Liquid calcium products are not substitutes for gypsum. As mentioned in a previous post, calcium movement from leaves or roots to pegs and pods is inadequate to supply the needs of developing pegs and pods. When comparing liquid calcium formulations versus gypsum, the amount of liquid product needed to provide what the pegs and pods need versus gypsum is cost prohibitive (see 2026 Peanut Information for a comparison of rates needed to supply adequate calcium in soil.) A second challenge with liquid calcium is whether the calcium reaches the soil at high enough levels (even if high rates were applied.) This most likely would not be the case.