Organic fertilisers of the mac trial and their impact on soil quality, environment and climate change

After 8 years, the MAC field trial in Lelystad, the Netherlands, shows the effects of different fertiliser strategies, ranging from animal manure to plant compost to mineral fertiliser. The impact on yield, soil quality, soil health, environment and climate change is discussed. The trial is unique in monitoring the effect of so many types of fertilisers over so many year

Compost uit natuur en landschap

Bij het beheer van natuurgebieden en landschapselementen zoals houtwallen, rietlanden en singels, komen grote hoeveelheden plantaardig materiaal vrij. Afvoer en verwerking van dit materiaal drukken zwaar op de beheerskosten. Biologische boeren kunnen die druk verlichten door het materiaal na compostering te gebruiken. Sinds enkele jaren onderzoekt het Louis Bolk Instituut de mogelijkheden. Landbouwkundige, natuurlijke en juridische overwegingen spelen een rol

Unraveling idea development in discourse trajectories

Conference Theme: The Future of LearningShort Paper Session: SP 6.7With the present paper we want to shed light onto an issue that is central within the knowledge building theory but only little studied – the development of ideas in collaborative learning discourse. Starting from the construction of a network of explicit and implicit relations between ideas, we apply a scientometric method to tackle the temporality of collaborative processes based on the structure of successive ideas. The resulting discourse trajectories are shown to give a holistic and also a detailed view on how knowledge advances when their interpretation is combined with a qualitative analysis of the content of the ideas and their relations. The weighted relevance of relations between ideas enables the identification of sub-topics in the discourse, important ideas, and influence or uptake events.postprintThe 10th International Conference of the Learning Sciences (ICLS 2012), Sydney, Australia, 2-6 July 2012. In ICLS 2012 Proceedings, 2012, v. 2, p. 162-16

Revisiting the value of information sharing in two-stage supply chains

There is a substantive amount of literature showing that demand information sharing can lead to considerable reduction of the bullwhip effect/inventory costs. The core argument/analysis underlying these results is that the downstream supply-chain member (the retailer) quickly adapts its inventory position to an updated end-customer demand forecast. However, in many real-life situations, retailers adapt slowly rather than quickly to changes in customer demand as they cannot be sure that any change is structural. In this paper, we show that the adaption speed and underlying (unknown) demand process crucially effect the value of information sharing. For the situation with a single upstream supply-chain member (manufacturer) and a single retailer, we consider two demand processes: stationary or random walk. These represent two extremes where a change in customer demand is never or always structural, respectively. The retailer and manufacturer both forecast demand using a moving average, where the manufacturer bases its forecast on retailer demand without information sharing, but on end-customer demand with information sharing. In line with existing results, the value of information turns out to be positive under stationary demand. One contribution, though, is showing that some of the existing papers have overestimated this value by making an unfair comparison. Our most striking and insightful finding is that the value of information is negative when demand follows a random walk and the retailer is slow to react. Slow adaptation is the norm in real-life situations and deserves more attention in future research - exploring when information sharing indeed pays off

Burgercooperaties: Speler of speelbal in de nieuwe verhoudingen tussen overheid, markt en samenleving

Burgers hebben in Nederland het afgelopen decennium in allerlei sectoren initiatieven ontwikkeld en coöperaties opgericht om zelf voorzieningen en diensten tot stand te brengen en te beheren. Kennelijk slagen overheid en markt er onvoldoende in om in bepaalde behoeften en daarmee samenhangende waarden van burgers leven te voorzien. Hoewel burgercoöperaties jonge organisaties zijn die zichzelf grotendeels nog moeten bewijzen, zijn de koplopers een bron van inspiratie, innovatie en navolging. Tegelijk kunnen we constateren dat er weinig kennis beschikbaar is over deze nieuwe organisatievorm. Het ontbreekt tot nu toe aan empirische sectorstudies en een systematische vergelijking. Dit themanummer inventariseert en vergelijkt the state of art van burgercoöperaties op het terrein van energie, zorg, breedband en wonen. Hoe effectief en duurzaam zijn burgercoöperaties en hoe verhouden ze zich tot overheden, marktpartijen en maatschappelijke organisaties? De vergelijkende analyse laat zien dat burgercoöperaties moeten leren om te gaan met de spanning tussen het streven naar zelfbeheer en de behoefte tot professionalisering. Ook moeten ze leren samen te werken met andere partijen in hun omgeving. Coöperaties moeten leren het spel mee te spelen zodat zij geen speelbal van andere partijen worden

Organic fertilisers of the MAC trial and their impact on soil quality, environment and climate change.

After 8 years, the MAC field trial in Lelystad, the Netherlands, shows the effects of different fertiliser strategies, ranging from animal manure to plant compost to mineral fertiliser. The impact on yield, soil quality, soil health, environment and climate change is discussed. The trial is unique in monitoring th eeffect of so many types of fertilisers over so many years