Browsing by Subject "käyttäytymiskoe"

Biochar is currently being intensively studied as a soil conditioner in agriculture and as a potential carbon sink to mitigate climate change. The knowledge of the effects of biochar field application on soil fauna remains very limited. This is underlined by the absence of field experiments on the effects of biochar on earthworms, a globally common and important faunal group in arable soils. The purpose of our study was to determine the effects of biochar on arable soil earthworms under both laboratory and field conditions in a Boreal loamy sand soil. An earthworm avoidance test with Aporrectodea caliginosa was conducted for periods of 2 and 14 days with 1.6% w:w spruce chips biochar application (produced at 550-600 ° C, application rate corresponding to 30 t/ha biochar). The effect of field application of the same biochar on earthworm density and biomass was studied over one growing season in experiment growing wheat. In the avoidance test, application did not affect the habitat choice of earthworms when incubation lasted for two days, but after two weeks, a significant (P = 0.033) avoidance of biochar was observed. We suggest that the avoidance under the two-week incubation occurred due to soil desiccation caused by high water retention of biochar. In the field trial, after BC application there were no statistically significant differences in the total density and biomass of earthworms between biochar or fertilizer treatments. Due to the short duration of the field trial, our results do not allow conclusive evaluation of the treatment effects on earthworms. The time scale of the study can only be considered sufficient for unraveling immediate avoidance reactions caused by biochar application, for which we found no evidence. In order to thoroughly investigate matter further, the follow-up of the experiment should be continued.