Arbuscular Mycorrhiza Fungi Integrated with Single Super Phosphate Improve Wheat-nitrogen-phosphorus Acquisition, Yield, Root Infection Activity, and Spore Density in Alkaline-calcareous Soil

The potential productivity of calcareous soils is high when adequate nutrients can be available. However, these soils are frequently deficient in nitrogen (N) and phosphorus (P) and cannot meet plant nutrient requirements. The application of microbes with chemical fertilizers can be beneficial in fulfilling plant-nitrogen-phosphorus (NP) requirements. Given that, a field experiment was conducted to determine the effect of arbuscular mycorrhiza fungi (AMF) infected roots of maize and single super phosphate (SSP) in improving NP acquisition, yield, root infection activity, and AMF spore density in alkaline-calcareous soil. The experiment was composed of five levels of SSP (0, 30, 60, 90, 120 kg ha⁻¹) and two levels of AMF (with and without) arranged in a two factorial randomized complete block design (RCBD) with three replications. Yield-related parameters were significantly (P ≤ 0.05) improved with the addition of AMF and SSP. Post-harvest soil total N, extractable soil P, plant N, and plant P concentration and its uptake by wheat plants were also significantly (P ≤ 0.05) improved by the combined application of AMF and SSP compared to sole SSP application. Very often, the performance of 90 kg ha⁻¹ SSP with AMF was either similar to or better than 120 kg ha⁻¹. Moreover, AMF inoculation was found effective in soil AMF spore density and root infection intensity leading to an increase of 18 to 48/20 g soil and 19 to 42% compared to no AMF inoculation. It was proved that wheat-NP requirements could be improved with AMF inoculation, and it has the potential to increase crop yield in alkaline calcareous soils.