Bruus, M. | Search bioRxiv

bioRxiv2024

Toxicity of nitrification inhibitors to soil-living animals

The toxicity of four substances appearing in nitrification inhibitors (DMPP, nitrapyrin, triazole and methylpyrazole) was tested towards three selected soil fauna species, i.e. the springtail Folsomia candida, the enchytraeid Enchytraeus albidus and the earthworm Eisenia fetida. Range-finding and definitive tests were performed according to OECD standard protocols. Test results were compared to expected exposure in order to assess the risk of using nitrification inhibitors. Especially nitrapyrin was estimated to pose a potential risk to soil fauna.

ecology↗

bioRxiv2018

The effect of spatial variation for predicting aphid epidemics

In order to improve forecasting of aphid epidemics, it is important to know the spatial scale at which specific forecasts are reliable. To investigate the spatial scale of aphid epidemics, we have developed a spatio-temporal stochastic aphid population growth model, and fitted the model to empirical spatial time-series aphid population data using a Bayesian hierarchical fitting procedure. Furthermore, detailed spatial data of the initial phases of epidemic development was investigated in a semivariogram. Our results suggest that there is limited spatial variation in the initial occurrence probability at a spatial scale of 10 km. Consequently, the results support the hypothesis that initial aphid population sizes and epidemics may be predicted in fields within a 10 km radius. For farmers, this may imply that they can rely their decision of whether to spray against aphids on observations made by other nearby farmers or by the consultancy service.

ecology↗