Single spin asymmetry for the Drell-Yan process

We calculated the single spin asymmetries for the reaction $P+P(\uparrow)\rightarrow l \overline{l}+X$ in the framework of twist-3 QCD for HERA energies. The necessary imaginary phase is produced by the on-shell contribution of the quark propagator, while the long distance part is analogous to that providing the direct photon asymmetry calculated by J. Qiu and G. Sterman. The asymmetry turns out to be generally of the order percent.Comment: 7 pages, 4 figures, LaTe

Understanding the JD7760 round module picker impacts

This paper communicates further the findings, pertaining to the John Deere 7760 (JD7760) round module picker, of the Cotton Growing Practices 2013 industry survey and current research at the National Centre for Engineering in Agriculture. The grower data is used to highlight decision making processes used and provides insight into potentially latent impacts on system components, particularly the land resource. Adoption drivers and considerations are discussed against machine potential, the Australian picker market and the potential for soil compaction is demonstrated to contrast considerations

Effect of controlled traffic farming on energy saving in Australian grain cropping systems

Controlled traffic farming (CTF) is a system in which all machinery has the same or modular working and track widths so that field traffic can be confined to the least possible area of compacted permanent traffic lanes. In well-designed CTF systems permanent traffic lanes usually occupy less than 15% of cropped area, and this has been widely adopted in Australia. CTF is a practical and cost-effective facilitator of no-tillage farming, and the basis for more precise cropping systems. Controlled traffic systems are often claimed to reduce power and fuel requirements of cropping operations, because motion resistance to traffic should be less on permanent lanes, and draft requirement of tilling or seeding should be less in non-compacted soil. Experimental work was conducted to assess the effects of tractor wheel compaction on the energy requirements of soil-engaging operations, particularly, during tillage and planting. Preliminary results from this investigation indicate that on average the draft of tillage sweeps, planter openers, and chisel tines increased by approximately 35%, 37%, and 54%, respectively, when positioned behind a tractor wheel

Controlled traffic farming effects on productivity of grain sorghum, rainfall and fertiliser nitrogen use efficiency

Controlled traffic farming (CTF) is a mechanisation system in which all machinery has the same (or modular) working and track width so that field traffic can be confined to the least possible area of permanent traffic lanes. CTF enables productivity of non-compacted crop beds to be optimised for given energy, fertiliser and water (rainfall) inputs. This study investigated the agronomic response and economic return of grain sorghum grown in compacted and non-compacted soils to represent the conditions of non-CTF and CTF systems, respectively. Yield-to-nitrogen (N) responses were derived following application of urea, 3,4-dimethyl pyrazole phosphate-treated urea (DMPP), and urea ammonium nitrate (UAN, 32% N) at rates between 0 and 300 kg ha−1 N. Selected soil properties were measured to guide parametrisation of the Agricultural Production Systems Simulator (APSIM), which was used to assess long-term (55 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall use efficiency (RUE) and develop rainfall-runoff relationships. Grain yield and yield components (harvest Index, grain thousand-grain weight, number of grains) were significantly higher in CTF compared with non-CTF. On average, the most economic N rates, and corresponding grain yields, were 144 and 3428 kg ha−1, and 100 and 1796 kg ha−1 for CTF and non-CTF, respectively. When N inputs were optimised, agronomic efficiency calculations showed 18% increase in CTF compared with non-CTF. Nitrogen use efficiency (NUE) was 1.75 times higher in CTF than in non-CTF. Rainfall-use efficiency was about 65% higher in CTF, which concurrently reduced the amount of runoff compared with non-CTF. Average rainfall season (330–450 mm in-crop) grain yield was 30% lower in non-CTF compared with CTF. For subtropical conditions of Australia, long-term APSIM simulations showed that increased productivity and inter-season yield stability can increase gross margin of grain sorghum by AUD74 ha−1 or greater depending on the adopted tillage system and in-crop rainfall. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilisers, such as DMPP-treated urea, cannot compensate for other stresses caused by soil compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF delivers improved resource-use efficiency and profitability in rainfall-limited environments

Quantifying the impacts of coal seam gas (CSG) activities on the soil resource of agricultural lands in Queensland, Australia

Coal seam gas (CSG) activities in the Surat and Bowen Basin areas of Queensland, Australia, cover approximately 300,000 km2 including regions of good quality agricultural lands. Without adequate knowledge of soil properties, hydrologic processes and control measures, the disturbed soil structure and landform in these regions are highly susceptible to soil degradation. The construction and installation of CSG infrastructures (e.g. roads, pipelines, hardstand and plant areas) cause various degrees of disturbance to the soil physical, chemical and biological characteristics. This disturbance may result in soil degradation through various forms including compaction, erosion processes, changes to organic carbon and soil nutrient store, exposure of potentially reactive/poor quality soils (e.g. acid sulphate soils, hyper-saline soils) or introduction of outside contaminants (poor quality water, weeds). Not only are soils directly disturbed by the footprint of the CSG operation but the surrounding soil landscape may be disturbed by secondary processes such as erosion and sedimentation. Soil compaction changes caused by CSG operations, including vehicle impacts and trench line installation, have been assessed by soil bulk density measurements. This measurement has been identified as a common impact by CSG operation and a key element of soil degradation of agricultural areas contributing poor vegetation establishment, tunnel and surface erosion processes and an ongoing decline for soil productivity. Quantifying the impacts of CSG activities on soils will inform the development of industry guidelines for impact minimisation and management of the soil resource on joint CSG-agricultural lands

Agronomic performance of wheat (Triticum aestivum L.) and fertiliser use efficiency as affected by controlled and non-controlled traffic of farm machinery

Controlled traffic farming (CTF) is a mechanization system that confines all load-bearing wheels to permanent traffic lanes, thus optimizing productivity of non-compacted crop beds for given energy, fertilizer and water inputs. This study investigated the agronomic and economic performance of winter wheat (Triticum aestivum L.) grown in compacted and non-compacted soils to represent the conditions of non-CTF and CTF systems, respectively. Yield-to-nitrogen (N) responses were obtained by applying urea (46% N), urea treated with 3,4-dimethyl pyrazole phosphate (DMPP), commercially known as ENTEC® urea (46% N), and urea ammonium nitrate (solution, 30%N) at rates between 0 (control) and 300 kg ha-1 N at regular increments of 100 kg ha-1 N. The results showed that the CTF system increased grain yield, total aboveground biomass, and harvest index by 12%, 9%, and 4%, respectively compared to the crop grown under the non-CTF system (P<0.05). Overall, the agronomic efficiency was approximately 35% higher in CTF compared with non-CTF (≈4 vs. 3 kg kg-1, respectively). Nitrogen use efficiency (NUE) was approximately 50% higher in CTF compared with non-CTF; however, there was not fertilizer type effect on NUE. On average, the optimal economic nitrogen application rates and corresponding grain yields were 122 kg ha-1 and 3337 kg ha-1, and 175 and 3150 kg ha-1 in the CTF and non-CTF systems, respectively. This work demonstrated that significant improvements in fertilizer-N recoveries may not be realized with enhanced nitrogen formulations alone and that avoidance of (random) traffic compaction is a pre-requisite for improved fertilizer use efficiency

Measurement of the Collins and Sivers asymmetries on transversely polarised protons

The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large values of the Bjorken x variable non-zero Collins asymmetries are observed both for positive and negative hadrons while the Sivers asymmetry for positive hadrons is slightly positive over almost all the measured x range. These results nicely support the present theoretical interpretation of these asymmetries, in terms of leading-twist quark distribution and fragmentation functions.Comment: 9 Pages, 5 figure

A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations.Comment: 40 pages, 28 figure

Rural Development Programme measures on cultivated land in Europe to mitigate greenhouse gas emissions – regional ‘hotspots’ and priority measures

© 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.Agriculture is a significant source of GHG emissions, contributing 10% of total emissions within the EU-28. Emissions from European agriculture have been reduced, albeit at the expense of crop yield and the risk of production displacement (the transfer of production, and associated emissions, to land outside of Europe). This article assesses the impact on GHG emissions of selected European Rural Development Program measures, representative of a diversity of management strategies implemented on cultivated land, within nine European Member States. Climatic zone and underlying spatial environmental variables were accounted for using a novel technique, “Regional Variation Categories,” developed with European-scale GIS data sets. Production displacement is assessed with two benchmarks: (1) compared with existing crop production and (2) relative to a “minimum requirement” land management scenario, where an emissions reduction of less than this does not constitute mitigation. Most measures reduce emissions relative to the baseline crop scenario; however, many do not reduce emissions beyond the “minimum requirement,” this being limited to measures such as catch crops and within-field grass areas to prevent soil erosion. The selection and targeting of measures to maximize agricultural GHG mitigation on cultivated land within Europe is discussed...Peer reviewedFinal Published versio