ABSTRACT

A model was developed within a GIS environment using the transverse spread pattern and GPS driving track
during spreading to map actual fertilizer application at any point in a paddock. The spreading vehicle required a GPS of sufficient accuracy in order to provide proof of placement and guidance assistance to the driver. The method was used to assess the effect of field size and shape on actual application rate and application variation. At a target application rate of 80 kg ha−1, measured application rates ranged from 51.8 to 106.7 kg ha−1 of urea (46% N) fertilizer over 102 paddocks on four farms. Average field variation calculated over all paddocks was 37.9%. Irregular-shaped paddocks were found to have higher application variation (40.8%) compared to regular-shaped paddocks (35.9%). Hot spot analysis was performed to identify areas receiving statistically significant high and low application rates.

Abstract
The buffering technique in the Geographic Information Systems (GIS) was used to estimate the land area of a fadama for inland farming. The investigation was carried out in Akure (7°15´N, 5°15´E) in May 2008. The Ikonos satellite image of the five hundred hectare land area at 4 m  resolution was georeferenced using ArcView 3.3 GIS software to make locations on the image align to positions on the earth’s surface. A submap of the image that contained a perennial stream was generated and the stream buffered at a distance of 100 m away from the stream on all sides. The buffered zone depicting the fadama land was polygonized and the total area computed as 34.19 hectares and locations for soil studies in the buffered zone identified on the map. The field work entailed locating on the ground with the use of the Global Positioning System (GPS) receiver the points for soil studies already identified on the digital map. Soil samples were taken from the surface (0-30 cm) and subsoil (30-100 cm) for laboratory analysis of soil physical and chemical properties.

Abstract
The potential of land for agronomy and horticulture use is determined by an evaluation of biophysical variables. The climate, soil and geomorphologic environmental components are important agro-ecological variables. Evaluation of biophysical variables is usually a first step in land use analysis. Geographic Information System (GIS) was used to identify suitable areas for rapeseed crop production in Isfahan and Chahar Mahaal va Bakhtiari provinces, Iran. Relevant environment components such as climate (precipitation, temperature, humidity, etc.), soil (chemical and physical characteristics including texture, gravel percentage, pH, EC, soil depth, etc.), agronomic management (sowing method and date, soil fertilization, irrigation, weed and pest control, etc.) and topography (DEM) at different spatial and temporal resolutions were considered.

Abstract
The process of transformation of rainfall into runoff over a catchment is very complex and exhibits both temporal and spatial variability. However, in a semi-arid area this variability is mainly controlled by the physical and chemical properties of the soil sur- 5 face. Developing an accurate and easily-used model that can appropriately determine the runoff generation value is of strong demand. In this study a simple, an empirically based model developed to explore effect of soil properties on runoff generation. Thirty six dry-farming lands under follow conditions in a semi-arid agricultural zone in Hashtroud, NW Iran were considered to installation of runoff plots. Runoff volume 10 was measured at down part of standard plots under natural rainfall events from March 2005 to March 2007. Results indicated that soils were mainly clay loam having 36.7% sand, 31.6% silt and 32.0% clay, and calcareous with about 13% lime.

Abstract

Marginalisierung der Landwirtschaft, verbunden mit Bewirtschaftungsaufgaben landwirtschaftlicher Flächen und der Ausdehnung der Waldflächen, führt zu wesentlichen Änderungen der Land(wirt)schaft. Der Beitrag untersucht am Fallbeispiel zweier oberösterreichischer Katastralgemeinden (Trattenbach in Ternbeg und Prandegg in Schönau), auf der Maßstabsebene von Einzelparzellen, welche sozioökonomischen und biophysikalischen Faktoren einen Rückzug aus der agrarischen Flächenbewirtschaftung fördern. Landschafts- und Parzellencharakteristika wie Exposition und Bodenbonität spielen im Entscheidungsprozess über die künftige Flächennutzung ebenso eine hochsignifikante Rolle, wie auch sozioökonomische (Erwerbsform, Arbeitskapazitäten, Hofnachfolge, Alter, ÖPUL-Teilnahme) Faktoren. Ziel des Forschungsvorhabens war es, ein GIS-gestütztes Verfahren zu entwickeln, welches es ermöglicht, jenes Risiko abzuschätzen, mit dem Agrarflächen in Zukunft aus der agrarischen Nutzung fallen.

Zusammenfassung
Mit dem zunehmenden Anbau von Bt-Mais in Deutschland steigt das Risiko der Anpassung von heimischen Populationen des Maiszünslers, Ostrinia nubilalis (Hübner), an Toxine von Bacillus thuringiensis. Durch das Anlegen von Refugien mit anfälligem Mais soll dieser Entwicklung nachhaltig begegnet werden.

Nitrogen Fluxes through Unsaturated Zones in Five Agricultural Settings across the United States

The main physical and chemical controls on nitrogen (N) fluxes between the root zone and the water table were determined for agricultural sites in California, Indiana, Maryland, Nebraska, and Washington from 2004 to 2005. Sites included irrigated and nonirrigated fields; soil textures ranging from clay to sand; crops including corn, soybeans, almonds, and pasture; and unsaturated zone thicknesses ranging from 1 to 22 m. Chemical analyses of water from lysimeters and shallow wells indicate that advective transport of nitrate is the dominant process aff ecting the flux of N below the root zone.