Effect of KI on Leaf Mineral Uptake in Soybean Plants.

Iodine has been reported as having beneficial role in promoting growth, yield, and increased stress tolerance in certain plant species. In human, iodine is an essential element in regards to normal functioning of thyroid gland and as a valuable source of antioxidant in lowering the risk of certain cancer and other cognitive functions. Since, iodine deficiency remains as one the most common nutritional deficiency, it seems relevant to explore iodine biofortification in agricultural practices to achieve adequate iodine intake from food. In the present study, soybean plants were treated with 30mmol of KI and KNO3 in soil at V3 stage. After 10 days of chemical treatments, the leaves were sampled, dried in oven. 2.0 grams of dry leaves samples were sent for mineral analysis. Briefly, nutrients were analyzed by digesting 0.5g of samples in a microwave digestion system. Nutrients were determined using ICP. KI treatment increased K, Mg, P, S, B, Cu and Zn by 32.0%, 8.0%, 60.8%, 38.7%, 53.6%, 36.3%, and 55.2% respectively and decreased Mg by 34.9%. While comparing the two treatments KNO3 vs KI, KNO3 did increase K, B, and Cu concentration in the leaves by 11.9, 23.0 and 11.5%, but iodine anion increased uptake and accumulation of several other minerals in the leaves. The concentration of the KI treatment used in our study though increased the uptake of minerals in the leaves caused toxicity due to which most plants died in few weeks. In conclusion, further study using different lower concentraions of KI is required to find the best treatment possible.