Extractable soil water and transpiration rate of mycorrhizal corn

Abstract EN

Plants were grown in pots with or without mycorrhizal fungi.

Plant extracting soil water was tested based on physiological definition of the upper and lower end-point.

In both mycorrhizal (M+) and nonmycorrhizal (M-) treatments, a decrease in plant productivity was not observed until the soil water decreased to the level where approximately one third of the water that could be extracted by plants remained in the soil.

No significant differences were observed in the volume of extractable soil water at the lower end-point between water-stressed mycorrhizal and nonmycorrhizal treatments (0.139 and 0.155 m3m-3), respectively.

In contrast, mycorrhizal plants extracted (significantly at P=0.02) more soil water (0.400 m3m-3) than did the nonmycorrhizal plants (0.329 m3m-3) at the upper end-point.

More important, extraction soil water in the water-stressed mycorrhizal plants did not change until fraction transpirable soil water (FTSW) was below 0.195.

However, extraction of soil water in water-stressed nonmycorrhizal plants starts to change when FTSW was 0.236.

Higher dry matter yield were observed for both water-stressed and well-watered mycorrhizal plants than for the nonmycorrhizal plants in the respective treatments.

These results form the basis for additional studies to examine the role of mycorrhizal fungi on shoot and root enzymatic activities under drought conditions.Substantial research has been done to describe plant response to mycorrhizal fungi association and drought conditions.

There is, however, a lack of information about the roles of mycorrhizal association in plants under various transpiration rates and soil water availabilities.

This study assumes that soil physical properties alone are not sufficient to define the amount of extractable water from soil without having knowledge of mycorrhizal fungi biophysical activities.