A study of cultivation and sowing systems for cereals.

End of Project ReportDue to the pressure on cereal margins growers are seeking ways of reducing their costs of production. Reduced cultivation may provide cheaper and faster crop establishment, but in the past has been subject to problems with (poor crop establishment) weeds and soil compaction. With modern cultivation and sowing technology and methodology it may be possible to overcome these difficulties. In addition reduced cultivation is considered to be more environmentally friendly and sustainable than the conventional plough-based system. With these considerations in mind it was decided to start an experiment in autumn 2000 to compare the conventional system (PL) with reduced cultivation (RC) for crop establishment, and to examine the effect of incorporating the straw into then soil or baling and removing it. The treatments were assessed on winter wheat, and winter and spring barley. The parameters assessed included – crop establishment, yield and quality effects on disease levels, invertebrate pests and beneficials (aphids, slugs, earthworms, beetles), and soil conditions. The work reported here was conducted on four trial sites at Oak Park, Carlow and Knockbeg, Co. Laois from 2000 to 2003. the objectives were to establish the efficacy of RC compared with PL and to its effects on the parameters outlined above. Plant establishment was lower after RC in most of the experiments. Winter wheat yields were good irrespective of the number of plants established and there were no significant differences between cultivation or straw disposal method. The relative yields of the PL and RC treatments in winter barley varied over the three years; in 2001 there was no difference, in 2002 PL yielded 1 t/ha more than RC, while in 2003 the PL area produced 2 t/ha extra. Spring barley yields were similar on the PL and RC treatments. Broadleaved weeds were not a problem on the PL or RC treatments but there were more annual grass weeds on the RC plots. This was particularly serious in the winter barley experiments where sterile brome (Bromus sterilis) had a big effect on yield by 2003. annual meadow grass (Poa annua) was a problem in both PL and RC areas if not controlled by timely herbicide application; this was particularly so on the headland areas in the spring barley field. Disease assessment on the winter wheat trail showed no significant differences in Take-all or Eyespot levels between cultivation or straw disposal methods, although Take-all levels tended to be lower on the RC plots. Soil strength as measured by cone penetrometer and shear vane was higher on the RC treatments. In the winter wheat there was no difference in slug numbers between any of the treatments. Leaf damage by slugs increased in RC relative to PL but not significantly, in 2003. No below ground slug damage was found. Earthworm numbers in the winter barley increased significantly on the RC treatment relative to the PL as the study progressed. Straw incorporation increased earthworm numbers on both PL and RC treatments. Allolobophora chlorotia was the most common species in 2004. In the winter wheat the RC and straw incorporation increased earthworm numbers. Cultivation method had a greater effect on ground beetle numbers than method of straw disposal. Large species (e.g. Pterostichies malanarius) were favoured by RC while smaller species (e.g. Bembidon species) were more numerous in the PL plots. Molecular studies on virus diseases, vectors and vector-predators are underway in progress. In the invertebrate pests and beneficials investigations the RC winter barley had 11% fewer aphids and 27% less BYDV than the PL. Incorporating straw reduced aphid numbers and virus incidence by 36% and 32% respectively; the comparable values for the PL + straw treatment were 15% and 15%. In the winter wheat there was less BYDV in the RC plots than the PL + less were the straw was incorporated than where the straw was removed. Aphid infestation of wheat ears was low in the three years of the experiment. The insecticide seed treatment imidacloprid significantly reduced aphid numbers and virus incidence in winter barley but was less effective than a single insecticide spray in controlling the disease. The seed treatment was more effective in controlling BYDV in RC than in the PL plots. Estimations of slug numbers in the winter barley showed that the dominant species was the grey field slug (Deroceras reticulatum). Slug numbers increased significantly on all treatments between 2001 and 2004. In November 2004, slugs were significantly more numerous in the RC treatments than in the PL areas. Leaf damage was proportional to slug populations, but the slugs did not damage the barely seed or reduce plant populations in continuous winter barley under RC. Root and stem diseases (Take-all and Eyespot) were not nay worse under RC than after PL. In fact there was a tendency towards lower disease levels on the RC areas and there was significantly less sharp eyespot on the RC treatment

Variational Approach to the Modulational Instability

We study the modulational stability of the nonlinear Schr\"odinger equation (NLS) using a time-dependent variational approach. Within this framework, we derive ordinary differential equations (ODEs) for the time evolution of the amplitude and phase of modulational perturbations. Analyzing the ensuing ODEs, we re-derive the classical modulational instability criterion. The case (relevant to applications in optics and Bose-Einstein condensation) where the coefficients of the equation are time-dependent, is also examined

Gaussian quantum operator representation for bosons

We introduce a Gaussian quantum operator representation, using the most general possible multimode Gaussian operator basis. The representation unifies and substantially extends existing phase-space representations of density matrices for Bose systems and also includes generalized squeezed-state and thermal bases. It enables first-principles dynamical or equilibrium calculations in quantum many-body systems, with quantum uncertainties appearing as dynamical objects. Any quadratic Liouville equation for the density operator results in a purely deterministic time evolution. Any cubic or quartic master equation can be treated using stochastic methods

Evidence for a narrow dip structure at 1.9 GeV/c2^2 in 3π+3π−3\pi^+ 3\pi^- diffractive photoproduction

A narrow dip structure has been observed at 1.9 GeV/c$^2$ in a study of diffractive photoproduction of the $~3\pi^+3\pi^-$ final state performed by the Fermilab experiment E687.Comment: The data of Figure 6 can be obtained by downloading the raw data file e687_6pi.txt. v5 (2nov2018): added Fig. 7, the 6 pion energy distribution as requested by a reade

Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio