Effect of 4R stewardship based potassium fertilization on the harvest index of iron, zinc and copper in wheat

Two-year field experiments were conducted at the research farm of ICAR–Indian Agricultural Research Institute, New Delhi, to study the effect of 4R nutrient stewardship based potassium (K) fertilization on the uptake and translocation of Zn, Fe & Cu in wheat. Results from the study revealed that the rate of K application and its time of application have a significant role in the uptake and translocation of Fe, Cu, and Zn in wheat. The source of K fertilizer had a non-significant effect. Interestingly the concentration of Fe, Cu, and Zn in grain improved with increasing the dose of K application upto 60 kg K 2 O/ha. Similarly, two split applications of 60 kg K 2 O/ha recorded higher grain nutrient concentration (Fe, Zn & Cu) than basal application. In the absence of top dressing of K fertilizer, the foliar application of 2.5% K recorded a statistically equal effect to that of top dressing. The harvest index of Zn (52.3–57.4%), Fe (21-26.5%) and Cu (27.5–31.3%) shows more than 1/2th, 1/5th and 1/3th of the absorbed Zn, Fe and Cu is remobilized to grain respectively. The remobilization of Zn, Fe, and Cu from straw to grain is enhanced by the best potassium fertilization management. Thus, Fe, Zn & Cu bio-fortification through balanced application of potassium fertilizer based on 4R nutrient stewardship is an effective approach to fight hidden hunger/ malnutrition.