rocks formed under intense heat and pressure

layered rocks that are weathered by wind and water

the process of rocks breaking down and becoming other rocks

to break down organic matter to become part of the soil

rocks formed when red-hot magma cools

the process of growing plants without soil, but by adding the plants' nutrients directly to the water

to use wisely, not wastefully

the practice of planting different things each year, in order to maintain the nutrients in the soil of a field