The document summarizes mechanisms and techniques for the uptake and movement of secondary nutrients calcium, magnesium, and sulfur in plants. It discusses that plants absorb these nutrients from the soil in ionic form through both active and passive mechanisms. It then describes the pathways of nutrient movement within the plant, including mass flow, diffusion, and transporters. The document reviews various techniques used to study nutrient uptake and transport, such as radiotracer methods, microelectrode techniques, and patch-clamping.