbations.Comment: 35 pages, no figures. Improved treatment of damping, including both Landau and Silk damping; inclusion of late-time effects; several references added; minor changes and corrections made. Accepted for publication in Phys. Rev. D1

Coherent States of the q--Canonical Commutation Relations

For the $q$-deformed canonical commutation relations $a(f)a^\dagger(g) = (1-q)\,\langle f,g\rangle{\bf1}+q\,a^\dagger(g)a(f)$ for $f,g$ in some Hilbert space ${\cal H}$ we consider representations generated from a vector $\Omega$ satisfying $a(f)\Omega=\langle f,\phi\rangle\Omega$, where $\phi\in{\cal H}$. We show that such a representation exists if and only if $\Vert\phi\Vert\leq1$. Moreover, for $\Vert\phi\Vert<1$ these representations are unitarily equivalent to the Fock representation (obtained for $\phi=0$). On the other hand representations obtained for different unit vectors $\phi$ are disjoint. We show that the universal C*-algebra for the relations has a largest proper, closed, two-sided ideal. The quotient by this ideal is a natural $q$-analogue of the Cuntz algebra (obtained for $q=0$). We discuss the Conjecture that, for $d<\infty$, this analogue should, in fact, be equal to the Cuntz algebra itself. In the limiting cases $q=\pm1$ we determine all irreducible representations of the relations, and characterize those which can be obtained via coherent states.Comment: 19 pages, Plain Te