Application of Excess Nitrogen, Phosphorus, and Potassium Fertilizers Leads to Lowering of Grain Iron Content in High-Yielding Tropical Rice

Abstract

Influences of nitrogen (N), phosphorus (P), and potassium (K) fertilizer doses were assessed on iron (Fe) accumulation in leaves and grains of three high-yielding rice cultivars differing in grain Fe concentration. Effects of these treatments were also measured on grain yield, leaf area, and plant biomass of the cultivars. Nitrogen, P, and K applications improved plant biomass and grain yield of all cultivars. Among the nutrients, N was most effective in increasing leaf Fe concentration, followed by P and K in all three rice cultivars. Sharbati accumulated the greatest concentration of leaf Fe followed by IR-64 and Lalat. However, greater doses of these nutrients adversely affected grain yield and Fe content of leaf and grain. Application of excess N, P, and K fertilizers may, thus, sometimes results in lowering of grain Fe content in rice. Judicious application of the elements is recommended for prevention of Fe-induced malnutrition.

Keywords:

• Iron
• nitrogen
• phosphorus
• potassium
• rice

Acknowledgments

Binay Bhushan Panda and Avijit Das thank the Department Science and Technology, Government of India, for financial support for the experiments. Pravat Kumar Mohapatra acknowledges support given by the Council of Scientific and Industrial Research, India, in the form of an emeritus fellowship.