Impact of foliar diseases in organically grown barley: Influence of fertilization, nutrient content in leaves, varietal disease resistance characteristics and yield potential

Significant increase in severity of powdery mildew,leaf rust and net blotch with increasing N-content in plant leaves 30 days after germination (all years where the relevant diseases were present at a substantial level). This may explain: · Most of the environmental main effects (field) on disease. · Effect of treatments, i.e., treament 4 resulted in reduced N/increased K content in leaves, which coincided with reduced levels of disease. We observed no clear effect of P, Ca, S, and Zn content in leaves on disease. Micronutrients as Cu, Mo and Mn showed significant effects on powdery mildew in one year but not the other; further interpretation may not be possible due to inter-correlation among the effect of micro-nutrients. The diseases had a significant yield reducing effect, in particular powdery mildew and net blotch, which occurred at highest severities. In addition, net blotch affected root development, resulting in significant shorter roots, whereas powdery mildew did not. The effect of disease on root length was of the same order of magnitude as the factor 'variety', but larger than effects of 'year'

Nitrate leaching from arable crop rotations in organic farming

Nitrate leaching from crop rotations for organic grain production were investigated in a field experiment on different soil types in Denmark from 1997 to 2002. Three experimental factors were included in the experiment in a factorial design: 1) proportion of grass-clover and pulses in the rotation, 2) cover crop (with and without), and 3) manure (with and without). Two four-course rotations were compared. They had one year of grass-clover as a green manure crop, either followed by spring wheat or by winter wheat. The nitrate leaching was measured using ceramic suction cells. The nitrate leaching did not differ between the rotations, as a change in leaching following the grass-clover was compensated by a reverse effect in the grain crops. Use of cover crops reduced N leaching by 23 to 38% at crop rotation level with the highest reduction on the coarse sandy soil. Simulation of N leaching using the FASSET model showed that a practice of using part of the summer period in the grass-clover as a bare fallow to control couch grass could increase leaching substantially, in particular on the sandy soil

Using C-Tool to simulate soil carbon and radiocarbon development

Tho model framework C-TOOL was used to simulate soil carbon and radiocarbon development. A simple three-compartment model was sufficient for describing the data

Sustainability in Software Engineering

The intersection between software engineering re- search and the problems related to sustainability and green IT has been the subject of increasing attention. In spite of that, we observe that sustainability is still not clearly defined, or understood, in the field of software engineering. This lack of clarity leads to confusion about e.g. what is relevant to measure or the research implications over time or space. This paper provides an overview of how the research so far has defined sustainability, and how this definition has been used to guide which research areas. To this end, we carried out a systematic mapping study for selecting, classifying and analyzing relevant publications. In this study, we investigate which knowledge areas and which time scope of sustainability effects are mostly targeted in scientific research. Our analysis shows research trends and discusses gaps to be filled

Do nutrient uptakes and grain yields differ between spring barley varieties grown for organic farming as mono-crop and in mixture: Characteristics of spring barley varieties for organic farming

Manure application increased yield. Hence the study was conducted under the conditions of moderate nutrient stress and in all probability nitrogen stress. Under this condition nutrient uptakes, biomass production and grain yields did vary between Otira, Orthega, Landora, Brazil, Svani, NK96-300, Mixture 1 (Otira, Orthega, Landora) and Mixture 2 (Brazil, Svani and NK96-300). Interaction between variety and soil fertility treatments were also significant. These findings open new possibilities for selection or plant breeding for genotypes with improved capability of nutrient acquisition from soils at different soil fertility levels e.g. in organic farming. Cropping of barley varieties in mixtures seems to increase (stimulate) nutrient uptakes (N, P, S, K, Mg, Ca, Mn, Zn, Cu and Mo) and biomass production

An experimental setup for high resolution 10.5 eV laser-based angle-resolved photoelectron spectroscopy using a time-of-flight electron analyzer

We present an experimental setup for laser-based angle-resolved time-of-flight (LARTOF) photoemission. Using a picosecond pulsed laser, photons of energy 10.5 eV are generated through higher harmonic generation in xenon. The high repetition rate of the light source, variable between 0.2-8 MHz, enables high photoelectron count rates and short acquisition times. By using a Time-of-Flight (ToF) analyzer with angle-resolving capabilities electrons emitted from the sample within a circular cone of up to \pm15 degrees can be collected. Hence, simultaneous acquisition of photoemission data for a complete area of the Brillouin zone is possible. The current photon energy enables bulk sensitive measurements, high angular resolution and the resulting covered momentum space is large enough to enclose the entire Brillouin zone in cuprate high-Tc superconductors. Fermi edge measurements on polycrystalline Au shows an energy resolution better than 5 meV. Data from a test measurement of the Au(111) surface state is presented along with measurements of the Fermi surface of the high-Tc superconductor Bi2212.Comment: 9 pages, 7 figure

Arbeidet mot utelivsvold : en teoretisk oppgave

Bachelor i politiutdannin