Effect of phosphorus activators on soil legacy phosphorus availability and its uptake by maize hybrid COH(M) 6 in calcareous soil

Abstract

Continuous application of phosphatic fertilizers in association with its low recovery results in the insoluble legacy P buildup in agricultural soils. In this study, a field experiment was conducted with maize hybrid COH(M) 6 to know the effect of different P activators (Farmyard Manure, Humic acid, Phosphorus Solubilising Bacteria, and Phytase) on increasing the legacy phosphorus (P) availability. The P activators were combined and applied along with the different doses of P fertilizer (100%, 75%, and 50% soil test dose of P fertilizer). The results showed that the application of Farmyard manure (FYM) and Humic acid (HA) significantly (p < 0.05) increased the soil available P (18.54 kg ha-1) and notably reduced the calcium P fraction (93.08 mg kg-1). The application of FYM and HA with 100% soil test dose of P showed a similar grain (9.98 kg ha-1) and stover P uptake (12.67 kg ha-1) response as that of FYM and HA with 75% soil test dose of P. The study suggested that FYM and HA application has activated the fixed calcium phosphorus in soil and increased its availability for crop utilization. The findings have illustrated that even the reduced dose of P fertilizer application can support the nutrient uptake if they are applied along with P-activators such as FYM and HA. This could promote soil health by reducing the P overload and further P loss in soil.