Intra-Row Weed Control by use of Band Steaming

Disinfection of the soil by means of steaming has been a common method for eliminating weeds and fungal diseases. However, surface steaming of soil is a very energy-intensive process, and consequently, efforts have been made to develop a machine for narrow-band steaming of the soil under and around rows of cultivated plants prior to seeding. The use of this machine may achieve up to 90% energy savings, and will also reduce the amount of damage to the flora and fauna. Tests have shown that soil temperatures exceeding 70C will be needed to protect against germination of weed seeds. For band heating such a treatment in 50 cm rows requires about 5.8 GJ/ha

Factors affecting zooplankton biodiversity in an arctic fjord: an analysis of three decades of data from Kandalaksha Bay, White Sea, Russia

Masteroppgave i marin økologi - Universitetet i Nordland, 2012The seasonal and intra-annual zooplankton community structure, biodiversity and abundance trends in Kandalaksha Bay, White Sea, were described and related to climate related and biological environmental variability over the period 1964 - 1998. 22 taxa, containing both holoplanktonic and meroplanktonic forms were studied. Seasonal variability of the White Sea zooplankton was characterized by overlapping peaks in abundance and biodiversity from the start of June to the start of October. A shift from predominately negative to positive zooplankton abundance and temperature anomalies, signifying an increase in total abundance and a warming of Kandalaksha Bay was observed from the mid eighties. The two most abundant species, Oithona similis and Pseudocalanus minutus showed opposite trends in relative abundance over the study period; O. similis decreased in relative abundance while P. minutus increased in relative abundance. There was also indication of long-term changes among other species: Calanus glacialis and Sagitta elegans increased, whereas relative abundance of A. longiremis, larval Bivalves, larval Echinoderms and Oncea borealis decreased. Yet, overall biodiversity, expressed by the Shannon index remained relatively stable during the years of study, and showed no clear signs of a long-term trend. All species had significant (p < 0.01) multiple regression models and the regressions analysis yielded high degree of explanatory value for the species S. elegans, C. glacialis and P. minutus

Rækkedampning, effekter og økonomi

Der er udviklet en maskine til dampbehandling af jorden inden såning med henblik på at ødelægge ukrudtsfrøs spireevne. Princippet i maskinen er, at processen sker i et lukket kammer, som trækkes hen over det bånd der ønskes behandlet. Dampen ledes ind i kammeret og penetrerer effektivt ind i jordpartiklerne. Resultater har vist, at der kan opnås en effektiv ukrudtskontrol ved en behandlingstemperatur på 80-90 grader. Energiforbruget har ligget på ca. 400 l olie per ha. Økonomiske overslagsberegninger viser at der for et 4-rækket system vil være økonomisk balance i økologisk dyrkede gulerødder og løg ved arealstørrelser på ca. 8 ha

Rækkedampning bruger mindre olie

Information to practise about the new band-steaming technology and its benefits for horticultur

Organic Food and Health: A new project to study the effects of plant cultivation methods (organic and conventional) on nutritional value, health and reproduction in an animal experiment

Many consumers believe that food from plants grown under certain conditions, such as organic agriculture, will benefit health more than conventional food. This cannot be determined simply by analysing the material, since our understanding of the connections between food components and health is still to imprecise for such a purpose. Rather than waiting until basic research provides the knowledge needed for this approach, in the spring of 2001 we have initiated a project to study physiological effects of plant quality directly, in an animal experiment. The following cultivation treatments are used to grow plants that are typical ingredients for a human diet (potato, mature peas, kale, spring wheat, oilseed rape, carrots and apples): 1. A model of a distinct conventional cultivation system, with high input of mineral nutrients and use of as much pesticides as is allowed. 2. A model of a distinct organic cultivation system, with low input of organic plant nutrients and no use of pesticides. 3. A combination of model 1 and 2, with low input of nutrients and use of pesticides. The materials from each cultivation treatment will be thoroughly characterised, by measuring contents of nutrients (protein, minerals, energy content, vitamins), the biological value of major protein sources of feed plants will be assessed, selected secondary metabolites including known anti-nutrients will be measured and other quality indicators will be assessed including biocrystallization. Based on these results, 3 feed mixtures will be prepared, either based on defined weight percentages of each material from each treatment, or, if large variation in biological value is found, one or two feed mixtures can be adjusted to provide the same availability of protein and energy as the reference treatment (model 1). Potato, mature peas and kale will be cooked and freeze-dried, wheat is ground and baked to biscuits, oil is produced from the rapeseed, and raw carrots and apples are shredded and freeze dried, before feed pellets with the desired composition are prepared from the material. Three groups of rats are each provided one of the dietary treatments during 2.5 generation, and reproductive characteristics and performance are recorded. Subgroups of the last generation are selected for an intensive study in which uptake and excretion of energy and protein and selected micronutrients are determined. Respiration trials are performed to assess the energy metabolism, and simultaneous measurements of the activity levels of the rats are performed. In addition, blood and tissue samples of the rats will be obtained to study the effect of the dietary treatments on the immunological and antioxidant status of the rats. Data from the experiments are assembled and analysed using relevant statistical models, and the relationship to the nutritional characteristics of the plant material is described. Funding for the core project for a 4-year period is secured from the Danish Research Centre for Organic Farming (DARCOF). However, the intention is to provide a platform for international collaboration, since the well-documented material of plants and animals can provide multiple opportunities for associated projects. To investigate other aspects of plant composition or health than what is foreseen in the present project, or to follow up on it with additional experiments

Computer Aided Verification of Lamport's Fast Mutual Exclusion Algorithm - Using Coloured Petri Nets and Occurrence Graphs with Symmetries

In this paper, we present a new computer tool for verification of distributed systems. As an example, we establish the correctness of Lamport's Fast Mutual Exclusion Algorithm. The tool implements the method of occurrence graphs with symmetries (OS-graphs) for Coloured Petri Nets(CP-nets). The basic idea in the approach is to exploit the symmetries inherent in many distributed systems to construct a condensed state space. We demonstrate a signigicant increase in the number of states which can be analysed. The paper is to a large extent self-contained and does not assume any prior knowledge of CP-nets (or any other kinds of Petri Nets) or OS-graphs. CP-nets and OS-graphs are not our invention. Our contribution is development of the tool and verification of the example.Index Terms: Modelling and Analysis of Distributed Systems, Formal Verification, Coloured Petri Nets, High-Level Petri Nets, Occurrence Graphs, State Spaces, Symmetries, Mutual Exclusion

Snow-creep pressure on masts

Snow-pressure measurements have been carried out on two masts at the NGI avalanche station in Grasdalen, western Norway. These two tubular masts have diameters of 0.22 and 0.42 m, respectively, and are situated on a 25° slope with a deep snow cover. The most important conclusions are that within a homogeneous snow-pack there is a close correlation between snow-creep pressure and the product of acceleration due to gravity, g, density, ρ, and snow depth, H, that the highest pressures are recorded in late winter when the snow-pack is at the 0°C isothermal, and finally that a weak 0° C isothermal snow layer at ground level appears to increase snow pressure