Summer survival of arbuscular mycorrhiza extraradical mycelium and the potential for its management through tillage options in Mediterranean cropping systems

Abstract

The potential to manage arbuscular mycorrhizal (AM) colonisation within Mediterranean agricultural systems likely depends on the summer survival of the extraradical mycelium. To investigate this further a three-stage experiment was undertaken. The first stage was the creation of two contrasting levels of extraradical mycelium development, achieved by two contrasting levels of soil disturbance (typifying full tillage or no-till).. In the second stage this differential mycelial inoculum was subjected to Mediterranean summer temperature and soil water regimes, representing the post-harvest fallow. During the third stage, corresponding to the next growing season, its survival was evaluated without further soil disturbance (typifying no-till conditions) using wheat as host crop. The results clearly indicated that the extraradical mycelium survived the prevailing summer conditions. Knowing that extraradical mycelium can survive over the Mediterranean summer encourages the use of tillage systems that minimize mechanical disturbance of the soil, such as no-till. Knowledge gained in this study suggests that by making the appropriate choice of crops to establish a mycorrhizal-supportive rotation there can be opportunities for agro-ecosystem management to benefit from the symbiotic relationship.