Native and Added Nitrogen Relationship in Opium Poppy (PapaverSomniferum L.)

A laboratory incubation experiment and a pot experiment were conducted to follow the soil and fertilizer N relationship with respect to mineralization and availability of indigenous N to opium poppy (Papaver somniferum L.) at increasing rates of ¹⁵N application (0, 50, 100, 150 and 200 mg kg⁻¹ soil). A significant increase in the mineralization of native soil N occurred after 10 days of incubation and it remained unchanged or decreased marginally during the subsequent period of incubation. Soil N contribution to N uptake by plant increased with increasing levels of N application. The ¹⁵N balance sheet indicates that recovery of added ¹⁵N in plant and soil decreased (79–61%) and unaccounted ¹⁵N increased (21–39%) with increased doses of N application.