If one were to boil this whole process down, it is the system developed to produce the metal type that would prove to be the most innovative. Many of the processes used to print these books generally existed in one form or another, but the metal type is a stroke of genius as nothing like it had existed before.
Soil Conservation. Soil conservation is a combination of all methods of management and land use that safeguard the soil against depletion or deterioration by natural or human-induced factors.
Growth of terrestrial plants without soil in mineral nutrient solutions was called solution culture. It quickly became a standard research and teaching technique and is still widely used. Solution culture is now considered a type of hydroponics where there is no inert medium.