: Effect of Soil Application of Five Trace Elements and Citric Acid on Soybean Plants Leave's Mineral Content during Vegetative (V3) Stage.

Soybean seed is a major source of protein and oil for human diet. In our earlier study  we had explored the effect of soil application of iron and chelating agents like citric and salicylic acids and EDTA on soybean leaves and also on  soybean seed Protein, oil, and fatty Acids. This present study was expanded to cover five more trace elements, compounds of Mn, Cu, Zn, Mo, B (*mainly chlorides except Mo as oxide, and B as boric acid) and plant chemical Citric acid (CA).

Soybean cultivar (Bolivar with maturity group V) was grown in a repeated greenhouse experiment in a randomized complete block design. The compounds were applied either separately or in a combined combination of the compounds with chelating agent CA (example, Mn + CA) to three-week-old soybean plants two times (one weeks apart) before the vegetative (V3) stage, and one time before R3 (beginning of seed pod initiation) stage. After application, the plants were allowed to grow until harvest maturity under greenhouse conditions.  Half of the plants during the vegetative stage after two treatments were pulled out and were analyzed for macro and trace elements. The Mn, Cu, Zn,  Mo, CA and most combo treatments  of these metals with CA increased Calcium (Ca) content by 19-36%, while same treatments decreased  potassium (K)  by 7.6 to 12.54%. Similarly these treatments decreased the Magnesium (Mg) by 4.8 to 12% except Zn and CA treatments. Similarly most of these treatments decreased the Phosphorous (P) by 13- 12 % except Mo, Zn and B. Mo and B treatments increased the B and rest decreased the B. All treatments increased copper drastically 20-80% except Zn. Most of the treatments decreased the iron (Fe) 135-10% except Mo treatment. These treatments increased Mn by 6 to 61%.  The Mo and Mo + CA treatments increased Mo by 180 and 464% respectively. Zn, Mo, B and CA treatments increased the Zn by 13 to 3 %.  In summary, the uptake of varying amount of minerals to get in to the leaves varies and competition of minerals to get in or to reduce or increase some selective other minerals is visible in the data that we have. A possible compound that can alter seed composition may exist and can be used to select for desirable seed composition constituents.