Partially Correct. The hypothesis is partially correct since any given plant does gain nutrients in order for cellular growth through the soil, but soil isn't the only source from which plants need in order to grow (e.g. sunlight, carbon dioxide, water). One way to disprove the statement would be to take a plant and place it inside an airtight container that prevented the plant from being exposed to sunlight. This would show how the plant does not "gain material" for solely the soil.
Work Step by Step
The numbers are from the inside back cover of the textbook.