Microwave Based Weed Control and Soil Treatment

The Yearbook mirrors the annual activities of staff and visiting fellows of the Maimonides Centre and reports on symposia, workshops, and lectures taking place at the Centre. Although aimed at a wider audience, the yearbook also contains academic articles and book reviews on scepticism in Judaism and scepticism in general. Staff, visiting fellows, and other international scholars are invited to contribut

Microwave Based Weed Control and Soil Treatment

The Yearbook mirrors the annual activities of staff and visiting fellows of the Maimonides Centre and reports on symposia, workshops, and lectures taking place at the Centre. Although aimed at a wider audience, the yearbook also contains academic articles and book reviews on scepticism in Judaism and scepticism in general. Staff, visiting fellows, and other international scholars are invited to contribut

Study on the Response Time of Direct Injection Systems for Variable Rate Application of Herbicides

Progress in the technology of weed detection using cameras combined with image processing requires improvements in spray technology. Spraying systems of current design distribute herbicides uniformly across the field. Applying the chemical agents only at locations with weeds according to the indications of a weed treatment map (off-line application) or of a weed detection system (on-line application) will reduce costs significantly and contribute to environmentally friendly crop farming. Direct injection systems inject chemical agents into the hydraulic system of the sprayer in a manner that allows the rate and type of herbicide to be varied during field operation. A disadvantage of current injection systems lies in long response times, i.e. the time until the required concentration of spray solution is reached at the nozzles. Application errors occur because the flow rate of the active ingredient at the nozzles is not adjusted rapidly enough to meet the herbicide requirement at a given location in the field. For on-line application, the distance between the point of injection and the nozzle has to be minimized. This study presents results concerning the response time analysis of a direct injection system with two different locations of the injection point. The concentration development of a tracer as measured by a conductivity sensor was employed to determine lag and response times. The experiments were carried out with various carrier and tracer flow rates as well as different tubing sizes and tracer viscosities.Untersuchung der Verzögerungszeit von Direkteinspritzsystemen für die teilflächenspezifische Ausbringung von Herbiziden Fortschritte in der Unkrauterkennung mittels Kameras in Kombination mit Bildverarbeitungstechniken erfordern Verbesserungen der Applikationstechnik. Aktuelle Spritzsysteme verteilen die Herbizide gleichmäßig auf dem Feld. Die Beschränkung der Anwendung von Chemikalien auf Teilflächen mit Unkrautbesatz, der auf einer Unkrautkarte verzeichnet ist (offline-Ausbringung) oder von einem Unkrauterkennungssystem angezeigt wird (online-Ausbringung), würde die Kosten deutlich senken und einen Beitrag zu einem umweltfreundlichem Pflanzenbau leisten. In Direkteinspeisungssystemen werden die Chemikalien so in das hydraulische System der Spritze eingeleitet, dass sich Art und Menge des Herbizids während des Feldbetriebs verändern lassen. Ein Nachteil aktuell verfügbarer Einspritzsysteme liegt in ihrer langen Reaktionszeit, d.h. der Zeit, die vergeht, bis die Spritzlösung an den Düsen die erforderliche Konzentration erreicht. Ausbringungsfehler sind darauf zurückzuführen, dass sich die Fließgeschwindigkeit des Wirkstoffs an den Düsen nicht schnell genug ändert, um an einer bestimmten Stelle auf dem Feld die erforderliche Herbizidmenge zur Verfügung zu stellen. Für die online-Ausbringung muss der Abstand zwischen dem Einspeisungsort und der Düse möglichst klein sein. Diese Arbeit stellt die Ergebnisse von Reaktionszeitanalysen vor, die an einem Direkteinspeisungssystem mit zwei verschiedenen Einspeisungsorten durchgeführt wurden. Tot- und Reaktionszeiten wurden anhand des mit einem Leitfähigkeitssensor erfassten Konzentrationsverlaufs eines Indikators ermittelt. Die Versuche wurden mit verschiedenen Fließgeschwindigkeiten von Trägerflüssigkeit und Indikator sowie mit verschieden dimensionierten Rohrleitungen und mit Indikatorflüssigkeiten unterschiedlicher Viskosität durchgeführt

The movement of pesticides within a mixed land use catchment

Although the application of UK non-agricultural pesticides (mainly herbicides) comprises only 3% of the total amount used, similar concentrations of agriculturally and non-agriculturallyderived pesticides are routinely detected in surface waters. This has led to concern regarding the contamination of drinking water resources at concentrations above the statutory limits of the EC Drinking Water Directive (ECDWD), and the consequent risk to human health. Before the risks to drinking water resources can be fully assessed, it is important to understand and subsequently predict the chronic and transient levels of herbicide occurrence in receiving surface waters as a result of their normal application. The factors which influence herbicide transport to the aquatic environment from sites of application, particularly from the wide variety of application substrates, are not fully understood. This project addresses this lack of knowledge through an eighteen-month programme (January 1992-March 1993) of storm event herbicide monitoring on a mixed land use catchment at North Weald (Essex) which periodically received applications of common agricultural and non-agricultural herbicides including chlorotoluron, isoproturon, diuron, simazine and atrazine. To support the field monitoring programme a robust multi-residue pesticide method was developed for the simultaneous determination of the previously mentioned compounds from storm water. This was based on liquid-liquid extraction into dichloromethane and high performance liquid chromatography using photo diode array detection. The pesticide runoff data from agricultural land agreed with similar experiments carried out in the UK. The ECDWD was frequently exceeded in baseflow conditions and more frequently during storm event periods. The extent of the exceedance was found to be related to the period which had elapsed between the herbicide application and the timing of the surface water sampling. The range of application losses for the agricultural data-set was 4.0xlO-4-O.204% (median; 4.6x10-2%). The range of peak storm event concentrations was 0.03-10.0jJg/1 (median; 0.34pg/I). Similar exceedances of the ECDWD were observed during storm and non-storm conditions for discharged waters from the urban land area of the catchment. For the urban runoff data-set, the range of application losses was 0.01-45.1% (median; 0.28%) and the range of peak storm event concentrations was 0.2-238.4pg/1 (median; 0.7pg/l). The results of the monitoring programme show that the underlying factor that differentiated between the fates of herbicides applied to the North Weald catchment was the difference in the application substrate properties. Specifically, the hard surfaces, where low infiltration capacity promotes the generation of relatively high volumes of surface runoff and where poor retention behaviour exists, allow applied herbicides to be readily transported in storm event runoff to receiving surface waters. The simazine, isoproturon, chlorotoluron and diuron runoff data produced during the monitoring programme were successfully modelled using the fugacity-based Soilfug model. In the case of chlorotoluron, this model s performance was compared with a statistical model produced using multiple linear regression analysis, which showed the former approach to be superior since it required less input data and was not site specific

Precision Agriculture Technology for Crop Farming

This book provides a review of precision agriculture technology development, followed by a presentation of the state-of-the-art and future requirements of precision agriculture technology. It presents different styles of precision agriculture technologies suitable for large scale mechanized farming; highly automated community-based mechanized production; and fully mechanized farming practices commonly seen in emerging economic regions. The book emphasizes the introduction of core technical features of sensing, data processing and interpretation technologies, crop modeling and production control theory, intelligent machinery and field robots for precision agriculture production

Precision Agriculture Technology for Crop Farming

This book provides a review of precision agriculture technology development, followed by a presentation of the state-of-the-art and future requirements of precision agriculture technology. It presents different styles of precision agriculture technologies suitable for large scale mechanized farming; highly automated community-based mechanized production; and fully mechanized farming practices commonly seen in emerging economic regions. The book emphasizes the introduction of core technical features of sensing, data processing and interpretation technologies, crop modeling and production control theory, intelligent machinery and field robots for precision agriculture production

Ecological and agronomic aspects of a pear and vegetable interculture system

The objectives of this study were to characterise the productivity and resource use efficiency of an experimental interculture system and to develop methods for the evaluation and optimisation of interculture. The experimental system consisted of a mature pear orchard intercropped vegetables. The first experiment used a phytometer technique in order to evaluate the response of a range of understorey vegetables (carrot, onion, pea, radish and lemon balm) to the aerial environment created/modified by the trees. The main conclusion was that most vegetables could be intercropped given a suitable soil environment. Some changes in crop morphology were identified in positions directly under the canopy. Radish was selected for further study. Novel techniques for the measurement of the transmissivity of the tree canopy to photosynthetically active radiation (PAR) were developed and tested. The canopy was found to be around 70% transmissive when averaged over the orchard floor. Areas directly under the canopy received around 50% of the incoming radiation. The response of radish to various levels of PAR was characterised using a shade experiment. A 50% reduction in PAR resulted and a 65% reduction in yield measured as mean bulb diameter but did not affect the mean total dry weight of the plants. This was due to the plants partitioning proportionately more dry matter to the leaves. A few individual plants, when grown at 30% PAR had bulb diameters equivalent to the 100% mean. This was taken as an indication of the potential for increasing yields by genotype selection. The land equivalents ratio for the system when calculated indicated that 50-100% more land would be required in order to obtain the same yield from monocultures, depending on the spatial arrangement selected. The radish component did underyield in positions directly beneath the canopy. Experiments with artificial fertiliser (NPK) and shade indicated that PAR intensity coupled with some soil factor other than NPK concentration were implicated

An investigation into the design of cultivation systems for inter- and intra-row weed control

The aim of this study was to investigate the factors that influence the design of soil engaging systems to mechanically control weeds between plants within the crop row in widely spaced field vegetables. A mass flow soil dynamics model based on particle dynamics was developed to aid designers in determining the lateral and forward displacement of soil as it is undercut by shallow working wide blades. The model was validated in soil bin laboratory experiments and used to design a novel mechanical inter- and intra-row weeding system.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Development and Application of Microwave Heating

Microwave heating has found many applications ranging from the microwave ovens in kitchen to heat food, to a sterilization apparatus for medical treatment, to materials processing in the various fields. In those applications, microwave heating demonstrates significant advantages over conventional methods in reduced processing time and less environmental impacts. This book is comprised of eight chapters within three parts highlighting different aspects covering both the basic understandings and the advanced applications. The included discussion on the application of microwave heating in the field of food-, chemical engineering-, agricultural-, forestry- and mineral processing industry will provide a passage for future research. As a monograph, it is designed to be a fundamental reference book, aiming to help the readers to concentrate on the key aspects behind the success in microwave heating