Have never used it but Have heard that it contains Gibberellic acid which promotes cell elongation and plant growth. It's a hormone. I suspect this is what makes the crop grow rather than the calcium. Altho Calcium is not a bad thing. We band spray calcium over the row at planting and consitently get lower moisture corn at harvest. About 2%.

Gib Acid on soybean seed

Gib acid to elongate first internode on Soybeans