4th Congress of the European Project Quality Low Input Food

The fourth annual scientific congress of the QLIF project took place during 19-20 June 2008 at the occassion of the 16th IFOAM Organic World Congress in Modena, Italy, where ISOFAR also organized their 2nd Scientific Conference. During the Organic World Congress QLIF offered a series of five outstanding workshops where central organic themes were highlighted during a synthesis paper written by a team of QLIF authors. Subseqently, the workshops made room for an exhaustive, moderated discussions

Entropy of Highly Correlated Quantized Data

This paper considers the entropy of highly correlated quantized samples. Two results are shown. The first concerns sampling and identically scalar quantizing a stationary continuous-time random process over a finite interval. It is shown that if the process crosses a quantization threshold with positive probability, then the joint entropy of the quantized samples tends to infinity as the sampling rate goes to infinity. The second result provides an upper bound to the rate at which the joint entropy tends to infinity, in the case of an infinite-level uniform threshold scalar quantizer and a stationary Gaussian random process. Specifically, an asymptotic formula for the conditional entropy of one quantized sample conditioned on the previous quantized sample is derived. At high sampling rates, these results indicate a sharp contrast between the large encoding rate (in bits/sec) required by a lossy source code consisting of a fixed scalar quantizer and an ideal, sampling-rate-adapted lossless code, and the bounded encoding rate required by an ideal lossy source code operating at the same distortion

Low-Resolution Scalar Quantization for Gaussian Sources and Absolute Error

This correspondence considers low-resolution scalar quantization for a memoryless Gaussian source with respect to absolute error distortion. It shows that slope of the operational rate-distortion function of scalar quantization is infinite at the point Dmax where the rate becomes zero. Thus, unlike the situation for squared error distortion, or for Laplacian and exponential sources with squared or absolute error distortion, for a Gaussian source and absolute error, scalar quantization at low rates is far from the Shannon rate-distortion function, i.e., far from the performance of the best lossy coding technique

An agronomic approach to yield comparisons between conventional and organic cropping systems

This paper discusses some relevant agronomic aspects related to the productivity of organic farming systems (OFS). In a first step some key requirements to ensure the validity of comparative studies including the consideration of rotation yields and the use of representative amounts of organic inputs are defined. A main chapter is dedicated to the potential of biological nitrogen fixation to substitute mineral nitrogen, which currently covers an estimated third of the total nitrogen input to agricultural field with increasing tendency. To bring forward OA as a sustainable method of food production with high process quality, it is suggested to focus rather on a large scale organic vegetable and fruit production than on global supply of calories and protein

Ertragspotentiale ökologischer Anbausysteme aus pflanzenbaulicher Sicht

The potential of Organic Agriculture to feed the world is currently under discussion. Contrasting statements concerning this issue are mainly due to missing distinction between socio-economic and biophysical impact factors, to methodical issues of yield comparisons and to sole regional observations. Instead of comparing individual data sets in meta-analyses it is proposed to explore yield potentials of different systems from an agronomic perspective. Yields in organic systems are predominantly restricted by N-availability as a function of legume growing. The potential of replacing mineral N by biological nitrogen fixation differs between regions, but generally limits the productivity of cereals. A major determinant for legume cultivation is low pressure on land use, i.e. where the availability of agricultural area per capita is high. Establishing organic systems with legumes in regions with intensive pure crop production, e.g. paddy rice in Bangladesh, would result in a significant decrease of cereal yield and production with a subsequent change in human diet

Cultivating the Future Based on Science = 2nd ISOFAR Conference in the Frame of the 16th IFOAM Organic World Congress

The 2nd scientific conference of ISOFAR 'Cultivating the Future based on Science' will be held in 2008, constituting the scientifc module (research track) of the IFOAM Organic World Congress 'Cultivate the Future' (OWC). The research track is held in parallel to the so-called system values track of the OWC. The scientific conference is coordinated by the International Society of Organic Agriculture Research (ISOFAR) in cooperation with International Federation of Organic Agriculture Movements (IFOAM) and the local organisers, the Consorzio Modena Bio 2008. All papers submitted to the scientific conference will have high scientific standards, including a peer-review system. Papers should be submitted to Organic Eprints by October 15, 2007

Speisekartoffelerzeugung im Organischen Landbau - Einfluß von Sorte und Rottemistdüngung auf Ertragsbildung und Knolleninhaltsstoffe.

In den Jahren 1995-1997 wurden an zwei Standorten Feldversuche mit Speisekartoffeln unter den Anbaubedingungen des Organischen Landbaus durchgeführt. Ziel der Untersuchungen war es, zu überprüfen, inwieweit sich der Ertrag und die Knollenqualität durch Variation der Anbaufaktoren Düngungshöhe (Rottemistgaben von 0 bis 240 kg Gesamt-N je ha), Düngungsart (organisch bzw. biologisch-dynamisch) und Sorte (Agria, Granola, Nicola, Provento) optimieren lassen. Wichtige Kenngrößen des Krautwachstums, des Knollenertrages und der Knollenqualität wurden ermittelt und einer varianz- und korrelationsanalytischen Auswertung unterzogen

Yield and quality of potato tubers: Effects of different intensity and kind of manuring (biodynamic or organic)

Biodynamic farming is the oldest organic farming movement in Germany. Since Dr. Rudolf Steiner’s “Course on Agriculture” held in 1924, the number of biodynamic farmers in Germany has grown continuously, with 1,317 farmers currently producing on 47,592 ha. One of the most distinctive aspects of biodynamic farming is the use of the so-called biodynamic preparations, which are applied in homeopathic doses. Biodynamic preparations are supposed to improve plant growth and food quality, minimising natural variations. This paper deals with investigations of influences of these preparations and increased manure application on potato yield and tuber quality. The results are drawn from extensive research on organic potato production carried out by several institutes of the University of Bonn, sponsored by the Deutsche Forschungsgemeinschaft (Bonn), and the Eden Foundation (Bad Soden)

Competitiveness of winter wheat stands against weeds: Effects of cultivar choice, row width and drilling direction

The need for competitive crop stands can be regarded as a basic requirement for weed control, potentially reducing the need for direct control measures. One way the crop may suppress weed growth is by the restriction of light through crop shading. As part of the EU-project ²Strategies of weed control in Organic Farming² (WECOF) trials with winter wheat were carried out to evaluate the potential of wheat shading ability as a weed control measure. Factors included were cultivar, row width and drilling direction. Results of the first experimental year are presented

Untersuchungen zur Nutzung der Esparsette (Onobrychis viciifolia) im Ökologischen Landbau

Field trials with four sainfoin cultivars as well as lucerne were carried out on two sites in southern Northrhine - Westphalia from 2003 to 2005. The objective of the experi-ments was to gain experience with the organic cultivation of sainfoin, an old fodder legume known for low yields but a high feeding value, particularly for horses. Crop development, dry matter yield and hay quality were determined. Crop dm yield on a loess soil site with a total lime content of 3207 mg kg-1 was very low (about 1t ha-1) in 2005. Dry matter yield on a loess soil site rich in lime (total lime content = 13974 mg kg-1) was comparatively high in 2004 (first cut: = 7.5 t ha-1), but decreased in 2005 (first cut: 1.6 t ha-1) mainly due to increasing weed infestation. Dry matter yield of sainfoin cv. Visnowsky was always lower compared with Lucerne, while digestable energy content tended to be higher in sainfoin. Sainfoin production may be an interest-ing option for organic horse fodder production, if soils are rich in lime and if weed pressure is manageable