Enhancing iron density and uptake in grain and straw of aerobic rice through mulching and rhizo-foliar fertilization of iron

Abstract

A field experiment was carried out during kharif seasons (June to October) of 2008 to 2009 at New Delhi, to study the Fe density and uptake in aerobic rice as influenced by mulching and iron nutrition. The treatments comprising four methods of rice production viz. bare soil (no mulch), wheat straw mulch (5 t ha-1), Sesbania aculeata mulch and transplanted rice (paddy control) in main plots and five treatments of Fe fertilization, that is, control, FeSO4 50 kg ha-1, FeSO4 100 kg ha-1, FeSO4 50 kg ha-1 + 2 foliar sprays of 2.0% FeSO4 and 3 foliar sprays of 2.0% FeSO4 at maximum tillering, pre-flowering and flowering in sub-plots, replicated thrice in a split plot design. Transplanted rice (Paddy control) was found to be superior for improving Fe concentration and their uptake in grain and straw of rice compared with other treatments. Application of mulch increased Fe concentration and uptake in grain and straw in aerobic rice compared to no mulch aerobic rice treatment. Application of 3 foliar sprays of 2.0% Fe SO4 recorded higher Fe concentration and with significant improvement in uptake in grain as well as in straw of aerobic rice. Fe application increased the Fe concentration 5.4 to 19.9% and 5.8 to 13.3% in grain and straw of aerobic rice. Besides that, methods of rice production increased the Fe concentration 5 to 11% and 4.1 to 6.3% over bare soil (no mulch) in grain and straw, respectively. Transplanted rice produced more yield compared to all aerobic rice treatments. But application of wheat straw/Sesbania mulch recorded significant higher yields compared to no mulch aerobic rice treatment. Application of Fe fertilizer increased the grain and straw yield 4 to 8.2% and 2.7 to 6.7% over control, respectively. Our study showed that, growing of aerobic rice with Sesbania mulch and Fe fertilization produced higher grain and straw yield of aerobic rice with sufficient Fe nutrition. Key words: Aerobic rice, Fe concentration, iron nutrition, Sesbania mulch, wheat straw mulch.