Effect of Soil Application of Five Trace Elements and Citric Acid on Soybean Seed Protein, Oil, and Fatty Acids.

The current study is aimed to investigate the effects of five more trace elements and citric acid (CA) and the combination of those elements with CA on soybean seed protein, oil, and fatty acids.  The five more trace elements used in treatments were, 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 in a combined combination of the compounds with chelating agent CA (example, Mn + CA) to three-week-old soybean plants vegetative (V3) stage, and one time R3 (beginning of seed pod initiation) stage.  After application, the plants were allowed to grow until harvest maturity under greenhouse conditions. The Mn, Cu and B treatments increased protein. Zn, Mo, Cu + CA, B + CA decreased the protein Zn, Mo, CA, Cu + CA, Zn + CA, Mo + CA and B + CA increased the oil Mn, Cu and decreased the oil/ The Mn, Mo, CA, Cu + CA, Zn + CA and Mo + CA treatments increased the palmitic acid (16:0) . The Cu, Zn, B, Mn + CA and B + Ca treatments decreased the palmitic acid. The CA, Mo + CA, B + CA increased the stearic (18:0). The Cu, B, Mn+ CA, Cu + Ca and Zn + CA treatments decreased the stearic acid. The Cu and B treatments increased the oleic acid (18:1) by 8.0 and 7.4 %. Treatments, Mn, Mo, CA, and combo treatments Mn + CA, Cu +CA, Zn + CA , Mo + CA and B + CA all decreased oleic acid (18:1) by 0.6  to 14.4%. The similar treatments of Cu, Zn, Mo, B, CA, Mn + CA, Cu + CA, Mo + CA and B + CA all increased linoleic acid by 1.3 to 6.5 %. Cu and B compounds behaved similarly to Fe compounds in that they increased oleic acid.   A possible compound that can alter seed composition may exist and can be used to select for desirable seed composition constituents.