Abstract
Biochar is widely studied as a combined soil conditioner in agriculture and a potential carbon sink. The knowledge of the effects of field application of biochar on soil fauna remains limited. Earthworms are a globally common and important faunal group in arable soils and the purpose of our study was to determine the effects of biochar on earthworms under both laboratory and field conditions in a boreal loamy sand. An avoidance test using the earthworm Aporrectodea caliginosa Sav. was conducted for periods of 2 and 14 days with 16gkg-1 spruce chip biochar. The same biochar was mixed into the top 10cm of soil at 0 or 30tha-1 and its effect on earthworm density and biomass was studied over four and half months in a field experiment where wheat was grown with or without inorganic fertilizer application. In the avoidance test, biochar application did not affect the habitat choice of earthworms in the first 2d, but after 14d, they tended to avoid it. The avoidance was possibly the avoidance was possibly caused by a slight decline in soil water potential. Under field conditions the highest earthworm densities and biomasses were measured in biochar amended soils. None of the differences among the treatments studied were, however, statistically significant (p>0.05). The time scale of the study was sufficient for reliably demonstrating the lack of strong toxic effects and immediate avoidance reactions caused by biochar application.
| Original language | English |
|---|---|
| Pages (from-to) | 150-157 |
| Number of pages | 8 |
| Journal | Agriculture, Ecosystems and Environment |
| Volume | 191 |
| DOIs | |
| Publication status | Published - 15 Jun 2014 |
| MoE publication type | A1 Journal article-refereed |
Funding
The authors thank Sampo Tukiainen (Preseco Oy) for providing the experimental biochar, Mikko Hakojärvi for his help with the TDR measurements and Johannes Mäkinen for his help during earthworm sampling from the field. The authors acknowledge Ilya Belevich for the scanning electron microscopy imaging, Miia Collander and Johanna Muurinen for technical assistance with the biochar and soil analysis, Festus Anasonye for PAH analyses of the biochar and Arja Tervahauta for the analysis of the H content of the biochar. The English language of the manuscript was revised by Dr F.L. Stoddard. The insightful comments from the editor and two anonymous reviewers significantly improved the quality of the manuscript. This study was financed by Jenny and Antti Wihuri Foundation and the Ministry of Agriculture and Forestry of Finland.
Keywords
- Aporrectodea caliginosa
- Biochar
- Earthworms
- Field experiment
- Lumbricus terrestris
- Wheat