Integrating the organic amendment with iron fertilization for improving productivity and Fe biofortification in rice under acidified calcareous soil

Iron (fe) bioavailability is the major issue of highly calcareous soils. iron fertilization in calcareous soils is not much effective due to their rapid conversion into unavailable form. a field experiment was conducted to evaluate the effect of fe fertilizer along with organic amendments for improving growth,yield and fe biofortification of rice by manipulating ph of calcareous soil. before transplanting rice seedlings,soil ph was lowered down up to 0.5-0.6 units by using 0.25% (w/w) elemental sulfur (s). for biofortification,fe fertilizer (feso4.7h2o) at the rate of 15 kg ha-1 was applied with biochar (bc) and poultry manure (pm) in s treated calcareous soils. results indicated that the combined application of fe along with bc and pm enhanced plant growth,physiology and paddy yield and improved nutritional value of grain in ph manipulated calcareous soil. applied treatments in s treated low ph soil resulted in increased fe mobilization and translocation from root to grain. grain fe concentration raised up to 2 fold and 1.8 fold in treatments where fe was applied with bc and pm in ph manipulated soil,respectively. ferritin concentration significantly increased up to 3 fold and 2.73 fold by using fe with bc and pm,respectively,in ph manipulated soil. iron applied in combination with bc decreased phytate and polyphenols contents up to 18 and 47%,respectively,in s treated soil. the results may imply that the combined use of fe with bc increased fe biofortification (ferritin) of rice in ph manipulated calcareous soil. this increased level of ferritin in rice grains might be helpful to eliminate fe deficiency in humans. © 2016,university of agriculture. all rights reserved.