Abstract

Amitava Rakshit and Pratapbhanu S. Bhadoria

The objective of the present investigation was to quantify the total hyphal length of maize and groundnut and its influence on simulation of P influx. The field experiments were carried out with three P levels i.e., P - 0 (no P), P - 50 (50 mg P kg -1 soil) and P - 400 (400 mg P kg-1 soil) . Test crops were maize and groundnut. Four harvests were made to cover whole growing season and at each harvest hyphal length was measured. Application of P fertilizer reduced hyphal length by 30 ¯ 50% in maize and 25 ¯ 50% in groundnut. At P-0, hyphal length of maize crop was higher (5.4 mg-1 ) than groundnut (3.8 mg -1 ). To assess the influence of hyphal length on calculated P influx, mechanistic model was used. The model was employed first to calculate the P influx with root hairs of both the crops and then substituting root hairs by arbuscular mycorrhizal (AM) hyphae. When root hairs were substituted by AM hyphae the calculated influx increased by a factor of 1.5 to 2 for plots receiving no P. Concentration profile around the root cylinder at P - 0 showed that hyphae was able to decrease the soil solution concentration more than the root hairs.