Hyphosphere regulation of earthworms and arbuscular mycorrhizal fungus on soil N and P availability

ABSTRACTEarthworms and arbuscular mycorrhizal (AM) fungi are important ecosystem engineers that co-occur in soil and belong to different guilds. In this study, hyphosphere interactions between earthworms and AM fungi on soil nitrogen (N) and phosphorus (P) availability were investigated under field conditions with a modified chamber near the maize root. The experimental design consisted of root exclusion chambers that either allowed (30 μm pores) or precluded (0.45 μm pores) growth of AMF hyphae (AM factor), with or without earthworm addition (earthworm factor). Hyphal length density, soil and content, soil available P concentration, urease and alkaline phosphatase activities were tested at maize VT (tassel), R1 (silking), R2 (blister), R3 (milk) and R4 (dough) stage. Results showed that earthworms did not impact hyphal length density in the hyphosphere. AM and AM + E treatments caused a decrease in available phosphorus, while the E treatment increased and content during the whole experiment period. AM an...