Enhanced Zn Biofortification of Rice through Zn Fertilizer and Water Management.

A moderate increase in the Zn content of the edible part of rice (Oryza sativa) through biofortification has the potential to improve human nutrition and immune system function for at-risk populations of rice consumers, especially in South Asia. Rice Zn biofortification depends on a combined approach of plant breeding and crop management. Newly developed high grain-Zn and low grain-Zn control genotypes were grown in one field and two greenhouse experiments under various crop management schemes, including different soil types, different rates and timings of zinc sulfate fertilizer application, and different water management strategies. The high grain-Zn genotypes met or exceeded the target level of 30 mg kg^-1 Zn (in brown rice) under all tested soil conditions, and addition of Zn fertilizer during grain-filling stage affected different genotypes differently, but increased the Zn content to 39 mg kg^-1 for one genotype.