Biofortification of iron in rice (Oryza sativa) grown in acid soil of Assam, India

Abstract

A pot experiment was conducted during 2019 under rain protected condition at Assam Agricultural University, Jorhat to know the effect of two different levels of soil iron (Fe) content on Fe content of rice tissues including grain (brown rice). Soils of initial DTPA extractable Fe content of 159.40±0.51 mg/kg was applied with 50 ppm Ferrous sulfate solution to increase the soil Fe content to 182.35±0.57 mg/kg. Two popular rice varieties, Ranjit and Mahsuri, and one traditional variety Kajoli Chakua were cultivated as winter rice under submerged condition in pots. There was no Fe toxicity symptom in the leaves for the plants grown at two different soil Fe content. At harvesting stage, the concentration of Fe in different tissues of rice were detected in the order: leaves>husk>grain. The Fe content of brown rice was significantly higher (>100% than that of control) in plants grown in soils of higher Fe content. Significant variation in the Fe content of brown rice was observed according to its position on the rachis, being the highest at the top and the lowest at the bottom. Considering initial soil Fe status, application of Fe fertilizer of suitable concentration to the soil was found to be successful in biofortification of Fe in brown rice, leading to increase of Fe content depending on varieties.