The role of Collembola for litter decomposition under minimum and conventional tillage

Background The role of soil mesofauna in decomposition processes still is debated and this applies in particular to arable systems. Aim This study investigates the role of Collembola in decomposition processes of crop residues in two different tillage systems. Methods We conducted a litterbag experiment in a long-term field site in Germany managed by conventional tillage (CT; mouldboard ploughing) and minimum tillage (MT). Litterbags filled with maize leaf litter of two mesh sizes (2 mm and 48 mu m) were used. Litterbags were buried at 23 cm (CT) and 5-8 cm (MT), and retrieved after 2, 5 and 7 months. Litter mass, concentrations of carbon and nitrogen, litter C/N ratio as well as the abundance and community structure of Collembola and the incorporation of maize-derived carbon into Collembola were investigated. Results Mesofauna enhanced the loss of litter carbon, while litter mass loss was reduced. Litter C/N ratio in MT was generally lower than that in CT and decreased faster in litterbags with coarse mesh size. Abundance of Collembola in litterbags in CT exceeded that in MT, but species composition remained unaffected by tillage. Overall, Collembola effectively colonised the litter irrespective of tillage system, but benefited in particular from translocation deeper into the soil by conventional tillage. Conclusions Mesofauna accelerates litter carbon loss and increases litter nitrogen accumulation irrespective of tillage system. This may reduce nitrogen losses due to leaching in winter and facilitate nitrogen capture from decomposing litter material by crops in the following season, thereby contributing to the sustainable management of arable systems.

Automated summary

This study investigates the role of Collembola in decomposition processes of crop residues in two different tillage systems. The results show that Collembola accelerates litter carbon loss and increases litter nitrogen accumulation in both conventional tillage and minimum tillage, contributing to the sustainable management of arable systems.