Variation in grain yield, and nitrogen, phosphorus and potassium nutrition of irrigated rice cultivars grown at fertile and low-fertile soils

Background and aims Rice cultivars bred for fertile soils may not be the best suited to nutrient limited environments. Therefore, rice cultivars suited to sustain productivity in low-fertile soils and their adaptive mechanisms for success need to be identified. Methods Field experiments were conducted in fertile and low-fertile sites for two and five seasons, respectively, using forty four widely grown rice cultivars in Sri Lanka. Growth and tissue nitrogen (N), phosphorus (P) and potassium (K) concentrations were measured. Key results Plant biomass and shoot- N, P and K contents were reduced by 41, 54, 74 and 36% under low soil fertility, respectively, while crop duration was extended by 12 days. Relationships between grain dry weight (DW- g plant −1 ) of a cultivar, and seed N, P and K concentrations were negative ( P